Transcript Zarin

The Human Body
Structure & Function of Major Systems of the Human Body
Zarin Rahman, AP Bio 2013
The Digestive System
Just Guts!
Function
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Turns food into energy needed to survive and packages
residue for waste disposal.
Mechanical and chemical breakdown of food.
Food enters mouth (mastication) › travels down
esophagus (deglutition) › enters the stomach and
intestine (digestion) › waste is eliminated (defecation).
Major and Accessory Organs
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Major organs of digestion:
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Mouth
Esophagus
Stomach
Small intestine
Large intestine
Rectum
Anus
Accessory organs of digestion:

Gallbladder, pancreas, and liver.
Part One: Mastication

When food enters the mouth, digestion starts by
mastication, a form of mechanical digestion, and the
contact of saliva.
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Saliva, secreted by salivary glands, contains salivary
amylase, an enzyme that digests starch in food.
Food forms into bolus.
Part Two: Deglutition
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Bolus is pushed into esophagus through the pharynx.
Using smooth muscle contractions known as
peristalsis, the esophagus delivers food to stomach.
At junction of the esophagus/stomach,
ring-like muscle (lower esophageal
sphincter) closes passage between.
As food approaches, the
sphincter relaxes and allows
the food to pass through to
the stomach.
Part Three: Digestion
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Stomach is a small, 'J'-shaped pouch with walls made of
thick, distensible muscles.
Food enters the stomach through the cardiac orifice,
further broken apart and thoroughly mixed
with gastric acid, pepsin and other digestive
enzymes to break down proteins.
Enzymes require optimum pH to
create acidic conditions in which
they work best.
Part Three: Digestion
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Pepsin in the stomach denatures proteins, reducing
polypeptide bonds and disrupting salt bridges, which
causes a loss of 2˚, 3˚, or 4˚ protein structure.
Parietal cells of stomach also secrete a glycoprotein
called intrinsic factor, which enables the absorption
of vitamin B-12.
Mucus neck cells of stomach secrete mucus, which
along with gastric juice lubricates and protects
mucosal epithelium from excoriation by highly
concentrated hydrochloric acid.
Part Three: Digestion
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Small molecules (i.e. alcohol) are absorbed, passing
through membrane of stomach and entering
circulatory system directly.
Food in the stomach is in semi-liquid form, which upon
completion is known as chyme. (approx. 2-4 hours
after mastication & deglutition)
Part Three: Digestion
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Peristaltic contractions begin, help break down food
and move it onward. Chyme reaches the opening to
the duodenum (pylorus) and retropulsion exerts
additional force and further grinds down food into
smaller particles.
Gastric emptying occurs, releasing of food from
stomach into the duodenum.
After being processed in the stomach, food is passed to
small intestine via pyloric sphincter.
Majority of digestion and
absorption occurs after the milky
chyme enters the duodenum.
Part Three: Digestion
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Chyme mixed with 3 other liquids:
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Bile: emulsifies fats to allow absorption, neutralizes chyme,
used to excrete waste products such as bilin and bile acids.
Bile is produced by the liver and then stored in the
gallbladder where it will be released to the small intestine
via the bile duct.
Part Three: Digestion
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Pancreatic juice made by the pancreas, which secretes
enzymes such as pancreatic amylase, pancreatic lipase,
and trypsinogen (inactive form of protease). Helps digest
proteins, carbohydrates, and fats.
Part Three: Digestion
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Intestinal juice secreted by the intestinal glands in the small
intestine. It contains enzymes such as enteropeptidase, erepsin
(which further digests polypeptides into amino acids,
completing protein digestion), trypsin, chymotrypsin,
maltase, lactase and sucrase (all three of which process
only sugars).
Small, finger-like structures (villi) and their epithelial
cells covered with numerous microvilli improve absorption
of nutrients by increasing surface area of intestine,
enhancing speed of absorption.
Blood containing absorbed nutrients is carried from small
intestine via the hepatic portal vein to the liver for filtering,
removal of toxins, and nutrient processing.
Part Three: Digestion
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Whatever material is left goes into the large intestine.
Function: storage and fermentation of indigestible
matter.
Four parts: ascending colon, descending colon,
transverse colon, and sigmoid colon.
Part Three: Digestion
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Less vigorous in absorption activity.
Digestion is retained to allow fermentation due to the
action of bacteria, which breaks down some of the
substances that remain after processing in the small
intestine; some of the breakdown products are
absorbed. In humans, these include most complex
saccharides.
Large intestine absorbs water from the chyme and
stores feces.
Part Four: Defecation
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Waste product is stored in the rectum for a certain
period and then waste is eliminated from the body
through contraction and relaxation through the anus.
The exit of this waste material is regulated by the anal
sphincter.
A Closer Look: Breakdown & Absorption
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Proteins
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Occurs in the stomach and duodenum in which 3 main
enzymes, pepsin secreted by the stomach
and trypsin and chymotrypsin secreted by the pancreas,
break down food proteins into polypeptides that are then
broken down by
various exopeptidases and dipeptidases into amino acids.
A Closer Look: Breakdown & Absorption
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Fats
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Can begin in the mouth where lingual lipase breaks down
some short chain lipids into diglycerides. Presence of fat in
small intestine produces hormones that stimulate the
release of pancreatic lipase from the pancreas and bile from
the liver for breakdown of fats into fatty acids. Complete
digestion of one molecule of fat (a triglyceride) results in 3
fatty acid molecules and one glycerol molecule.
A Closer Look: Breakdown & Absorption
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Carbohydrates
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Bonds between glucose molecules broken by salivary and
pancreatic amylase, resulting in smaller chains of glucose.
Results in simple sugars glucose and maltose that can be
absorbed by the small intestine.
Lactase breaks down the disaccharide lactose to its
component parts, glucose and galactose. Glucose and
galactose can be absorbed by the small intestine.
Sucrase breaks down the disaccharide sucrose. Sucrose
digestion yields the sugars fructose and glucose which are
readily absorbed by the small intestine.
A Closer Look: Breakdown & Absorption
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DNA & RNA
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DNA and RNA are broken down into mononucleotides by
the nucleases deoxyribonuclease and ribonuclease (DNase
and RNase) from the pancreas.
Chemical vs. Mechanical Digestion
CHEMICAL
MECHANICAL
•Catabolism
•Glandular
structures, dispersed
throughout the body,
are involved in
breaking food into
simple molecules
that can be absorbed.
•Use of enzymes.
• Mastication
Break down of food
into usable energy
molecules.
•Food is crushed and
liquefied by the teeth,
tongue
• Peristalsis
•Waves of involuntary
muscle contraction of the
stomach and small
intestine.
Disorders of the Digestive System
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Celiac Disease
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an autoimmune disorder of the small intestine that occurs
in genetically predisposed people of all ages from middle
infancy onward
caused by a reaction to gliadin, a prolamin (gluten protein)
found in wheat, and similar proteins found in the crops of
the tribe Triticeae (which includes other common grains
such as barley and rye)
Disorders of the Digestive System
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Celiac Disease: Signs & Symptoms
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Pale, loose and greasy stool (steatorrhoea).
Weight loss or failure to gain weight (in young children).
Intermittent diarrhea
Abdominal pain
Bloating
Irritability or depression, anemia, stomach upset, joint pain,
muscle cramps, skin rash, south sores, dental and bone
disorders (such as osteoporosis), tingling in the legs and
feet (neuropathy) may also occur.
Disorders of the Digestive System
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Celiac Disease : Prevalence
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Affects between 1 in 1,750 in the world, and 1 in 105 people
in the United States.
Almost all people with celiac disease have either the
variant HLA-DQ2 allele or (less commonly) the HLADQ8 allele. However, about 20–30% of people without celiac
disease have also inherited either of these alleles. This
suggests additional factors are needed for celiac disease to
develop.
Disorders of the Digestive System
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Celiac Disease: Treatment
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Diet- To manage the disease and prevent complications, it's
crucial to avoid all foods that contain gluten, including:
barley, bulgur, durum, farina, graham flour, rye, semolina,
spelt (a form of wheat), triticale, wheat
Supplements- Take vitamin and mineral supplements
recommended by doctors or dietitian to help correct
deficiencies: Calcium, folate, iron, vitamin B-12, vitamin,
vitamin K
Disorders of the Digestive System
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Crohn’s Disease
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Type of inflammatory bowel disease that may affect any
part of the gastrointestinal tract from mouth to anus,
causing a wide variety of symptoms.
Causes inflammation
of the lining of your digestive tract.
Disorders of the Digestive System
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Crohn’s Disease: Signs & Symptoms
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Diarrhea
Abdominal pain and cramping
Blood in stool
Ulcers
Reduced appetite and weight loss
Other symptoms include: fever, fatigue, arthritis, eye
inflammation, mouth sores, skin disorders, inflammation of
the liver or bile ducts, delayed growth or sexual
development (in children)
Disorders of the Digestive System
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Crohn’s Disease: Prevalence
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Affects between 400,000 and 600,000 people in North
America.
Prevalence estimates for Northern Europe have ranged
from 27–48 per 100,000.
Crohn's disease tends to present initially in the teens and
twenties, with another peak incidence in the fifties to
seventies, although the disease can occur at any age.
Disorders of the Digestive System
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Crohn’s Disease: Treatment
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There is currently no cure for Crohn's disease, and there is
no one treatment that works for everyone.
Treatment for Crohn's disease usually involves drug therapy
or, in certain cases, surgery.
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Anti-inflammatory drugs: Sulfasalazine, Mesalamine,
Corticosteroids.
Immune system suppressors: Azathioprine, Mercaptopurine,
Infliximab, Adalimumab, Certolizumab pegol, Methotrexate,
Cyclosporine, Natalizumab.
Antibiotics: Metronidazole, Ciprofloxacin.
Other drugs: anti-diarrheals, laxatives, pain relievers, vitamin B-12
shots, supplements.
Digestive System: A Summary
The Endocrine System
Why was the endocrine student so upset?
He failed a teste.
Function
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System of glands, each of which secretes different types
of hormones directly into the bloodstream to maintain
homeostasis.
An information signal system like the nervous system.
Hormones regulate various human functions,
including metabolism, growth and
development, tissue function, sleep, and
mood.
Homeostasis & the Endocrine System
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What is homeostasis?
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The human body’s ability to maintain balance or return
systems to functioning within a normal range. Interactions
within the body facilitate compensatory changes supportive
of physical and psychological functioning.
The liver, the kidneys,
and the brain
(hypothalamus,
the autonomic
nervous system and
the endocrine system)
help maintain
homeostasis.
Homeostasis & the Endocrine System
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Role of endocrine system:
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synthesizing and releasing hormones, chemical messengers.
major areas of control and integration include responses to
stress and injury, growth and development, absorption of
nutrients, energy metabolism, water and electrolyte
balance, reproduction, birth, and lactation.
many endocrine glands are linked to neural control centers
by homeostatic feedback mechanisms. The two types of
feedback mechanisms are negative feedback and positive
feedback.
most are negative feedback mechanisms
Negative Feedback Mechanisms
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Negative feedback mechanisms act like a
thermostat in the home. As the temperature rises
(deviation from the ideal
normal value), the thermostat
detects the change and triggers
the air-conditioning to turn on
and cool the house. Once the
temperature reaches its
thermostat setting (ideal
normal value), the air
conditioning turns off.
Negative Feedback Mechanisms
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Blood calcium level.
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parathyroid glands secrete parathyroid hormone, which regulates the
blood calcium
if calcium decreases, parathyroid glands sense the decrease and
secrete more parathyroid hormone. Parathyroid hormone stimulates
calcium release from bones and increases the calcium uptake into the
bloodstream from the collecting tubules in the kidneys.
conversely, if blood calcium increases too much, the parathyroid
glands reduce parathyroid hormone production.
both responses are examples of negative feedback because in both
cases the effects are negative (opposite) to the stimulus.
Negative Feedback Mechanisms
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Blood calcium level.
Insulin and Cell Signaling
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Insulin is the major hormone controlling critical
energy functions such as glucose and lipid metabolism.
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insulin activates the insulin receptor tyrosine kinase (IR),
which phosphorylates and recruits different substrate
adaptors.
activated Akt induces glycogen synthesis, and cell survival.
insulin stimulates glucose uptake in muscle and adipocytes
via translocation of GLUT4 vesicles to the plasma
membrane.
The Endocrine System
Insulin and Cell Signaling
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Complex insulin
cell signaling
involving all
intermediates.
Insulin and Cell Signaling
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Low glucose vs. Elevated glucose level and the action of
insulin.
Type I Diabetes vs. Type II Diabetes
TYPE I DIABETES
Body make no insulin.
Usually in children and
teens.
5% -10% of total
cases.
TYPE II DIABETES
Can be due to genetic
factors.
Feeling tired or ill,
frequent urination,
tiredness, unusual
thirst, weight loss,
blurred vision,
frequent infections
and slow wound
healing,
asymptomatic.
Body can’t use its
insulin.
Also due to obesity.
Usually in adults and
the elderly
90%- 95%-of total
cases.
Disorders of the Endocrine System
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Acromegaly
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syndrome that results when the anterior pituitary gland
produces excess growth hormone (GH) after epiphyseal
plate closure at puberty.
most commonly affects adults in middle age, and can result
in severe disfigurement, complicating conditions, and
premature death if unchecked. Because of
its pathogenesis and slow progression, the disease is hard
to diagnose in the early stages and is frequently missed for
years until changes in external features, especially of the
face, become noticeable.
acromegaly is often associated with gigantism.
Disorders of the Endocrine System
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Acromegly: Signs and Symptoms
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Enlarged hands and feet
Coarsened, enlarged facial features
Coarse, oily, thickened skin
Excessive sweating and body odor
Small outgrowths of skin tissue (skin tags)
Fatigue and muscle weakness
A deepened, husky voice due to enlarged vocal cords and sinuses
Severe snoring due to obstruction of the upper airway
Impaired vision
Headaches
Enlarged tongue
Pain and limited joint mobility
Menstrual cycle irregularities in women
Erectile dysfunction in men
Enlarged liver, heart, kidneys, spleen and other organs
Increased chest size (barrel chest)
Disorders of the Endocrine System
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Acromegaly
Disorders of the Endocrine System
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Acromegaly: Prevalence
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approximately 4,676 cases per million population, and the
incidence is 116.9 new cases per million per year.
Disorders of the Endocrine System
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Acromegaly: Treatment
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The goals of treatment are to reduce GH production to
normal levels, to relieve the pressure that the growing
pituitary tumor exerts on the surrounding brain areas, to
preserve normal pituitary function, and to reverse or
ameliorate the symptoms of acromegaly. Currently,
treatment options include surgical removal of the
tumor, drug therapy, and radiation therapy of the pituitary.
André René Roussimoff, aka Andre the
Giant, famous actor and wrestler, suffered
from acromegaly. He was 7 feet 4 inches
and 520 pounds when he died from heart
compliations (due to acromegaly) at age
46.
Disorders of the Endocrine System
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Acromegaly: Treatment
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Drugs
Somatostatin analogues
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The primary current medical treatment of acromegaly is to use
somatostatin analogues – octreotide (Sandostatin)
or lanreotide (Somatuline). These somatostatin analogues are
synthetic forms of a brain hormone, somatostatin, which stops GH
production.
Dopamine agonists
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For those unresponsive to somatostatin analogues, treatment
using one of the dopamine agonists, Bromocriptine (Parlodel)
or Cabergoline.
Disorders of the Endocrine System
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Acromegaly: Treatment
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Surgery
Surgery is a rapid and effective treatment, of which there
are two alternative methods. The first method, a procedure
known as Endonasal Transphenoidal surgery, involves the
surgeon reaching the pituitary through an incision in
the nasal cavity wall. The wall is reached by passing through
the nostrils with microsurgical instruments. The second
method is Transsphenoidal surgery during which an
incision is made into the gum beneath the upper lip.
Disorders of the Endocrine System
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Acromegaly: Treatment
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Radiation Therapy
Radiation therapy has been used both as a primary
treatment and combined with surgery or drugs. It is usually
reserved for patients who have tumor remaining after
surgery. These patients often also receive medication to
lower GH levels. his treatment lowers GH levels by about 50
percent over 2 to 5 years.
The Excretory System
Looking for jokes about the excretory system?
Well urine luck.
Function
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A passive biological system that removes excess,
unnecessary materials from an organism, so as to help
maintain homeostasis within the organism and prevent
damage to the body.
Responsible for the elimination of the waste
products of metabolism as well as other liquid and
gaseous wastes, as urine.
Organs of the Excretory System
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Kidney
 essential in the urinary system; serve homeostatic functions such as
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the regulation of electrolytes, maintenance of acid–base balance, and
regulation of blood pressure (via maintaining salt and water
balance).
natural filter of the blood, and remove wastes which are diverted to
the urinary bladder
excrete wastes such as urea and ammonium, and they are also
responsible for the reabsorption of water, glucose, and amino acids.
produce hormones including calcitriol, erythropoietin, and the
enzyme renin.
Organs of the Excretory System
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Ureters
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tubes made of smooth muscle fibers that propel urine from
the kidneys to the urinary bladder.
usually 25–30 cm (10–12 in) long and ~3-4 mm in diameter
arise from the renal pelvis on the medial aspect of each
kidney before descending towards the bladder on the front
of the psoas major muscle.
Organs of the Excretory System
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Bladder
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organ that collects urine excreted by the kidneys before
disposal by urination.
hollow muscular, and distensible (or elastic) organ
Organs of the Excretory System
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Urethra
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tube that connects the urinary bladder to the genitals for
the removal of fluids from the body
external urethral sphincter is a striated muscle that allows
voluntary control over urination
The Kidney
Nitrogenous Wastes
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Ammonia is a toxic by-product of the metabolic
removal of nitrogen from proteins and nucleic acids.
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Dilute solutions of ammonia
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Urea
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Most aquatic animals get rid of ammonia by excreting it in very dilute
solutions with the water.
Terrestrial animal would have to urinate copiously; toxic, could only be
transported in the animal and excreted in a very dilute solution. Mammals
and most 1 amphibians excrete urea; handled in much concentrated form.
Uric acid
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Land snails, insects, birds, and some reptiles excrete uric acid.
Thousands of times less soluble in water than either ammonia or urea,
uric acid can be excreted as a precipitate after nearly all the water has
been reabsorbed from the urine. In birds and reptiles, the pastelike
urine is excreted into the cloaca and eliminated along with feces from
the intestine.
A Closer Look at the Kidney: A Nephron
A Closer Look at the Kidney: A Nephron
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Filtration
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approximately 20 percent of the blood gets filtered under
pressure through the walls of the glomerular capillaries and
Bowman's capsule.
filtrate is composed of water, ions (sodium, potassium,
chloride), glucose and small proteins
filtration process is “much like the making of espresso or
cappuccino”
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water is forced under pressure through a fine sieve containing the
filtrate
filtrate enters the Bowman's capsule, it flows through the lumen of
the nephron into the proximal tubule.
A Closer Look at the Kidney: A Nephron
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Reabsorption
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inside the lumen of the nephron, small molecules, such as
ions, glucose and amino acids, get reabsorbed from the
filtrate
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Proteins called “transporters” located on nephron membrane
Grab small molecules as they pass by; each transporter grabs 1 or
2 types of molecules; some transpoters require energy (active),
some do not (passive)
A Closer Look at the Kidney: A Nephron
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Secretion
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transfer of materials from peritubular capillaries to renal
tubular lumen; caused by active transport.
Usually ouly a few substances are secreted; substances are
present in great excess , or are natural poisons.
A Closer Look at the Kidney: A Nephron
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Excretion
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Small toxicants (both polar and lipid-soluble) filtered with
ease by the glomerulus.
Large molecules (including some that are protein-bound)
may be secreted (by passive transfer) from the blood across
capillary endothelial cells and nephron tubule membranes
to enter the urine.
Substances that are ionized remain in the urine and leave
the body.
Lipid-soluble toxicants can be reabsorbed and re-enter the
blood circulation, which lengthens their half-life in the body
and potential for toxicity.
Disorders of the Excretory System
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Interstitial Nephritis
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disorder in which the spaces between the kidney tubules become swollen
(inflamed).
may be temporary (acute), or it may be long-lasting (chronic) and get worse
over time.
may be caused by:
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Allergic reaction to a drug (acute interstitial allergic nephritis)
Autoimmune disorders such as anti-tubular basement membrane disease,
Kawasaki’s disease, Sjogren syndrome, systemic lupus erythematosus, or
Wegener’s granulomatosis
Infections
Long-term use of medications such as acetaminophen (Tylenol), aspirin, and
nonsteroidal anti-inflammatory drugs (NSAIDS). This is called analgesic
nephropathy.
Side effect of certain antibiotics (including penicillin, ampicillin, methicillin,
sulfonamide medications, and others)
Side effect of other medications such as furosemide, thiazide diuretics, omeprazole,
triamterene, and allopurinol
Too little potassium in your blood
Too much calcium or uric acid in your blood
Disorders of the Excretory System
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Interstitial Nephrities: Signs and Symptoms
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can lead to acute kidney failure
half of the cases will have decreased urine output
common signs include:
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Blood in the urine
Fever
Increased or decreased urine output
Mental status changes (drowsiness, confusion, coma)
Nausea, vomiting
Rash
Swelling of the body, any area
Weight gain (from retaining fluid)
Disorders of the Excretory System
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Interstitial Nephritis: Prevalence/100,000 inhabitants
Disorders of the Excretory System
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Interstitial Nephritits: Treatment Options
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Treatment depends on the cause of the problem. Avoiding
medications that lead to this condition may relieve
symptoms quickly.
Limiting salt and fluid in the diet can improve swelling and
high blood pressure. Limiting protein in the diet can help
control the buildup of waste products in the blood
(azotemia) that can lead to symptoms of acute kidney
failure.
If dialysis is necessary, it usually is required for only a short
time.
Corticosteroids or stronger anti-inflammatory medications
such as cyclophosphamide can sometimes be helpful.
Disorders of the Excretory System
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Kidney Stones
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small, hard deposits that form inside your kidneys, made of
mineral salts
some may need nothing more than to take pain medication
and drink lots of water to pass a kidney stone.
other instances, surgery may be needed.
Disorders of the Excretory System
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Kidney Stones: Signs and Symptoms
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Severe pain in the side and back, below the ribs
Pain that spreads to the lower abdomen and groin
Pain that comes in waves and fluctuates in intensity
Pain on urination
Pink, red or brown urine
Cloudy or foul-smelling urine
Nausea and vomiting
Persistent urge to urinate
Urinating more often than usual
Fever and chills if an infection is present
Disorders of the Excretory System
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Kidney Stones: Prevalence
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Each year in the United States, people make more than a
million visits to health care providers and more than
300,000 people go to emergency rooms for kidney stone
problems
Disorders of the Excretory System
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Kidney Stones: Treatment Options
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Drinking water.
Pain relievers.
Medical therapy.
Using sound waves to break up stones.
Surgery to remove very large stones in the kidney.
The Immune System
Function
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System of biological structures and processes within
an organism that protects against disease.
To function properly, an immune system must detect a
wide variety of agents: viruses, parasitic worms, and
distinguish them from the organism's own healthy
tissue.
Consists of:
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Fluid Immunity:
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Innate Immunity:
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The Blood System and Lymph System
Surface Barriers or Mucosal Immunity, Normal Flora, Phagocytes
Adaptive or Acquired Immunity
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Cell-mediated Immunity and Humoral Immunity
Immunity: The Fluid System
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The Blood System
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Hemocytoblasts mature into three types of blood cells:
erythrocytes (red blood cells or RBCs), leukocytes (white
blood cells or WBCs), and thrombocytes (platelets).
The leukocytes are further subdivided into granulocytes
agranulocytes. The granulocytes consist of neutrophils,
eosinophils, and basophils. The agranulocytes are
lymphocytes (consisting of B cells and T cells) and
monocytes.
Immunity: The Fluid System

The Blood System


Lymphocytes circulate in the blood and lymph systems, and
make their home in the lymphoid organs.
White blood cells play an important role in phagocytosis of
intruders.
Immunity: The Fluid System

The Lymph System


Lymph is an alkaline fluid that is usually clear, transparent,
and colorless. It flows in the lymphatic vessels and bathes
tissues and organs in a protective covering.
The human lymphoid system has the following:


primary organs: bone marrow and the thymus gland (located
behind the breastbone above the heart)
secondary organs at or near possible portals of entry for
pathogens: adenoids, tonsils, spleen, lymph nodes (along the
lymphatic vessels with concentrations in the neck, armpits,
abdomen, and groin), Peyer's patches (within the intestines), and
the appendix.
Immunity: Recognition of Pathogens


An antigen is any substance that elicits an immune
response, antibodies recognize/differentiate antigens
Parts of the immune system are:






antigen-specific: they recognize and act against particular
antigens
systemic: not confined to the initial infection site, but work
throughout the body
some have memory: recognize and mount an even stronger
attack to the same antigen the next time
Self/non-self recognition through major histocompatibility
complex (MHC). Cells not displaying this is treated as nonself and attacked.
Sometimes this process breaks down and the immune
system attacks self-cells, known as autoimmune diseases
Some immune response to harmless substances is extreme,
known as allergies
Immunity: Innate Immunity

Innate Immnunity

Immune system we are born with, consisting of:



Surface Barriers or Mucosal Immunity: skin, cilia movement in
lungs (coughing), sticky mucus, acidic secretions in stomach and
various other parts of the body, lyzozyme in saliva, tears, and nasal
secretions.
Normal Flora in the Intestines: many different types of bacterium
Macrophages: participate in phagocytosis
Immunity: Acquired Immunity

Acquired Immunity

Consists of lymphocytes:





Blood contains 20–50% of circulating lymphocytes, the rest move in
the lymph system.
80% of them are T cells, 15% B
Lymphocytes constitute 20–40% of the body's WBCs.
Their total mass is about the same as that of the brain or liver.




B cells and T cells
B cells are produced in the stem cells of the bone marrow. Produce antibody
and oversee humoral immunity.
T cells are nonantibody-producing lymphocytes which are also produced in
the bone marrow but sensitized in the thymus and constitute the basis of cellmediated immunity.
Parts of the immune system are changeable and can adapt to better
attack the invading antigen.
Two fundamental adaptive mechanisms: cell-mediated immunity and
humoral immunity.
Immunity: Innate vs. Acquired
Immunity: Active Immunity

Active Immunity





Type of immunity or resistance developed in
an organism by own production of antibodies in response to
an exposure to an antigen, a pathogen or to a vaccine.
Active immunity is generally long-term
Can be acquired by infection followed by B cells and T
cells activation, or artificially acquired by vaccines,
immunization.
Active immunity often involves humoral immunity (B-cells)
and cell-mediated immunity (T-cells).
Immunity: Passive Immunity

Passive Immunity


Type of immunity acquired by the transfer of antibody from one
individual to another, (i.e. mother to offspring).
Two routes:




Naturally acquired passive immunity
Artificially acquired passive immunity.
Passive immunity acquired naturally happens when a mother
transfer antibodies to her offspring via placental route
during pregnancy and via colostrum during breastfeeding.
Passive immunity acquired artificially is done by
injecting antibodies to an organism via a vaccination
Immunity: Active vs. Passive Immunity
ACTIVE IMMUNITY
Acquired through
YOUR OWN body’s
formation of
antibodies after
dieasease, or
vaccination
PASSIVE IMMUNITY
Long-term
May be acquired
through vaccination
Acquired through
passing of
antibodies through
placenta or
breastfeeding
Originally
immunity may have
been acquired
through disease
resistance or
vaccination
Immunity: Humoral Immunity

Humoral Immunity



Immature B-lymphocyte stimulated to maturity when an antigen
binds to its surface receptors and helper T-cell nearby (to release a
cytokine).
Sensitizes or primes the B-cell; undergoes clonal selection, which
means it reproduces asexually by mitosis. Clones become plasma
cells.
Antibodies, (immunoglobulins or Igs)


Soluble proteins secreted by the plasma offspring (clones) of primed
B-cells.
Inactivate antigens by:




complement fixation: proteins attach to antigen
surface and cause holes to form, i.e., cell lysis
neutralization: binding to specific sites to prevent
attachment
aglutination: clumping
precipitation: forcing insolubility and settling out
of solution)
Immunity: Cell-mediated Immunity

Cell-mediated Immunity



Macrophages engulf antigens, process them internally, then
display parts of them on their surface together with some of their
own proteins.
Sensitizes the T-cells to recognize antigens.
T cells are primed in the thymus.




Cytotoxic or killer T-cells: release lymphotoxins, which cause cell
lysis.
Helper T-cells: serve as managers, directing the immune response.
Secrete chemicals called lymphokines that stimulate cytotoxic T-cells
and B-cells to grow and divide, attract neutrophils, and enhance the
ability of macrophages to engulf and destroy microbes.
Suppressor T-cells: inhibit the production of cytotoxic T cells once
they are unneeded, lest they cause more damage than necessary.
Memory T-cells: program to recognize and respond to a pathogen
once it has invaded and been repelled.
Immunity: Humoral vs Cell-mediated
HUMORAL
B-cells
differentiate to
create
antibodies that
attack
pathogens in
various methods
(see Humoral Immunity)
CELL-MEDIATED
Responses are
specific for a
particular
antigen
Result in longterm memory,
both rely on
lymphocytes.
Various T-cells
function in
different ways to
destroy and
remember
pathogens
(see Cell-mediated Immunity)
Immunity: A Closer Look at Lymphocytes
B-CELLS
Bind soluble antigens
Bound antigen
molecules are engulfed
into the B-cell
by receptor-mediated
endocytosis.
The antigen is digested
into fragments which
are then displayed at
the cell surface
T-CELLS
•Integral
membrane
proteins.
•Present in
thousands of
identical copies
exposed at the
cell surface.
•Encoded by
genes assembled
by the
recombination of
segments of DNA.
•Unique binding
site.
Recognize their
cognate antigen in
a processed form,
as a peptide
fragment presented
by an antigen
presenting cell's
MHC molecule to
the T cell receptor.
Antigen destroyed
by participation of
many forms of Tcells
Immunity: A Closer Look at Lymphocytes
B-CELLS
T-CELLS
Immunity: Bacteria, Virus, and Antibiotics

Antibiotics

Selective poison:





Chosen to kill the desired bacteria, but not the cells in your body.
Each different type of antibiotic affects different bacteria in
different ways.
Antibiotics do not work on viruses because viruses are not
alive, whereas bacterium is a living, reproducing lifeform.
Virus is solely DNA (or RNA).
With a virus there is nothing to "kill," so antibiotics don't
work on it.
Disorders of the Immune System

HIV/AIDS




Chronic, potentially life-threatening condition caused by the
human immunodeficiency virus (HIV).
Damages immune system.
Sexually transmitted infection. Spread throug infected
blood, or from mother to child during pregnancy, childbirth
or breast-feeding.
May take years before HIV weakens your immune system to
the point that you have AIDS.
Disorders of the Immune System

HIV/AIDS: Signs & Symptoms

Primary infection











Fever
Muscle soreness
Rash
Headache
Sore throat
Mouth or genital ulcers
Swollen lymph glands, mainly on the neck
Joint pain
Night sweats
Diarrhea
Due to flu-like, mild symptoms, the first infection stage is
usually unnoticed by people.
Disorders of the Immune System

HIV/AIDS: Signs & Symptoms

Progression to AIDS










Soaking night sweats
Shaking chills or fever higher than 100 F (38 C) for several weeks
Cough and shortness of breath
Chronic diarrhea
Persistent white spots or unusual lesions on your tongue or in
your mouth
Headaches
Persistent, unexplained fatigue
Blurred and distorted vision
Weight loss
Skin rashes or bumps
Disorders of the Immune System

HIV/AIDS: Prevalence

2010 estimated 1,148,200 persons aged 13 and older were
living with HIV infection in the United States, including
207,600 (18.1%) persons whose infections had not been
diagnosed.
Disorders of the Immune System

HIV/AIDS: Treatment

There's no cure for HIV/AIDS, but a variety of drugs can be
used in combination to control the virus. Each of the classes
of anti-HIV drugs blocks the virus in different ways.





Non-nucleoside reverse transcriptase inhibitors (NNRTIs).
Nucleoside reverse transcriptase inhibitors (NRTIs).
Protease inhibitors (PIs).
Entry or fusion inhibitors.
Integrase inhibitors.
Disorders of the Immune System

Lupus

Lupus is a chronic inflammatory disease that occurs when
your body's immune system attacks your own tissues and
organs. Inflammation caused by lupus can affect many
different body systems — including your joints, skin,
kidneys, blood cells, brain, heart and lungs.
Disorders of the Immune System

Lupus: Signs & Symptoms

No two cases of lupus are alike, but common signs include:









Fatigue and fever
Joint pain, stiffness and swelling
Butterfly-shaped rash on the face that covers the cheeks and
bridge of the nose
Skin lesions that appear or worsen with sun exposure
Fingers and toes that turn white or blue when exposed to cold or
during stressful periods (Raynaud's phenomenon)
Shortness of breath
Chest pain
Dry eyes
Headaches, confusion, memory loss
Disorders of the Immune System

Lupus: Prevalence







Primarily a disease of young women
Occurs from infancy to old age, with peak occurrence between ages 15 and
40
Blacks (and possibly Hispanics, Asians, and Native Americans) are affected
more than whites.
Although there is a
strong familial
aggregation, the disease is
relatively uncommon and
most cases are sporadic.
May occur with other
autoimmune conditions
Ranges as high as
1,500,000.
2006 study estimated a 2005
prevalence of 161,000 with
definite SLE and 322,000 with
definite or probable SLE
Disorders of the Immune System

Lupus: Treatment

Treatment for lupus depends on your signs and symtoms.
Medications most commonly used include:




Nonsteroidal anti-inflammatory drugs (NSAIDs)
Antimalarial drugs
Corticosteroids
Immune suppressants
The Nervous System
Function


Part of the body that coordinates the voluntary and
involuntary actions and transmits signals between
different parts of its body.
Usually consists of two main parts, the central nervous
system (CNS) and the peripheral nervous
system (PNS).


The CNS contains the brain and spinal cord.
The PNS consists mainly of nerves, which are long fibers
that connect the CNS to every other part of the body.

The PNS includes motor neurons, mediating voluntary movement,
the autonomic nervous system, comprising the sympathetic
nervous system and the parasympathetic nervous system.
The Central Nervous System (CNS)


Part of the nervous system that combines the
information that it receives from, and coordinates the
activity of, all parts of the bodies of bilaterian
It contains the majority of the nervous system and
consists of the brain and the spinal cord.
The Peripheral Nervous System (PNS)




Consists of the nerves and ganglia outside of
the brain and spinal cord.
Mainly functions to
connect CNS to the
limbs and organs.
Divided into the somatic
nervous system and the
autonomic nervous
system.
The cranial nerves
are a major part of the
PNS.
A Closer Look: The Neuron
A Closer Look: Reflex Arc
Stimulus received from
outside stimulates
sensory neuron to
transmit signal to the
spinal cord which conveys
the message to a motor
neuron which causes a
muscle to move.
A Closer Look: The Brain
Sodium, Potassium, Action:
The Physiology of a Nerve Impulse

Polarization of the neuron's membrane: Sodium is on
the outside, and potassium is on the inside.

The outside of the cell contains excess sodium ions (Na+);
the inside of the cell contains excess potassium ions (K+).
The Physiology of a Nerve Impulse

2. Resting potential allows neuron to wait for stimuli.

When the neuron is inactive and polarized, it's said to be at
its resting potential. It remains this way until a stimulus
comes along.
The Physiology of a Nerve Impulse

3. Action potential: Sodium ions move inside the
membrane.


Stimulus allows gated ion channels to open suddenly and
allow the Na+ that was on the outside of the membrane to
go rushing into the cell. As this happens, the neuron goes
from being polarized to being depolarized.
Each neuron has a threshold level — the point at which
there's no holding back.
The Physiology of a Nerve Impulse

Repolarization: Potassium ions move outside, and sodium
ions stay inside the membrane.


After concentration of Na+, the gated ion channels on the inside of
the membrane open to allow the K+ to move to the outside of the
membrane. With K+ moving to the outside, the membrane's
repolarization restores electrical balance, although it's opposite of
the initial polarized membrane that had Na+ on the outside and
K+ on the inside. Just after the K+ gates open, the Na+ gates close;
otherwise, the membrane couldn't repolarize.
Hyperpolarization: More potassium ions are on the outside
than there are sodium ions on the inside.

When the K+ gates finally close, the neuron has slightly more K+
on the outside than it has Na+ on the inside. This causes the
membrane potential to drop slightly lower than the resting
potential, and
The Physiology of a Nerve Impulse

Refractory period puts everything back to normal:
Potassium returns inside, sodium returns outside.

The refractory period is when the Na+ and K+ are returned
to their original sides: Na+ on the outside and K+ on the
inside.
Neurotransmitters

Neurotransmitters are chemicals that transmit signals
from a neuron to a target cell across a synapse.


Neurotransmitters are packaged into synaptic vesicles on
the presynaptic side of a synapse.
They are released into and diffuse across the synaptic cleft,
where they bind to specific receptors in the membrane on
the postsynaptic side of the synapse.

Release of neurotransmitters usually follows arrival of an action
potential at the synapse, but may also follow graded electrical
potentials.
Neurotransmitters: IPSP vs. EPSP
IPSP
-Less likely to
generate action
potential
-Associated with
influx of Cl- or
efflux of K+
-Moves farther
from the
threshold.
EPSP
-Types of synaptic
potential
gradients.
-More likely to
generate action
potential
-Associated with
influx of Na+
-Moves closer to
the threshold.
Disorders of the Nervous System

Alzheimer’s Disease



Progressive disease that destroys memory and other
important mental functions.
Most common cause of dementia — a group of brain
disorders that results in the loss of intellectual and social
skills.
Connections between brain cells and the brain cells
themselves degenerate and die, causing a steady decline in
memory and mental function.
Disorders of the Nervous System

Alzheimer’s Disease: Signs & Symptoms





Forgetfulness and/or mild confusion
Memory lapses
Disorientation and misinterpreting spatial relationships
Trouble speaking and writing, thinking and writing, making
judgments and decisions, performing familiar tasks
Personality changes









Depression
Social withdrawal
Mood swings
Distrust in others
Irritability and aggressiveness
Changes in sleeping habits
Wandering
Loss of inhibitions
Delusions, such as believing something has been stolen
Disorders of the Nervous System

Alzheimer’s Disease: Prevalence

Estimated 5.4 million Americans of all ages have AD(2012).

5.2 million people age 65 and older, 200,000 individuals under age
65 who have younger-onset Alzheimer’s.



One in eight people age 65 and older
Nearly half of people age 85 and older
Most are non-Hispanic Caucasian Americans
Disorders of the Nervous Sytem

Alzheimer’s Disease: Treatment


AD is not curable, but can be offset.
Drugs




Cholinesterase inhibitors
Memantine
Creating a safe & supportive environment
Exercise & nutrition
Disorders of the Nervous System

Multiple Sclerosis



Multiple sclerosis (MS) is a potentially debilitating disease
in which your body's immune system eats away at the
protective sheath (myelin) that covers your nerves.
Damage to myelin causes interference in the
communication between your brain, spinal cord and other
areas of your body.
This condition may result in
deterioration of the nerves
themselves, a process that's not
reversible.
Disorders of the Nervous System

Multiple Sclerosis: Signs & Symptoms

Various types of symptoms, including:


Numbness or weakness in one or more limbs
Partial or complete loss of central vision, usually in one eye, often
with pain during eye movement (optic neuritis)








Double vision or blurring of vision
Tingling or pain in parts of your body
Electric-shock sensations that occur with certain head movements
Tremor, lack of coordination or unsteady gait
Slurred speech
Fatigue
Dizziness
Heat sensitivity
Disorders of the Nervous System

Multiple Sclerosis: Prevalence





Affects more than 350,000 people in the United States and 2.5
million worldwide.
In the United States, 90 per 100,000 population.
MS symptoms can start anywhere between 10 and 80 years of
age, but
usually
between 20
and 40 years.
Women
outnumber
men by a ratio
of almost 2 to 1
Affects
Caucasians more
than African
Americans
Disorders of the Nervous System

Multiple Sclerosis: Treatment

Drugs



Corticosteroids and plasma exchange treat MS attacks
Beta interferon, glatiramer acetates, fingolimod, natalizumab,
mitoxantrone, and teriflunomide slow progression of the disease
Physical therapy and muscle relaxants target physical symptoms
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
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
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
http://http://my.clevelandclinic.org/anatomy/digestive_system/hic_the_structure_and_function_of_the_digestive_syste
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
http://www.pennmedicine.org/health_info/body_guide/reftext/html/endo_sys_fin.html#homeostatic

http://www.cellsignal.com/reference/pathway/Insulin_Receptor.html

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
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
http://www.acromegaly.org/

http://www.emc.maricopa.edu/faculty/farabee/biobk/biobookexcret.html

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
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
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
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
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
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
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
http://www.mayoclinic.com/health/alzheimers-disease/DS00161