Transcript Albert - Brookings School District

The Human Body
By Albert Wu
Organ Systems
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Digestive System
Circulatory System
Respiratory System
Excretory System
Immune System
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Skeletal System
Endocrine System
Sensory System
Muscular System
Nervous System
Reproductive System
The Digestive System
Functions
 Provides intake of food for nourishment
 Breaks down the food into components which can be
absorbed and utilized by the body
 Excretes solid waste
The Process of Digestion
 The digestive tract absorbs food mainly by diffusion or active
transport.
 Large food molecules can’t diffuse and are too large to fit the
active transport pumps.
 Therefore, food molecules have to be broken down and
absorbed. The digestive system performs both of these
functions.
Parts of the Digestive System
Mouth
Teeth
Lip
Tongue
Salivary Glands
Pharynx
Esophagus
Liver
Gallbladder
(under liver)
Large Intestine
Stomach
Pancreas
(under stomach)
Rectum
Small Intestine
Appendix
Anus
The Alimentary Canal
 The alimentary canal consists of the organs that form the
main digestive tract.
 The alimentary canal includes:
 Mouth, Pharynx, and Esophagus
 Stomach
 Small Intestine
 Large Intestine
 Rectum and Anus
The Mouth, Pharynx, and
Esophagus
 The mouth physically breaks down food (using the teeth) and also
begins to chemically digest carbohydrates. The tongue senses
different foods.
 The pharynx connects the mouth to the esophagus, which pushes
food into the stomach by means of peristaltic contractions. The
food enters the stomach via the esophageal sphincter.
The mouth and
associated organs.
The Stomach
 The stomach is a muscular pouch that receives chewed food from the
esophagus.
 The stomach secretes hydrochloric acid as well as a number of
enzymes which chemically digest proteins in food. The half-digested
food is called chyme.
 Muscular contractions of the stomach wall help mix the digesting
food and push it into the small intestine through a valve called the
pyloric sphincter.
The Small Intestine
 The final stages of chemical breakdown of food occur in the small
intestine, which is a long muscular tube.
 Most nutrients are absorbed in the small intestine.
 The small intestine’s great length (5.5-6 meters) and internal folds
(villi and microvilli) helps give the maximum surface area for
absorption of food.
 Muscular contractions mix the food and move it down the
intestine.
Right: the lining of the
small intestine, seen
through a microscope.
Parts of the Small Intestine
 The small intestine has three main sections. In order from the
closest to the stomach, they are the duodenum, the jejunum,
and the ileum.
 The first 25 cm is the duodenum. Pancreatic and liver
secretions enter the duodenum.
 The next 2.5 m is the jejunum. It is relatively thick and exhibits
high activity in its vascular wall. The pH of the jejunum and the
ileum ranges from 7-9.
 The final 2-4 m is the ileum. The ileum houses a large
population of symbiotic bacteria and has many lymph nodes.
The Large Intestine
 The chyme (now mostly digested) enters the large intestine through
the ileocecal sphincter. The large intestine absorbs water and
electrolytes from it.
 Indigestible waste material (feces) is pushed into the rectum.
 The large intestine is shorter than the small intestine but much wider.
Parts of the Large Intestine.
 The large intestine has five main parts. They occur in this order,
beginning with the closest to the small intestine.
 The cecum is a pouch that hangs below the ileocecal sphincter. It is
connected to the appendix, a small, wormlike structure.
 The ascending colon stretches up from the cecum to the liver.
 The transverse colon extends across the abdomen.
 The descending colon drops down to the pelvic girdle.
 The sigmoid colon is s-shaped and connects to the rectum.
The Rectum and Anus
 The rectum collects feces (indigestible material) and
periodically excretes them (defecation).
 The anus is a muscular ring that acts as a valve for the
rectum.
Accessory Organs
 The accessory organs secrete substances into the alimentary
canal which assist the process of digestion. They are not
actually part of the alimentary canal.
 The accessory organs include:
 Salivary Glands
 Pancreas
 Liver and Gallbladder
The Salivary Glands
 The salivary glands produce saliva, which contains enzymes
that break down carbohydrates and kill certain pathogens.
 Saliva also contains bicarbonate ions which buffer the saliva
to prevent enzyme denaturation.
The Pancreas
 The pancreas produces “pancreatic juice”, which is secreted into the small
intestine.
 Pancreatic juice contains a variety of enzymes, including those listed
below.
 Amylase: digests starch
 Lipase: digests lipids
 Trypsin: digests proteins
 Nuclease: digests nucleic acids
The pancreas.
 Pancreatic juice also contains bicarbonate ions, which make an optimum
environment for pancreatic enzymes and help neutralize stomach acid.
 The pancreas is also part of the endocrine system.
The Liver and Gallbladder
 The liver and gallbladder help digest lipids.
 The liver secretes a liquid called bile, which contains
pigments, salts, and cholesterol.
 The gallbladder collects bile, concentrates it, and secretes it
into the small intestine.
 Bile salts cause lipids to form globules (emulsification) and
aid enzymes in digesting the lipids.
Enzymes
 Enzymes are proteins which act as catalysts.
 They are important in breaking down large food molecules.
 Different parts of the digestive system produce different
enzymes.
 Digestion of different types of food molecules takes place in
different locations.
Digestion of Molecules
Molecule
Location of
Digestion
Mouth
Carbohydrates
Small Intestine
Stomach
Proteins
Small Intestine
Digestive Enzyme
Salivary Amylase
Salivary Glands
Sucrase, Maltase, Lactase
Small Intestine
Pancreatic Amylase
Pancreas
Pepsin
Stomach
Peptidase
Small Intestine
Trypsin, Chymotrypsin
Carboxypeptidase
Stomach
Lipids
Nucleic Acids
Small Intestine
Small Intestine
Enzyme Producer
Pancreas
Gastric Lipase
Stomach
Intestinal Lipase
Small Intestine
Pancreatic Lipase
Pancreas
Nuclease
Pancreas
Physical and Chemical Digestion
Physical Digestion
Chemical Digestion
 The physical breakdown of
 The chemical breakdown
pieces of food
 Increases surface area of
food for chemical digestion
to be effective
of food molecules
 Breaks large molecules into
smaller molecules which
can be absorbed
 Happens at a molecular
level
Diseases of the Digestive System
 Pinworms
 Caused by a small parasitic worm, Enterobius vermicularis.
 Symptoms: itching in the crotch area, may cause weight
loss/anemia.
 Nearly 1/3 of the world’s population is infected with
pinworms, but symptoms are usually mild.
 Treated with repeated doses of medication to ensure the death
of all the pinworm eggs.
Diseases (continued)
 Colorectal Cancer
 Caused by uncontrolled mitosis of cells in the large intestine
 Symptoms include abdominal pain, bloody stools or diarrhea, or
changes in bowel movements.
 4th most common cancer in world, more common in older
people or alcoholics, 20% have family history
 Treated with radiation or chemotherapy
Sources
 Shier, David, Jackie Butler, and Ricki Lewis. Hole’s Human




Anatomy and Physiology. New York, McGraw-Hill: 2007.
http://www.google.com/
http://en.wikipedia.org/
http://www.ncbi.nlm.nih.gov/
http://digestive.niddk.nih.gov/ddiseases/pubs/yrdd/
The Circulatory
System
Functions
• To move blood around the body, ensuring that all tissues
get an adequate supply of nutrients and oxygen. Wastes
and carbon dioxide are removed.
• To circulate white blood cells for defense against
infection and to circulate platelets for damage repair.
The Heart
• The heart is a muscular pump that contracts forcefully to
pump blood through the blood vessels.
• The heart has four chambers to pump blood in two
circuits: the pulmonary circuit (to the lungs) and the
systemic circuit (to the body).
• The heart’s rate of contraction can change to suit the
body’s oxygen or nutrition needs (example: heart rate
increases during exercise).
The Heart
Aorta
Superior Vena Cava
Left Pulmonary Artery
Right Pulmonary Artery
Left Pulmonary Veins
Right Pulmonary Veins
Left Atrium
Right Atrium
Pulmonary Trunk
Coronary Vessels
Mitral Valve
Aortic Valve
Tricuspid Valve
Pulmonary Valve
Right Ventricle
Papillary Muscles
Inferior Vena Cava
Left Ventricle
Chordae Tendineae
Interventricular Septum
How the Heart Works
• 1. Deoxygenated (oxygen poor) blood arrives at the right
atrium through the venae cavae, the right atrium
contracts, the blood moves to right ventricle through
tricuspid valve, the tricuspid valve closes.
• 2. The right ventricle contracts, pumping blood through
the pulmonary valve and pulmonary artery to lungs where
the blood picks up oxygen, the pulmonary valve closes.
• 3. Oxygenated blood arrives at left atrium via pulmonary
veins, left atrium contracts, the blood moves to left
ventricle through mitral valve, the mitral valve closes.
See the heart diagram on slide 25.
How the Heart Works
• 4. Left ventricle contracts, pumping oxygenated blood
through the aortic valve and aorta into the body, where
the blood gives up its oxygen. The cycle starts again.
• The tricuspid and mitral valves are operated by the
chordae tendineae and the papillary muscles. The
pulmonary and aortic valves are semilunar valves, which
are closed by blood pressure.
Blood
Vessels
• There are several types of blood vessels.
• Arteries and arterioles: carry blood away from the heart.
• Capillaries: allow exchange of oxygen and nutrients
between blood and tissues.
• Veins and venules: carry blood back to the heart.
Here is a cross section of an artery
(right) and a vein (left). Notice the
difference in thickness of the walls of
the vessels.
Arteries and Arterioles
• Arteries and arterioles carry blood away from the heart.
Arterioles are small arteries.
• Blood pumped from the heart is under high pressure, so
arteries and arterioles have a very thick and muscular
wall to deal with the pressure.
A cross section of an artery.
Veins and Venules
• Veins and venules carry blood back to the
heart.
• Veins and venules have a wide diameter to
carry large volumes of blood.
• Veins and venules have thin walls because the
blood is at low pressures.
• Low pressure blood tends to flow back down
the veins due to gravity, so veins are equipped
with internal valves.
A cross section of a vein.
Capillaries
• Capillaries are the smallest blood vessels – they are so
small that red blood cells can only pass through single
file.
• The thin walls of capillaries (only one cell thick) facilitate
the exchange of nutrients and waste, along with oxygen
and carbon dioxide.
The Blood
• Blood is a connective tissue and the only liquid tissue in
the body. It is pumped through the blood vessels and
lungs by the heart.
• Blood is important for homeostasis. It carries oxygen and
nutrients to tissues and takes away carbon dioxide and
wastes.
• White blood cells, which fight infections, are circulated
through the body through the blood.
Composition of Blood
• Blood is composed of plasma, red blood cells, white
blood cells, and platelets.
• 55% of blood is composed of plasma, a watery fluid
which contains proteins important for homeostasis and
blood clotting.
Red Blood Cells
• Nearly 45% of blood is made up of red blood cells.
• Red blood cells carry oxygen and carbon dioxide. They
have an iron-containing protein called hemoglobin, which
can bind to oxygen and carbon dioxide.
• Red blood cells have a biconcave disc shape which
allows them to squeeze through narrow capillaries to
perform oxygen exchange.
Notice the unique shape of these
red blood cells.
White Blood Cells
• White blood cells fight infections. There are two main types: granulocytes
and agranulocytes.
• Granulocytes
• Neutrophil: phagocytize bacteria and small particles
• Eosinophil: kill parasites and regulate allergic responses
• Basophil: regulate immune response by secreting histamine
• Agranulocytes
• Monocyte: differentiate into macrophages (phagocytize large particles)
• Lymphocytes
• T lymphocytes: kill virus-infected cells and cancers
• B lymphocytes: produce antibodies
Platelets
• Platelets are small cell fragments that are produced in the
bone marrow. They are important in homeostasis and
healing of wounds.
• If a blood vessel is punctured, platelets form a plug to
prevent blood loss. They also secrete proteins which
combine with other blood proteins to form a sticky mesh.
This mesh entangles other cells to create a clot.
Open and Closed
Circulatory Systems
• There are two types of circulatory systems: open and
closed.
• A closed circulatory system has blood contained within
vessels. Most vertebrates (including humans) have a closed
circulatory system.
• An open circulatory system simply circulates blood within
the main body cavity. Most insects and invertebrates have
an open circulatory system.
A fish (on the left) has a closed
circulatory system. A crayfish (right)
has an open circulatory system.
Hearts of Vertebrates
• Not all animals have hearts similar to those of humans.
• Mammals (including humans) and birds have a complete
four-chambered heart (2 atria, 2 ventricles).
• Amphibians have a three-chambered heart (2 atria, 1
ventricle) with channels that reduce mixing of blood
between the two circuits. Reptile hearts are similar, but
the ventricle has an incomplete partition.
• Fish have a two-chambered heart (1 atrium, 1 ventricle)
that only pumps blood in one circuit.
Circulatory Systems of Animals
Pulmonary
Circuit
Systemic
Circuit
Fish
Reptiles* and Amphibians
Birds and Mammals
*A reptile heart has a partially divided ventricle, but is still similar to the amphibian heart.
Disorders of the Circulatory
System
• Heart Disease
• A narrowing of the arteries due to buildup of cholesterol
“plaques” inside the arteries.
• Symptoms include chest pain, shortness of breath, high
blood pressure, or exhaustion.
• 82% of sufferers over 65 years old, men 2-5 times more
likely than women, also associated with obesity.
• Treated with exercise, special low-fat diets, or drugs which
interfere with cholesterol intake.
Disorders of the Circulatory
System
• Sickle Cell Anemia
• Genetic (autosomal recessive) disorder which causes production
of an abnormal form of hemoglobin, causing red blood cells to
form “sickle” shapes and clog blood vessels. This causes tissue
damage.
• Symptoms include shortness of breath, bone pain, exhaustion,
jaundice, and rapid heart rate.
• The number of people with sickle cell anemia varies from
country to country, but 75% of all cases occur in Africa.
• Symptoms are lessened with folic acid supplements or blood
transfusions. A bone marrow transplant is the only cure.
Sources
• http://www.google.com/
• http://en.wikipedia.org/
• Shier, David, Jackie Butler, and Ricki Lewis. Hole’s
Human Anatomy and Physiology. New York, McGrawHill: 2007.
• http://universe-review.ca/R10-19-animals.htm
The Respiratory System
Functions
 To take oxygen into the body and to remove carbon
dioxide from the body.
 The respiratory system works in conjunction with the
circulatory system. Deoxygenated blood is pumped
through the lungs, where it picks up oxygen and
releases carbon dioxide.
Parts of the Respiratory System
Nasal Cavity
Mouth
Pharynx
Larynx
Trachea
Bronchi
Right Lung
Bronchioles
Left Lung
Bronchiole
Alveoli
Blood Vessel
Alveolar Sac
Breathing
 The process of breathing is called respiration.
 First, air is taken into the lungs by the process of
inhalation. A large sheet of muscle under the lungs
called the diaphragm contracts, increasing the volume
and decreasing the pressure in the lungs about 2 mm
Hg. Additional chest muscles may assist in this process.
 The air moves into the nasal cavity and then into the
trachea. It then enters the lungs by passing through the
bronchi, the bronchioles, and finally the alveoli, where
gas exchange is performed.
Breathing
 Finally, air is then forced out of the lungs, a process
called exhalation. The diaphragm relaxes, and the
elasticity of the organs and the chest cavity is usually
enough to decrease the volume of the lungs and
increase the pressure (by about 2 mm Hg) to force
the air out. Chest muscles may also help in forced
expiration.
The Alveoli
 Alveoli are the tiny air sacs at the end of the
bronchioles. Gas exchange takes place in the alveoli.
 They provide a huge surface area – 70-80 square
meters – for efficient gas exchange.
 Alveoli have thin walls made out of single-layered
epithelial tissue for maximum efficiency. They produce
a compound called surfactant to prevent water
surface tension from sticking the walls together.
 Capillaries line the sides of the alveoli. Oxygen and
carbon dioxide can diffuse through the walls of the
alveoli.
Transport of Gases
 The blood transports oxygen and carbon dioxide to
the lungs and to the body.
 Oxygen is primarily carried on a bright red, ironcontaining protein called hemoglobin that is in red
blood cells.
 Carbon dioxide is carried in three different ways.
 Dissolved in plasma: 7%
 Carried by hemoglobin: 15-25%
 Bicarbonate ions: 62-72%
Diseases of the Respiratory System
 Lung Cancer
 Caused by uncontrolled cell division of lung tissue.
 27% of all cancer deaths are due to lung cancer, there are
220,000 new cases every year. It is much more likely to
occur in smokers.
 Can cause difficulty breathing, coughing up blood, chest
pain, fatigue, or difficulty swallowing.
 Treated with chemotherapy, radiation, or (if the tumor
has not spread) surgical removal of the affected area of
the lung.
Tumor
Diseases of the Respiratory System
 Asthma
 An inflammation of the trachea and bronchi that can
(but not always) be caused by allergies.
 Tightness in chest, wheezing, and coughing are common
symptoms. Severe cases can obstruct the airways and
become life-threatening.
 Affects 20 million people in the U.S. each year. It is more
common among children and people with allergies.
 Asthma cannot be cured, but it can be prevented by
avoiding allergens and taking medication (often in
inhalers).
Sources
 Shier, David, Jackie Butler, and Ricki Lewis. Hole’s
Human Anatomy and Physiology. New York, McGrawHill: 2007.
 http://www.google.com/
 http://en.wikipedia.org/
 http://www.nhlbi.nih.gov/health/healthtopics/topics/hlw/system.html
 http://www.medicinenet.com/lung_cancer/article.htm
THE EXCRETORY SYSTEM
FUNCTIONS
 To filter the blood and remove wastes.
 To keep the body under homeostasis by regulating the
concentration of solutes in the blood.
 The excretory system consists of two kidneys and a bladder.
The kidneys filter the blood and the bladder collects the
wastes.
The Kidney
Cortex
Medulla
Renal Artery
Renal Pelvis
Renal Vein
Ureter
Interlobular
Blood Vessels
Arcuate Blood
Vessels
Interlobar
Blood Vessels
HOW THE KIDNEY WORKS
 1 . Blood enters the renal artery, into the interlobar arteries,
and then into the interlobular arteries in the cortex.
 2. The blood flows into nephrons, which are structures located
in the cortex and the medullae. The nephrons remove wastes
and salts from the blood.
 3. The blood flows back out into the interlobular veins, the
interlobar veins, and finally into the renal vein, where it goes
back to the heart.
 4. The extracted wastes, known as urine, flow down to the
bladder, where it accumulates and is periodically excreted.
The Nephron
Proximal
Convoluted
Tubule
Efferent
Arteriole
Peritubular
Capillary
Nephron
Loop
Collecting
Duct
Interlobular
Artery
Interlobular
Vein
Glomerulus
Afferent
Arteriole
Glomerular
Capsule
Distal
Convoluted
Tubule
THE NEPHRON
 The nephrons are the main functional units of the kidneys. Each
kidney contains about 1 million nephrons.
 1 . Blood enter s via the interlobular ar teries.
 2. The blood passes through a glomerulus, a cluster of capillaries
contained within a glomerular capsule. The glomerulus filters out
water and small molecules.
 3. The blood flows by the proximal convoluted tubule, which
reabsorbs cer tain substances such as water and glucose and also
secretes organic wastes.
 4. The blood then flows via the peritubular capillaries through the
nephron loop, which controls the concentration of urine.
 5. The last step of urine formation occurs when the blood passes by
the distal convoluted tubule, which regulates the concentration of
urine. The blood exits into the interlobular veins.
 6. Wastes flow into the collecting duct and into the ureter.
THE NEPHRON
 The nephron does several dif ferent jobs.
 Filtration is the filtering of substances from the blood by diffusion. It
mainly occurs in the glomerular capsule.
 Reabsorption is the uptake of substances from the urine. Water,
salts, glucose, amino acids, and proteins are actively transported
back into the blood. The proximal convoluted tubule reabsorbs most
of the wastes.
 Secretion is the active transport of substances into the urine.
Hydrogen ions are secreted throughout the renal tubule, and other
section secrete certain organic molecules.
 Excretion is the removal of wastes from the body. The final products
of the kidneys, urine, flows down the ureters and collects in the
bladder. The bladder periodically discharges the urine (micturition)
when it is full.
NITROGENOUS WASTES
 There are three main nitrogenous wastes in the urine. They
are urea, uric acid, and ammonia.
 Dif ferent animal groups secrete dif ferent compounds in their
urine.
 Ureotelic animals mainly secrete urea. Mammals, some cartilaginous
fish, certain invertebrates, and adult amphibians are ureotelic.
 Uricotelic animals mainly secrete uric acid. Birds, most reptiles, and
most terrestrial arthropods are uricotelic because uric acid can be
safely stored in eggs.
 Ammoniotelic animals mainly secrete ammonia. Ammonia can only
be eliminated by dissolution in large quantities of water, so
ammoniotelic animals are primarily aquatic. Amphibian larvae, most
fish, and other aquatic animals are ammoniotelic.
DISEASES OF THE EXCRETORY SYSTEM
 Kidney stones
 Accumulations of solid salts or uric acid crystals that can get stuck in
the kidney.
 Can cause severe kidney pain or blood in the urine.
 Different compositions of stones occur in different groups of people.
They can form in people who do not drink enough water or whose diet
is high in certain substances, such as calcium. They also may form in
some people with metabolic disorders.
 About 60% of kidney stones are passed naturally. Smaller stones can
be treated with drugs that dissolve the stones. Larger stones can be
broken with external shockwaves (extracorporeal shockwave
lithotripsy) or removed surgically. Dietary changes can alleviate some
types of kidney stones.
DISEASES OF THE EXCRETORY SYSTEM
 Gout
 Usually caused by an inability of the kidneys to eliminate uric acid or
sometimes an overproduction of uric acid. The uric acid crystallizes in
joints, causing friction and damage to the tissues.
 Joint pain is a common symptom, usually in the joint of the big toe,
ankle or knee joint. The joint may redden and swell.
 Affects 1-2% of western people; older people, obese people, and
diabetics are more susceptible.
 Treated with painkillers. Diets with low amounts of purine
nucleotides and alcohol help prevent progression of the disease.
SOURCES
 Shier, David, Jackie Butler, and Ricki Lewis. Hole’s Human
Anatomy and Physiology. New York, McGraw -Hill: 2007.
 http://www.google.com/
 http://en.wikipedia.org/
 http://www.biology -questions-and-answers.com/the-excretory system.html
*
*
* To recognize organisms and substances that
would otherwise harm the body.
* To protect the body from such organisms and
substances.
*
* Bone marrow: produces blood cells, including
white blood cells.
* Lymph vessels: carry a watery fluid called
lymph that contains white blood cells. That is
filtered from surrounding tissues and is
eventually mixed with blood. Lymph nodes may
swell during an infection.
* Lymph nodes: house white blood cells,
interconnected by lymph vessels.
* Thymus: helps produce T lymphocytes.
* Peyer’s Patches: fight infections in intestine.
* Spleen: houses large numbers of white blood
cells and recycles old red blood cells.
* Tonsils: fight infections in the throat.
Lymph nodes, thymus and
spleen.
*
* “Built in” immunity; coded
* Immune response caused by exposure
* General immune response,
* Not coded for in DNA, but immune
* Example: when the skin is
* Specific responses to each pathogen;
by DNA.
such as inflammation and
swelling.
cut, the surrounding area
swells up and becomes
painful.
to pathogens.
system will “remember” how to fight
them in the future.
for example, different antibodies are
produced against different bacteria.
* Example: the immune system has
trouble fighting smallpox at first, but
once it fights the smallpox off, it will
continue to do so and the person will
never get smallpox again.
*
* Immunity developed after
* The transmission of
* Example: Once a person
* Example: breast milk
the body is infected and
fights off the pathogen.
gets strep throat, the
immune system fights the
infection. The person will
be less prone to infection
next time because the
immune system has already
fought strep throat.
antibodies from one person
to another.
contains antibodies that
protect the baby.
*
* Immunity created by
* Immunity created by
* Present in some degree at
* Includes activation of T cells
antibodies already floating
in the blood plasma.
all times.
activities of white blood
cells.
and B cells.
* Can create humoral
immunity when activated
cells produce antibodies.
*
* There are two different types of lymphocytes: B and T lymphocytes.
* B (bursa derived) cells mature in the bone marrow.
* Naïve B cells have not yet encountered pathogens. When they do
encounter pathogens, they become memory B cells which will respond
quickly to the same antigen by dividing. They are activated by helper T
cells.
* Plasma cells differentiate from B cells and produce large amounts of
antibodies.
* T (thymus) cells mature in the thymus.
* Helper T cells detect foreign antigens, often presented to them by
macrophages.
* Cytotoxic T cells kill cancer cells and virus-infected cells.
* Memory T cells “remember” previous encounters with antigens and alert
other cells if the antigen is encountered again.
*
* Antibiotics are substances that are used to help treat infections.
* Antibiotics kill bacteria and fungi in a variety of ways. They can
inhibit transcription or translation, damage the cell wall, or bind
to proteins.
* Viruses are unaffected by antibiotics. Viruses have no internal
processes to be targeted by antibiotics. They also reproduce
inside other cells, which makes them difficult targets.
Penicillin
Ciprofloxacin
Cephalexin
*
* Acquired Immunodeficiency Syndrome (AIDS)
* Caused by the infection of the human immunodeficiency virus (HIV),
a retrovirus which attacks white blood cells.
* No symptoms at first, but later causes fever, chills, swollen lymph
nodes, and increased frequency of infections.
* 33.4 million people worldwide have AIDS. Drug addicts who share
needles and sexually active people are more susceptible because the
virus can only be transmitted through bodily fluids or sexual
contact.
* No cure yet, but infected people can live a fairly normal life by
taking antiretroviral drugs.
*
* Leukemia
* A cancer caused by uncontrolled production of
white blood cells in the bone marrow. These are
immature and incapable of fighting infection,
and also crowd out other normal blood cells.
* Symptoms include fatigue, mild fever, and mild
hemophilia.
* Causes 33% of all cancer cases in children. About
140,000 people in the United States suffer from
leukemia. People exposed to carcinogens or highenergy radiation are at risk.
* Treated with chemotherapy, radiation, or bone
marrow transplants. Five-year survival rate is
about 90%.
Leukemic white
blood cells.
*
* Shier, David, Jackie Butler, and Ricki Lewis. Hole’s
Human Anatomy and Physiology. New York, McGrawHill: 2007.
* http://www.google.com/
* http://en.wikipedia.org/
* http://www.lymphnotes.com/article.php/id/151/
* http://www.lymphomation.org/lymphatic.htm
 To provide support for the body and to provide solid points
for skeletal muscle attachment.
 To protect delicate organs from physical damage.
 To house tissues that store nutrients and produce blood cells.
Parts of a Long Bone
Yellow Marrow
Articular
Cartilage
Epiphysis
Periosteum
Medullary
Cavity
Diaphysis
Blood Vessels
Compact
Bone
Epiphyseal Plate
(Growth Plate)
Spongy Bone and
Red Marrow
 The human skeleton is composed of 206 bones. Infants have more bones
because some bones fuse together as a person grows up.
 Humans, other mammals, reptiles, birds, and amphibians have an
endoskeleton – a skeleton composed of bones on the inside of their body.
Bones are made form protein and calcium salts. Muscles are attached to the
surface of the bones.
 Arthropods, on the other hand, have an exoskeleton – a skeleton composed of
a shell on the outside of the body. The shell is usually made of chitin and
cannot support as much weight as an endoskeleton. Muscles are attached on
the inside of the exoskeleton.
 Some animals, such as mollusks, may have a hydrostatic skeleton - a skeleton
composed of a fluid-filled internal cavity. Muscles create movement by
compressing the fluid and utilizing hydraulic pressure.
 Bones provide a solid structure for muscles to pull on.
 Muscles contract when stimulated by a nervous impulse, moving the bones
and tissues that are supported by the bones.
 Tendons firmly connect muscles to bones. They are made out of tough
connective tissue, like cartilage.
 Ligaments connect bones to other bones. Like tendons, they are made of
connective tissue.
 Osteoporosis
 A gradual loss of bone density.
 Symptoms can be subtle, but include bone pain (from small stress
fractures), high frequency of broken bones, loss of height, or
deformation of stress-bearing bones.
 More common among older women who have reached menopause
as well as malnourished children who cannot get enough vitamin D.
 Treated with calcium or vitamin D supplements. Women who have
reached menopause may be given artificial hormones.
 Osteogenesis imperfecta
 Brittle bones caused by an autosomal
dominant mutation in the gene that codes
for collagen, a protein found in bones.
Rare, recessive forms of the disease also
exist.
 Symptoms can include deformation of the
bones, increased frequency of fractures,
blue tint in the whites of the eyes, and
deafness.
 Affects 1 per 20000 live births; more
common in certain peoples of Zimbabwe
and South Africa.
 Treated with physical therapy, surgery,
physical aids, or nutritional supplements.
 Shier, David, Jackie Butler, and Ricki Lewis. Hole’s Human
Anatomy and Physiology. New York, McGraw-Hill: 2007.
 http://www.google.com/
 http://en.wikipedia.org/
 www.ncbi.nlm.nih.gov
» To regulate body functions by secreting
chemicals called hormones, which influence the
functions of other organs and tissues.
» The endocrine system is very important in
maintaining homeostasis as well as growth,
development, and reproduction.
Major Organs of the Endocrine System
Hypothalamus
Pineal Gland
Pituitary Gland
Thyroid Gland
Thymus
Parathyroid Gland
Adrenal Gland
Kidney
Pancreas
Ovary (only in
females)
Testis (only in males)
» Hypothalamus: secretes gonadotropin-releasing hormone, which causes
secretion of gonadotropins, which in turn increases reproductive activity.
» Pituitary Gland: secretes growth hormone, which triggers cell division and
elongation of epiphyseal plates of bones.
» Pineal Gland: secretes melatonin, which controls circadian rhythms (sleep
cycles).
» Thyroid Gland: secretes thyroxine, which increases metabolic rate (rate of
energy use of the body).
» Parathyroid Glands: secrete parathyroid hormone, which increases the
concentration of calcium ions and decreases the concentration of
phosphate ions in the blood.
Melatonin
Structure of parathyroid
hormone.
Thyroxine
» Thymus: secretes thymosin, which increases the growth rate of T
lymphocytes.
» Pancreas: secretes insulin, which increases storage of glucose.
» Adrenal Glands: secrete epinephrine, which increases heart rate,
dilates airways, and triggers the “fight or flight” response; it is
secreted in response to stress.
» Kidneys: secrete renin, which helps maintain blood pressure.
» Ovaries: secrete estrogens, which causes development of female
characteristics such as breast and uterus growth.
» Testes: secrete testosterones, which causes development of male
characteristics such as enlarged muscle and body hair.
Left: Estradiol, an estrogen
Right: Testosterone.
» Homeostasis is the body’s ability to maintain a
stable internal environment.
» The endocrine system secretes hormones to
carefully control internal conditions.
» Negative feedback is used by the endocrine
system to regulate the secretion of hormones
to maintain homeostasis.
» Negative feedback helps regulate secretion of
hormones.
» Endocrine glands reduce production of hormones when
it senses these stimuli.
˃ Change in concentration of hormone or in the process the hormone
controls.
˃ Action the hormone has on the body.
˃ Stimulation by nervous system in response to secretion of the
hormone.
» This helps keep internal processes relatively constant.
» Example: the pancreas secretes less insulin when
glucose concentration is low, and secretes more insulin
when glucose concentration is high.
» Diabetes
˃ An inability of the pancreas to produce enough insulin. There are two
types of diabetes: Type I and Type II.
» Type I Diabetes
˃ Caused by the autoimmune destruction of the pancreatic islet cells
that produce insulin. Usually present from an early age.
˃ Symptoms include persistent thirst and hunger, weight loss, numbness
in feet, fruity breath, or rapid breathing. Glucose is present in the
urine, and this is used to detect both types of diabetes. Coma and
death can result if untreated.
˃ It is more common among Hispanics and Africans, as well as young
children.
˃ Treated with artificial insulin injections and a diet to control glucose
intake. A pancreas transplant can be done, but it is rather difficult and
the patient still has to take immunosuppressive drugs.
» Type II Diabetes
˃ Caused when tissues fail to respond correctly when insulin is secreted
(insulin resistance). Adequate amounts of insulin are produced,
however.
˃ Symptoms include thirst, hunger, numbness in hands or feet, blurred
vision, or increased urination.
˃ Native Americans, Pacific Islanders, and South Asians are more likely
to have Type II diabetes. People can be genetically predisposed to
have it. Type II diabetes is also much more common among obese
people, and is one of the fastest growing health problems.
˃ Treated with weight loss and special diets, as well as drugs that
increase responsiveness to insulin.
» Gigantism
˃ Caused by an overproduction of
growth hormone, usually due to a
tumor on the pituitary gland.
Robert Wadlow, the tallest man
ever, had this condition.
˃ Symptoms include extremely large
size, delayed puberty, large hands,
double vision, weakness, or (in
females) irregular menstruation.
˃ The demographics of gigantism are
poorly documented but it can run
in families.
˃ Treated with removal of pituitary
gland tumor (if present) or drugs
that inhibit growth hormone.
Robert Wadlow
(8’ 11”), with his
father (5’ 11”).
Mamadou
N’diaye (7’ 5”, 17
years old as of
2012) had a
golf- ball-sized
pituitary gland
tumor.
» Shier, David, Jackie Butler, and Ricki Lewis. Hole’s
Human Anatomy and Physiology. New York, McGrawHill: 2007.
» http://www.google.com/
» http://en.wikipedia.org/
» www.ncbi.nlm.nih.gov/
» http://www.diabetes.org/diabetes-basics/diabetesstatistics/
» http://www.cbsnews.com/8301-31751_162-5737071510391697/mamadou-ndiaye-7-foot-5-high-schoolbasketball-player/


To collect information about the outside world
so it can be relayed to and interpreted by the
nervous system.
The senses include touch (skin), taste, (tongue),
sight (eyes), hearing (ears), and smelling (nose).
These senses are all important in interacting
with the outside environment.
The Eye
Sclera
Iris
Retina
Vitreous Humor
Cornea
Pupil
Aqueous
Humor
Lens
Optic Nerve


Rhodopsin is a protein that found in the retina. It
participates in cell signaling in the eye and is essential
to sight.
Rhodopsin is a photoreceptor protein.



When light hits rhodopsin, it changes shape to release opsin.
Opsin becomes an active enzyme and catalyzes the formation
of other proteins in a rapid cell signaling pathway.
At the end of the pathway, the cell membrane is
hyperpolarized and stimulates adjacent nerve cells which can
relayed to the brain.

Mechanoreceptors


Thermoreceptors


These are “touch receptors”. They detect changes in pressure or
movement and are found all over the skin and are concentrated
on the fingertips. They are also found in the ears (to detect
changes in air pressure which create sound).
Thermoreceptors sense temperature. They are also present all
over the skin, but are especially numerous on the fingertips and
the lips.
Chemoreceptors

Various chemicals can be detected by chemoreceptors. Each
chemoreceptor is usually adapted to detect one type of
chemical (acid, base, salt, etc.). They occur on the surface of the
tongue (housed inside the taste buds) and the roof of the nasal
cavity (to detect smell).

Photoreceptors


Photoreceptors detect light. They are present in the retina of the
eyes. Humans have several different types of photoreceptors to
detect different colors and see in dim light.
Pain Receptors

Pain, usually caused by trauma to the body, is detected by pain
receptors. They can be found in large numbers in the fingertips,
lips, and tongue, although they occur throughout the body.



Shier, David, Jackie Butler, and Ricki Lewis.
Hole’s Human Anatomy and Physiology. New
York, McGraw-Hill: 2007.
http://www.google.com/
http://en.wikipedia.org/
The Muscular System
Functions
• To move parts of the body by contraction. This
includes:
▫
▫
▫
▫
▫
Moving the limbs
Pushing food through digestive system
Breathing
Heartbeat
And more!
Sarcomere
A sarcomere is the basic unit of a muscle cell.
Actin
I Band
Head of Myosin Filament
Myosin
A Band
Z Line
H Zone
M Line
Types of Muscle
Skeletal Muscle has distinct striations and
an orderly structure. It is made of large,
multinucleated cells and is under
voluntary control. It is found in skeletal
muscles that are attached to bones.
Cardiac Muscle is also striated but has a less
organized structure. The cells each have one
nucleus and are under involuntary control. The
cells are separated by intercalated disks which are
a type of cellular junction that allows movement
of nervous impulses. It is found in the heart.
Smooth Muscle is not striated and has a
relatively unorganized structure. The cells
each have a single nucleus and are under
involuntary control. Smooth muscle is found
in internal organs and ducts.
How a Muscle Works
• 1. A neuron contacts a muscle cell at a neuromuscular
junction. To signal the muscle to contract, the neuron
releases acetylcholine, a neurotransmitter.
• 2. Acetylcholine stimulates the sarcoplasmic reticulum
(modified smooth endoplasmic reticulum) to release
calcium ions.
• 3. The calcium ions bind to proteins located on the actin
filaments. This allows the heads of the myosin filaments
to bind to the actin, forming cross bridges.
How a Muscle Works
• 4. The heads of the myosin filaments, powered by ATP,
tug on the actin filaments. This pulls the filaments closer
together, causing the muscle to contract.
• 5. To relax the muscle, acetylcholine secretion by the
neuron is halted and an enzyme in the neuromuscular
junction quickly digests the acetylcholine.
• 6. The calcium ions are actively transported back into the
sarcoplasmic reticulum by an ATP-powered calcium
pump. The myosin-actin cross bridges disconnect and
the elastic muscle relaxes.
Diseases of the Muscular System
• Duchenne Muscular Dystrophy
▫ A recessive, X-linked mutation in a gene coding for the
protein dystrophin causes this disease. The mutation causes
the muscles to progressively degenerate. It mostly affects
boys.
▫ Symptoms include fatigue, lack of motor skills, weakness,
inability to walk, or skeletal deformities.
▫ 1/3500 boys worldwide are affected. The disease is genetic
so it may run in families.
▫ No treatment yet, but physical therapy and physical aids,
such as braces or wheelchairs, can help people with
Duchenne muscular dystrophy.
Diseases of the Muscular System
• Tetanus (“Lockjaw”)
▫ Caused by the bacterium Clostridium tetani, which
produces a chemical which inhibits the enzyme that digests
acetylcholine. The muscles become continuously activated
by acetylcholine.
▫ Symptoms include muscle spasms, fever, sweating, or
continuous contraction of muscles. Severe cases can stop
breathing.
▫ More common in 3rd world countries without adequate
sanitation.
▫ Treated with antibiotics and muscle relaxants. Vaccines for
tetanus are usually quite effective.
Sources
• Shier, David, Jackie Butler, and Ricki Lewis. Hole’s
Human Anatomy and Physiology. New York, McGrawHill: 2007.
• http://www.google.com/
• http://en.wikipedia.org/
• www.genome.gov/19518854
• www.rightdiagnosis.com/d/duchennemd/stats.htm
• www.ncbi.nlm.nih.gov/
• Kapit, Wynn, and Lawrence M. Elson. The Anatomy
Coloring Book. United States, Wynn Kapit and Lawrence
M. Elson: 1993.
Functions
 To receive and process information from the outside
world (usually collected by the senses system).
 To signal the rest of the body to respond accordingly to
external and internal stimuli.
 The nervous system primarily consists of neurons,
which are cells that are modified to carry information.
The Neuron
Synapse (space between
adjacent neurons)
Dendrite
Chromatophilic
Substance
Nucleus
Schwann Cell
Axon
Node of Ranvier
Reflex Arc
2. A sensory (afferent) neuron
sends a message to the spinal cord.
1. Stimuli are detected.
4. The efferent neuron
relays a message to an
effector organ, usually
a muscle or a gland.
5. The effector
organ reacts to the
stimulus.
3. The spinal cord
processes the information
and an interneuron
transmits a message to a
motor (efferent) neuron.
The Central and Peripheral Divisions
 The central nervous system consists of the brain (itself
made of the cerebrum, cerebellum, brainstem, and
diencephalon) and the spinal cord. It serves to process
and store information as well as output information to
the rest of the body.
 The peripheral nervous system is made of the nerves
and sensory receptors scattered throughout the body.
It collects information and sends it to the central
nervous system. The peripheral nervous system also
relays the central nervous system’s messages to the
rest of the body.
Neurotransmission
 A neuron pumps sodium ions outside the neuron and
potassium ions inside the neuron using an active transport
pump (sodium-potassium pump). This creates a membrane
potential. When not excited, the neuron’s membrane
potential is at its resting potential (-70 millivolts).
 1. Another neuron’s axon stimulates the neuron’s dendrites
with neurotransmitters.
 2. The stimulation opens ion channels in the cell membrane. If
the stimulation is great enough, the threshold potential (-55
mV) is reached and an action potential is started in the
neuron.
Neurotransmission
3. Voltage-gated ion channels
open, allowing sodium ions in
and depolarizing the neuron.
4. Potassium ions move out
of the neuron, repolarizing
the neuron. The impulse
moves down the axon of the
neuron.
5. While the impulse travels down the axon, the neuron cannot be stimulated again
for a short period of time called the refractory period.
6. When the impulse reaches the end of the axon, the neuron secretes neurotransmitters
into the synapse between the next neuron, which starts the cycle over again.
Neurotransmitters
 Neurotransmitters are compounds secreted by neurons
across the synapses to communicate with other
neurons. Different neurotransmitters evoke different
responses.
 Excitatory neurotransmitters facilitate the
depolarization of the next neuron. These include:
 Acetylcholine
 Epinephrine
 Norepinephrine
Neurotransmitters
 Inhibitory neurotransmitters inhibit the depolarization
of the nerve cell membrane. These include:





Dopamine
GABA
Glycine
Serotonin
Endorphins
Diseases of the Nervous System
 Alzheimer’s Disease
 A progressive loss of mental function due to protein
deposits (amyloid plaques) that build up in brain tissue. It is
most likely caused by many distinct factors.
 Symptoms include amnesia, changes in mood, insomnia,
poor judgment, and difficulty in counting and other everyday
mental activities.
 35 million people worldwide have Alzheimer’s. It mostly
occurs in older (>60 years old) people.
 No cure exists yet, but there is a variety of medications that
can partly alleviate the symptoms.
Diseases of the Nervous System
 Poliomyelitis
 A viral infection, caused by the poliovirus, that can
attack the central nervous system.
 Less severe infections can cause diarrhea, fever,
and stiffness. Severe infections cause fever,
abnormal sensations, muscle weakness, muscle
spasms, and possible paralysis. Some forms can be
asymptomatic.
 Poliomyelitis often affects younger children,
especially in rural areas. There are about 1,000
cases every year.
 There is no cure for poliomyelitis, but painkillers,
braces, and wheelchairs can help those affected by
it. However, it can be prevented by vaccination.
The poliovirus.
Sources
 Shier, David, Jackie Butler, and Ricki Lewis. Hole’s
Human Anatomy and Physiology. New York, McGrawHill: 2007.
 http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0001
767/
 www.alzinfo.org/Alzheimers_Disease
 http://www.ncbi.nlm.nih.gov/pubmedhealth/PMH0002
375/
 http://www.google.com/
 http://en.wikipedia.org/
To produce offspring.
 To produce eggs/sperm that will fertilize
each other to produce a zygote.
 To nourish the embryo as it is growing.

Asexual



Sexual



Rapid and requires relatively simple
processes.
Offspring are nearly identical to parents,
leading to lack of genetic diversity that
makes species extinction-prone.
Some echinoderms, sponges, worms,
insects, and reptiles reproduce asexually.
Time consuming and requires many
different processes such as meiosis.
Offspring are genetically diverse which
allows species to adapt to changes.
Most animals have some form of sexual
reproduction, although the asexual form
may dominate in simpler animals.
Spermatogenesis
Spermatogenesis is the production of sperm.
First meiotic
division and
crossing
over
Second meiotic
division
Maturation
Secondary
Spermatocyte
Primary
Spermatocyte
Spermatid
Spermatozoa
Oogenesis
Oogenesis is the production of eggs.
First meiotic
division and
crossing
over
Fertilization
by sperm
Secondary
Oocyte
Second meiotic
division
Zygote
Second Polar
Body
Primary Oocyte
First Polar Body
Spermatogenesis produces four sperm
cells for every primary spermatocyte.
 Oogenesis produces one egg cell for
every primary oocyte, with the
cytoplasm dividing unequally to form
two polar bodies. This ensures that the
single egg has all the necessary cellular
components to survive.



The menstrual cycle is used by great apes and
humans. Animals that menstruate will shed the
endometrium (inner lining) of the uterus if the egg is
not fertilized. They also can be sexually active at
any time of the cycle.
The estrous cycle is used by most other animals.
Animals that used the estrous cycle reabsorb the
endometrium if the egg is left unfertilized, and they
are only active during certain stages of the estrous
cycle.

Humans and primates use the menstrual cycle. It is
split into the ovarian cycle and the uterine cycle.
› The ovarian cycle occurs in the ovaries.
› The anterior pituitary gland secretes luteinizing hormone and
follicle-stimulating hormone, causing an oocyte to form in a
follicle in the ovaries.
› At about 14 days into the cycle, the levels of luteinizing
hormone and follicle-stimulating hormone peak, causing the
follicle to rupture, and ovulation (release of the egg into the
uterine tube) occurs.
› The ruptured follicle becomes a corpus luteum, which secretes
estrogen and progesterone. These act as negative feedback
that causes the pituitary gland to stop secreting hormones.
› The corpus luteum degenerates and becomes a corpus
albicans in about 28 days, and the cycle starts over again.

The other part of the menstrual cycle is the uterine
cycle.
› The uterine cycle occurs in the uterus.
› Growing levels of estrogen and progesterone cause the
endometrium (lining of the uterus) to become thicker and
grow more blood vessels.
› Estrogen levels peak at about 14 days into the cycle,
causing rapid growth.
› The corpus luteum continues to secrete estrogen and
progesterone. The endometrium continues to grow until
about 28 days, when the corpus luteum entirely
degenerates and the endometrium peels off and is
ejected.




When the embryo is first fertilized by the sperm, it starts
to divide (cleavage) into a solid ball of cells called a
morula.
As the morula continues to grow, it becomes a hollow
ball of cells called a blastula.
The blastula later gastrulates (caves in) to form a
gastrula, a double-layered ball of cells with a pore
(blastopore) at one end.
Finally, organogenesis occurs, which is the
differentiation of cells into organs.
Left:
Morula.
Left:
Blastula.
Left:
Gastrula.




The gastrula is divided into three germ layers: the
endoderm, mesoderm, and ectoderm.
The endoderm is the inner layer of cells. It forms the
inner lining of the digestive tract, stomach,
intestines, colon, liver, lungs, and urinary bladder.
The mesoderm is the middle layer of cells. It forms
the skeletal muscles, skeleton, heart, blood,
kidneys, and spleen.
The ectoderm is the outer layer of cells. It forms the
upper layer of skin, the lenses of the eyes, and the
nervous system.
Shier, David, Jackie Butler, and Ricki Lewis. Hole’s
Human Anatomy and Physiology. New York,
McGraw-Hill: 2007.
 http://www.google.com/
 http://en.wikipedia.org/
 http://answers.yahoo.com/question/index?qid=20
070828195917AAE6j0y
 http://www.embryology.ch/anglais/evorimplantati
on/furchung01.html
