Transcript Respiratory System

Respiratory System
Upper Respiratory Tract
Figure 21.3a
Superior, middle, and inferior nasal
conchae
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Covered with a mucous membrane.
Warm and moisten the air
Increase the turbulence in the flow of air
through the nasal cavity
Sensory receptors to enhance the sense of
smell.
When you have a cold and get extra fluid
(edema)  runny nose.
Nasal Conchae
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A cartilage nasal septum divides the right
and left sides of the nose.
The nasal conchae contain blood vessels
that can dilate, causing the tissue to swell,
closing off one side of your nasal airway at
a time. This allows the closed side to
increase its moisture.
Then it will open again and the other side
may close. These cycles occur every eight
hours throughout the day.
What causes snoring?
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When we are asleep the area at the back
of the throat sometimes narrows. The
same amount of air passing through this
smaller opening can cause turbulence in
the airflow and some vibration of the
tissues in the nose and mouth. Different
people who snore have different reasons
for the narrowing. The narrowing can be
in the nose, mouth, or throat.
Snoring
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Some people cannot breathe through their
noses because of obstruction of the nasal
passages. This can be caused by a
deviation of the nasal septum, allergies,
sinus infections, swelling of the turbinates,
or large adenoids (tonsils in the back of
the throat). Many mouth breathers snore,
because the flow of air through the mouth
causes greater vibration of tissues.
Snoring
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When we lie on our backs, gravity pulls the
palate, tonsils, and tongue backwards. This
often narrows the airway enough to cause
turbulence in airflow, tissue vibration, and
snoring. Frequently, if the snorer is gently
reminded to roll onto his or her side, the tissues
are no longer pulled backwards and the snoring
lessens.
Some medications as well as alcohol can lead to
enhanced relaxation of muscles during sleep.
This will increase snoring.
Apnea
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An apnea is a period of time during which
breathing stops for 10+ seconds or the
breath is 25% less than normal. Apnea is
also a term for blood oxygen levels 4%
less than normal.
These episodes often occur during sleep.
The two types of sleep apnea are Central
Sleep Apnea and Obstructive Sleep Apnea.
Polyps
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Nasal polyps are overgowths of the
mucosal tissue in the nasal cavities.
Usually caused from chronic allergies
Can cause difficulty breathing through
nose, loss of smell, headaches.
Treated with steroid sprays or surgery.
Sinuses
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The nasal cavity is connected to PARANASAL
SINUSES (ETHMOID, SPHENOID,
FRONTAL, AND MAXILLARY SINUSES).
They are also lined with the same kind of
mucosa.
When you have a cold, you get stuffed up, and
the pressure can cause sinus headaches.
Some people with headaches and sinus pain
assume they have a sinus headache, but the CT
scan shows clear sinuses. They actually have a
problem with cranial nerve V, causing referred
pain to the sinuses. They need to see a
neurologist.
The Paranasal Sinuses
Figure 7.11a, b
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Fig. 23.2b(TE Art)
Nasopharynx
Oropharynx
Laryngopharynx
LARYNX
Pharynx
1. NASOPHARYNX: a continuation of the nasal
cavity.
The EUSTACIAN TUBE is located here.
2. OROPHARYNX is the back of the mouth; visible
when you open your mouth and look all the way
back.
Separating the oropharanyx and the nasopharynx:
SOFT PALATE: feel it with your tongue
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UVULA: located at the end of the soft palate
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The function of the soft palate and uvula is to move
upward when swallowing, to prevent food from
going into nasal cavities. (They don’t close during
vomiting)
3. LARYNGOPHARYNX: Can see the vocal cords
here.
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Pharynx
Figure 21.3a
LARYNX
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It has two functions:
1. Produce sounds (vocal cords)
2. Prevent food from entering lungs
Made up of nine separate cartilages:
EPIGLOTTIS
THYROID CARTILAGE
CRICOID CARTILAGE
(2) ARYTENOID CARTILAGES
(4) Smaller cartilages we’re not going to name
Anatomy of the Larynx
Figure 21.5a, b
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GLOTTIS is the opening. It stays all the way
open when you are breathing hard.
EPIGLOTTIS flaps over the glottis when you
swallow so nothing will go into the trachea.
When you get hiccoughs, it’s from a sudden
movement of air into the lungs, so the epiglottis
closes to prevent more air from going in. It’s
unknown why you get hiccoughs. All the
treatments you can try involve interrupting the
normal breathing patterns.
Vocal Cords
Figure 21.6
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VOCAL CORDS (vocal folds)
Vocal cords are attached to the
ARYTENOID CARTILAGES. If these
cartilages move, the vocal cords open.
When they go back to normal, the glottis
will close. The ability to vary the pitch of
the voice results from varying the tension
in the vocal folds.
Vocal Cords
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For air to move through, muscles have to
contract. If muscles here are paralyzed, the
airway closes. In surgery, have to intubate. In
an emergency, have to do a tracheotomy above
the jugular notch.
The type of sounds you make depend on how
far apart the vocal cords are.
Way open = no sound (like when breathing)
Mostly closed = sounds
Men: their thyroid cartilage is larger, so their
vocal cords are longer = deeper voice.
Problems with vocal cords
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LARYNGITIS: inflamed vocal cords
(↓ sound production)
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Singers can get scar tissue nodules,
requires surgery.
FUN FACTS
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What is the Adam's apple and what does it do?
It’s really a part of the larynx or voice box. When boys
go through puberty, hormones cause the larynx to grow
rapidly, deepening their voices and causing the bulge to
form. Girls' voices also deepen with puberty, but since
their larynxes don't tend to grow as much, they don't
usually develop an "Eve's apple." The protrusion is
actually composed of thyroid cartilage. Your larynx is
surrounded by a skeleton of cartilage plates that
prevents it from collapsing. Some folks undergo cosmetic
surgery to make it less prominent.
FUN FACTS
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Definition of Adam's apple
Adam's apple: Enlargement of the Adam's apple is
considered, like pubic hair growth, one of the secondary
sexual characteristics.
Origin of the term: It is usually said that Adam's apple
takes its name from the biblical story about Adam, Eve.
The serpent and the apple. A piece of the forbidden fruit
stuck in Adam's throat and created the anatomic Adam's
apple. So the story goes. However, it may be wrong.
Adam's apple in Latin is "pomum Adami." This may have
been a mistranslation of the Hebrew "tappuach ha
adam" which also means male bump. Between Latin and
English there's many a slip.
FUN FACTS
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Why does your voice sound funny after you inhale
helium from a balloon?
A healthy 13-year-old boy suffered a cerebral gas
embolism after inhaling helium from a pressurized tank
at a party. A word to the wise: Pressurized, industrial
tanks are not for human consumption! Repeated
inhalation of helium can hinder your ability to breathe.
Helium is an inert gas that is lighter than air. Sound is
produced by vibration, the movement of air around our
vocal chords. Because helium gas is lighter than the
usual oxygen/nitrogen blend, it changes the resonant
frequency of the human vocal tract, causing a faster
vibration and a higher-pitched, cartoon-character sound.
TRACHEA
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This is a tube that carries air from the larynx to
the lungs.
It’s fairly rigid from about 16 rings of cartilage.
The purpose of the cartilage rings is to keep the
trachea open. Otherwise, when you inhale, the
trachea would collapse like when you suck hard
on a straw. That’s why your vacuum cleaner
has rings on the hose.
The Trachea
Figure 21.7a
Histology of the trachea
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MUCOSA (Inner, most superficial layer)
 EPITHELIUM (pseudostratisfied ciliated
epithelium) and goblet cells. Function of goblet
cells is to produce mucous to trap dirt. Cilia move
dirt to larynx  swallowed.
 LAMINA PROPRIA (loose connective tissue) with
lots of elastic fibers to make the trachea flexible.
SUBMUCOSA (Deep to the mucosa) This is the
serous portion to humidify the air.
ADVENTITIA (Deepest layer) This is dense
connective tissue with hyaline cartilage.
BRONCHI
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The trachea branches into the RIGHT and LEFT
BRONCHUS (the primary bronchi).
These branch into the secondary bronchi, which
branch into the tertiary bronchi.
The layers become thinner, and the hyaline
cartilage no longer has nice rings; just bits.
The tertiary bronchi are microscopic. The distal
part of the tertiary bronchi are called terminal
bronchioles. These are the last parts of the
respiratory tree that have smooth muscle and
bits of hyaline cartilage. Beyond them are the
respiratory bronchioles.
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If you inadvertently inhale something, which
lung does it go into? Right lung.
Lung cancer occurs slightly more frequently in
the right lung than in the left lung (about 53%
vs. 47% of the time). The most logical
explanation for this is that the right primary
bronchus is wider than the left one (and the
right lung is larger than the left lung), so the
right lung receives slightly more carcinogenic
cigarette smoke with each puff.
The left lung has a cardiac notch; this is where
the heart sits.
The left lung has TWO lobes, but the right lung
has THREE lobes.
Cardiac Notch
Cardiac Notch
Figure 21.8a
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Apex
Fig. 23.9b(TE Art)
Superior
lobe
Pulmonary
arteries
Secondary
bronchi
Pulmonary
veins
Hilum
Middle
lobe
Inferior
Lobe
Pulmonary
Ligament
Diaphragmatic
surface
BRONCHIOLES
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(simple columnar epithelium, no cilia, no mucosa)
Surrounding bronchioles are a smooth muscle layer,
which functions to direct the flow of air to particular
portions of the lungs.
Right now, only a small percentage of lungs are needed,
compared to if you are running.
Since there are no cilia, any particle that gets down that
far has to be eaten by macrophages or just stay there.
In allergic conditions, bronchioles will constrict,
blocking air flow to the lungs = ASTHMA. Asthma
can also be caused by irritants in the environment,
especially by pollution in the city.
Respiratory Bronchioles
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Distal to the terminal bronchioles, the
branches of the respiratory tree are now
called respiratory bronchioles.
These end in alveoli (air sacs)
ALVEOLI
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Respiratory bronchioles branch into
TERMINAL BRONCHIOLES (simple
cuboidal), which empty into a sack =
ALVEOLUS (simple squamous
epithelium).
This sac is like a balloon surrounded by a
capillary bed.
Within the alveoli are macrophages.
Structures of the Respiratory
Zone
Figure 21.9a
Alveoli
Figure 21.10b
Alveoli
Figure 21.10c, d
Partial Pressure of Oxygen
(pO2)
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The air we breath is a mixture of gasses: primarily nitrogen, oxygen,
& carbon dioxide. So, the air you blow into a balloon creates
pressure that causes the balloon to expand.
However, the total pressure generated by the air is due in part to
nitrogen, in part to oxygen, in part to carbon dioxide.
That part of the total pressure generated by oxygen is the 'partial
pressure' of oxygen, while that generated by carbon dioxide is the
'partial pressure' of carbon dioxide. A gas's partial pressure,
therefore, is a measure of how much of that gas is present (e.g., in
the blood or alveoli).
The pO2 of blood therefore refers to the amount of dissolved
oxygen in the blood plasma.
The Respiratory Tree
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As the conducting tubes of the respiratory tree
become smaller, the following changes occur
 Cartilage rings are replaced by irregular plates
of cartilage
 Cartilage disappears in the bronchioles
 The lining epithelium thins
 Elastin remains in the walls
DIAPHRAGM
• When the
diaphragm
muscle contracts,
the size of the
thoracic cavity
increases and air
rushes into the
lungs.
Inspiration
• The diaphragm
and the external
intercostals are
the muscle group
that produces
inspiration.
FUN FACTS
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Exactly what happens when you get the
wind knocked out of you?
It’s all about your diaphragm. This dome-shaped
muscle sits below your lungs, and it helps your
windbags inhale and exhale. When you get hit in
the abdomen, this can cause a pressure
difference that makes your diaphragm spasm for
a few seconds. You can't catch your breath until
the spasm stops.
FUN FACTS
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MYTH: Cover your head or catch a cold:
Although 90% of the heat lost from the
body is lost from the head, covering your
head will not prevent this heat loss. The
heat is lost from the warm air that you
exhale.
Lung Damage
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Smoking destroys cilia, and smoke of any kind is
toxic. Particles in the lungs can’t clear.
Cigarettes contain tar, which is the same kind of
tar used to pave roads.
When there is a thin lining of tar on the alveoli,
there is no oxygen exchange to the lungs there.
Large chunks of the lung become useless.
Damage to the lungs shows up several ways.
CHRONIC OBSTRUCTIVE PULMONARY
DISEASE (COPD)
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Number 5 killer in the USA.
It is a combination of two conditions:
CHRONIC BRONCHITIS: inflammation of the
bronchi, produces mucous, the openings
become smaller = obstructed.
EMPHYSEMA: scarring of elastic tissue on the
bronchioles and alveoli, which collapse now
during exhalation.
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Characterized by a person with a large, “barrel” chest.
Barrel Chest of Emphysema
Emphysema
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A person with emphysema is like this:
Inhale all the way, then exhale a little bit, and
hold it. Now inhale and exhale to that same
point.
They cannot exhale all the way. They start using
their abdominal muscles, and get a large, barrel
chest.
They have chronic acid-base balance problems,
and the kidneys have to work harder. They
usually develop kidney problems.
Smoking
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If a person stops smoking after 10 years,
damage will repair. Longer than 10 years may
have some residual damage. It takes 7 years
for lungs to repair.
Smoking right after exercise is worse because
you are breathing more deeply.
Pollution in the air can also cause particles in the
lungs, and the ozone can damage the lungs.
Living in southern California is like smoking one
pack a day.
A mother who smokes during pregnancy will
give birth to a baby with a lower birth weight.
Smoking
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Smoking also is associated with heart
disease, cancer of the lung, bladder, and
pancreas.
It also causes emphysema, pneumonia,
and bronchitis.
Some people try to quit smoking by
smoking less, trying not to inhale, or
switching to chewing tobacco, but there is
no safe way to use tobacco.
Pneumonia
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An infectious illness that results in the
accumulation of fluid in the alveoli.
Respiratory Disorders
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Upper Respiratory Infection (URI)
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Lungs are not involved
Usually caused by a cold virus or allergies
Usually not associated with a fever
Lower Respiratory Infection (LRI)
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Lungs are involved
Usually caused by bacteria
Usually associated with a fever
Other Lung Conditions
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INFLUENZA
LUNG CANCER
RESPIRATORY DISTRESS SYNDROME
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SURFACTANT
PLEURISY
PNEUMOTHORAX
INFLUENZA
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This is the “flu” caused by a virus.
This is what you are vaccinated against
when you get the flu vaccine.
LUNG CANCER
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There are many types of lung cancers.
About 150,000 die each year from them.
It is the #1 or #2 most deadly form of
cancer.
85% of lung cancer is caused from
smoking.
LUNG CANCER
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The problem is that it starts as a hard nodule
deep in the spongy tissue of the lung, where it
has no symptoms until it presses against a
structure. By then, it has also metastasized.
Surgery on a smoker won’t work because the
lungs are too weak, and they can’t do without
the lung tissue. There are no good screening
procedures for lung cancer.
In lung cancer, the cancer cells usually arise
from the epithelium lining a large bronchus.
RESPIRATORY DISTRESS
SYNDROME
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SURFACTANT is a detergent produced
within the alveoli, which coats it.
It functions to help with lung inflation by
keeping the walls of the alveoli from
sticking together when they collapse
during exhalation.
If you have two wet pieces of paper and
stick them together, they are hard to pull
apart without ripping. Put soapy water
between them, and you can pull them
apart.
RESPIRATORY DISTRESS
SYNDROME
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Surfactant is not produced in a fetus until the
ninth month, so premature babies don’t have
enough surfactant  RESPIRATORY
DISTRESS SYNDROME, which is the #1 cause
of death in premature babies.
You know how hard it is to blow up a brand new
balloon? Imagine a baby having to do that with
every single breath. You get tired.
The treatment is to spray artificial surfactant
into the lungs, and put them on a respirator to
push air in. The more distal regions are still
collapsed, so there are problems.
Pleura
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Lining the thoracic cavity is PARIETAL
PLEURA.
Lining the lungs is the VISCERAL PLEURA.
Both of these are made of 2 layers (simple
squamous epi and loose fibrous ct), same as the
pericardium. Between these pleura is a tiny
space: PLEURA CAVITY.
The pleura lubricate the lungs so when the lungs
move, it is smooth. They also form an airtight
seal to allow the lungs to inflate.
Diagram of the Pleural Cavities
Figure 21.11
PLEURISY
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The rubbing together of inflamed pleural
membranes that produces a stabbing pain
in the chest with every breath; it feels like
a broken rib.
Usually the inflammation is caused from
an infection.
It is fairly common.
Breathing
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When the lungs inflate, the thoracic cavity
expands for two reasons:
The diaphragm pulls down, increases
volume
The rib cage expands, increases volume.
When the diaphragm contracts, the size of
the thoracic cavity increases, the pressure
inside the thoracic cavity drops, and air
flows into the lungs.
Changes in Thoracic Volume
Figure 21.15d
PNEUMOTHORAX
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If there is a hole in the pleura (injury from
broken rib, knife), it’s like opening the
stopper; air flows in through the hole, and
the lungs don’t inflate =
PNEUMOTHORAX (air in thorax) 
COLLAPSED LUNG.
TUBERCULOSIS
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An infection of a really bad bacteria that get in
the lungs and make themselves a capsule to
hide in, where antibiotics can’t reach. They set
up shop in the lungs and reproduce. Soon, the
lungs fill up with these hard nodes and make it
difficult to breathe. It causes extreme coughing,
and then lots of these bacteria break off and get
spewed into the air, where someone else can
inhale them. It is extremely contagious and very
deadly.
TUBERCULOSIS
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If a person gets TB, the State Health Department has to be notified.
If it is active TB, you must be hospitalized.
If it is not an active infection, you still need medicines.
They will show up at your house every morning for six months and
stand there and watch you take your pills.
If you don’t accept this, they have the right to haul you away to a
lock-up facility and force the medicine in you for six months.
There are only a few diseases where the State Health Department
will step in like this: anthrax, typhoid fever, and bubonic plague are
other diseases where you don’t get a choice; you are forced into
isolation.
Diseases like TB and the plague have almost wiped out Europe!
TUBERCULOSIS
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A TB test will be positive if you have been exposed to
the organism at any point in your life.
Then you’ll have to go in for an x-ray to see if it is an
active case of TB or not.
Once you recover from TB you will always have a
positive TB test, so tell the nurse that in advance.
You may have to provide documentation that you have
been treated for it already.
Most employers require TB tests before hiring. I had to
take one to work here.
CYSTIC FIBROSIS
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Cystic fibrosis is an inherited disease that
causes thick, sticky mucus to build up in
the lungs and digestive tract. It is one of
the most common type of chronic lung
disease in children and young adults, and
may result in early death.
CYSTIC FIBROSIS
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Millions of Americans carry the defective CF
gene, but do not have any symptoms. That's
because a person with CF must inherit two
defective CF genes -- one from each parent. An
estimated 1 in 29 Caucasian Americans have the
CF gene. The disease is the most common,
deadly, inherited disorder affecting Caucasians
in the United States. It's more common among
those of Northern or Central European descent.
CYSTIC FIBROSIS
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Most children with CF are diagnosed by
age 2. A small number, however, are not
diagnosed until age 18 or older. These
patients usually have a milder form of the
disease.
RENAL SYSTEM
Organs of the Renal System
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Kidneys
Ureters
Urinary bladder
Urethra
Not many
structures, but
very important!
Figure 23.1a
Functions of Urinary System
Regulate electrolytes (K, Na, etc)
Regulate pH in blood
Regulate blood pressure
Regulate blood volume (removes excess
fluid)
Removing metabolic wastes
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Urea, uric acid, and creatinine
This is the least important of the kidney’s functions.
You can survive for a few weeks without excreting
waste products in the urine, but hour by hour, the
other functions are more important.
Relationship of the Kidneys to
Vertebra and Ribs
They are retroperitoneal
and are located in the
abdominal
cavity.
They are at the level of
T12 to L3, so they are at
the costal margin, and
the ribs protect them a
little.
Even though they are
protected by thoracic ribs,
they are NOT in the
thoracic cavity because
they are below the
diaphragm.
Figure 23.1b
STRUCTURES WITHIN THE
KIDNEY
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The RENAL CAPSULE surrounds the kidney,
dense fibrous connective tissue.
A layer of adipose tissue surrounds the capsule,
called PARARENAL FAT (ADIPOSE). It
cushions and protects.
Around that is a connective tissue layer =
RENAL FASCIA, made of loose connective
tissue. It anchors the kidney to the surrounding
peritoneum and abdominal wall. Not very
strong. Jumping up and down can cause
tearing.
Position of the Kidneys with in
the Posterior Abdominal Wall
Figure 23.2a
Gross Anatomy of the Kidneys
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Renal cortex (Most superficial layer)
Renal medulla
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Renal pelvis
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Renal pyramids (drain into the calyx)
Calyx (drains into hylus  ureter)
Ureter
Renal fascia
Interlobar arteries
Interlobular arteries
Arcuate
arteries
Internal Anatomy of the Kidneys
Interlobar artery
Figure 23.3b
Blood Supply to Kidney
AORTA  RENAL ARTERY  SEGMENTAL ARTERIES 
INTERLOBAR ARTERIES  ARCUATE ARTERIES (form arcs) 
INTERLOBULAR ARTERIES
INTERLOBULAR VEIN  ARCUATE VEIN  INTERLOBAR VEINS
 SEGMENTAL VEINS  RENAL VEIN  INF. VENA CAVA
Summary of Blood Vessels
Supplying the Kidney
Figure 23.10
Internal Anatomy of the Kidneys
Interlobar artery
Figure 23.3b
Microscopic Anatomy of the
Kidneys
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Just like the unit of function of the lungs is
the alveolus, the unit of function of the
kidney is the NEPHRON.
Each kidney has about 100,000 nephrons.
They carry out all of the various functions
of the kidneys.
Microscopic Anatomy of the Nephron
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GLOMERUS WITH A CAPSULE
PROXIMAL CONVOLUTED TUBULE
LOOP OF HENLE
 DESCENDING LIMB
Thick portion
 Thin portion
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ASCENDING LIMB
Thick portion
 Thin portion
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DISTAL CONVOLUTED TUBULE
COLLECTING DUCT
Nephron
Position of Nephron in Kidney
Figure 23.4a
Glomerulus of a Nephron
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JUXTAGLOMERULAR
APPARATUS
The juxtaglomerular apparatus (JGA) consists of cells
located in and around the glomerulus and the glomerular
capsule.
The glomerulus is the first part of the nephron, where
the filtration occurs.
The glomeruli are located only in the renal cortex.
A glomerulus (“ball of yarn”) is a tuft of capillaries
surrounded by a glomerular capsule (Bowman’s capsule)
made of simple squamous epithelium. The glomerulus
fits in the capsule like a fist punched into an
underinflated balloon.
The capsule collects the plasma from the arterioles and
drains it into the convoluted tubules, which empty into a
collecting duct, which exits the body.
The plasma is further filtered along the way.
Glomerulus
of a
Nephron
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
Normally at the end of the capillary bed you
have venuoles. But this is the only part of the
body that is different: here we have another
arteriole, called the EFFERENT ARTERIOLE,
which takes blood away from the glomerulus.
The efferent arteriole drops down straight, next
to the Loop of Henle. While it is straight, it is
called VASA RECTA (straight capillaries).
There are capillaries that come off the
efferent arteriole which surround the loop of
Henle. Here, they are called peritubular
capillaries. They then leave the area to become
the interlobular vein, which leaves the kidney.
Nephron
Efferent arteriole
Afferent arteriole
Glomerulus
FUNCTION OF THE
NEPHRON




Blood comes in from the AFFERENT ARTERIOLES.
Plasma leaks out and enters the glomerular capsule.
The plasma contains nutrients, waste products, etc. As
the plasma moves through the proximal convoluted
tubule, all of the nutrients, and most of the water, and
most of the ions are absorbed back out of the nephrons
and into the blood.
In the Loop of Henle, almost all of the rest of the water
and salt are removed  blood.
Everything that is not reabsorbed (the waste products)
goes into the collecting duct and is excreted as urine.
This is also how the water-salt balance is maintained, as
well as the acid-base balance.
Nephron
FUNCTION OF THE
NEPHRON




In the distal convoluted tubule, the rest of the
water and salt are removed.
The rest of the liquid goes into the collecting
duct.
The distal convoluted tubule and the collecting
duct fine-tune the water and salt absorption and
excretion. If you are well hydrated, the water
will be allowed to leave  urine.
If you are thirsty, the water will be absorbed.
The purpose of the capillary bed is to absorb
these things from the nephron into the blood.
Figure 23.5
Renal Corpuscle and the
Filtration Membrane
Figure 23.6c
Diuretics




Diuretics are medicines that increase the amount
of urine that is produced.
People who have high blood pressure might be
prescribed diuretics to decrease the blood
volume.
Alcohol is a diuretic and this is what
contributes to the symptoms of a
hangover. The best way to prevent a
hangover after drinking is to consume a lot
of water before you go to bed.
Caffeine is also a diuretic, so coffee and
regular Coca-cola are diuretics.
HISTOLOGY OF THE NEPHRON

PROXIMAL AND DISTAL
CONVOLUTED TUBULES


This area absorbs nutrients, water, and salt.
Only about 1% of the fluid filtered by the
kidney actually becomes urine.
LOOP OF HENLE

This is where you get diffusion of water. It is
located in the renal medulla.
Urine Production



Filtration – filtrate of blood leaves kidney
capillaries
Reabsorption – most nutrients, water, and
essential ions reclaimed
Secretion – active process of removing
undesirable molecules
Figure 23.9a
Collecting Duct (tubule)

Receives urine from distal convoluted
tubules, empties into ureter.
Figure 23.4a
Kidney Problems



Things can happen to the kidney: infection,
excess proteins, pH change, blood pressure
drops, and can lead to kidney failure.
Treatment is DIALYSIS, which removes blood,
send it through a filter, and return it without the
wastes. Done three times a week. Ideally, need
a kidney transplant because the kidney has
other functions as well.
The brain, heart, and kidney are the only three
organs in the body that have to get oxygen to
sustain life.
Ureters

These are long tubes that connect the
renal pelvis to the urinary bladder

MUCOSA


TRANSITIONAL EPITHELIUM (for expansion)
LAMINA PROPRIA (has elastic tissue to
recoil)
MUSCULAR LAYER (smooth muscle)



INNER CIRCULAR
OUTER LONGITUDINAL
ADVENTITIA


Provides protection, strength for organs, and
attaches ureters to surrounding structures
URINARY BLADDER



The structure is identical to ureter except
mucosal layer has folds = RUGAE which
allow for expansion.
The mucosal folds in the bladder (rugae)
have the same basic function as
transitional epithelium—accommodating
stretch as the bladder fills.
You can hold up to one liter of urine,
although at 500ml, you’ll be dancing.
Urinary Bladder


Rugae:
allows for
expansion
-A full
bladder is
roughly the
size of a
soft ball
Figure 23.14
URINARY BLADDER


At the base of the urinary bladder, the
muscle layer is thicker and is called the
DETRUSOR MUSCLE, which allows
emptying of the urinary bladder.
The function of the urinary bladder is just
to store urine.
Detrusor Muscle
URETER entrance to BLADDER


The URETER comes in at the base of the
urinary bladder, not the top.
As the bladder fills, it presses down on the
ureters to prevent urine from backing up
into the kidneys.
BLADDER





The TRIGONE is a triangular area where the ureters
come in and the urethra goes out.
Between the urethra and the urinary bladder are two
sphincters:
INTERNAL URETHRAL SPHINCTER: smooth muscle
EXTERNAL URETHRAL SPHINCTER: skeletal muscle.
Although it is primarily under voluntary control, it will
contract if the urine volume is too much.
If the patient is in a coma or under anesthesia for a long
time, the internal sphincter will be closed, like when you
are asleep, so a catheter is needed to open it to drain
the urine out.
Urethra





Drains the urine to the outside.
Its histology is the same as the
ureter
Females: 4cm
Males 20 cm (varies with mood)
Therefore, women (esp. little girls)
are more susceptible to UTI.
Problems


URETHRITIS = infection and
inflammation of the urethra
CYSTITIS = infection of the urinary
bladder.
UREA



Urea is a waste product of amino acid
metabolism.
Remember, proteins are made of amino
acids, so when you break down proteins,
you break down amino acids, and the
waste product left over is urea.
This is the main waste product in urine.
COLOR OF URINE



When you urinate, it should be mostly
clear with almost no yellow color.
The more yellow the urine is, the more
dehydrated you are.
If the urine is very dark yellow, you are
burning too much protein (as in food
deprivation). This is often seen in
diabetes.
Problems

KIDNEY STONES



Develop in the renal pelvis
Stones are made out of a variety of things:
uric acid, calcium, etc.
They keep growing.
KIDNEY STONES



They can block the ureter, causing the kidney to
enlarge. As the kidney stretches, the capsule
stretches, causing excruciating pain in cycles of
hours. As pressure builds up around the stone,
urine can pass, and the kidney stone moves
down the urethra slowly.
Symptomatic kidney stones are pea sized or
larger (up to 1 ½ inches).
They get stuck in three places:



Renal pelvis
In the ureter as it bends over the common iliac artery
In the urinary bladder at the trigone.
Kidney stones get stuck in three places:



Renal pelvis
In the ureter as it bends over the common
iliac artery
In the urinary bladder at the trigone.
Where
kidney stones
get stuck
Renal pelvis
Ureter
Common
iliac
artery
Urinary
bladder
trigone
KIDNEY STONES TREATMENT

ULTRASOUND LITHOTRIPSY


STENT


Put a powerful speaker on the outside of the kidney,
sends a shock wave which the tissues absorb, but the
stones shatter so the pieces can pass easier.
(1 ½ foot long tube) in to keep the ureter open along
its entire length. Insert under general anesthetic,
remove without.
To help prevent kidney stones, drink enough
fluid so your urine stays clear and light colored.
Other Kidney Problems





Pyelitis: infection of the renal pelvis and
calyces
Nephritis: inflammation of the nephrons.
Hydronephritis: excess fluid in the
nephron.
Cystitis: inflammation of the urinary
bladder.
Glucose in the urine: indicates diabetes.