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268 Cards in this Set

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What is the first organ that begins to function in an embryo?
heart
In week 2, what does the heart organ form?
Cardiogenic plate
In week 2, what does two parallel blood vessels fuse together to form?
a sac
What week does the heart begin to pump?
week 3
What is the pathway of the blood when the final destination is to the lungs?
Blood back from everything else -> right atrium -> right ventricle -> goes out pulmonary trunk -> gives blood to cappillary beds around the aveoli.
Pulmonary pump
the right side of the heart that supplies to aveoli beds in the lungs.
What is the pathway of the blood from the lungs to everything else?
blood back from lungs -> left atrium -> left ventricle -> out the aorta
Systemic pump
the left side of the heart that pumps blood to everything else.
What is the job of the atrium?
to contract and fill the venticle w/ blood.
What is the job of the ventricle?
It does the actual pumping of the blood in the heart.
What are the valves for in the heart?
It prevents the backflow of blood.
What does the tricuspid valve do?
Prevent backflow of blood in the right atrium.
What does the bicuspid (mitral) valve do?
Prevent backflow of blood in the left atrium.
What do the semilunar valves do?
It prevents backflow of blood in both the left and right atrium.
(aka. pulmonary valve and aortic valve)
Where are the semilunar valves located?
at the base of the pulmonary trunk.
Where does the pulmonary vein carry blood to and what kind of blood?
It carries oxyenated blood to the left atrium.
What kind of openings are on the semilunar valves?
coronary arteries.
What do the papillary muscles do?
Prevent the valves from being flipped inside out.
Where are the tips of the flaps of the valves anchored to?
chordae tendineae.
What causes the valves to open and close?
Due to pressure charge, NOT contraction of papillary muscles.
What kind of circulatory path does the heart have?
It has its own circulatory path.
What is the coronary sinus?
A expanded vein of the papillary muscle on the posterior side.
What does the coronary sinus do for the heart?
It collects blood full of CO2 and this flows into the right atrium.
How many openings doe the right atrium have and what are they for?
right atrium has 3 openings: 2 large ones (superior and inferior vena cava) and 1 small opening for coronary sinus.
What is nodal tissue?
Modified cardiac muscle tissue, which allows heart to act independently from the nervous system
What can nodal tissue do?
give out regular spontaneous action potentials and forms specific conduction pathways.
Why is the sinoatrial node important?
It has the fastest rate and provides the action potential that allows the heart to beat.
Where is the sinoatrial node located?
It is located on the side of the right atrium. The action potentials arise here and allow the atrium to contract.
What is the atrioventricluar node useful for?
Conducts much more slowly and action pontential slows down. It allows the atrium to contract and fill the ventricles, allowing a delay.
What is the speed of conduction for the atrioventricular node?
1/10 of the speed of conduction node pathways.
What are the smaller divisions of the AV bundle called?
Purkinje fibers
What is the nodal tissue from large to fine?
Sinoatrial (SA)node -> atrioventrical (AV) node -> AV bundle ->purkinje fibers
What is the QRS complex?
Ventricular contraction and depolarization.
From looking at a electrocardiogram (ECG), describe a single cycle of contraction and relaxation.
P wave (atrial contraction and depolarization), QRS complex, T wave-relaxation and repolarization of ventricle
Why is the sinoatrial node important?
It has the fastest rate and provides the action potential that allows the heart to beat.
Where is the sinoatrial node located?
It is located on the side of the right atrium. The action potentials arise here and allow the atrium to contract.
What is the atrioventricluar node useful for?
Conducts much more slowly and action pontential slows down. It allows the atrium to contract and fill the ventricles, allowing a delay.
What is the speed of conduction for the atrioventricular node?
1/10 of the speed of conduction node pathways.
What are the smaller divisions of the AV bundle called?
Purkinje fibers
What is the nodal tissue from large to fine?
Sinoatrial (SA)node -> atrioventrical (AV) node -> AV bundle ->purkinje fibers
What is the QRS complex?
Ventricular contraction and depolarization.
From looking at a electrocardiogram (ECG), describe a single cycle of contraction and relaxation.
P wave (atrial contraction and depolarization), QRS complex, T wave-relaxation and repolarization of ventricle
What percent of ventricle is full of blood?
80% of ventricle is full of blood
What percent of blood gets expelled from the ventricle?
50% gets expelled from ventricle (not all of the blood leaves the ventricle.
Atria are in systole for what proportion of the cardiac cycle?
1/8
Ventricles are in systole for what proportion of the cardiac cycle?
3/8
What proportion of the time is the cardiac cycle in diastole?
4/8
When the left side of the heart is relaxed, which valves are opened and which are closed?
The bicuspid valve is open, the aortic semilunar valve is closed, and the blood flows in.
When the left ventricle contracts, which valves are opened and which are closed?
The bicuspid valve closes, the aortic semilunar valve opens, and blood flows in.
systolic pressure:
the pressure during systole.
diastole pressure:
that pressure during diastole.
When the tricuspid valves and bicuspid valves are closed during contraction, what valve opens?
semilunar valve opens.
What is the systolic pressure for a healthy young adult?
120mmHg
What is the diastolic pressure for a healthy young adult?
80mmHg.
What controls the heart?
The cardiac center in the medulla.
Where are the sympathetic neurons located?
Cardiac nerves
Where are the parasympathetic neurons located?
Vagus nerves
What does the neurons do in the cardiac center (heart)?
sympathetic neurons stimulate the SA and the parasympathetic neurons slow down the SA node. The balance between these regulates the rate of the SA node.
Where and why does the cardiac center send sympathetic neurons other than the SA?
To the muscle cells in ventricles. This increase the force of contraction in the ventricles.
How does the heart regulate systemic control?
cardiac center receives input from baroreceptors and chemoreceptors
baroreceptors
regulate blood pressure?
chemoreceptors
monitor blood oxygen and carbon dioxide levels.
The baroreceptors and chemoreceptors are everywhere, but the most important ones are located where?
aortic arch (where blood pressure is highest) and carotid sinus (monitor blood flow to brain, chemoreceptors)
cardiac output
volume of blood pumped in a given amount of time.
stroke volume
volume of blood pumped per beat
What is the formula for the cardiac output?
cardiac output = heart rate x stroke volume
Stroke volume is controlled in two ways:
1. sympathetic neurons that connect the cardiac center to the muscles of the ventricles
2. Frank/Starling Law: the more the ventricles are stretched, the harder they will contract (intrinsic capability of heart)
What is the resting heart rate?
75 beats per minute
What is the average stroke volume?
80 ml/beat
What is the cardiac output?
6 L/min
When you increase heart rate, how much increase is the cardiac output?
you can get a 2.5 fold increase.
When you increase the stroke volume, how much incrase is the cardiac output?
you can get a 2 fold increase.
An average person overall get how much of an overall incrase in cardiac output?
5.5 increase
What are the names of the blood vessels in the order of the pathway starting with the distribution of blood throughout the body?
Arteries -> arterioles -> capillaries -> venules -> veins
What is the inner layer of the blood vessel?
tunica intima (endothelium)
What is the midle layer of the blood vessel?
tunica media (double layer of elastic connective tissue and smooth muscle)
What is the outer layer of the blood vessel?
tunica externa or tunica adventitia
All of the blood vessels have the three layers of tissue except for which type of blood vessel?
capillaries
What is the characteristic of the tunica meida in arteries?
rich in elastic connective tissue so they act as a passive shock absorber.
What is the characteristic of the tunica meida in arterioles?
rich in smooth muscle - they actively change diameter
What the capillaries there for?
passive barriers
What are the characteristics of tissues for the venules and veins and what is the purpose of large veins?
The tunica media is thin, the tunica externa is thicker. Large veins act as passive blood reserviors.
What is the blood distribution for the heart out of the entire body?
7%
What is the blood distribution for the pulmonary circuit out of the entire body?
9%
What is the blood distribution for the systemic circuit out of the entire body?
84%
Of the 84% in the systemic circuit, what percent is in arteries and arterioles?
13%
Of the 84% in the systemic circuit, what percent is in capillaries?
7%
Of the 84% of blood in the systemic circuit, what percent is in veins and venules?
64%
What are the three types of capillaries?
continous capillaries, fenestrated capillaries, sinusoids
Continuous capillaries:
found everywhere except the epithelia and cartilage. Allow water, ions, and some small molecules to pass.
Fenestracted capillaries:
Found in chloroid plexuses, small intestine, glomerulus of nephron, and some endocrine organs. They can pass molecules up to the size of a small peptide.
Sinusoids:
very permeable, pass molecules up to the size of a small protein. Found in liver, bone marrow, adenohypopesis, and adrenal cortex.
One way valves
there's no backflow and gravity pull blood away from heart.
What are the three regulations to blood pressure?
systemic regulation, hormone regulation, local regulation
hormone regulation
number of hormones that influence blood pressure
local regulation
conrol individual capillaries (local chemicals)
control by local independent factors, independent w/ whole system
where is the systemic regulation found and what does it perform?
made by the nervous system in the vasomotor center in the medulla.
Performs balancing act between system pressure and distribution of blood.
Can the diameter of the arterioles be changed and what system has this function?
yes its dynamically controlled and is a function of the sympathetic nervous system.
What kind of muscles is the arterioles surrounded by?
smooth muscles
Vasomotor constriction
When there's increase stimulation to the muslce, it will constrict the diameter.
What are the three effects to vasocontriction?
1. increase systemic blood pressure
2. incrase resistance to blood flow through ateriole
3. blood pressure in the organ being supplied by the arteriole will go down.
What is vasodilation?
When the blood vessel dilates, and the diameter of the blood vessel increases.
What are the three effects to vasodilation?
1. reduce systemic blood pressure
2. decrease resistance to blood flow throughout the arteriole
3. increase blood pressure in the organ being supplied by the arteriole
When does the vasomotor center dilate blood vessels and when does it constrict blood vessels?
the vasomotor center dilates blood vessels when there are places that need more blood. The vasomotor center constricts blood vessels to push the blood to other places.
Does the brain need a constant supply of blood at all times? if yes, how much?
Yes, 750 ml/min.
What are the hormones that cause change in blood pressure?
ADH, angiotensin, erythropoietin, epinephrine, histamine, atrial natriuretic hormone
What does ADH do to blood pressure?
increase blood volume and blood pressure
What does angiotensin do to blood pressure?
regulates Na and K balance - increase blood pressure by vasoconstriction.
What does erythropoietin do to blood pressure?
increases red blood cell volume and visocisty of the blood. Then the heart has to pump harder and this increases the blood pressure.
Epinephrine
increases blood pressure by vasoconstriction.
Histamine
decreases blood pressure by vasodilation.
atrial natriuretic hormone
secret by atrium of heart in response to the stretching of the atrium, decreases blood pressure
How do the local control have control over the blood pressure?
The capillary beds are controlled by chemicals produced at local levels.
What are the precapillary sphincters?
rings of smooth muscled that can constrict or dialate. They are controlled by local chemical factors.
Relaxation of the precapillary sphincter results from:
1. decrease in oxygen
2. high carbon dioxide
3. increase in H+ concentration (lowers pH)
4. increase in temperature
when do precapillary sphincters constrict?
when there's tissue damage.
Constriction of precapillary sphincters results from:
thromboxane, endothelin, prostaglandins
thromboxane:
released when platelet plug is formed.
endothelin:
when endothelium (lining of blood vessel) is cut.
prostaglandins:
cause contraction/dilation of sphincters and local blood flow.
Describe the skeletal pump when you move.
postural muscles squeeze on the veins and the blood will try to flow in both directions but will get pushed toward the heart.
Describe the skeletal pump when you stand still.
the blood pressure decreases and the blood will pool in the large veins because the skeletal muscle pumps will not be activated.
What system is considered the body's other circulatory system?
lymphatic system
Do lymphatic systems have valves?
yes.
What are the functions of the lymphatic system?
1. phagocytsis (macrophages)
2. immunity (b-lymphocytes)
3. absorbs digested fats
4. returns lost water to circulation
what is the largest lymphatic vessel and where does it return circulation?
thoracic duct, returns to circulation at the subclavian veins.
What system is the spleen involved in and what's its function?
It is involved in the lymphatic system. It has white pulp, which is concentrations of lymphatic tissue and also red pulp.
It is involved in immune response.
What all the capillary walls permeable to?
water
What are the two major factors that affects the permeability of capillary walls?
simple blood pressure and colloid osmotic pressure
Simple blood pressure:
every time the blood goes through the capillary bed it will lose some water.
colloid osmotic pressure (COP):
the blood has plasma proteins but the interstitial fluid doesn't.
Sets up osmotic prssure that pushes water into the capillary to dilute the plasma proteins.
How would you calculate the net flow of in the system?
net flow is water loss at the arteriole end and water gained at the venule end. Usuall overall, you slightl more than you gain.
What is the key function of the lymphatic system?
Restore water that is lost.
What is edema?
swelling that occurs if water isn't picked back up.
In the embryo, where does the respiratory system develop from?
head and digestive tract.
How do the lungs develop?
Laryngotracheal bud begins as a bud then divides into two lung buds, which develop into lungs.
What is the order from top of body to bottom of body of the respiratory system?
Nasopharynx -> oropharynx -> laryngopharynx -> larynx -> trachea -> bronchus -> bronchioles -> alveoli
eustachian tube
auditory tube that connects nasopharynx to middle and ensures even pressure.
left bronchus
line w/ ciliated pseudostratified epithelium
bronchioles
can contract and relax its muscled walls
what type of tissue is the alveoli?
made up of simple squamous epithelium
uvula
lymphoidal tissue hanging an oropharynx.
How come food does not go down the respiratory system?
bc the epiglottis covers the opening of the larynx.
Describe the respiratory membrane.
double membrane of simple squamos epithelium - one membrane belongs to the alveolus and the other to the capillary (containing blood cells)
For how long is blood in the capillaries?
3/4 of the time.
How thick is the respiratory membrane and what does it seperate?
5/1000 mm thick and seperates between air and blood.
What kind of cavity is the lung attached to?
it is attached to the pleural cavity and it is lined w/ pleura.
How are the lungs held inflated?
by surface tension of two wet membranes.
What supports the pleural cavity?
The diaphragm forms the floor of the pleural cavities.
what muscles is breathing controlled by?
voluntary skeletal muscles
During quiet respiration, when do you need to use your muscles?
only inhalation requires muscles; exhalation is passive.
Muscles used for quiet inspiration (inhalation) are located where?
diaphragm and external intercostals.
During inhalation, what does the diaphragm do?
It contracts, the muscle fibers pull out radially in all directions. The diaphragm flattens out, which increases the volume and draws air in.
If the diaphragm stops contracting, what does it do?
It will relax back into the dome shape and push air out.
What are the intercostals?
Sheets of muscles between adjacent ribs.
When the intercostals contract, what happen to the ribs?
The top ribs don't move but the bottom ribs pivot up and down - they pull each rib up towards the rib above it so the entire rib cage moves up. This increases the volume of the pleural cavity and pulls air in. When they relax the ribs fall back down and push air out.
When are the only times you use muscles to exhale and what muscle do you use to do this?
when you exercise or forced expiration. The internal intercoastals contract, they pull the rib cage down and in which forces air out.
On a spirogram, what is the tidal volume?
The amoutn of air you exchange in quiet inhalation.
What is the average tidal volume?
half liter.
what is the avg. of a person's expiratory reserve?
1 liter.
What is residual volume?
volume that is always in your lungs.
what is the average residual volume?
a little more than a liter.
How do you find the total volume?
total volume = tidal volume + expiratory reserve + residual volume + inspiratory reserve
What is the total lung volume for an average male?
6 L.
What is the total lung volume for an average female?
4.2 L.
Vital capacity and how can you calculate vital capacity:
the maximum amount of air you can exchange.
total volume - residual volume
What are the general facts about oxygen in blood?
1. transported primarily by hemoglobin
2. 2% is dissolved in plasma
3. 98% is on the heme group of hemoglobin
What are the general facts about carbon in blood?
1. 7% dissolved in plasma
2. 23% carried on globin part (protein part) of hemoglobin and plasma protein
3. 70% as carbonic acid: most CO2 is transformed in carbonic acid and also transported as carbonic acid.
How is carbonic acid created and what does it dissociate to?
CO2 + H2O -> H2CO3 [->H+ + HCO3-]
What is carbonic anhydrase?
an enzyme that makes blood an effective carbon dioxide transporter. It can drive the reaction either way based on pH.
What is hemoglobin designed for?
to be an efficient oxygen transporter.
Bohr effect:
rightward shift of the dissociation curve caused by hight H+, which decreases affinity of hemoglobin for oxygen.
Fetal oxygen-hemoglobin dissociation curve:
It shifts to the left because it has an even greater affinity for oxygen.
Describe the curve of the oxygen-hemoglobin dissociation curve.
Very steep saturation curve, which means that a small change in pO2 will make hemoglobin give up its O2 during lower pO2 pressure.
What is respiration controlled by?
centers in the medulla called respiratory rhythmicity center.
What respiration functions do the medulla have?
dorsal respiratory group (DRG, only inspiratory center)
Ventral respiratory group (VRG, both inspiratory and expiratory center)
What respiration functions does the pons have?
apneustic center (A) and pneumotaxic center(P)
P inhibits A which will allow you to exhale bc I will shut down.
What are the sensory input that controls DRG and VRG during rapid breathing?
H+ in cerebrospinal fluid, CO2 in blood, O2 in blood
What is the strong sensory input that controls DRG and VRG during rapid breathing?
H+ in cerebrospinal fluid. Chemoreceptors for this are located in the medulla. As H+ increases, it signals the VRG and DRG to increase the respiratory rate and the depth of respiration.
CO2 in blood, a sensory input that controls DRG and VRG during rapid breathing:
chemoreceptors are in the aortic arch and carotid sinus. As CO2 increases, it stimulates the VRG and DRG to increase the rate and depth of respiration.
O2 in blood, a sensory input that controls DRG and VRG during rapid breathing:
chemoreceptors are in the aortic arch and the carotid sinus. This actually does not have much of an effect on respiration.
Why isn't O2 in blood much of a sensory input that controls DRG and VRG during rapid breathing?
bc the partial pressure of oxygen must get down to about 60 before you can see an effect triggered by oxygen. It normally does not affect respiration because the blood near the receptors is normally 98% saturated w/ oxygen.
How is deep breathing controlled?
Oscillation between DRG and VRG.
Things that develop from the digestive tract in the embryo:
lungs, liver, salivary glands, gallbladder, pancreas, thyroid, and parathyroids
Going down in the digestive tract:
Oral cavity -> oropharynx -> laryngopharynx -> esophagus -> stomach -> pyloric valve -> small intestine -> Ileocaecal valve -> large intestine -> rectum ->internal and external anal sphincters
What is the pyloric valve?
Thick ring of smooth muscle that can completely clamp shut the opening to the small intestine.
What are the three parts of the small intestine and how long is each part?
duodenum (10"), jejunum (1/2 of remaining small intestine), ileum (1/2 of remaining small intestine)
Ileocaecal valve:
another sphincter found at end of small intestine
Describe the internal and external anal sphincters.
the internal one is involuntary while the external one is voluntary. the internal sphincter is inside the external one.
What is the digestive tract line w/?
lined w/ sketetal muscles from the top to about half way down the esophagus and also in the internal and external anal shpincters. Everything in between is involuntary.
Most of the walls of the digestive organs have the same structure. What are the four layers?
mucosa (very thin, innermost layer), submucosa, tunica muscularis, serosa
submucosa:
much thicker than mucosa and more complex. Contains a plexus called Meissner's plexus.
Meissner's plexus
in submucosa, responsible for local control of secretion.
Tunica Muscularis
double layer of smooth muscle (except for stomach(3 layers))
- inner circular fibers
- Auerbach's plexus is in between - responsible for local control of movement of muscle contraction
- Outer longitudinal fibers
Serosa
outermost laeyer (diaphragm has no serosa), exposed to abdominal cativity.
How type of digestion does the mouth do?
mechanical digestion occurs in mouth (chopping food)
What parts of the digestive tract secrete mucus?
All parts; for protection/easier for digestion (acts as lubricant)
What is the mucus in the mouth secreted by?
salivary glands.
What does saliva contain?
carbohydrate digesting enzyme amylase.
What does protase digest?
protein
What does lipase digest?
fats.
What are the two factors involved in activating the salivary glands to secrete?
1. arrival of food in mouth
2. psychological effect: sight or thought of food.
Stomach:
temporary storage - only absorbs molecules that do not need to be digested (medincines)
Stomach secretes?
1. mucus (goblet cells) - protective function
2. HCl (parietal cells) - protects against infection.
3. Pepsinogen (chief cells)
How is HCl formed in the stomach?
H+ and Cl- ions are secreted by separate active mechanism and then becomes HCl only when they are within the protective mucus-lined walls of the stomach.
What is pepsinogen and how do you activate it?
Inactive form of protease (protein digesting enzyme). HCl converts pepsinogen into pepsin which breaks proteins into peptides but does not completely digest proteins.
How long does food stay in the stomach and where does it go afterwards?
Food stays in stomach for 30-45min then becomes chyme (mixed food). The pyloric valve opens and close and dump food into the small intestine little by little.
What are the three stages of digestion?
1. cephalic phase (+)
2. gastric phase (+)
3. Intestinal phase (-)
cephalic phase in digestion:
taste or smell of food triggers an increase in secretion and motility in stomach; psychological effect does the same thing (extends only as far has stomach)
Gastric phase in digestion:
short reflex: sensory neurons detect food and stimulate secretion and motility in the stomach.
long (=vagus) reflex: plexus detects food and sends a signal to the hypothalamus. The hypothalamus then sneds motor instructions through the vagus nerve to stimulate an increase of secretion and motility.
Gastrin: local hormone secreted by the stomach in the blood - increases secretion and motility.
Intestinal phase in digestion:
inhibits secretion and motility and the opening of the pyloric valve.
short reflex: sensory neuron in the small intestine sends a message to the stomach to decrease secretion and motility.
Secretin - local hormone secreted by the small intestine.
Cholecysotokinin: as chyme is neutralized, the secretion of secretin stops and undigested fats tigger the release of cholecystokinin.
Secretin has three effects in the intestinal phase:
1. temporarily inhibits secretion and mobility in the stomach
2. stimulates bile secretion by liver
3. stimulates secretion of NaHCO3 by the pancreas.
What are the two effects of cholecystokinin in the intestinal phase?
1. contraction of gallbladder to squeeze bile into the small intestine.
2. secretion of digestive enzymes of pancreas (including lipases).
what's the only organ that secretes lipases?
pancreas.
Virtually the entire process of digestion and absorption occurs where?
small intestine
What does the plicae circulares do?
increase the surface area of the small intestine.
What does the villi do in the small intestine and what is it made up of?
villi gives texture. Each villi contains a capillary bed and lacteal. There are also microvilli.
What long and thick is the small intestine?
15 feet long and 1 inch in diameter.
What is the actual surface of the small intestine?
2200 square feet
What occurs in the large intestine?
have an extensive population of intestinal bacteria which secrete vitamin K. reabsorption of water and ions also occurs in the large intestine.
what does the gallbladder contain?
stores bile which also contains bile pigments and bile salts (emulsify fats). Gallbladder metabolic transtion for liver, the place for stuff liver doesn't want.
What kind of organ is the liver?
Metabolic organ
What are the functions of the liver?
1. produce bile
2. makes plasma proteins and non-essential amino acids.
3. 60% of fat synthesis (phospholipids, lipoproteins, cholestoral derivatives)
4. stores glucose (as glycogen) and si a major site of gluconeogenesis
5. stores fat soluble vitamins A, D, E, and also stores iron (as ferretin)
6. makes vitamin A
7. site of phagocytosis (Kupffer cells, macrophages)
8. detoxification, inactivation of steroid hormones
W/ chemical digestion, what does proteins break down into?
w/ protase, it breaks down into amino acids
W/ chemical digestion, what does starches break down into?
w/ amylase, it breaks down into monosaccharides
Waht is the only organ that can regrow?
liver.
What are absorbed into capillary beds of the liver?
amino acids and monosaccharides
How are the triglyceride fats broken down into?
triglyceride fats -> glycerol + 3 fatty acids - absorbed into lacteals
hepatic portal system:
blood supply to the digestive tract.
Where are the two capillary beds located in the hepatic portal system?
digestive tract and liver
What is the absorptive phase and what absorbs what?
couple of hours after eating and active digestion of small intestine.
- most cells use glucose
- liver uses amino acids/protein
Postabsoptive phase: what absorbs what?
- most cells use fats
- neurons use glucose
What are the functions of the urinary system?
1. excretion (removal of toxic nitrogen-containing wastes)
2. osmoregulation (regulation of water balance)
3. ionic regulation
4. pH balance
5. hormonal regulation
6. blood pressure regulation
Nephrotomes:
two long strips of mesoderm that develop into kidneys.
What is the pronephrous and when does it form and what is it used for?
When the anteriors parts are differentiated and nephrons are formed, they connect to the mesonephric duct. It appears at week 4. It degenerates.
What is the mesonephros and when does it form and what is it used for?
The posterior nenphrotomes being to differentiate and form nephrons. It begins at week 4. Functions for about a month as an embryonic kidney and then deteriorates.
Where does the permanent kidney begin to develop?
Begins as a bud on the tail of the mesonephric duct, the mesonephros. It begins to form early in week 5 and begins to function week 8.
In males, what happens to the mesonephric duct?
It will remain and become taken over by and associated w/ the male reproductive system.
In females, what happens to the mesonephric duct?
The duct disappears.
What is the Bowman's capsule?
material passes through blood in capsule and filtrate is formed. The pressure of the blood forces every molecule into the capsule that can fit through the membrane. The filtrate consists of everything in the blood in the same concentrations except for the plasma proteins and blood cells which are too big to fit through.
How is the distal convoluted tubule shaped?
It is folded up.
Juxtaglomerular apparatus
the apparatus where the distal convoluted tubule meets the arteriole.
What are the two capillary beds in the urinary system?
The glomerulus is the first capillary bed and the second capillary bed is the peritubular capillary bed, which encompasses the entire nephron tubule.
What are the three main processes in filtrate:
1. filtration: pressure driven diffusion
2. active tubular secretion (material passed from blood -> filtrate)
3. active tubular reabsorption (material passed from filtrate -> blood)
The end product is urine
Autoregulation:
the kidney can regulate its own function. based in the juxtaglomerular apparatus.
What is the only function that the nervous system can control the kidney to do?
filtration, everything else is hormonally regulated.
Glomerular filtration rate (GFR)
volume of filtrate that passes from blood -> filtrate
How is the GFR regulated?
by the nervous system by regulating the blood pressure of the glomerulus.
How do you regulate the pressure of the glomerulus?
By controlling the diameter of the arteriole.
constrict arteriole -> less filtrate is formed
Dilate arteriole -> more filtrate is formed
How would you calculate effective pressure?
effective pressure = blood hydrostatic pressue - (blood colloid osmotic pressure + capsular hydrostatic pressure)
When percentage of the cardiac output does the kidney get when the body is at rest?
20-25%
What is the typical glomerular blood flow?
660 mL/min
What is the average GFR?
125mL/min
Osmoregulation
distribution of water in the body
What percent of osmoregulation is intracellular in the urinary system?
63%
What percent of osmoregulation is extracellular and what are the parts that contain extracellular fulid in the urinary system?
interstital fluid (23%), plasma (7%), lymph (3.5%), transcellular (3.5%)
If one part of the extracellular lose water, what will happen?
The rest will readjust to reestablish these ratios because they are all fully permeable to water.
Glomerular filtration rate (GFR)
volume of filtrate that passes from blood -> filtrate
How is the GFR regulated?
by the nervous system by regulating the blood pressure of the glomerulus.
How do you regulate the pressure of the glomerulus?
By controlling the diameter of the arteriole.
constrict arteriole -> less filtrate is formed
Dilate arteriole -> more filtrate is formed
How would you calculate effective pressure?
effective pressure = blood hydrostatic pressue - (blood colloid osmotic pressure + capsular hydrostatic pressure)
When percentage of the cardiac output does the kidney get when the body is at rest?
20-25%
What is the typical glomerular blood flow?
660 mL/min
What is the average GFR?
125mL/min
Osmoregulation
distribution of water in the body
What percent of osmoregulation is intracellular in the urinary system?
63%
What percent of osmoregulation is extracellular and what are the parts that contain extracellular fulid in the urinary system?
interstital fluid (23%), plasma (7%), lymph (3.5%), transcellular (3.5%)
If one part of the extracellular lose water, what will happen?
The rest will readjust to reestablish these ratios because they are all fully permeable to water.