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Physiology Exam IV:
Carl Christensen ACC Respiratory, Kidneys, Acid / Base Balance
242
Health Care
Undergraduate 3
11/10/2009

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Cards

Term
Ion regulation is a key feature of kidney function. What happens to the resting membrane potential of a neuron if extracellular K+ levels decrease?
Definition
If extracellular K+ decreases, more K+ leaves the neuron, and the membrane potential hyperpolarizes.
Term
What happens to the force of cardiac contraction if plasma Ca+ levels decrease substantially.
Definition
If plasma Ca+ decreases, the force of contraction decreases.
Term
What would happen to the body if filtration continued at a normal rate but reabsorption dropped to half the normal rate?
Definition
If reabsorption decreases to half the normal rate, the body would run out of plasma in under an hour
Term
If systemic blood pressure remains constant but the afferent arteriole of a nephron constricts, what happens to renal blood flow and FGR in that nephron?
Definition
If the afferent arteriole constricts, the resistance in that arteriole increaes, and blood flow through that arteriole is diverted to lower r esistance arterioles. GFR will decrease in the nephron whose arteriole constricted.
Term
Explain why a decrease in plasma protein concentration causes an increase in GFR?
Definition
The primary driving force for GFR is blood pressure opposed by fluid pressure in Bowman's capsule and colloid osmotic pressure due to plasma proteins. With fewer plasma proteins, the plasma has lower than normal colloid osmotic pressure. With less colloid osmotic pressure opposing GFR, GFR increases.
Term
How does reabsorbed fluid get into the capillaries from the interstitial fluid?
Definition
The driving force for reabsorption from the interstital fluid into the capillaries is the low hydrostatic pressure that exists along the entire length of the peritubular capillaires.  This low pressure favors reabsorption.
Term
If plasma creatinine = 1.8/ 100 mL plasma, urine creatinine = 1.5 mg/mL urine, and urine volume is 1100 mL in 24 hours, what is the creatinine clearance? What is GFR?
Definition

Creatinine clearance = creatinine exretion rate / (creatinine) plasma which is

1.5 mg cretinine / mL urine X 1.1 L urine / day/1.8 mg creatinin / 100 mL plasma. Creatinine clearance is about 92 L/day and GFR is equal to creatinine clearance.

Term
Describe teh changes in hte conducting ducts of hte lungs as respiratory ducts get smaller. From Ciliated columnar epithelium to Simple Squamous epithelium.
Definition
Ciliated columnar epithelium with goblet cells, changes to ciliated columnar epithelium with no goblet cells, changes to simple cuboidal epithelium, changes to simple squamous epithelium.
Term
Without cilia and mucous to trap bacteria, dust, etc., our lungs must rely on WHAT to remove debris and microbes?
Definition
Macrophages
Term
As respiratory ducts get smaller, what happens to the amount of cartilage? What happens to the amount of smooth muscle?
Definition
Amount of cartilage decreases and the amount of smooth muscle increases
Term
Put the following in order from largest to smallest. Bronchioles, terminal bronchioles, alveolar ducts, primary bronchus, secondary bronchi, tertiary bronchi, pharynx, trachea, larynx, respiratory bronchioles, alveolar sacs.
Definition

1. pharynx

2. larynx

3 trachea

4 primary bronchi

5 secondary bronchi

6 tertiary bronchi,

7bronchioles

8 terminal bronchioles

9 respiratory bronchioles

10 alveolar ducts

11 alveolar sacs

Term
Where does gas flow stop and diffusion take over in the respiratory tree?
Definition
Respiratory bronchioles
Term
Name 2 types of alveolar cells and briefly describe the function of each
Definition

Type 1 - simple squamous epithelial; fxn, Diffusion

Type II - surfactant producing cells

Term
Explain the function of surfactant
Definition
Soapy substance that reduced surface tension of water coating inside alveoli so that cells do not stick together during expiration; necessary so that alveoli can reinflate (expand)
Term
What is the advantage of a lung being composed of 150 million alveoli over a lung composed of one big sac?
Definition
Increased surface area so that more gas diffusion can take place
Term
Name a condition that reduces the # of alveoli?
Definition
emphysema
Term
What are the 4 major steps of respiration?
Definition

1. Pulmonary ventilation

2. Pulmonary Respiration

3. Tissue Respiration

4. Cellular Respiration

Term
Pulmonary Ventilation
Definition
Breathing; gas exchange between atmosphere and lungs
Term
Pulmonary Respiration
Definition
gas exchange between external environment and blood
Term
Tissue respiration
Definition
Gas exchange between blood and tissues
Term
Cellular respiration
Definition
aerobic respiration (glycolysis, pyruvic acid oxidation, Kreb's cycle, electron transport system); oxygen is the final electron acceptor in the ETC
Term
Pulmonary ventilation involves gas exchange between?
Definition
atmosphere and the lungs
Term
Explain the linings of the pleural cavity.
Definition
Pleural cavity is lined with parietal pleura (serious membrane); lungs are covered with visceral pleura (serous membrane) ; between the two membranes is a thin layer of pleural fluid.
Term
What are the 3 pressures involves in pulmonary ventilation?
Definition

1. Atmospheric (barometric) pressure

2. Intrapulmonary (intra-alveolar) Pressure

3. Intrapleural (intrathoracic) pressure

Term
Atmospheric (barometric) pressure
Definition
pressure exerted by air surrounding body (760 mm Hg at sea level)
Term
Intrapulmonary (intra-alveolar) pressure
Definition
pressure within the alveoli; fluctuates with phases of breathing
Term
Intrapleural (intrathoracic) pressure
Definition
pressure within the pleural cavity; fluctuates with breathing phases, but is about 4 mm Hg less than intrapulmonary pressure during an inspiration
Term
What is atmospheric pressure at sea level?
Definition
760 mmHg
Term
Why must intrapleural pressure alwyas be a little less than intrapulmonary pressure?
Definition
If intrapleural pressure equals or exceeds intrapulmonary pressure, the lungs will collapse immediately. It's the difference between the intrapulmonary and intrapleural pressures that keeps the alveoli open (called transpulmonary pressure)
Term
What might cause intrapleural pressure to equal or exceed intrapulmonary pressure?
Definition

1. If amount of pleural fluid (seroud fluid) in pleural cavity increaes (pleurisy from inflammation)

2. Pneumothorax - wound allows air to enter intrapleural space

Term
Explain Boyle's Law
Definition
Volume changes lead to pressure changes; which lead to the flow of gases to equalize the pressure; increase volume, decrease pressure; decrease volume, increase pressure
Term
How do we increase the volume of the thoracic cavity?
Definition
It is an active process involving skeletal muscle contraction; diaphragm and extern intercostals muscles.
Term
How do we decrease the volume of the thoracic cavity?
Definition
It is a passive process involving skeletal muscle relaxation; diaphragm and external intercostal muscles.
Term
Describe the diaphragm in its relaxed state and in its contracted state
Definition

1. Relaxed diaphragm - diaphragm is long and it bubbles up into the thoracic cavity.

2. Contracted diaphragm - diaphragm is short and it stretches across the bottom of the thoracic cavity.

Term
Atmospheric pressure is 749 mm Hg. Lung pressure is 747. What will happen?
Definition
Inspiration - air moves from high pressure to low pressure into the lungs
Term
How can you increase the amount of air exhaled?
Definition
Forced expiration; Contract abdominal muscles; they compress the abdomen, pushing up on the diaphragm, causing it to bubble up more into the thoracic cavity; this decreases the volume of the thoracic cavity even more, which increases pressure wven more. Also contract internal intercostal muscles - they pull the rib cage down even more, reducing volume and increasing pressure.
Term
What are 3 major factors influecing ventilation?
Definition

1. airway resistance

2. elastic recoil

3. Lung compliance

Term
Airway resistance
Definition
Friction or drag encountered in respiratory passageways.
Term
Elastic recoil
Definition
refers to how readily the lungs rebound (return to original volume) after being stretched.
Term
lung compliance
Definition
the stretchiness of the lungs; the ease with which they expand
Term
What determines airway resistance?
Definition
Friction or drag caused by the wall of the tube
Term
What is the relationship between gas flow and resistance?
Definition
Inverse; increase resistance (ex, decreased Diameter - COPD) ----> decrease gas flow
Term
Explain elastic recoil - recoil depends on what 2 factors
Definition

Refers to how readily the lungs rebound (return original volume) after being stretched; responsible for lungs returning to pre inspiratory volume when diaphragm and ext. intercostals relax.

2 factors:

1. elastic connective tissue in lungs

2. alveolar surface tension

Term
How does surfactant effect elastic recoil?
Definition
Surfactant decreases surface tension therefore decreases recoil. you do not want them to completely collapse; surfactant prevents this
Term
Exactly how does surfactant reduce surface tension?
Definition
Surface tension is due to the attraction between water molecules ( due to H bonds, water molecules are attracted to one another) This attraction (high surface tension) could cause the complete collapse of the alveoli during inspiration (the sides of the alveoli are attracted to one another). Surfactant is a soapy substance. The soap molecules get in between the water molecules, disrupting the H bonds between them, and therefore reducing surface tension. You want the lungs to recoil, but not completely collapse.
Term
What is Pneumothorax? What occurs durning this conditoni?
Definition
Occurs as the result of an open chest wound; when air enters the intrapleural space, pressure rises until its equal to atmospheric pressure. When intrapleural pressure is the same as intrapulmonary pressure (atmospheric pressure) the lung cannot expand and it collapses away from the chest wall.
Term
Lung compliance has to do with what?
Definition
How stretchy the lungs are
Term
What is affected by lung compliance?
Definition
Inspiration
Term
Name a condition that causes reduced compliance
Definition
pulmonary fibrosis - infiltration of lung tissue with connective tissue proteins.
Term
What is the maximum amount of air a person can exhale after taking the deepest breath possible (TV + IRV + ERV),
Definition
vital capacity
Term
What is the amount of air inahled over and above the tidal volue durnig a forced inspiration?
Definition
Inspiratory reserve volume
Term
What is the amount of air exhaled over and above the tidal volume during a forced expiration?
Definition
Expiratory reserve volume
Term
What is air entering the respiratory tract taht fails to reach the alveoli?
Definition
Dead space air volume
Term
What is the amount of air that enters the lungs during a normal quiet inspiration?
Definition
tidal volume
Term
What is the amount of air that leaves the lungs du ring a normal quiet expiration?
Definition
tidal volume
Term
What is the volume of air in lungs at end of normal passive expiration? (ERV + RV)
Definition
functional residual capacity
Term
What is normal value for vital capacity?
Definition
4500 to 4800 mL (around 5000 mL)
Term
What is a normal Tidal Volume?
Definition
500 mL
Term
What is normal dead space air?
Definition
150 mL
Term
Explain why d uring expiration, 500 mL of air is exhaled, but only 350 mL of that is alveolar air. Where does the other 150 mL come from?
Definition
The other 150 comes from the dead space air that was already in the conduction zone; it fails to reach the respiratory zone.
Term
Explain why during inspiration 500 mL of fresh atmospheric air is inhaled, and on the next expiration, 150 mL of that fresh air is exhaled (how does it stay fresh?
Definition
500 mL of fresh air came in, but only 350 made it to the respiratory zone; 150 mL of frsh air became dead space air. So that on the expiration, air from the alveoli pushed the dead space air (fresh air) out ahead of it.
Term
How much blood passes through the lungs each minute?
Definition
5 liters
Term
How much oxygen does oxygen rich blood have?
Definition
1000 mL
Term
How much oxygen does oxygen poor blood have?
Definition
800 mL
Term
How much oxygen is transported to xygen poor blood from alveoli each minute?
Definition
200 mL
Term
Is more oxygen exhaled or inhaled each minute?
Definition
exhaled
Term
What is the importance of still having lots of oxygen in "oxygen poor blood"?
Definition
oxygen reserve in case breathing is arrested
Term
In the lungs oxygen concentration are greater in the alveoli or arterioles?
Definition
alveoli
Term
in the lugns carbon dioxide concentrations are greater in the alveoli or arterioles?
Definition
arterioles
Term
What does hemoglobin saturation mean?
Definition
Every hem in a hemoglobin molecule is bound to an oxygen molecule for a total of 4 oxygen molecules carried by one hemoglobin moleucle
Term
What are the 3 ways and percentages that carbon dioxide can be transported in the blood?
Definition

70% as bicarbonate ion in the plasma

23% as carbaminohemoglobin in the rbc

7% as dissolves CO2 in the plasma

Term
Write the chemical reaction that converts carbon dioxide in to hydrogen ion and bicarbonate ion
Definition

Most of the CO2 in the blood (70%) diffuses from tissues into the rbc's in the capillaries and is combined with water to form carbonic acid. Carbonic acid dissociates into hydrogen ions and bicarbonate ions, which diffuse out of the rbc's and into the plasma.

CO2 + H20 ---> H2CO3   then

H2CO3 ---> H+ HCO3-

 

HCO3- then diffuses out of the rbc's and into the plasma and H+ binds to hemoglobin, so hemoglobin acts as a buffer

Term
Most carbon dioxide in the blood difsues into red blood cells and is combined with _________ to form _________ The acid then dissociates into _____________ ions and ____________ ions. The ____________ ions combine with hemoglobin.  __________ ions diffuse out of the red blood cells into the plasma
Definition
Most carbon dioxide in the blood difsues into red blood cells and is combined with water to form carbonic acid. The acid then dissociates into hydrogen ions and bicarbonate ions. The hydrogen ions combine with hemoglobin.  Bicarbonate ions diffuse out of the red blood cells into the plasma
Term
What is a buffer? How does hemoglobin act as a buffer?
Definition
Buffers help maintain pH by combining with or releasing hydrogen ions. Hemoglobin binds to H+ released by the dissociation of carbonic acid (hemoglobin acts as a base)
Term
What chemical reactions occur in the lung capillaries so that carbon dioxide can be released?
Definition
C02 + H20  <---- H2CO3 <---- H2CO3 <--- H+ HCO3-
Term
Carbon dioxide can bind directly to __________ in the rbc to produce a molecule called ____________ The carbon dioxide binds to the ________ of Hb, so it does not compete with _________ for binding sites
Definition
Carbon dioxide can bind directly to hemoglobin in the rbc to produce a molecule called Carbaminohemoglobin The carbon dioxide binds to the globin of Hb, so it does not compete with oxygenfor binding sites
Term
A small percentage of carbon dioxide is dissolves in blood......?
Definition
plasma
Term
Explain Dalton's Law of partial pressure
Definition
The total pressure of a gas mixture (air) is equal to the sum of the pressures tha teach gas in the mixture would exert independently (called partial pressure)
Term
What are the percentages of nitrogen, oxygen, and carbon dioxide in the atmospheric air?
Definition
79% nitrogen, 21% oxygen, 0.04% carbon dioxide
Term
How do you calculate partial pressure for a particular gas?
Definition
The partial pressure of a particular gas is equal to the percentage of that gas in the atmosphere times the total atmospheric pressure
Term
What is the effect of water vapor on the partial pressure of oxygen?
Definition
decreases the partial pressure of oxygen. The partial pressure of a particular gas is diluted by the presence of water vapor.
Term
The relative humidity of air in the respiratory zone is what compared to atmospheric air?
Definition
more than atmospheric air.
Term
What is the relative humidity of air once it reaches the respiratory zone? why?
Definition
100%. The air becomes completely saturated with water as it passes through the respiratory tree (humidified and warmed by goblet cell columnar epithelum
Term
The capacity of air to contain water dpeneds on what?
Definition
temperature
Term
Does the relative humidity of air in the respiratory zone fluctuate? Why?
Definition
No - Body temperature is realtively constant.
Term
What is the partial pressure of water vapor in the respiratory zone?
Definition
47 mm Hg
Term
How does increasing altitude affect atmospheric pressure?
Definition
decreases atmospheric pressure as you gain altitude.
Term
What happens to the partial pressure of oxygen as you inrease altitude?
Definition
decreases
Term
As you increase altitude - do lungs work harder for inspiration or expiration? Why?
Definition
Inspiration - remember that air will only move from high pressure to low pressure, so lung pressure has to be lower than atmospheric pressure for an inspiration to occur. At high altitudes ( low pressure) it is difficult to make lung pressure lower than thsi low atmospheric pressure, thus the body does not get enough oxygen.
Term
How can decompression sickness be prevented?
Definition
Slow ascent to allow nitrogen to leave the blood in expiration. Decompression sickness can occur when giong from high pressure to low pressure. if the change is made too quicly, then dissolves nitrogen comes out of solution, forming gas bubbles, w hich can block small blood vessels.
Term
Why would the partial pressure for oxygen in the blood of pulmonary veins be the same as taht in the systemic arteries?
Definition
They both carry high oxygen "oxygen rich" blood.
Term
Why would the partial pressure for oxygen in the blood of pulmonary arteries be the same as that in the systemic veins?
Definition
They both carry low oxygen "oxygen poor" blood.
Term
What do oxyhemoglobin curves tell us?
Definition
The % of hemoglobin molecules that have oxygen attached at a given PO2 partial pressure of oxygen.
Term
What is the relationship between partial pressure of oxygen and hemoglobni saturation?
Definition
High partial pressure promotes oxygen loading and saturation.
Term
If rbc's lack mitochondria, how do they produce ATP?
Definition
Glycolysis, (it is anaerobic, makes ATP without oxygen; not linked to the ETC that uses oxygen as the final electron acceptor)
Term
What metabolite from glycolysis is important in oxygen loading unloading by hemoglobin?
Definition
2-3 DPG
Term
Production of 2,3 DPG increases or decreases in the absence of oxyhemoglobin?
Definition
increases
Term
When might oxyhemoglobin levels be low?
Definition
Anemia or high altitude.
Term
What effect does 2,3 DPG have on oxygen loading by hemoglobin?
Definition
favors unloading.
Term
The Bohr effect - as pH DECREASES hemoglobin releases oxygen more readily Why?
Definition
H+ combines with the hemoglobin protein, changes its shape and causing it to unload oxygen.
Term
Low pH maens what to hydrogen ion concnetration?
Definition
higher hydrogen ion concentration
Term
higher hydrogen ion concentration promotes oxygen binding or release and in what capillaries?
Definition
higher hydrogen ion concentration promotes oxygen binding in the pulmonary capillaries.
Term
What is the relationship between CO2 and pH?
Definition
Inverse; Increase CO2 levels ---> increase carbonic acid levels ----> increase H + levels ----> decrease pH
Term
Describe the Haldane effect.
Definition
Resutls from Bohr effect; deoxygenation of hemoglobin increases its affinity for H+ allows more CO2 to be removed from the tissues ( remember CO2 combines with water to form carbonic acid, which dissociaties into H+ and bicarbonate ion
Term
In lung capillaries is pH higher or lower than systemic capillaries. How does this effect oxygen loading?
Definition
Lung capillaries enjoy a higher pH favoring oxygen loading.
Term
Lower pH promotes oxygen loading or unloading?
Definition
unloading like in active tissues.
Term
Higher temperatures promote oxygen binding or release?
Definition
release
Term
If sufficient oxygen is not present what kind of metabolism occurs?
Definition
Anaerobic fermentation (lactic acid fermentation
Term
Explain the Hering-Breuer Reflex and baroreceptors
Definition
Visceral pleurae and respiratory passageways contain stretch receptors (baroreceptors) taht are stimualted when lugns are infalted; they send inhibitory impulese to the medulla oblongata via the vagus nerves; this ends inspiration and allows expiration to occur; as the lung recoil (go back to their original volume) the baroreceptors become quiet (they are only stimualted on the inspiration) and the medulla oblongata halts its inhiboitory influence. This allows next inspiration to occur.
Term
What stimulates mechanoreceptors?
Definition
stretch.
Term
mechanoreceptors have an inhibitory effect to bring an end to?
Definition
inspiration
Term
Where are chemorecptors sensitive to blood oxygen and blood pH found?
Definition

Aortic Bodies

Carotid Bodies

Medulla Oblongata

Term
What stimulates hyperventilation?
Definition
High CO2 levels.
Term
What stimulates hypoventilation?
Definition
Low CO2 levels.
Term
Why does excercise cause you to hyperventilate?
Definition

1. Increase CO2 produced from inreased metabolism in skeltal muscles

2. anaerobic fermentation produces lactic acid.

Term
Why does vomiting cause you to hypoventilate?
Definition
Vomiting depletes the stomach of hydrochloric acid (HCl) so blood H+ levels decrease as the body tries to replace stomach acid.
Term
What is the effects of Nicotine on the lungs?
Definition
Nicotine constricts terminal bronchioles and this decreases airflow in and out of hte lungs
Term
What is the effect of CO on the l ungs?
Definition
CO in smoke binds to hemoglobin and reduces its oxygen carrying capacity
Term
What is the effects of irritants on the lungs
Definition

Irritatns in smoke cause increased fluid secretion by the mucosa of the bronchial tree and swelling of the mucosal lining, impeding airflow. Irritants also inhibit the movement of cilia of the columnar epithelial cells, thus excess fluid and foreign debris are not easily removed.

Smoking also leads to the destruction of elastic fibers in the lungs, causing emphysema.

Term
Describe what occurs in the lungs during an asthma attack?
Definition
Chronic, Inflammatory disorder that produces sporadic narrowing of airways, Attacks are brought on by spasms of the smooth muscles in the walls of the smaller bronchi and bronchioles, causing bronchoconstriction. There may also be excessive secretion of mucous. Common triggers may include allergens (pollen, dust mite, molds fods,) emotion upset, aspirin, Sulfiting agents (used in beer, wine etct) excercise,a dn cig smoke.
Term
What happens in the lungs of cystic fibrosis patients?
Definition

Thick mucous secretions build up in the airways blocking them.

This disease also affects the pancrease. So the patient fails to produce digestive enzymes.

Term
If asthma and COPD are both obstructive pulmonary diseases, how are they different?
Definition
Obstruction with asthma is largely reversible with inhalation of a bronchodilator like albuterol. COPD is not. The vast majority of patients with COPD are smokers, Asthma can be caused by a variety of allergens.
Term
What 3 endocrine hormones are produced by the kidneys?
Definition

1. Erythropoietin - stimulates the production in red bone marrow when blood oxygen levels are low.

2. Calcitriol - from vitamin D. increases calcium absorption in the small intestines

3. Angiotensin II - mechanism that increases blood pressure

Term
What is a toxic waste product formed from protein metabolism?
Definition
Ammonia
Term
How does Ammonia increase blood pH?
Definition
It acts as a base, combining with H+ ions
Term
How is urea formed?
Definition
From 2 ammonia and CO2, it is produced by the liver and excreted by the kidneys
Term
What is a waste product formed from nucleotide metabolism?
Definition
Uric Acid
Term
What causes gouty arthritis?
Definition
diet high in nucleic acids, crystals of a salt formed from sodium urate and result in gouty arthritis.
Term
Why is it important that the kidneys maintain an isotonic environment for body cells?
Definition
so that lysis/crenation of cell does not occur
Term
Why is it important that kidneys help maintain pH homeostasis?
Definition
Extreme pHs affect protein structure, which then affects protein function
Term
Each renal pyramid terminates in a _________________ which projects into a cup shaped tube called a _____________
Definition

Each renal pyramid terminates in a renal papilla which projects into a cup shaped tube called a 

renal calyx

Term
Name the 2 types of nephrons?
Definition
Cortical and juxtamedullary nephrons
Term
There are more of which type of nephron?
Definition
Cortical nephrons
Term
Which type ha sa long loop of Henle?
Definition
Juxtamedullary nephrons
Term
Which type has vesa recta capillaries?
Definition
Juxtamedullary nephrons
Term
Which type has peritubular capillaries?
Definition
Cortical nephrons
Term
What are the 2 main structures of each nephron?
Definition
renal corpuscle and renal tubule
Term
name 2 parts of the renal corpuscle?
Definition
Glomerulus and bowmans' capsule
Term
Wha tlayer of the capsule covers the glomerulus?
Definition
viscerla layers
Term
what layer of the capsule forms the outer wall fo the capsule?
Definition
parietal
Term
what "foot cells" make up the VISCERAL layer of the Bowman's capsule?
Definition
podocytes
Term
What are teh 3 layers of the filtration membrane?
Definition

1. fenestrated capillary wall (endothelium) of glomerulus - fenestrations and pores

2. Basement membrane of glomerulus  - loose meshwork of fibers

3. podocytes (visceral layer of Bowman's capsule) - special epithelial cells that cover the glomerular capillaries; each podocyte contains foot like structures called pedicels; spaces between pedicels are called filtration slits; a slit diaphragm spans the filtration slit

Term
The fenestrated capillary wall prevents filtration of?
Definition
red blood cells.
Term
The basement membrane prevents filtration of?
Definition
large proteins
Term
The slit diaphragm across filtration slits between podocytes pedicels prevents filtration of?
Definition
small proteins
Term
How is the PCT different from the loop of Henle and DCT?
Definition
Microvilli on surface of PCT cuboidal epithelial cells increase surface area for reabsorptoin and secretion
Term
What does JGA stand for and where is it located
Definition
Juxtaglomerular apparatus and located mostly in the afferent arteriole ( a little in the efferent arteriole)
Term
Name the 2 types of cell sin the juxtaglomerular apparatus Give a function for each?
Definition

1. Macula densa cells - specialized columnar epithelial cells found in the wall of the DCT where the tubule makes contact with the afferent/ efferent arterioles; epithelial cells monitor Na= and Cl- concentration fluid in tubule lumen (filtrate)

2. Granular cells (specialized smooth muscle cells in wall of afferent / efferent arterioles - stimualted by the macula densa to produce renin.

Term
What does Renin do?
Definition
catalyzes thechemical reaction that produces Angiotensin I that then is converted to angiotensin II
Term
What structure is responsible for the function of tubuloglomerular feedback?
Definition
Juxtaglomerular apparatus
Term
Name the blood vessels taht supply and drain each glomerulus?
Definition
afferent artiolres supplies; efferent arteriole drains
Term
How is the glomerular capillary bed unlike other capillary beds?
Definition
It is fed and drained by arterioles; regular capillary beds are fed by an arteriole and drained by a venule.
Term
Why is the afferent arteriole typically larger in diameter than the efferent arteriole?
Definition
The efferent arteriole is smaller in diameter than the afferent arteriole; this causes glomerular pressure to be extremely high (important for filtration) Think of a sprayer on the end of a garden hose. The afferent arteriole is the hose. The efferent arteriole is the sprayer ( you can change the size of the hole and thus pressure by rotating the head of the sprayer)
Term
Collecting ducts empty urine into what caup shaped tubes?
Definition
Renal calyces
Term
The effferent arterioles branch around another set of capillaries that wrap around the renal tubules? What are these capillaries called?
Definition
Peritubular capillaires in cortical nephrons and vasa recta in juxtamedullary
Term
What are the 3 main processes of urine formation?
Definition

1. Filtration

2. Reabsorption

3 Secretion.

Term
What part of the nephron is responsible for filtration?
Definition
Glomerulus ( and visceral layer of Bowman's capsule)
Term
What parts of the nephron is responsible for reabsorption and secretion?
Definition
Renal tubule
Term
The filter is selective based on what?
Definition
the size of the molecule  - not the type of hte molecule
Term
What is one major different between plasma and filtrate?
Definition
Protein concentration; higher protein concentration in plasma (most proteins are too big to be filtered)
Term
Why is it important that most blood proteins not be filtered at the glomerulus?
Definition
If too much solute was filtered, water would follow and too much water would be lost to the urine (in other words  you want blood osmotic pressure to be higher tahn the capsular osmotic pressure)
Term
What small protein is filtered by the glomerulus in small amounts?
Definition
albumin
Term
Protein or blood cells in urine indicates a problem with what part of the nephron?
Definition
Filtration membrane
Term
Why does "good stuff" end up in the filtrate in the first place?
Definition
The filtration membrane filters by size, not type of molecule; for example, glucose is small enough to pass through the filtration membrane, - In reabsorption we return the good stuff to the blood.
Term
Why doesnt all the bad stuff get filtered at the glomerulus?
Definition

Filtration is a passive process; theres only enough time for some of the wastes to be filtered; of the 625 ml of blood that goes to each nephron each minute, only 125 is actually filtered at teh glomerulus; the remaining 500 ml will pass inot the efferent arterioel and then into the peritbular capillaries.

- With Secretion we will take care of the bad stuff that does not make it into the tubule.

Term
What are the 3 pressures controlling Net filtration pressure?
Definition

1. Blood Hydrostatic Pressure (BHP)

2. Blood Osmotic Pressure (BOP)

3. Capsular Hydrostatic Pressure (CHP)

Term
Blood Hydrostatic Pressure (BHP)
Definition
- Blood pressure in the glomerulus, promotes filtration - blood pressure generated by left ventricle contraction, forces water and small solutes through the filter and into the Bowman's capsule. Glomerular capillary blood pressure is increased due to the diameter difference in the afferent / efferent arterioles. Hydro = water, hydrosatic pressure is the force a fluid exerts against the walls of the container.
Term
Blood osmotic pressure (BOP)
Definition
opposes filtration - due to pressence of proteins (albumins, globulins, fibrinogen) in blood plasma; the greater the solute concentration, the greater its osmotic pressure; because the plasma has mroe proteins some water moves from the filtrate back into the glomerula rcapillaries.
Term
Capsular Hydrostatic pressure CHP
Definition
opposes filtration - as filtrate is forced into the capsular space between the visceral and parietal wall of the capsule, it meets 2 forms of resistance; the wall of the capsule and the fluid that has alreadyu filled the tubule; as a result, mroe filtrate is pushced back into the glomerular capillaries.
Term
What is the formula for calculating NFP?
Definition
NFP = BHP - (BOP + CHP) normal value for  NFP is 10 mm Hg
Term
What happens ot NFP if blood pressure increases?
Definition
NFP Increases
Term
What happens to NFP if blood osmotic pressure decreases?
Definition
NFP increases
Term
What could cause a lower blood osmotic pressure?
Definition
Loss of protein from the blood
Term
If one were to lose protein would this effect urine volume?
Definition
increase urine volume.
Term
What is glomerular filtration rate?
Definition

125 ml / min

The amount of filtrate formed in all renal corpuscles of both kidneys each minute

Term
What happesn in the reabsorption process if GFR is too high?
Definition
filtrate moving too fast through the tubule; not enough time for reabsorption, results in salty filtrate.
Term
What happens in th ereabsorption process if GFR is too low?
Definition
filtrate moving too slow thorugh tubule; too much time for reabsorptoi; dilute filtrate.
Term
Increasing NFP does what to GFR?
Definition
increases
Term
What happens to GFR if blood hydrostastic pressure (BHP) drops to 45 mmHg
Definition
GFR drops to 0 ml / min
Term
How is GFR regulated intrinsically? what structure?
Definition
Juxaglomerular apparatus
Term
If MAP drops, macula densa cells are stimualated by what mechanism?
Definition

low sodium concnetrations (dilute filtrat) and decreases stretch

Term
If MAP drosp what does the macula ddensa do to the efferent or afferent arterioles?
Definition
Vasodilation of afferent arteriole; vasoconstriction of efferent arteriole; increases BHP/NFP/GFR
Term
Wha tturn on the renin/angiotensin mechanism?
Definition
Macula densa activates the granular cells to produce renin; macula densa activated by low sodium concentrations (dilute filtrate) and decreases stretch
Term
What are the four functions of angiotensin II?
Definition

1. vasoconstrictor of peripheral arterioles

2. activates thirst center in hypothalamus

3. increases aldosterone productino by adrenal cortex

4. increases ADH production by hypothalamus

Term
Aldosterone is produced by what gland?
Definition
Adrenal cortex
Term
What is aldosterone's target?
Definition
DCT
Term
What is Aldosterone's actions on the DCT?
Definition
Reabsorb mroe Na+, water follows, so more water is returned to the blood
Term
What is aldosterone's effect on urine volume?
Definition
decreases
Term
What is the effect on blood volume?
Definition
increases
Term
What is the effect on blood pressure?
Definition
increases
Term
What does ADH stand for?
Definition
Antidiuretic hormone
Term
ADH is produced by what gland?
Definition
hypothalamus
Term
What gland stores ADH?
Definition
Posterior pituitary
Term
What are the 3 targets of ADH and action on each target?
Definition

1. tunica media  of blood vessels; results in vasoconstrictino (except afferent arteriole)

 

2. sweat glands 0 turns them off so water is not lost to evaporation

 

3. targets collecting duct - opens water channels so more water can be reabsorbed and returned it to the blood (facultative water reabsorptoin)

Term
What is the effect of ADH on urine volume?
Definition
decreases
Term
What is the effect of ADH onblood volume?
Definition
increases
Term
What is the effect of ADH onblood pressure?
Definition
increases
Term
What is the effect of the Sympathetic division on the autonomic nervous system of GFR?
Definition
decreases
Term
SWhy would you want to reduce blood supply to the kidneys?
Definition
Blood needs to be diverted to skeletal muscles to help you get the heck out of there if you need to
Term
Where in the tubule does most reabsorption take place?
Definition
PCT
Term
Reabsorptoni of what is the key to the transport of almost all other substances?
Definition
Sodium
Term
Explain how sodium is reabsorbed and its entry into the peritubular capillaries?
Definition
sodium passively diffuses from filtrate into tubule cells (cuboidal cells ) Na+/K+ pumpts it out of the tubule cells into the interstitial fluid when it can then passively enter the peritublar capillaries
Term
reabsorption of Na promotes reabsorption of water by???
Definition
osmosis, water follows salt.
Term
How does the reabsorptoin of water lead to the reabsorption of other solutes?
Definition
water movement dilutes solute concnetratoin , so then other soultes follow water; also water is charged and other charged molecules are attracted to it.
Term
The mechanism of solut efollowing solvent is called?
Definition
solvent drag
Term
The transport of glucose, amno acids, and vitamins si called?
Definition
cotransport = meaning their transport is linked to sodium ions
Term
"Fine tuning" reabsorption takes place in the ???
Definition
DCT
Term
How is albumin reabsorbed?
Definition
Endocytosis (specifically pinocytosis since the filtrate is a liquid)
Term
What nitrogenous waste is NOT reabsorbed?
Definition
creatinine
Term
Describe the reabsorption of HCO3- / H2CO3. How does reabsorbing bicarbonate ions raise blood pH?
Definition
In the filtrate, HCO3- ion scombine with H+ ions secreted by the tubule cells to form H2CO3 (carbonic acid) H2CO3 then forms H20 and CO2 in the filtrate. CO2 diffuses into the tuble cells where it recombines with water to form carbonic acid, which then dissociates into H+ and  HCO3-. HCO3- ions then pass out of the tuble cell and into the capillaries. Reabsrobing bicarbonate ions and reutrning them to the blood raises the pH of the blood (HCO3- ions can combine with excess H+ to form carbonic acid) it may appear tha tbicarbone ions are bein reabsorbed and returned directlly to the blood, but there are some chemical reactions that must occur in the tuble cell to get it out of the filtrate and back into the blood.
Term
What determines the transport maximum for absorbed substances?
Definition
The number of carrier proteins
Term
List the 4 major functions of tubular secretions
Definition

1. Disposing of any substances taht were not filtered by the glomerulus. such as nitrogenous wastes and certain drugs; reason why some drugs may have to be taken mor ethan once a day.

2. Sometimes undesirable substances such as urea and uric acid are reabsorbed and have to be secreted back into the tubule.

3. Controlling blood pH - when the blood pH is too low (too acidic) H+ are se creted inot the tuble and HCO3- are reabsorbe dfrom the filtrate and reabsorbed to the blood; when blood ph is too high (too alkaline) H+ are reabsorbed fro mthe filtrate and returned to the blood and HCO3- are secreted into the filtrate.

4. Ridding the body of other excess ions (Ca and potassium)

Term
How would tubular srection raise blood pH?
Definition
H+ ions are secreted, HCO3- are reabosrbed
Term
Osmolality is similar to ?
Definition
tonicity
Term
What is the effect of Atrial Natriuretic peptide on the kidney?
Definition
Causes them to secrete (not reabsorb) more salt and therefore more water (increases urine volume, decreaes blood volume, decreaes blood pressure)
Term
ANP is the antagonist of what 2 hormontes?
Definition
Aldosterone, ADH
Term
How are urine volume and concentration regulated?
Definition

1. Adjust ADH and aldosterone levels

2. Maintain a medullary osmotic gradient (a salty medulla using the countercurrent multiplier mechanism)

Term
The solut eload of the body fluisd is around?
Definition
300 mOsm
Term
Filtrate entering the PCT is what compared to plasma and the surroudning cortex interstitail fluid?
Definition
isotonic
Term
The descending limb is impermeable to  what and permeable to waht?
Definition
impermeable to salt and permeable to water
Term
The ascending limb is impermeable to what and permeable to what?
Definition
The ascending limb is impermeable to water and premeable to salt
Term
The osmolality of the filtrate in the elbow of the loop of Hnle is about what?
Definition
1200 mOsm
Term
The osmolality of the interstitial fluid of the medulla is about what?
Definition
1200 mOsm
Term
The osmolalit of the filtrate at the DCT is about what?
Definition
100 mOsm
Term
The _______ limb prdocues salty filtrate (so water is returned tothe blood) and the __________ lim buses the high salt concentration to maintain the high osmolality of hte interstitail fuid of the __________
Definition

The descending  limb prdocues salty filtrate (so water is returned tothe blood) and the ascending lim buses the high salt concentration to maintain the high osmolality of hte interstitail fuid of the medulla

Term
Why do the vasa recta preserve and not destroy the medullary gradient?
Definition
Their walls are very porous so have the same osmolality as the tubule ( water and salt leave and enter the vasa recta as in the tuble)
Term
Ordinary capillaries would absorb massive amounts of what? destroying the medullary gradient?
Definition
salt
Term
How is dilute urine formed?
Definition
Previously described; kidneys allow hypoosmotic filtrate coming out of the DCT to continue out of the collecting ducts, calyces pelvis and urter, no adjustments need to be made in the collecting duct
Term
Urine is concnetrated where? under what influence?
Definition
Urine is concentrated in the collecitn ducts and under the influence of ADH
Term
Because water reabsorption depends on the presence of ADH this mechanism is called?
Definition
facultative water reabsorption
Term
Define renal clearance?
Definition
Renal clearance is the volume of plasma cleared of a substance in one minute
Term
Why are some drugs / toxins cleared from the blood more rapidly than woudl be possibe by just glomerular filtration?
Definition
Due to secretion (excretion for theses drugs woudl equal filtration + secretion)
Term
What protein carriers secrete thses drugs /toxins into the filtrate?
Definition
Organic anion transporters (OATS)
Term
They are able to acomplish this because they are
Definition
polyspecific (they can transport mroe than one kind of molecule)
Term
What is inulin and why is it used to calculate GFR?
Definition
Inulin is a plant compound tha tis only filtered (no reabsorption nor secretion
Term
Why is creatinine RC used more often than inulin to calculate GFR
Definition
It is naturally found in the blood and does not ahve to be infused into the patient as with inulin
Term
Why is thi smethod not as precise as the inulin method?
Definition
It is secreted in small amounts
Term
Abnormal decreases in GFR would do what to plasma creatinen levels?
Definition
increase plasma creatinine levels.
Term
What effects does an increase in plasma creatinine levels have on RC of creatinine?
Definition
RC would decrease (remember RC = the amount fo blood cleared in a minute; in this case less blood would be cleared of creatinin per minute b/c GFR is too low or too slow
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