Exam 4 terms Flashcards
(123 cards)
1
Q
Hemodynamics
A
Are the 2 principles that describe the movement of blood in the circulatory system.
2
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Resistance
A
is the tendency of the cardiovascular system to oppose blood flow.
3
Q
Laminar flow
A
When blood flows in a long smooth vessel it streamlines into layers with the contents of each layer staying the same distance from the vessel wall. the innermost layer has the least resistance; the outermost has the most
4
Q
Velocity of flow
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is the distance that a fixed volume of bloodtravels in a given period of time (cm/sec or cm/min).v = Q/A
5
Q
Mean arterial pressure (MAP)
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s blood pressure in the large arteries averaged over time MAP= DBP+ (SBP–DBP)/3
6
Q
Diastolic arterial pressure
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the lowest arterial blood pressure of a cardiac cycle occurring during diastole of the heart
7
Q
Systolic blood pressure
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the highest arterial blood pressure of a cardiac cycle occurring immediately after systole of the left ventricle of the heart
8
Q
Sphygmomanometer
A
Arterial blood pressure is commonly measured in the brachial artery using this
9
Q
Total peripheral resistance (TPR)
A
he resistance to blood flow imposed by friction between the flowing blood and the walls of all of the vessels within the systemic circulatory route. TPR= Rarteries+ Rarterioles+ Rcapillaries+ Rvenules+ Rveins
10
Q
cardiac output (CO)
A
The amount of blood ejected by the left (or right) ventricle into the aorta (or pulmonary trunk) per minute.
11
Q
Stroke volume
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(volume per beat) ×Heart Rate (HR; beats/min)
12
Q
heart rate
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beats/min
13
Q
Frank-Starling law
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The volume of blood ejected by the ventricle (SV) depends on the volume present in the ventricle at the end of ventricular diastole
14
Q
End diastolic volume (EDV)
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Same as Frank-Starling law
15
Q
Preload
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Same as Frank-Starling law
16
Q
skeletal muscle pumping (milking)
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Contraction of skeletal muscles pumps blood in the veins back to the heart. Valves in the veins keep the blood moving toward the heart.
17
Q
Respiratory pump
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caused by movements of the diaphragm during breathing
18
Q
Cardiovascular center (CVC)
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ANS control of CO comes primarily from here (CVC) located in medulla oblongata (and pons) of the brainstem.
19
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Cardiac accelerator nerves
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Sympathetic neurons extend from the CVC down the spinal cord and emerge out of sympathetic trunk ganglia) as the cardiac accelerator nerves that innervate the SA and AV nodes, and most portions of the ventricular myocardium
20
Q
baroreceptors
A
pressure receptors in the aorta and carotid arteries
21
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chemoreceptors
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in the aorta and carotid arteries monitor chemical changes in blood (pH, CO2, O2) and under certain conditions can initiate neural reflex pathways that control HR
22
Q
capillary bed
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extensive branched network of capillaries where exchange occurs
23
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Capillary filtration (bulk flow)
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s the mass movement of fluids (and solutes) between the blood and IF as a result of the hydrostatic and osmotic pressure gradients that exist across the walls of the capillaries
24
Q
Starling forces
A
the 4 fources that drive bulk flow: -Capillary hydrostatic pressure (P_c) -Interstitial fluid hydrostatic pressure (P_if) -Plasma colloid osmotic pressure(or oncotic pressure)(pi_p) -Interstitial fluid colloid osmotic pressure (pi_if)
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capillary hydrostatic pressure (P_c)
is the blood pressure in the capillary bed. It varies depending on arterial pressure, venous pressure, precapillary and post-capillary resistance. (37-17mm Hg)
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Interstitial fluid hydrostatic pressure (P_if)
is extremely low (≈1 mm Hg)throughout the capillary bed under normal conditions.
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Plasma colloid osmotic pressure (pi_p)
Osmotic pressure created by the presence of non-filterable proteins in the plasma. (25mm Hg)
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Interstitial fluid colloid osmotic pressure (pi_f)
Osmotic pressure created by the presence of non-filterable proteinsin the plasma. (0mm Hg)
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Ultrafiltration
Net exchange pressure= (37 +0) –(1+ 25)= 11 mm Hg which means ultrafiltration occurs in the arteriolar end. (usually exceeds reabsorption by 3L/day
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Reabsorption
Net exchange pressure= (17 +0) –(1 + 25) = -9 mm Hgwhich means reabsorption occurs on the venular end
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Net exchange pressure
= (P_c+ pi_if) –(P_if+ pi_p)
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edema
Excessive accumulation of interstitial fluid in a tissue
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lymphatic capillaries
are closed-ended vessels found widely dispersed in the capillary beds of most tissues.
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lymph
Once interstitial fluid (containing its solutes and particulates)enters the lymphatic capillaries, it is referred to as lymph
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lymphatics
contain a system of one-way valves and movement of lymph is driven by skeletal muscle contractions, lymphatic vessel contraction, andtissue pressure. There is no dedicated pumpfor lymph circulation
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lymph nodes
act as lymph filters to remove foreign particles like bacteria and viruses and to help orchestrate immune responses to pathogens.
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pathogens
disease causing microorganisms
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bacteria
unicellular prokaryotic organisms that are capable of living outside of a host, or within the tissues (extracellular) and cells (intracellular) of a host (e.g. E. coli, Salmonella).
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viruses
obligate intracellular pathogens consisting of a nucleic acid core(DNA or RNA)surrounded by a protein coat (e.g. Influenza virus is an RNA virus, Herpes virus is a DNA virus).
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parasites
both unicellular and multicellular eukaryotic organisms that are capable of living outside of a host, or within tissues (extracellular) and cells (intracellular) of a host (e.g. protozoa like amoeba(dysentery) or plasmodium (malaria);worms like tape worms and roundworms)
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innate immune system
(Nonspecific defenses): Inherited defense mechanisms thatd o not distinguish between specific pathogens
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adaptive (or acquired) immune system
(Specific defenses or Immunity): Defenses against specific types of pathogens.
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Cytokines
Low molecular weight proteins(over 100 have been identified)that usually act in a paracrine or autocrine fashion to regulate the intensity and duration of immune defenses.
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infection
When the physical barriers that protect the surfaces of the animal are breached by a pathogen, infection of the underlying tissues takes place. Infection leads to activation of both innate and adaptive immune systems.
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Inflammation or inflammatory response
An orchestrated host response that occurs at the site of pathogenic infection.This response is usually strongest for bacterial infections.
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phagocytes
Cells that engulf (eat) and destroy pathogens or other cellular debris.
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diapedesis (extravasation)
Some phagocytes, like neutrophils and monocytes, along with lymphocytes are attracted to sites of inflammation by chemotaxis (movement of cells toward chemical attractants).
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opsonization
is the process of targeting cells for phagocytic destruction by tagging the pathogen’s cell surface with eitherbound: 1)Antibodies (Ab)released as part of the specificimmune response or 2)Complement proteins
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phagocytosis
ll eating”is the process by which phagocytes engulf (eat) and then destroy pathogens (and other particles).
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complement
A component of the innate defenses consisting of plasma proteins designated C-1 to C-9 (essentially proteases madeby the liver)
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fever
elevation of the set point for body temperature
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endogenous pyrogens
cytokines released from macrophages in response to the presence of bacterial components like endotoxin from gram-negative bacteria. These pyrogens stimulate the anterior hypothalamus to elevate the set point for body temperature.
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interferons
alpha-Interferons are cytokines, released by virally infected cells, thatact as messengers to neighboring cells making them resistant to viral infection
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Natural killer (NK) cells
lymphocytes that constantly monitor the body’s tissues for cells with abnormal antigens on their surfaces like tumor (cancer) cells or virus-infected cells. Does not need prior contact and can kill tumor cells
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antigens
Foreign (“nonself”) molecules that stimulate the activation of the immune system. Antigens are either molecules released by the pathogen or molecules on the surfaceof an invading pathogen
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T-lymphocytes (T-cells)
Lymphocytes that move from bone marrow and seed thymus gland become T-cells. Unlike B-cells, T-cells do not secrete Ab into body fluids (humors). Instead, T-cells provide cell-mediated immunity for an organism.
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Major Histocompatability complex (MHC) proteins
Family of cell surface markers (proteins) that are involved in presenting processed antigens to T-cells.
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Killer (cytotoxic) T-cells
Destroy infected host cells. After binding to the infected host cell, killer T-cells secrete perforins,which are proteins that form pores in the cell membrane leading to fluid influx and lysis (death)of the infected cell
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Helper T-cells
Indirectly participate in immune protection by regulating response of both killer T-cells and B-cells to pathogens.
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B-lymphocytes (B-cells)
Provide humoral immunity. combat pathogenic infections by secreting antibodies (Ab) into body fluids or humors (blood and lymph) that then target the pathogen for destruction by other components of the immune system (e.g. phagocytes,complement)
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Plasma cells
Some activated B-cells become plasma cells that produce approximately 2000 Ab/sec to help combat the current infection.
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Antibodies (Ab)
Ab or immunoglobulins (gamma-globulins) are plasma proteins. All Ab molecules have a similar structure. However, each Ab has a variable region (Fab)that serves as a binding site for a specific antigen.
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Pulmonary ventilation
breathing---consists of alternating inspirations(breathing in) and expirations (breathing out), which moves air between the atmosphere and the alveoli of the lungs.
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inspiration
breathing in
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expiration
breathing out
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external (pulmonary) respiration
exchange of O2 and CO2 between air in alveoli of lungs and blood in pulmonary capillaries
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internal (tissue) respiration
exchange of O2 and CO2 between bloodin the systemic capillaries and the tissues cells
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emphysema
a condition in which the air sacs of the lungs are damaged and enlarged, causing breathlessness.
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pulmonary edema
fluid accumulation in the lungs
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Dalton's law of partial pressures
the sum of the partial pressures of all gases in a mixture equals the total pressure of the mixture.PB= PN2+ PO2+ PCO2+ PH2O
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Henry's law
The amount of gas that will dissolve in a liquid, like blood plasma, is proportional to: 1. The partial pressure (concentration) of the gas that the liquid is in equilibrium with.2. The solubility of the gas in the liquid Cx= Px× solubility
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Bohr shift
In an acidic environment (low pH, high [H+]), Hb’s affinity for O2is lower (right shift) making it easier for O2 to split from Hb. This occurs because excess H+bind to HbO2, promoting release of O2
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Chloride shift
s [HCO3-] builds up in RBC, bicarbonate is exchanged for plasma Cl-through the band III protein, a passive anion exchanger (antiporter). Thus, Cl-moves into RBCand HCO3-moves into the plasma
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Band III protein
a protein that assists in respiration
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Haldane effect
Binding of O2 to Hb facilitates release of CO2 from Hb. In the presence of low PO2(tissues), more CO2binds to Hb. In the presence of high PO2(lungs), less CO2binds to Hb
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Alveolar ventilation rate
(VA; volume of air inspired and expired into and out of the alveoli per unit time -usually ml/min) is tightly controlled, both with respect to breathing rate and tidal volume. VA = (VT–VD) × breathing rate VT is tidal volume; VD is deadspace volume
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respiratory center
located in the brainstem Respiratory center consists of widely dispersed groups of neurons in the medulla and pons.
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medullary rhythmicity center
Located in the medulla oblongata. Neurons in this center take the form of a central pattern generator that has intrinsic rhythmic activity that arises from pacemaker neurons with unstable membrane potentials (similar to SA nodein the heart).
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Dorsal respiratory group (DRG)
is the “respiratory pacemaker” and is located in the medulla oblongata. It is partof nucleus tractus solitarius
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ramp signal
Inspiration-Impulses are sent from the DRG to inspiratory muscles as a “ramp signal”. They last about 2sec; acts as a positive feedback loop
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ventral respiratory group (VRG)
Located in the medulla oblongata, contains both an expiratory and inspiratory centers that send signals along spinal nerves to expiratory muscles and some inspiratory muscles. This group is almost totally inactive during restful breathing. But, it becomes the primary driver of expiration during times of high alveolar ventilation rates(labored or forced breathing).
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central chemoreceptors
Primary controller of alveolar ventilation rate. These receptors are located in the “chemosensitive” area on the surface of the ventral medulla close to the cerebrospinal fluid (CSF)near the respiratory center.
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peripheral chemoreceptors
are found in the walls of aorta and carotid arteries, and are connected to the respiratory center by CN IX (glossopharyngeal) and CN X (vagus). These chemoreceptors monitor pH, PCO2, and PO2 of arterial blood.
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cough
sudden expulsion of air from the lungs that clears irritants from pharynx and lower respiratory system
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sneeze
sudden expulsion of air from the lungs that clears irritants from nasal cavity
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hiccup
an involuntary spastic contraction of the diaphragm accompanied by the closing of the glottis.
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yawn
a prolonged smooth contraction of inspiratory muscles usually triggered by fatigue or boredom.
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urea
Nitrogenous waste produced from ammonia using the urea cyclein the liver. Urea is less toxic to cells than ammonia. Most abundant organic waste in urine. 21 grams/day in humans
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creatinine
A waste product of the breakdown of creatine phosphate in skeletal muscles. 1.8 grams/day in humans.
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uric acid
Nitrogenous waste generated by the breakdown and recycling of RNA. 480 mg/day in humans
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glomerular filtration
is the forcing of fluids and solutesfrom theblood in the glomerular capillaries across the endothelial:capsular membrane into the surrounding Bowman’s capsule
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filtrate or ultrafiltrate
the fluid produced from glomerular filtration
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tubular fluid
When the filtrate enters the renal tubule of the nephron, it is commonly referred to as tubular fluid.
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glomerular blood hydrostatic pressure (GBHP)
Blood pressure within glomerulus drives fluid across the endothelial-capsular membrane into the surrounding Bowman’s capsule. the major driving force for filtrate formation. typically around 55 mm Hg,which is high relative to other capillary beds.
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capsular hydrostatic pressure (CHP)
Pressure in Bowman’s capsule due to previously filtered fluid in capsule and renal tubule. Typically, CHP = 15 mm Hg
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blood colloid osmotic pressure (BCOP)
The presence of un-filterable proteins in blood plasma makes the osmotic pressure of the blood in the glomerulus higher than the filtrate in the Bowman’s capsule. Typically, BCOP = 30 mm Hg
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net filtration pressure (NFP)
is the positive driving forces of filtration minus those forces that oppose filtration. NFP= GBHP -(CHP + BCOP)
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anuria
no urine production
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oliguria
reduced urine production
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glomerular filtration rate (GFR)
is the amount of filtrate formed in both kidneys per minute. GFR = 125 ml/min or 7.5 liters/h = 180 liters (50 gallons) per day.
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renal autoregulation
Control of the GFR through myogenic, paracrine and endocrine mechanisms centered within the kidney that are independent of outside control systems(e.g. nervous system).
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juxtaglomerular apparatus (JGA)
(JGA; juxta = near or close by) JGA modulates GFR by secretion of substances involved in controlling the diameter ofboth afferent and efferent arterioles
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renin
is a protease that cleaves angiotensinogen (a plasma protein produced by the liver)into angiotensin I.
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angiotensinogen
a plasma protein produced by the liver
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angiotensin I
As angiotensin Ipasses through the pulmonary capillaries, an enzyme called angiotensin-converting enzyme (ACE)cleaves it into angiotensin II, the active form of this hormone
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angiotensin-converting enzyme (ACE)
cleaves angiotensin I into angiotensin II (found in pulmonary capillaries)
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angiotensin II
increases blood pressure and blood volume
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antidiuetic hormone (ADH; also called vasopressin)
stimulates increased reabsorption of water from the filtrate in the kidneys, which decreases urine volume and helps to maintain blood volume
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aldosterone
a steroid hormone(mineralocorticoid),that enhances reabsorption of Na+by the principal cellsin the collecting ducts. Na+reabsorption leads to increased water reabsorption by osmosis, which helps to maintain blood volume
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obligatory water loss
Minimum production of urine (400 ml/day for humans) that is necessary to excrete metabolic wastes.
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tubular reabsorption
is the movement of components of the filtrate back into the blood in the peritubular capillaries.Fluid and solutes move from lumen of renal tubule (filtrate) into the peritubular capillaries (blood)
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Na+ -glucose symporters
a method to reabsorb nutrients via secondary active transport found in lumenal membrane of renal epithelial cells
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Na+ -amino acid symporters
a method to reabsorb nutrients via secondary active transport found in lumenal membrane of renal epithelial cells
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renal threshold
is the plasma concentration of a substance at which the substance begins to be excreted in the urine because its Tm has been surpassed
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glucosuria
(or glycosuria) is observed in diabetics. In diabetics, glucose enters the filtrate at a concentration above the Tm. As a result, not all the glucose is reabsorbed in the PCT. This means that glucose is present in the tubular fluid after the PCT where it serves as an osmolyte, which holds water in the tubular fluid.
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polyuria
increases in urine volume due to glucosuria
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polydipsia
increased thirst due to polyuria due to glucosuria
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countercurrent structure
is any set of parallel passages in which the contents flow in opposite directions. i.e. (Descending and ascending limbs of LOH, along with descending and ascending limbs of the vasa recta)
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principle cells
contain few microvilli and basolateral folds. In these cells, permeability to water and solutes is hormonally controlled(e.g. ADH and aldosterone
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intercalated discs
contain more microvilli than principal cells. Primary function is to actively secrete H+by primary active transport into the filtrate during period of acidosis.
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Law of Mass Balance
If the amount of a substance in an organism is to remain constant, any gain of that substance must be offset by an equal loss.
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aquaporins
increase in water permeability of principle cells is due to insertion of aquaporins into the lumenal membranes
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tubular secretion
is a process that moves solutes (that are not needed by the body) from the blood in the peritubular capillaries into the filtrate in the renal tubule (and subsequently to the urine). Tubular secretion occurs mainly in PCT, DCTand collecting duct
