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90 Cards in this Set
- Front
- Back
what is cardiac output and its formula
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volume of blood ejected by each ventricle per unti time
CO- H.R x SV |
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Heart rate
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number of heart beat per time
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Stroke Volume
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volume of blood ejected by each ventricle/beat
SV= EDV-ESV |
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End diastolic volume
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blood in ventricle at end of diastole
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End systolic volume
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blood in ventricle at end of systole
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Name the main parts and location of the human heart
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what is cardiac output and its formula
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volume of blood ejected by each ventricle per unti time
CO- H.R x SV |
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Heart rate
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number of heart beat per time
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Stroke Volume
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volume of blood ejected by each ventricle/beat
SV= EDV-ESV |
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End diastolic volume
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blood in ventricle at end of diastole
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End systolic volume
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blood in ventricle at end of systole
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phase 4- resting potential exists across a cell mebrane due to the concentration gradiets of ions in and outside the cell relative to each other
phase 0 rapid rise of sodium in the cell and rise in calcium channels phase 1- repolirarization due to closing of sodium channels phase 2- plateau phase consist of slow repolirization due to the slow decrease in calcium channels closing and potassium remains lower than its resting value phase 3- increaseing rates of calcium and an increase in potassium in the cell |
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what are the factors that regulate the heart rate
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the rytthmicity of the heart us determined by the AP of the SA node mostly the rate of phase 3 action potential
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what is the most important specialization of cardiac cells
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they do not require signals from nerve fibers to generate action potentials and the also have properties of automaticity and gap junctions that allow the heart to behave electrically as a functioal syncytium
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What is the above system describing and be very specific
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The intrinsic conduction system is a group of specialized cardiac cells that pass an electrical signal throughout the heart. This ensures that heart muscle tissue depolarizes and contracts in a sequential manner (from atria to ventricles) resulting in a coordinated heart beat. The intrinsic conduction systme is composed of the SA (sinoatrial) node, the AV (atrioventrical) node, the bundle of His, right and left bundle branches, and the Purkinje fibers. Referring to the figure below, you can see that these components spread the depolarization waves from the top (atria) of the heart down through the ventricles. In a healthy heart, this highly coordinated series of events happens correctly and the heart ejects blood efficiently to ensure proper blood flow to the entire body.
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what makes the autonomic nervous special when talking about the neuronal connectivity
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they are arranged of ganglion that gives better control of the nervous system
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what are the effectors of SNS and ANS
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skeletal mucles
cardiac muscle smooth muscle and glands |
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what os the role of the parasympathetic division
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concerned with keeping the body energy use low involves digestion defacation and diuresis does not innervate muscle skin nor both blood vessels
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what is the role of the sympathetic division
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is involved in the fight or flight respons exercise excitement emergency and embarrassment
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explain how one can tell whether or not we are looking atatomically at a parasympathetic or sypathetic region
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well in parasympathetic the preganglionic cell bodies of nuclei of brainstem is mostly in the cranial and sacral regions of the vertebra and ganglionis near the organ while sympathetic is in the lumber region with short preganglion and long postganglion
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what are the two types of neurons and how are the chemical function different
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cholinergic neurons and adrenergic neurons they are different because of the receptors that they bind too C. nicotinic and muscarinic releasing Acetylcholine A, alpha and beta receptors release norepinephrine
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parasympathetic neurotransmitters pre and post ganglion release which chemical
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pre release acetylcholine and have cholinergic nicotinic receptors and post release acetylcholine and are muscarinic receptors
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what are the pre and post receptor chemicals post release norepinephrone
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release norepinephrone
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what chemical will increase the heart rate and contractility of the ventricles
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norepinephrine
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define the segments of the EKG waves
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p wave- corresponds to the depolirization of SA node
QRS is the ventricular depolarization T wave ventricular repolization atrial repoliration record is masked by the larger QRS complex |
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the determines the PR interval
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AV delay
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diastole
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relaxation of the heart muscle "filling"
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Systole
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contraction of the heart muscle "ejection"
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Frank starling effect
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When the diastolic filling of the heart is increased or decreased with a given volume, the displacement of the heart increases or decreases with this volume.
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describe phase 1 of the cardiac cycle
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Av valves open and semilunar valves closed
This phase is noted by the p wave on the ECG representing the depolarization of the atria this causes the contraction of the atria which forces blood into the ventricle most blood passively flowed the little pressure can be noted as the a wave after this contraction the pressure of the atria falls and AV valves close and at this time ventricular volumes are at its maximum end diastolic volume |
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phase 2 of cardiac cycle
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Isovolumetric contraction
All valves are closed This begins with the QRS complex representing ventricle depolarization closure of all valves you can hear the first heart sound during this time ventricular pressure rises rapidly without a change in volume it can not change because all valves are closed (isovolumic) |
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phase 3 of cardiac cycle
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Rapid ejection
Aortic and pulmonic valves open; AV valves remain closed this phase represents the rapid ejection of blood to the aorta and pulmonary arteries from the left and right ventricles. Ejection begins when the intraventricular pressure exceeds the pressure within the aorta and pulmonary artery which causes the aortic and pulmonary valves to open no heart sounds should be noted if there are sounds disease |
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phase 4 cardiac cycle
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Reduced Ejection
Aortic and Pulmonic valves are open; AV valves remain closed Ventricular repolarization occurs which is shown by the T wave outflow of blood but decline in ventricular tension is taking place rate of ejection falls left and right atrial pressures gradually rise due to continuous venous return from the lungs and systemic circulation |
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phase 5 of cardiac cyclce
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isovolumetric relaxation
All valves are closed When the intraventricular pressures falls sufficiently at the end of phase 4 the aortic and pulmonary valves close and this is the second heart sound there is a small backflow of blood into the ventricles and a characteristic notch in the aortic and pulmonary artery pressure the volume of blood that remains in the ventricle is called the end systolic volume The left atrial pressure continues to rise because of increased venous return from the lungs v wave |
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phase 6
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Av valves open
As the intraventricular pressures continue to fall below atrial pressures AV valves will rapidly open and ventricular filling will begin despite the inflow of blood from atria the intraventricular pressure is still falling because ventricles are still undergoing contraction when they are completely relaxed that is when the pressure will begin to rise |
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phase 7
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As the filling process continues the ventricles become less compliant and intraventricular pressure increase aortic pressure and pulmonary pressures continue to fall during this period
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The space in the middle of the thoracic cavity where the heart resides is the:
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mediastinum
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The foramen ovale in the fetal heart is located in the
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) interatrial septum
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If communication between the SA node and the AV node becomes blocked which is most certainly affected
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the ventricles will contract at a slower rate
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Which blood vessel does NOT bring blood directly to the heart:
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great cardiac vein
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If there is a blockage between the AV node and AV bundle, how will this affect the appearance of the ECG
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there would be more P waves than QRS complexes
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What effect would compressing the inferior vena cava just below the diaphragm have on cardiac function
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a) stroke volume would decrease
b) cardiac output would decrease c) sympathetic stimulation of the heart would eventually increase d) heart rate would eventually increase |
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A valve damaged by rheumatic fever fails to open completely. This is called
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stenosis
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According to Starling's Law of the heart, cardiac output is directly related to:
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amount of blood returning to the heart
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A patient with CAD (coronary artery disease) is experiencing severe angina and self-administers sublingual nitroglycerin. This will act as a(n):
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coronary vasodilator
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The T wave on an ECG represents::
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ventricular repolarization
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During ventricular systole
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the AV valves are closed
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The blood vessels that play the most important role in the regulation of blood flow to a tissue and blood pressure are the
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arterioles
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The internal carotids and the basilar artery are interconnected by an anastomosis call the:
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circle of Willis
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As blood travels from the aorta to the capillaries
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resistance increases
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what are the factors that affect stroke volume
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preload, contractility, afterload
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what are some ways to regulate heart rate
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The increase in contractility is independent of the stretch of the heart and usually comes from certain hormones and calcium and increase sympathetic activation
Regulation of heart rate There are positive chronotropic factors that can increase heart rate while there are negative chronotropic factors that can decrease the heart rate |
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what two hormones increase heart rate
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epinephrine results and a fast heart rate and the thyroxine slower more sustained heart rate
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atherosclerosis
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is the narrowing of the lumen and this produces murmors
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Vascular Compliance
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The ability of a blood vessel wall to expand and contract passively with changes in pressure is an important function of large arteries and veins. This ability of a vessel to distend and increase volume with increasing transmural pressure (inside minus outside pressure) is quantified as vessel compliance (C), which is the change in volume (DV) divided by the change in pressure (DP).
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what is autoregulation
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is the manifestation of local blood flow regulation it is defined as the intrinsic ability of an organ to maintain a constant blood flow despite changes in perfusion pressure and occurs independently of hormonal and neural influences
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Sympathetic adrenergic nerves
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travel along arteries and nerves and are found in the adventitia (outer wall of a blood vessel). Varicosities, which are small enlargements along the nerve fibers, are the site of neurotransmitter release. Capillaries receive no innervation. Activation of vascular sympathetic nerves causes vasoconstriction of arteries and veins mediated by alpha-adrenoceptors.
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Parasympathetic fibers
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are found associated with blood vessels in certain organs such as salivary glands, gastrointestinal glands, and in genital erectile tissue. The release of acetylcholine (ACh) from these parasympathetic nerves has a direct vasodilatory action (coupled to nitric oxide formation and guanylyl cyclase activation). ACh release can stimulate the release of kallikrein from glandular tissue that acts upon kininogen to form kinins (e.g., bradykinin). Kinins cause increased capillary permeability and venous constriction, along with arterial vasodilation in specific organs.
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myogenic mechanisms
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originate in smooth muscle of blood vessels particularly in small arteries and arterioles
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describe the gross anatomy of the kidney
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The urinary system of the human body consists of two kidneys, two ureters, the bladder and a single urethra.
The kidneys are located on the posterior wall of the abdomen at waist level. Each kidney is roughly 10 cm long and 5 cm wide, and is encased in a fibrous outer capsule called the renal capsule. The main function of the kidneys is to control blood volume and composition. They do this by filtering the blood to remove waste products, salts and water. These are secreted in the form of urine. |
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what makes the kidney or vascular component different from other organs
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they have two arteriole afferent and efferent and two capallaries (glomerular, peritubular)
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The Glomerulus
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The glomerulus is the main filter of the nephron and is located within the Bowman's capsule. The glomerulus resembles a twisted mass of tiny tubes through which the blood passes. The glomerulus is semipermeable, allowing water and soluble wastes to pass through and be excreted out of the Bowman's capsule as urine. The filtered blood passes out of the glomerulus into the efferent arteriole to be returned through the medullary plexus to the intralobular vein.
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the tubular component of a nephron
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composed of segments which differ functionally along its length it starts at the bowmans capsule then proximal convoulted tube the the loop of henle into the collecting dock
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the vascular component
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the connection between the renal artery and the nephron is an ateriole called afferent arteriole followed by glomerular capallaries these empty in efferent arteriole supplying the second capallaries (peritubular) this drains into the veins
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why is blood pressure in the glomerulus high
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arterioles are high resistance vessels and the afferent arterioles have larger diameters than efferent arterioles
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peritubular beds
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low pressure porous capillaries adapted for absorption
arises from efferent arterioles cling to adjacent renal tubules empty into the renal venous return |
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vasa recta
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long straight efferent arterioles of juxtamedullary nephron
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breifly state the path of bloof flow in kidney
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renal artery-->afferent arteriole--> glomerulus--> efferent arteriole-->vasa recta--> vein
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what is the GFR equal to
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K=(deltaP-deltaii
k change in permeability p hydrostatic pressure ii oncotic pressure |
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normal values
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Gfr=125
rpf=630 ml/min filtration fraction= gfr/rpf=20 percent |
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What is the importance of the renal capsule
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to cover and protect the kidney
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what is a nephron
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the functional unit of the kidney
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what is the renal pyramid
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where all nephrons are located
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renal cortex
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is the outer layer of the kidney
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medulla
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is the inner layer of the kidney
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what is the function of the calyx
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is where urine is collected from the nephrons
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renal pelvis
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is where urine is collected from calyx before emptying to ureter
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vasa recta
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long straight efferent arterioles of juxtamedullary nephrons
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peritubular capallary beds function
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they are low pressure porous that arise from efferent arterioles and cling to adjacent renal tubules and empty into the renal venous system
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filtration membrane
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lies between the blood and the interrior of the glomerular capsule
composed of three layers fenestrated endothelium of the glomerular capillaries visceral membrane basement membrane composed of fused basal laminae of the other layers |
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glomerular filtration
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movement of protein free plasma from the glomerulus to bowmans capsule
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tubular secretion
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amount of substance that moves from the tubule to peritubular capillaries this movement is through the interstitial fluid
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what is the formula for amount excreted
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amount filtered + amount secreted- amount reabsorbed
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How can the size and charge of a particle change filterability ex (Dextran)
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increase the size and negative charge it you will decrease filterability
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why does oncotic pressure increase through the capillaries
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because the filtering fluid concentration increases along the capillary to achieve a balance of forces
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what happens constrict afferent arterioles
Pgc, RPF, GFR, FF(GFR/RPF) |
Pgr decrease
RPF decrease GFR decrease FF stays the same |
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what happens when you constrict efferent arterioles
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Pgr increase
RPF decrease GFR increase or stays the same FF increase |
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what happens when you dilate arterioles
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Pgr increase
RPF increase GFR increase FF stays the same |
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dilate efferent arterioles
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Pgr decrease
RPF Increase GFR decrease or stays the same FF decrease |
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tubuloglomerular feedback
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alteration of tubular flow is sensed by the macula densa of the juxtaglomerular appartus and produces a signal that alters GFR it is unclear if it is renin of reabsorption of NaCl
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