A&P Unit 5 Test

kidney function

regulation total body water volume

kidney function

acid base balance

kidney function

excreting metabolic wastes, toxins, drugs

ureters function

transport urine form kidneys to urinary bladder

urinary bladder function

temporary storage reservoir for urine

urethra function

transport urine out of body

perirenal fat capsule

a layer of supportive tissue around the kidney; protects

renal cortex location

superficial region of kidney

renal medulla location

deep to cortex

renal columns location

inward extensions of cortical tissue that separate pyramids

minor calyces location

subdivides from major calyx

major calyces

branching extensions from renal pelvis

nephrons

structural and functional units that filter blood and form urine

glomerulus

provides efficient formation of filtrate

glomerulus capsule

surrounds the nucleus

proximal convoluted tubule

reabsorbing H₂O, NaCl, and nutrients back into the bloodstream

nephron loop

pick up water and solutes reabsorbed from filtrate, formation of concentrated urine

distal convoluted tubule and collecting duct

reabsorption is hormonally regulated

cortical nephron function

filter urine

cortical nephron location

almost entirely in the cortex

cortical nephron anatomy

has a short nephron loop, a glomerulus further from the cortex medulla junction, and efferent arteriole supplying peritubular capillaries

juxtamedullary nephron function

filter and concentrate urine

juxtamedullary nephron location

inner medulla

juxtamedullary nephron anatomy

has a long nephron loop, glomerulus closer to the cortex medulla junction, and efferent arteriole supplying the vasa recta

peritubular capillaries

pick up water and solutes reabsorbed from filtrate (returning them to blood); arise from efferent arterioles and empty into nearby venules

vasa recta

pick up water and solutes reabsorbed from filtrates, involved in the formation of concentrated urine

juxtaglomerular complex location

most distal part of the ascending limb

juxtaglomerular complex purpose

important in regulating rate of filtrate formation and BP

macula densa

act as chemoreceptors that monitor NaCl content of filtrate entering DCT

granular cells

act as mechanoreceptors that monitor blood pressure

glomerular filtration

filtrate formed as blood is filtered through the glomerulus and through the filtration membrane into the glomerular capsule and into the tubules

tubular reabsorption

solutes and water are reabsorbed, the majorit of what is filtered through is reabsorbed

tubular secretion

through the influence of hormones like ADH and aldosterone but also others, solutes are secreted back into the tubules

filtration membrane location

between blood and lumen of glomerular capsule that excludes blood proteins and cells

filtration membrane purpose

allows water and solutes smaller than plasma proteins to pass into the capsule

hydrostatic pressure in glomerular capillaries

the force pushing water and small solutes out of capillaries

hydrostatic pressure in the capsular space

pushes out fluid pressure of filtrate

colloid osmotic pressure in glomerular space

pulling in plasma proteins

glomerular filtration rate

volume of filtrate formed per minutes by both kidneys

anuria

abnormally low urinary output; may indicate glomerular BP too low to allow filtration

diffusion

movement of solutes from an area of higher concentration of solutes to an area of lower concentration of solutes

osmosis

the movement of water; water moves from area of low concentration of solutes to higher concentration of solutes in order to "dilute" the solutes and equal the concentration

concentration gradient

where there are different concentrations of solutes

tubular reabsorption

reclaims most of the filtrate including water and solutes, returning them to the blood

tubular reabsorption

Na⁺ are key, water and other solutes follow sodium

tubular reabsorption

fat soluble substances can follow back into the blood making it difficult to excrete lipid-soluble drugs and environmental pollutants

proximal convoluted tube

region most active in reabsorption; normally reabsorbing all glucose and amino acids and most uric acid from filtrate before it leaves

ADH functions

inhibits diuresis which increases BP and blood volume

aldosterone

causes reabsorption of Na⁺ which raises BP by increasing blood volume

atrial natriuretic peptide

inhibits reabsorption of Na⁺ which lowers BP by lowering blood volume

parathyroid hormone

increase calcium reabsorption which decreases phosphate reabsorption

tubular reabsorption is important for

disposing of substances, such as certain drugs and metabolites, that are bound to plasma proteins

tubular reabsorption is important for

eliminating undesirable substances or end products that have been reabsorbed by passive processes

tubular reabsorption is important for

ridding body of excess K⁺

tubular reabsorption is important for

controlling blood pH by altering amounts of H⁺ or HCO₃^- excreted in urine

osmotic gradients

in the renal medulla is essential for concentrating urine

osmotic gradients

occur in the juxtamedullary nephrons that have long nephron loop

internal urethral sphincter

controlled by ANS (involuntary)

external urethral sphincter

voluntarily controls urination

intracellular fluids

found inside of the cells

extracellular fluids

found outside the cells (plasma and interstitial fluid)

electrolyte

compounds that dissociate into ions and water (conduct an electrical current)

examples of electrolytes

inorganic salts, acids, bases, some proteins

nonelectrolyte

molecules (mostly) organic that do not dissociate into charged particles

examples of nonelectrolytes

glucose, lipids, creatine, urea

main extracellular ion

Na⁺

main intracellular ion

K⁺

obligatory water loss

explain why we cannot live without water very long

insensible water loss

across skin and airways

sensible water loss

from urine, sweat, and feces

dehydration

cell shrink; weight loss, mental confusion, hypovolemic shock

hypotonic hydration

cells swell; metabolic disturbances, nausea, vomiting, muscular cramping

edema

accumulation of interstitial fluids; tissues swell, not cells

chemical buffers

system of one or more compounds (combing weak acid and weak base) that resist pH changes when a strong acid or base is added

respiratory system

eliminates CO₂ from blood

CO₂ unloading

reaction shifts left (H⁺ incorporated in H₂O)

CO₂ loading

reaction shifts right (H⁺ buffered by proteins)

renal mechanisms

most potent, but requires hours to days to correct acid-base imbalance

respiratory acidosis

CO₂ in the blood is too high causing pH to drop because CO₂ is acidic

causes of respiratory acidosis

failure of respiratory system to perform pH, hypoventilation, asthma

respiratory alkalosis

CO₂ in the blood is too low causing pH to increase

respiratory alkalosis causes

hyperventilation, pneumonia, sepsis

metabolic acidosis

low pH and HCO₃ ^- (bicarbonate) is too low; bicarbonate is a base

metabolic acidosis causes

too much alcohol, excessive loss of CO₃^-, lactic acid, ketosis is diabetic crisis or starvation, kidney failure

metabolic alkalosis

high pH and bicarbonate is too high

metabolic alkalosis causes

vomiting, intake of excess bases