Lecture 9: Urinary System Flashcards Preview

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Flashcards in Lecture 9: Urinary System Deck (32):
1

Kidney general function

FILTER plasma constituents from blood, then selectively REABSORB water and useful constituents from filtrate, then EXCRETE the excess

2

kidney location

dorsal part of abdominal, on each side of aorta and vena cava, ventral to lumbar vertebrae
-in cows the LEFT kidney is pushed to the middle by the stomachs

3

Renal hilus

concave depression of kidney, where blood vessels and nerves enter ureter and lymphatics leave

4

Renal pelvis

expanded origin of the ureter within the kidney
-receives urine from the collecting tubules of the kidney
-not all species have a pelvis

5

Major calyces

openings from medulla to renal pelvis

6

Medulla

portion surrounding the renal pelvis
-striated appearance due to radially collection of tubules that form the renal pyramids
-medulla contains the loop of henle

7

Cortex

located on top of the medulla
-granular appearance due to many renal corpuscles/nephrons
-proximal and distal convoluted tubules are located in cortex

8

How much of total blood supply goes to kidneys?

about 1/4

9

Blood vessels supplying kidneys: arteries and afferet arterioles

two renal arteries enter the hilus and divide into a number of large branches, the arcuate arteries, and afferent arterioles, each of which branch to form capillary networks called GLOMERULUS

10

Arteriae rectae

capillary network surrounding the nephron, collecting tubules, and loop of henle

11

Efferent arterioles

-efferent arteriole leaves the glomerulus and forms the capillary network surrounding the nephron called ARTERIAE RECTAE

12

arcuate vessels

artery and vein that border the cortex and medulla

13

Nephron

functional part of the kidney
-includes the glomerulus, glomerular (Bowman's) capsule, proximal and distal convoluted tubules

14

artery path:

interlobar arteries-arcuate arteries-interlobular arteries-afferent arterioles

15

Venous drainage pathway

venae rectae-arcuate veins-interlobar veins, and renal vein
lymph drains from kidney to the renal lymph nodes

16

Renal plexus

supply of sympathetic nerves connected to kidney
-follows blood vessels and terminate mainly at glomerular arterioles
-Vagus nerve may also supply

17

ureters

muscular tube that carries urine from the pelvis of kidney to the bladder

18

urinary bladder

hollow, muscular organ that varies in size depending on amount of urine
-as the bladder fills the walls become thinner, and most of the bladder is displaced up cranially toward the abdominal cavity, as it rests on the floor of the pelvis

19

bladder has a sphincter to...

control passage of urine into urethra at the neck of the bladder

20

pelvis, ureter, bladder, and urethra are all lined with what?

transitional epithelium

21

Micturition

expulsion of urine from the bladder
-a reflexive activity stimulated by distention/stretching of bladder
-voluntary control of the external sphincter around the neck of the bladder can prevent emptying reflex

22

Functions of the kidney

-excretion of waste products
-maintenance of homeostasis: the condition of internal environment including water balance, pH, osmotic pressure, electrolyte levels, and concentration of many plasma substances

23

glomerulus

network of capillaries (a tuft) at the beginning of the nephron, where filtration occurs

24

Glomerular capsule

the blind end of the tubule that surrounds the glomerulus
-visceral layer surrounds the capillaries, while the parietal layer is continuous with the proximal con. tube.

25

renal (malphighian) corpuscle, filtration part of nephron

part of the nephron. the complex of the glomerulus and the glomerular capsule
-where filtration of fluid from blood occurs
-approx. 100 times as much fluid passes through this filter as is eventually excreted
-blood pressure must be kept high to filter that quickly, which is ensured by capillaries being closer to an artery than a vein

26

Both arterioles control glomerular have smooth muscle in order to

control glomerular pressure

27

juxtaglomerular cells

present in afferent arterioles approaching glomerulus
-surrounded by a cuff of myoepithelial cells (act like both smooth muscle and epithelium)
-sites of RENIN production

28

myoepithelial cells

act like smooth muscle and epithelium
-surround the juxtaglomerular cells, which are the site of renin production

29

Stimulus of renin production

-fall in blood pressure in afferent arteriole
-decrease in plasma sodium concentration
-decrease in distal tubular osmolarity
-stimulation of sympathetic nerve fibers supplying afferent arterioles

30

Function of renin

-acts on globulin-angiotensinogen to produce angiotensin

31

angiotensin

-acts as a vasoconstrictor to increase blood pressure
-acts on adrenal gland to secrete ALDOSTERONE, which causes kidney to conserve sodium

32

aldosterone

increases sodium uptake from distal convoluted tuble and increased water uptake to increase blood pressure