anatomy and histology of the kidney

Question 1

5 segments defined by

Answer 1

non-anastomosing blood supply

Question 2

5 segments

Answer 2

apical 
upper
middle
lower 
posterior

Question 3

nerve supply

Answer 3

vasomotor

ie. if you have a transplant you need hormonal control

Question 4

parasympathetic innervation

Answer 4

vagus increases renal arterial flow

increase in glomerular filtration rate

Question 5

sympathetic innervation

Answer 5

lesser splanchnics

T10-11 via aorticorenal plexuses

Question 6

gross renal anatomy

Answer 6

renal lobes = cortex medullary pyramid

Question 7

cortex

Answer 7

outer tissue with renal column extensions (into medulla)

glomeruli and convoluted tubules (proximal/distal) + medullary rays

Question 8

medulla

Answer 8

pyramids contain the long tubules of the nephrons

loop of henle and collecting ducts and papilla

Question 9

medullary pyramid

Answer 9

papilla and pyramidal body and medullary rates (in cortex)

Question 10

nephron

Answer 10

1 million/kidney

Question 11

6 major components of a nephron

Answer 11

1. bowman’s capsule
2. glomerulus
3. proximal convoluted tubule
4. loop of henle
5. distal convoluted tubule
6. collecting ducts

Question 12

process of making urine

Answer 12

filter of the blood - glomerular filtration, BP dependant
reabsorb water salts and glucose
secrete some proteins - notable creatinine

Question 13

passive mechanisms

Answer 13

counter current flow between peritubular capillaries and tubules
concentration gradient established by selective transporters
osmosis and diffusion

Question 14

glomerulus

Answer 14

multi layered electro mechanical filter, representing joining of filtration and excretion side of system

Question 15

filtration side

Answer 15

coiled fenestrated capillary (70-90nm)

Question 16

3 cell types in the filtration side

Answer 16

mesangial cells
juxtaglomerular cells
macula densa

Question 17

excretion side

Answer 17

basement membrane and 2 sides of bowman’s capsule cells
parietal - cells of capsule wall
visceral - podocytes and their pedicel extensions

Question 18

cortical nephrons

Answer 18

short loops of henle

• glomeruli found further away from medulla
• mid cortical is a hybrid of cortical and juxta

Question 19

juxtaglomerular nephrons

Answer 19

at junction of cortex and medulla
loops of henle descend deeper into medullary pyramid
distal convoluted tubule interacts with afferent arteriole

Question 20

the deeper into the medullary pyramid

Answer 20

the higher the concentration of salts around the tube become

Question 21

proximal convoluted tubule

Answer 21

high amount of active transport 
high surface area = microvilli 
lots off mitochondria 
large irregular shaped cells 
few nuclei in cross section

Question 22

distal convoluted tubule

Answer 22

no microvilli
more nuclei in tubular cross sections
outer diameter often roughly equal to inner diameter of PCT
less active transport - less machinery in cell

Question 23

loop of henle

Answer 23

proximal thick segment
distal thick segment
thin segments have simple sqmaous epithelium

Question 24

collecting ducts

Answer 24

inner diameter roughly equal to out diameter of DTT/DCT
still cuboidal with crisp liminal surface
sensitive to aldosterone

Question 25

ureter

Answer 25

transitional epithelium
protects against stretch
stratified squamous near extorting opening - distal urethra

Question 26

layers of the ureter

Answer 26

mucosa

muscular externa - inner circular and out longitudinal

Question 27

ureter moves urine by

Answer 27

peristalsis

Question 28

urethra moves urine by

Answer 28

bladder and abdominal pressure

Question 29

tracing the ureter

Answer 29

passes through retroperitoneal fat

crosses the pelvic brim at bifurcation of common iliac arteries

Question 30

blood supply of the ureter

Answer 30

upper ureter - branches from renal arteries

lower ureter and bladder - branches from vesicular arteries

Question 31

nerve supply of the upper ureter

Answer 31

parasympathetic - vagus

sympathetic - least splanchnic

Question 32

nerve supply of the lower urete r and bladder

Answer 32

parasympathetic - pelvic splanchnics
via hypogastric plexus 
detrusor contraction of smooth muscle 
carry stretch afferents 
sympathetic - sacral splanchnic L1/2 spinal nerves - tighten sphincter

Question 33

micturition reflex

Answer 33

stretch triggers detrusor contraction

felt as an urge to pee, but can be consciously overridden

Question 34

4 surfaces of the pyramid

Answer 34

2 lateral - against the pubic bones
superior - covered in peritoneum
posterior - receives ureters