RENAL ANATOY AND PHYISOLOGY

Question 1

ANATOMY OF THE KIDNEYS

Answer 1

• 2 kidney
• between T12 & L3
• shape: bean
• colour: reddish brown
• Hilum: exit, entrance
• Most have 2
• Some people can be born with one kidney
• size: palm (like clenched fist)

Question 2

LOCATION OF KIDNEYS

Answer 2

Question 3

ATERIORAL VIEW OF URINARY TRACT

Answer 3

Question 4

SUPPORTIVE STRUCTURES

Answer 4

• renal capsule (fibrous & transparent outer coat)
• adipose capsule (fatty mass, holds the kidney in place against the trunk muscles)
• renal fascia (dense fibrous connective tissue anchors the organs to surrounding structures & encloses the adrenal gland)
• adrenal glands - produce various hormones: corticosteroids, glucocotricoids, testosterone)

Question 5

CORTEXT

Answer 5

CORTEXT - outer segment of the kidney 7 contains the capsule, which contains the glomeruli = the main functional unit of the kidney
MEDULLA: inner segment of the kidney made up of renal pyramids and renal columns
contains: loop of Henle, structures responsible for selection (reabsorption of ions & filtration of electrolytes, waste products & water)
PELVIS: made from calyx, feeds into the collecting ducts, attaches onto the ureters, which drain the resultant urine into the bladder

Question 6

KIDNEY BLOOD VESSELS

Answer 6

• The kidneys gain 25% of the cardiac output

Question 7

NEPHRONE

Answer 7

• each kidney = system of neuphtrones - collecting ducts functional part of the kidney
• GLOMERULUS - special capillary bed of interconnecting loops surrounding by bowman’s capsule = filiting the blood
• PROXIMAL TUBULE: reabosrbtion
• DISTAL TUBULE: filtering/secretion

Question 8

NEPHRONES

Answer 8

CORTICAL NEPRONS: shorter loops of henle, filtration of waste chemicals & toxins
- JUXTAMEDULLARY NEUPHRONES: deep loop of henle into the medulla invovled in concentrating the filtrate
- foudn there focused on primary fucntion based on their adapted strcutres

Question 9

GLOMERULUS

Answer 9

• Fenestrations stop passages from blood cells
• Basement membranes stop the passage of everything but the smallest protein
• helped by podocytes

Question 10

JUXTAGLOMERULAR APPARATUS

Answer 10

juxtaglomerular apparatus = macula densa & juxtaglomerular cells
- The nephron portion of the ascending limb of the loop of Henle makes contact with the afferent arterioles
- tubular cells: columnar & crowded cells called MACULA DENSA
- modified smooth muscle fibres called JUXTAGLOMERULAR CELLS

Question 11

THE BLADDER

Answer 11

• wall (stretch) epithelial lining

Question 12

EMBRYOLOGY

Answer 12

developments starts in week 4
pronephros
mesonephros
metanephros
ascents of kidney

Question 13

EMBRYOLOGY

Answer 13

pronephros: develops during the 4th week of uterine development; if it does, then it’s not functional
MESONEPHROS: The 2nd kidney that is functional starts to produce urine between 6-10 weeks, evident in week 12
METANEPHROS: The permanent kidney develops in week 5, leading to the development of ‘ureteric duct” emerged the urete, renal pelvis, calyces, bladder, renal tubules, collecting ducts

Question 14

DIFFERENCE BETWEEN MALE AND FEMALE:

Answer 14

Question 15

ASCENT OF THE KIDNEY

Answer 15

6th - 9th week, the kidney moved through the abdomen to react to its position
- process = complicated & malformations = happen

Question 16

FUNCTIONS OF THE KIDNEY

Answer 16

FLUID BALANCE
TOXIC WASTE REMOVAL
ELECTROYLTE BALANCE
BLOOD PRESSURE CONTROL
ACID BASE BALANCE
VIT D METABOLISM
RED BLOOD CELL PRODUCTION

Question 17

FUNCTIONS OF THE KIDNEY

Answer 17

• These functions happen because the kidneys act as a filter
• filtering out substances in blood & substances leave the body in urine
• The kidney control how much substance leaves the body in urine

FLUID BALANCE
TOXIC WASTE REMOVAL
ELECTROLYTES BALANCE
ACID BASE BALANCE

Question 18

ELECTROLYTES

Answer 18

potassium
sodium
calcium
chloride
magnesium
phosphate

Question 19

TOXIC WASTE

Answer 19

UREA: from protein metabolism
CREATININE: muscle metabolism

Question 20

ACID BASE BALANCE

Answer 20

ACID: hydrogen H+
ALKALINE (BASE): BICARB

Question 21

Filtration, Tubular Reabsorption and Secretion

Answer 21

• golmerulus
• proximal tubule
• loop of henle
• distal tubule
• collecting duct
• Blood enters via renal artery
  Capillary meets Nephron in the renal corpuscle
  Blood filtrate enters nephron – 180 litres / day are filtered
  Reabsorbtion of water nutrients, Na and Cl- these re-enter blood
  Secretion of toxins, drugs ( and variable secretion of water , sodium and calcium ions)
  Urine leaves kidney via collecting duct ( some reabsorbtion) Calyx,
  Ureter
  Bladder
  Entire plasma volume is filtered 65 times a day

Question 22

GLOMERULAR FILTRATION RATE

Answer 22

• the amount of plasma filtered through the glomeruli per unit of time
• normal in adults = 80-120
• autoregulation

Question 23

PROXIMAL TUBULE

Answer 23

Reabsorption:
Sodium & water (50-60%)
Potassium (50%)
Calcium, Magnesium (60%)
Phosphate (75%)
Bicarbonate(80-90%)
Glucose (Near 100%)
Amino acids. (Nearly 100%)
Pars recta is the straight part the tubular fluids osmolarity as it leaves the PT is the same as plasma

Question 24

LOOP OF HENLE

Answer 24

• concentrates the urine
• water is removed from the filtrates and reabsorbed into the blood
• sodium
• chloride

Question 25

NEUPHRON

Answer 25

Distal Convoluted Tubule: Electrolyte reabsorption Collecting Ducts: Water reabsorption. Several hormones act on the DCT and Collecting Ducts.

Question 26

HORMONES ACT ON DCT AND COLLECTING DUCTS

Answer 26

Question 27

TUBULAR SECRETION

Answer 27

Some substances are secreted into the tubule from the blood Hydrogen Potassium Creatinine Ammonium ions Urea Organic acids

Question 28

NON-REABSORBED SUSBTANCES

Answer 28

SUSBANCE CANT BE ABSORPED IF THEY ARE: To big. Not lipid soluble. Lack of carrier molecules. Urea, some is reabsorbed by solvent drag but 50% is not. 100% Creatinine remains unabsorbed.

Question 29

MICTURITION (PASSING URINE)

Answer 29

1. Bladder fills and stretches 2. Nerve impulse to spinal cord 3. Nerve impulse back to bladder - relaxation of internal sphincter 4. Conscious contraction of external sphincter. In infants nerve impulse (3) causes involuntary bladder contraction Infants do not have conscious control of external sphincter control (4)

Question 30

BLOOD PRESSURE

Answer 30

Kidneys control blood pressure by maintaining fluid balance. Also, control blood pressure by a complex system called: renin-angiotensin-aldsterone system

Question 31

Juxtaglomerular apparatus= Macula Densa and Juxtaglomerular cells

Answer 31

- In each nephron final portion of ascending limb of loop of henle makes contact with afferent arteriole - Tubular cells here different- columnar and crowded and called MACULA DENSA - Along side wall of afferent arteriole contains modified smooth muscle fibres called JUXTAGLOMERULAR CELLS (JG)

Question 32

Renin-angiotensin-aldosterone system

Answer 32

INCREASE IN BLOOD PRESSURE Red blood cells production Erythropoietin - stimulates bone marrow to produce red blood cells. Vitamin D production

Question 33

AGE RELEATED CHANGE IN KIDNEY FUNCTION

Answer 33

Week 10 gestation filtration of fluid and urine production begins. At 1 year- kidney function is that of an adult Natural decline in kidney function from 40 years old

Question 34

AGE-RELATED CHANGE IN THE BLADDER

Answer 34

Decline in ability to inhibit bladder contraction Urgency Frequency Nocturia Incontinence