ANATOMY: RENAL/URINARY SYSTYEM

Question 1

What are the functions of the kidney?

Answer 1

Functions:

• Waste removal (excretion)
• Blood pressure regulation

– By renin angiotensin system (RAS)

– Renal resistance adjusting, therefore, peripheral vascular resistance

• Blood volume regulation

– Water conserving or eliminating

• Vitamin D activation

– By hydroxylation

• Red cell production

– Production of erythropoietin

• Plasma modification

– Ion composition

• Especially sodium, potassium, chloride, phosphate

Question 2

What is the hilus?

Answer 2

In the kideny the hilus contains the port of entry for the renal artery and the port of exit for the renal vein & ureter

hilus - an indentation in the surface of a kidney, spleen, or other organ, where blood vessels, ducts, nerve fibers, etc., enter or leave it.

Question 3

What is the difference between the glomerulus and the glomerular?

Answer 3

Glomerulus: a cluster of capillaries around the end of a kidney tubule, where waste products are filtered from the blood.

• Tuft of capillaries
• The site of filtration of the plasma.

Glomerular / Bowman’s Capsule: A glomerulus and its surrounding Bowman’s capsule constitute a renal corpuscle, the basic filtration unit of the kidney. The rate at which blood is filtered through all of the glomeruli, and thus the measure of the overall renal function, is the glomerular filtration rate (GFR).

• Double layered conduit into which the filtered plasma enters
• Parietal layer
• Visceral layer

Question 4

What does the renal tubule consist of?

Answer 4

Consists of:

– Proximal Convoluted Tubule

– Loop of Henle

• Thick descending limb
• Thick ascending limb

– Distal convoluted Tubule

The renal tubule consists of long, fine, convoluted tubules conveying urine from the glomeruli to the renal pelvis in the vertebrate kidney. Water and salts are reabsorbed into the blood along their length.

The nephron is the basic structural and functional unit of the kidney. Its chief function is to regulate the concentration of water and soluble substances like sodium salts by filtering the blood, reabsorbing what is needed and excreting the rest as urine.

Question 5

What is the proximal convoluted tubule?

Answer 5

the convoluted portion of the vertebrate nephron that lies between Bowman’s capsule and the loop of Henle and functions especially in the resorption of sugar, sodium and chloride ions, and water from the glomerular filtrate https://www.brainscape.com/decks/4598747/cards/171560080/edit#

Question 6

What is the Juxtamedullary Nephron?

Answer 6

Juxtamedullary Nephron

– Few

– Renal Corpuscles

• in inner cortex near the medulla

– Loop of Henle

• Long
• Extension deep into the medulla

Question 7

What is the Cortical Nephron?

Answer 7

Cortical nephrons

– The Majority

– Renal corpuscles

• in the outer part of the cortex

– Loop of Henle

• Short
• Located mainly in the cortex with superficial extension into the medulla

Question 8

What are two types of collecting ducts in the renal system?

Answer 8

• Cortical Collecting Ducts:

– Each DCT empties into collecting tubules in the cortex

• Medullary Collecting Ducts:

– In the medulla the smaller collecting tubules join the collecting ducts

– @ the apex of the renal pyramid, they join larger ducts, Papillary ducts or ducts of Bellini

Papillary (collecting) ducts are anatomical structures of the kidneys, previously known as the ducts of Bellini. Papillary ducts represent the most distal portion of the collecting duct system. They receive renal filtrate (precursor to urine) from several medullary collecting ducts and empty into a minor calyx. Papillary ducts continue the work of water reabsorbtion and electrolyte balance initiated in the collecting tubules.

Question 9

Describe the ureters.

Answer 9

Ureters…

• From the kidneys to the bladder
• The muscular conduit for urine
• Paired retroperitoneal muscular tube
• Epithelium = transitional

Question 10

What are the three major areas of constriction in the ureters? (sites for potential obstruction of kidney stones)

Answer 10

3 constrictions:

1. At the UPJ (ureteropelvic junction): between the ureter and renal pelvis
2. At the pelvic brim: as it enters at the pelvic outlet
3. At the UVJ (ureterovesical junction): the port of entry of the ureters into the bladder wall

Question 11

What is the detrusor?

Answer 11

Detrusor

• smoothe muscle contracts to squeeze urine out
• autonomic innervation

Question 12

What is the sphincter urethrea? (aka external urethral spincter)

Answer 12

• skeletal muscle
• innervated by pudendal nerve

Voluntary

Question 13

What are the two regions of the kidney?

Answer 13

Each kidney is divided into two regions: the outer renal cortex and the inner renal medulla.

The renal cortex contains the:

• Glomeruli
• Convoluted tubules
• Cortical collecting ducts

The renal medulla contains the:

• Loops of Henle
• Medullary collecting ducts

Projections of the renal medulla form pyramids, topped by papilla.

• Each papilla drains urine into a minor calyx, which convene to form a major calyx.
• The major calyx drains urine into the ureters, and subsequently, the bladder.

Question 14

The kidney has 2 capillary beds in series; what are their names?

Answer 14

The kidney is relatively unique as it has 2 capillary beds arranged in series: glomerular capillaries and peritubular capillaries.

Glomerular capillaries are high pressure, allowing filtration of solute and water out of the systemic bloodstream and into the urine.

Peritubular capillaries are low pressure, allowing reabsorption of solute and water from urine into the systemic bloodstream.