Week 3 - renal system Flashcards
Learning Objective 1
List main functions of the urinary system and describe the gross anatomy of the kidney and a nephron.
Urinary system consists of
- Kidneys
- Ureters
- Urinary Bladder
- Urethra
Kidneys : Location
Located in the superior lumbar region
Situated against the posterior abdominal wall
Kidneys
Are retro-peritoneal membranes
- located behind the peritoneal membranes
Kidneys
Protected by
- Fibrous connective tissue capsule
- layer of perirenal fat
Kidneys
Supplied with blood through renal arteries
- derived from branches of the abdominal aorta
- blood drains through veins into inferior vena cava
Function of Kidneys
Regulation of fluid and electrolyte balance
- including solute content and therefore osmolarity of extra cellular fluid
Function of Kidneys
Excretion of metabolic wastes and foreign substances
- nitrogenous wastes e.g urea and creatine plus foreign wastes such as drugs
Function of pH (acid-base balance)
- By conserving or eliminating hydrogen (H+) and bicarbonate (HCO3-)
Function of the Kidneys
Maintenance of blood pressure
- through control of blood volume and production of renin
Function of the Kidneys
Regulation of erythropoietin
for stimulation of red blood cell cell production
Function of Kidney
Metabolic functions
- Activating vitamin D
- production of new glucose through gluconeogenesis when fasting/starving
Kidney : Gross anatomy
Three regions
- renal
- renal medulla
- renal pelvis
Kidney : Gross anatomy
Renal Cortex
- outer region containing cortical nephrons
Kidney : Gross anatomy
Renal Medulla
- cone shaped tissue called renal pyramids
Kidney : Gross anatomy
Renal Pelvis
- funnel shape continuous with ureter
- drains papillae into minor calyces, then into major calyces
The Nephron Function unit of the kidney
Nephron consists of
- renal corpuscle
- renal tubule
- renal corpuscle
- composed of tight collection or capillaries called glomerulus
- plus a surrounding glomerular (Bowman’s) capsule
Specialised for function
- The renal tubule
- Proximal tubule PT (proximal convoluted tubule)
- Nephron loop (loop of Henle)
- Distal tubule DT (distal convoluted tubule)
Reabsorption and secretion occur here.
Nephron drains into collecting dust CD
- not part of the nephron unit
Nephron : classes
Urine forming units of the kidney
Around 1 million per kidney
Divided into two type
- Cortical Nephron
- Juxtamedullary Nephrons
- Cortical nephrons
- found in renal cortex
