Case 3- renal anatomy Flashcards
Glomerulus
Where the blood is filtered to produce urine
Bowman’s capsule
Collection of glomerular filtrate
What’s absorbed in the Proximal tubules
Reabsorption of water, proteins, amino acids, glucose and carbohydrates
Loop of Henle
Creates Hypertonicity gradient (osmotic pressure) between the collecting duct and interstitium
Distal tubule- role
Controls pH and water balance. Absorption of water, Na+ and HCO3-. Excretion of K+ and H+
Collecting duct
Controlled reabsorption of water under the influence of ADH
Where are the nephrons locates
In the cortex or medulla, some cross both
Mesangium
Between the capillaries of the glomerulus, it provides support for the capillaries
Structure of Mesangium
Podocytes- interlocking foot like processes, provide epithelial lining for bowman’s capsule
Basement membrane- between the podocytes and fenestrated epithelium. Layers from outside in are the Lamina rara externa, the Lamina densa and the Lamina rara interna.
Fenestrated epithelium
Layers of the medulla
Outer and inner medulla
Juxtaglomerular apparatus
With the cortical labrynth. Mesangial cells and Lacis cells which are a type of Mesangial cell which provide support and have a role in the immune system. Juxtaglomerular cells secrete renin which regulates blood pressure in the kidneys.
What’s coarse control- renal
Happens in the proximal convoluted tubule, involves large amounts of reabsorption. Reabsorbs all glucose and most water, HCO3, Na and Cl.
Lower urinary tract
The pelvis of the kidney, urethra and ureter. Composed of the urothelium, which is surrounded by submucosa, then the loose spiral muscle (longitudinal) and tight spiral muscle (circular)
Lining of Glomerulus
The capillaries are surrounded by the fenestrated epithelium meaning it has holes in it, allowing filtration between the capillary walls.
Ureter structure
Contains smooth muscle so urine can be passed down by peristalsis, has ‘star-shaped’ lumens
Bladder layers
Contains the urothelium, then the submucosal layer (fibrocollagen) and the smooth muscle which has three layers. The smooth muscle and urothelium allow the bladder to extend when full.
Urothelium
Structure changes depending on the volume of urine. Its impenetrable to urine. Its in its non-distended state when it is empty, its in its distended state when full of urine and the cells are flattened.
Structure of urothelium
Are a type of stratified epithelium. On the top you have the umbrella (dome) cells, they are binucleated and are flattened in distension. They are large and rounded in non-distension. You then have intermediate cells which are polygonal and basal cells which are cuboidal at the bottom.
Structure of glomerular filtration barrier
Glycocalyx- luminal surface of endothelial cells in the capillaries of the Glomerular, negatively charged so repels large negatively charged proteins
Fenestrae- openings between the endothelial cells in the Glomerular, water and small molecules pass through. Increases permeability of barrier
Glomerular basement membrane- made of collagen, laminin, fibronectin and proteoglycans. Barrier to filtration. Negatively charged so repels negative particles
Podocytes- foot processes which interlock. Forms filtration slit, negatively charged
Peritoneum
A thin serous membrane which lines the abdominal cavity and produces serous fluid
Function of peritoneum
Provides serous fluid for lubrication, helps facilitate movement of the organs i.e. in peristalsis
Structure of Peritoneum
Has two layers. The visceral peritoneum covers the abdominal organs the parietal peritoneum which lines the abdominal cavity. Both layers are continuous with each other. The viscera peritoneum can be either intraperitoneal or retroperitoneal
Peritoneal cavity
The potential space between the two peritoneum layers, contains a small amount of serous fluid but is empty. The peritoneal reflections and the viscera divide the cavity into compartments.
Intraperitoneal
When the organs are completely surrounded by the peritoneum. Includes the liver, spleen, gallbladder, stomach, and most of the small and large intestine.