Urinary System Flashcards
What is the general overview + pathway of the urinary system?
What is the function of the urinary system?
- water and electrolyte homeostasis
- filtration of cellular wastes from blood
- selective reabsorption of water/solutes
- regulation of fluid balance
- maintain electrolyte homeostasis/acid-base balance
- excretion of metabolic waste products, bioactive substances (including drugs), and excess water
- production of hormones: renin + erythropoietin
- regulation of blood pressure
- juxtaglomerular apparatus
- activation of vitamin D
What are some clinical signs of renal and non-renal diseases related to the kidneys?
What is the basic structure of the kidney?
- capsule
- renal lobe/pyramid
- outer cortex
- inner medulla
- papillae/crest
- calices (dilations of renal pelvis)
- pelvis (dilation of proximal ureter)
Kidneys are composed of lobes that may be?
- single, multiple, or fused
What kinds of lobes are shown?
- unilobular: typical of carnivores
- multilobular: typical of large ruminants (each lobe is distinctly outlined by deep grooves, lacks a renal pelvis)
- multilobular: kidney of pig
What are the important tissues of the kidney?
What are features of the nephron?
- the functional unit of the kidney
- site of osmoregulation via:
- filtration of water and small molecules from blood plasma to form a filtrate
- selective reabsorption of most of the water and other molecules from the filtrate
What are important structures in the regions of the kidney?
- cortex
- renal corpuscles
- proximal tubules
- distal convoluted tubules
- collecting tubules
- peritubular capillary plexuses
- medulla
- loops of Henle
- collecting ducts
- vasa recta
What is this structure? What are some visible features?
- renal cortex
- renal corpuscles
What structure is shown? What are features indicated?
- renal cortex
- renal corpuscle
- proximal tubules
- distal convoluted tubules
What is the renal corpuscle composed of?
What is this? What are some features? What is its main function?
- glomerulus of a renal corpuscle
Describe filtration at the glomerulus
What is indicated in this image? What is its function?
- podocytes
- filtration
What are the 3 components of the filtration barrier? What is the outcome?
- ENDOTHELIUM of glomerular capillary loops (CL) w/ fenestrations
- glomerular BASEMENT MEMBRANE (GBM) =fused basal laminae of capillaries and podocytes
- PODOCYTES with pedicels (foot processes)
- outcome: albumin and larger molecules are retained, all smaller molecules cross freely with ultrafiltrate
What kind of endothelium is in kidneys?
- fenestrated
What feature is shown in the image?
- glomerulus of kidney
What are the steps of urine formation?
- primary/glomerular filtrate is produced by ultrafiltration of blood in renal corpuscle
- composition of ultrafiltration is similar to blood plasma, it does NOT contain most proteins
- Reabsorption of most substances: 98% of filtrate reabsorbed (most of water and NA+, all glucose and amino acids)
- tubular secretion: K+, H+, NH4+, bile salts, drug metabolites
- waste molecules + some water remain in tubular system and eventually empty into ureter, urine stored in bladder pending voiding/micturition
What are features of mesangial cells?
- phagocytic
- contractile
- support
- mesangial cells+ matrix = mesangium
What animals do not have glomerulus?
- teleostei fish
- renal tubule instead