Liver, Kidneys And Pancreas Flashcards
What is the key function of the liver, kidneys and pancreas?
Liver detoxifies blood, kidneys filter out waste substances + homeostasis, pancreas controls blood sugar levels.
What are the 4 main functions of the liver?
Detoxification
Storage of glycogen
Digestion - produces and secretes bile
Deamination of aa
What is the physiology of the liver?
Liver lobes made up of hepatic lobules, formed from hepatocytes. Sinusoids run between columns and contain blood from hepatic artery and portal vein.
Kupffer cells = type of macrophage.
What are the functions of the pancreas?
Endocrine - produces hormones
Exocrine - produces digestive substances, with Islets of Langerhans
What is the physiology of the kidneys?
Outer cortex and inner medulla. Collecting tubules from medulla drain into minor calyces - drain into major calyces, drain into renal pelvis.
What are the functions of nephrons?
- filtration
- reabsorption
- secretion
What is glomerular filtrate rate (GFR)?
Amount of liquid passing from glomerulus to BC via ultrafiltration.
What are the 2 types of reabsorption?
Between cells/paracellular - PCT
Through cells/transcellular - passive transport, AT etc.
What are features of the PCT?
Site of maximal reabsorption. Perm to water, not salt.
Na+ and Cl- absorbed and water follows by osmosis. Almost all glucose and aa by cotransport.
What are the features of the loop of Henle?
Has ascending and descending limb. Counter current hairpin system maximises reabsorption of water.
What are the features of the DCT?
Imperm to water, perm to salts. Reabsorbs Na+ and Cl-, in exchange for H+ and K+.
What are the features of the collecting duct?
Imperm to water. Filtrate drains into renal calyces and then ureter. Reabsorbs water in response to ADH.
How does the bladder function?
Urination aka micturition. Reflex as bladder tries to automatically empty when full. Stretch receptors in bladder signal spinal cord, walls contract and sphincters relax.
Inhibited by brain signals, takes time to develop.
