Gastrintestinal And Genitourinary Tract Anatomy And Physiology Flashcards
Main function of GI tract
Digestion via chemical (enzymes) and mechanical (motility like chewing)
Then absorption- movement of small molecules across gut wall into circulation
Fight or flight vs rest and digest basically what stimulates and inhibits digestion?
Parasympathetic nerves stimulate digestion
Sympathetic nerves inhibit digestion
Via autonomous nervous system
Quick overview of journey from mouth to stomach
Chewing (mechanical) and amylase secreted (chemical) then bolus of food is swallowed down oesophagus and peristalsis moves it down GI tract(muscle contractions involuntary)
Stomach stores food and begins digestion mechanical and chemical
What does gastric juice consist of
HCL kills bacteria catalyses cleavage of pepsinogens to pepsin
Pepsinogen becomes pepsin via HCL and breaks proteins into peptides
Mucus to protect the mucosa
Gastrin hormone leads to acid production
Roles of small intestines and name of three regions
Duodenum jejunum and ilium
Digest and absorption of food and movement of material
Absorptive epithelium
What does duodenum receive from what organs?
Gall bladder secretes bile and receives secretions from pancreas exocrine gland consisting of water, ions bicarb (these neutralise) and enzymes for digestion
Endocrine gland releases glucagon and insulin
Where does enzymatic digestion take place
Enzymatic digestion takes place in duodenum and jejunum enzymes provided by pancreas
Then absorbed by microvilli that are one cell thick
Large intestine regions and function/ facts
Removes water salts sugar and vitamins
Regions:Cecum which compresses material into shit
Ascending colon transverse colon descending colon sigmoid colon and rectum
Also tightly packed mucosa- goblet cells for mucus and teeming with bacteria
Vermiform appendix facts
Worm shaped
Possible function of storing good bacteria and lymphoid cells
Liver has a double blood supply name three blood vessels for it
Nutrient rich blood from intestines and oxygen rich blood from lungs
Hepatic artery oxygen blood
Portal vein nutrient rich blood
Hepatic vein deoxygenated blood leaves liver
Bike produced by liver stored in gall bladder
What are liver lobules and the portal triad?
Portal triad is bile duct portal vein and hepatic artery
Central canal is hepatic vein
The liver is divided into liver lobules
What is the livers main functions
Regulation of nutrient levels in the blood
Synthesis of plasma proteins and cholesterol
Detoxification of poisons
Breakdown of haemoglobin
Storage of nutrients vitamins and bile production
Main function of bile
Makes adequate pH for enzymes
Emulsification of fat to form Micelles
Excretion of waste products (cholesterol)
Bile delivered and neutralises chyme for pancreatic enzymes to work and fats emulsified for better digestion
Kidney main functions
Filters blood and regulate blood content and pressure
Regulate sodium and potassium and blood pH
Excrete urea and creatinine
Endocrine function is to produce hormones
What are the outer and inner region of the kidneys called
Outer region called cortex
Inner region called medulla
Both composed of nephrons
Nephrons functions
Also very complex with BOWMANS CAPSULE PCT LOOP OF HENLE DCT AND COLLECTING DUCT
Drain into calycles then ureters
Regulate concentration of water and soluble substances
Reabsorption of ions
Excretion of urine
What’s in the bowman’s capsule
Ball of capillaries (glomerulus) sits on the bowman’s capsule( acts as a strainer)
Fenestrations (small holes for water solutes and proteins)
Endothelial cells for larger proteins
What happens after plasma is filtered in bowman’s capsule
Reabsorption from nephron back into the plasma then secretion from plasma into the nephron for excretion
Where can Reabsorption take place?
In PCT loop of henle, DCT and collecting ducts
Describe micrurition
Urine storage and release is controlled
Stretch receptors indicate when 300ml of urine has accumulated
Coordinated control of bladder requires detection of fullness sphincter control contraction of bladder smooth muscle
