a4: Digestive system, Metabolism, Nutrition and Urinary System Flashcards
define metabolic rate?
energy released in body per unit of time
- measured as calories/per
define metabolism:
all chemical reactions in the body
balance between catabolic(breakdown) and anabolic(create)
define nutrition:
process of providing or obtaining food(nutrients) for health and growth
define catabolism:
the breakdown of molecules
define anabolism:
creation of molecules
what is metabolic rate?
= BMR(basal metabolic rate) + energy used in physical activity + thermic effect of food
what effects metabolic rate?
thyroid activity amount of muscle vs. fat temperature illness age, genes, dieting
what controls appetite?
hypothalamus
name the main nutrients:
water, carbohydrates, lipids, proteins, minerals, vitamins
describe the metabolism of carbohydrates(sugars):
complex sugars are ingested (glycogen)
- > stored in cells as complex sugars in the liver (glycogen)
- > broken into simple sugars in the small intestine (glucose)
what are lipids? give examples
organic compounds that cannot dissolve in water
eg. triglycerides, fatty acids, steroids, phospholipid cell membrane
describe transport of lipids:
lipids do not dissolve in plasma, so it is difficult to move lipids via blood
-> solution? surround lipids with proteins -> LIPOPROTEINS!
they can now travel freely in blood and recognise target cells
name types of lipoproteins:
Chylomicrons
Very Low Density Lipoproteins (VLDL)
Low Density Lipoproteins (LDL)
High Density Lipoproteins (HDL)
where does absorption of lipid take place?
small intestine!
function of liver
process, work out what you’ve ingested
eventually gets access to all of the nutrients
where are each of the lipoproteins produced?
Chylomicrons = small intestine
VLDL & HDL = liver
LDL = after fat deposited into adipose tissue
functions of urinary system?
filtration of blood plasma
regulates blood volume
regulates blood pressure
releases hormones
steps of sinus drainage?
minor calyces
major calyces
renal pelvis
ureter
what is the general structure of a nephron?
glamerulus(afferent & efferent blood vessel) -> glamerular capsule -> proximal convoluted tubule -> loop of henle [vasa recta in between loop] -> distal tubule -> collecting duct
function of nephron?
filter blood plasma, create urine to expel waste products
where does filtration occur in the nephron?
renal corpuscle
where does resorption occur in the nephron?
renal tubule
structure of glomerular filtration membrane?
fenestrated blood vessel wall
negatively charged basement membrane
layer of podocytes
function of glomerular filtration membrane?
restricts passing of cells and large proteins
allows passing of plasma, sugar, water, small proteins, waste products, salts, amino acids
what force drives filtration in glomerular corpuscle?
high blood pressure within glomerular capillaries
describe the micturition reflex:
(1) receptors detect stretch -> message sent to spinal cord
(2) Reflex action(message bounces back from spinal cord…micturition reflex)
(3) bounce back message tells bladder to contract & internal urethral to relax
(4) after baby age, message also sent to brain, then bounces back down telling external urethral to relax or contract
