a4: Digestive system, Metabolism, Nutrition and Urinary System

Question 0

define metabolic rate?

Answer 0

energy released in body per unit of time

- measured as calories/per

Question 1

define metabolism:

Answer 1

all chemical reactions in the body

balance between catabolic(breakdown) and anabolic(create)

Question 2

define nutrition:

Answer 2

process of providing or obtaining food(nutrients) for health and growth

Question 3

define catabolism:

Answer 3

the breakdown of molecules

Question 4

define anabolism:

Answer 4

creation of molecules

Question 5

what is metabolic rate?

Answer 5

= BMR(basal metabolic rate) + energy used in physical activity + thermic effect of food

Question 6

what effects metabolic rate?

Answer 6

thyroid activity
amount of muscle vs. fat
temperature
illness
age, genes, dieting

Question 7

what controls appetite?

Answer 7

hypothalamus

Question 8

name the main nutrients:

Answer 8

water, carbohydrates, lipids, proteins, minerals, vitamins

Question 9

describe the metabolism of carbohydrates(sugars):

Answer 9

complex sugars are ingested (glycogen)

• > stored in cells as complex sugars in the liver (glycogen)
• > broken into simple sugars in the small intestine (glucose)

Question 10

what are lipids? give examples

Answer 10

organic compounds that cannot dissolve in water

eg. triglycerides, fatty acids, steroids, phospholipid cell membrane

Question 11

describe transport of lipids:

Answer 11

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

Question 12

name types of lipoproteins:

Answer 12

Chylomicrons
Very Low Density Lipoproteins (VLDL)
Low Density Lipoproteins (LDL)
High Density Lipoproteins (HDL)

Question 13

where does absorption of lipid take place?

Answer 13

small intestine!

Question 14

function of liver

Answer 14

process, work out what you’ve ingested

eventually gets access to all of the nutrients

Question 15

where are each of the lipoproteins produced?

Answer 15

Chylomicrons = small intestine
VLDL & HDL = liver
LDL = after fat deposited into adipose tissue

Question 16

functions of urinary system?

Answer 16

filtration of blood plasma
regulates blood volume
regulates blood pressure
releases hormones

Question 17

steps of sinus drainage?

Answer 17

minor calyces
major calyces
renal pelvis
ureter

Question 18

what is the general structure of a nephron?

Answer 18

glamerulus(afferent & efferent blood vessel) -> glamerular capsule -> proximal convoluted tubule -> loop of henle [vasa recta in between loop] -> distal tubule -> collecting duct

Question 19

function of nephron?

Answer 19

filter blood plasma, create urine to expel waste products

Question 20

where does filtration occur in the nephron?

Answer 20

renal corpuscle

Question 21

where does resorption occur in the nephron?

Answer 21

renal tubule

Question 22

structure of glomerular filtration membrane?

Answer 22

fenestrated blood vessel wall
negatively charged basement membrane
layer of podocytes

Question 23

function of glomerular filtration membrane?

Answer 23

restricts passing of cells and large proteins

allows passing of plasma, sugar, water, small proteins, waste products, salts, amino acids

Question 24

what force drives filtration in glomerular corpuscle?

Answer 24

high blood pressure within glomerular capillaries

Question 25

describe the micturition reflex:

Answer 25

(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