Extretory System

Question 1

homeostasis

Answer 1

an organism’s ability to maintain a constant internal environment

Question 2

what does the internal environment involve

Answer 2

tempetature, fluid balance, chemistry in the body

Question 3

excretion

Answer 3

the removal of waste products of metabolism from the body

Question 4

what are the organs of excretion

Answer 4

skin
lungs
kidneys

Question 5

how does the excretory system play a role in homeostasis

Answer 5

by regulating body temp-skin
by maintaining fluid balance

Question 6

what is the largest organ in our body?

Answer 6

the skin

Question 7

what do the kidneys produce

Answer 7

urine

Question 8

what is urine made up of

Answer 8

urea, water, salt

Question 9

what does the skin excrete

Answer 9

sweat (water and salt)

Question 10

what do the lungs excrete

Answer 10

co2 + water vapour

Question 11

what do the kidneys excrete

Answer 11

urine

Question 12

what are the 2 layers of the skin

Answer 12

epidermis
dermis

Question 13

what is the epidermis made up of

Answer 13

malpighian layer
granular layer
cornified layer

Question 14

where is the epidermis

Answer 14

outer layer

Question 15

what does the malpighian layer produce

Answer 15

new cells due to lots of mitosis

Question 16

what does the granular layer produce

Answer 16

keratin produced causing cells to harden

Question 17

what does the cornified layer produce

Answer 17

cells die and shed

Question 18

melanin

Answer 18

pigment that gives us our skin colour
produced by specialised cells in the Malpighian layer

Question 19

what is the dermis made of

Answer 19

connective tissue and collagen

contains: sweat glands, hair follicles, sebaceous glands

Question 20

functions of the skin

Answer 20

protection
sense organ
vitamin D production
food storage
excretion of water and salts
temperature regulation

Question 21

what is the subcutaneous layer?

Answer 21

lies beneath the dermis. contains adipose tissue that protects internal structures and insulates the body

Question 22

how much does temperature fall by when sleeping

Answer 22

1 degree

Question 23

why does body temperature fall at night

Answer 23

because less respiration is happening

Question 24

why does our temperature rise when we are sick?

Answer 24

to destroy the invaders

Question 25

what things cause slight temperature fluctuations

Answer 25

puberty, menopause, menstrual cycle

Question 26

vasodilation

Answer 26

blood vessels in the skin expand and move closer to the surface of the skin causing heat loss and cooling us down

Question 27

sweat

Answer 27

salt and water released through pores onto skin. water evaporates off the surface of the skin cooling us down

Question 28

why is it important to drink fluids during and after excersise?

Answer 28

water lost through sweating must be replaced to maintain water balance

Question 29

piloerection

Answer 29

erector muscle contracts which cause hairs to stand up. a layer of warm air is trapped close to the surface of the skin by the hairs reducing heat loss

Question 30

vasoconstriction

Answer 30

blood vessels in the skin contract and move away from the surface of the skin when we are cold to reduce heat loss

Question 31

shivering

Answer 31

is the brains response to cold temperature is to cause muscles to contract and relax rapidly to raise body temperature

Question 32

what does the ureter do

Answer 32

carries urine from kidneys to bladder

Question 33

what does the urethra do

Answer 33

takes urine out of the body

Question 34

where is urea made?

Answer 34

the liver

Question 35

what is urea composed of

Answer 35

excess amino acids

Question 36

what is the kidneys' job

Answer 36

to filter the blood

Question 37

where does filteration occur

Answer 37

cortex

Question 38

where does reabsorption occur

Answer 38

medulla

Question 39

what molecules are too large to be filtered from the blood?

Answer 39

red blood cells and proteins

Question 40

what filters out of the blood?

Answer 40

amino acids, water, glucose, urea salts

Question 41

why is it important for glucose to be reabsorbed

Answer 41

if it is not, it is an indication of diabetes

Question 42

where is the bowmans capsule

Answer 42

cortex

Question 43

where is the loop of henele

Answer 43

medulla

Question 44

where is the distal/ convoluted tubules

Answer 44

medulla

Question 45

where exactly does filtration and reabsorption occur?

Answer 45

the nephron

Question 46

where in the nephron does filtration occur

Answer 46

bowmans capsule

Question 47

where in the nephron does reabsorption occur

Answer 47

proximal + distal convoluted tubules

Question 48

how many nephrons are there in each kidney

Answer 48

approx 1 million

Question 49

what is a nephron

Answer 49

structure in the kidney that filters blood and produces urine

Question 50

describe how filtration occurs in each nephron

Answer 50

bowman's capsule surrounds a glomerulus. here smaller molecules in the blood are forced under pressure out of the plasma forming the glomerular filtrate

Question 51

what is the glomerulus

Answer 51

a ball of capillaries

Question 52

what is glomerular filtrate

Answer 52

substances that have been removed from the blood

Question 53

how does the glomerulus help filtration

Answer 53

high pressure large surface area walls that are one cell thick

Question 54

describe how reabsorption works in the nephron

Answer 54

the body reabsorbs most of the glomerular filtrate back as it cannot afford to lose the useful chemicals

Question 55

describe the proximal convoluted tubule's role in reabsorption

Answer 55

most water reabsorbed by osmosis glucose/amino acids/vitamins reabsorbed by active transport and diffusion most salt reabsorbed by AT and diffusion

Question 56

describe the distal convoluted tubule's role in reabsorption

Answer 56

careful control of water salt and pH balance to determine the volume and concentration of urine ADH causes walls to become more permeable to water so some salts and water can be absorbed if necessary.

Question 57

describe the loop of Henle's role in reabsorption

Answer 57

descending = permeable to water only, some water and minerals reabsorbed ascending = impermeable to water. some salts are reabsorbed by diffusion and AT at the top of the loop

Question 58

describe the collecting duct's role in reabsorption

Answer 58

small amount of water reabsorbed by osmosis

Question 59

where do the left-over wastes go when they reach the collecting duct

Answer 59

forms urine, moves from collecting duct of nephron to pelvis of kidney

Question 60

what is osmoregulation

Answer 60

the kidney regulating the amount of water in the body by varying the amount of urine produced

Question 61

what hormone controls osmoregulation

Answer 61

ADH (anti-diuretic hormone)

Question 62

what does ADH control

Answer 62

whether the distal tubule and collecting ducts reabsorb water or not

Question 63

where is ADH made

Answer 63

hypothalamus

Question 64

where is ADH stored

Answer 64

the pituitary gland

Question 65

what happens if you drink enough water

Answer 65

the hypothalamus detects the diluted blood and turns off ADH production less water is reabsorbed so a larger volume of urine is produced

Question 66

what happens if you don't drink enough water?

Answer 66

ADH is secreted from pituitary gland more water is absorbed, and a small volume of urine is produced

Question 67

target area of ADH

Answer 67

distal convoluted tubule+ collecting duct

Question 68

effects of ADH

Answer 68

causes DCT and collecting duct to become more permeable to water

Question 69

what is the stem of the renal artery?

Answer 69

aorta

Question 70

what is the stem of the afferent arteriole

Answer 70

the renal artery