Unit 3 Homeostasis

Question 1

Homeostasis

Answer 1

the maintenance of a constant internal environment by negative feedback.

Question 2

what stays the same due to negative fed back

Answer 2

Core body temperature, pH and water potential, blood glucose

Question 3

Negative feedback

Answer 3

A receptor detects a deviation, The receptor sends instructions to a co-ordinator, communicates with one or more effectors, factor returns to normal (the set point),

Question 4

Excretion

Answer 4

removal of wastes produced by the body due to metabolism. The mammalian body

Question 5

kidneys functions

Answer 5

Excretion – the removal of nitrogenous waste from the body
Osmoregulation – the control of water potential of the body’s fluids

Question 6

Ultrafiltration

Answer 6

filtration under high pressure in the Glomerulus from High hydrostatic pressure

Question 7

where does blood enter the glomerulus

Answer 7

the afferent arteriole

Question 8

where does blood leave the glomerulus

Answer 8

the efferent arteriole

Question 9

what’s in the glomerulus filtrate

Answer 9

• Water
• Glucose
• Salts
• Urea
• Amino acids

Question 10

what’s produced in ultrafiltration

Answer 10

the glomerulus filtrate

Question 11

what separates the glomerulus and the bowman capsule

Answer 11

Bowman’s space

Question 12

what layers separate the glomerulus form the bowman space

Answer 12

-the capillary walls
-the basement membrane
- Squamous epithelial cell layer (Podocytes)

Question 13

calculating % blood filtered

Answer 13

volume of filtrate per minute
______________________
volume of blood entering kidney per minute

all x 100

Question 14

the capillary wall

Answer 14

one cell layer thick – this is the endothelium and contains fenestrations

Question 15

fenestrations

Answer 15

Tiny pores between cells

Question 16

Basement membrane

Answer 16

a selective molecular filter which only allows small molecules to pass through

Question 17

Podocytes

Answer 17

have extensions, called pedicels which wrap around a capillary, pulling it closer to the basement membrane. The gaps between the pedicels are called filtration slits.

Question 18

what’s Selective reabsorption done by

Answer 18

the proximal convoluted tubule

Question 19

Selective reabsorption

Answer 19

useful substances such as glucose, amino acids and salts are reabsorbed back into the blood plasma.

Question 20

The cells lining in the proximal convoluted tubule made of

Answer 20

highly specialised cuboidal
epithelial cells

Question 21

adaptions in the specialised cuboidal epithelium cell

Answer 21

• microvilli- surface area
• many mitochondria - ATP for active transport
• Tight junctions between cells - prevent molecules diffusing between adjacent cells
  *Basal channels-surface area

Question 22

how is salt reabsorbed

Answer 22

Mainly active transport, but some by facilitated diffusion

Question 23

how are Glucose & amino acids reabsorbed

Answer 23

Cotransport with sodium ions into the cell

Question 24

how’s water reabsorbed

Answer 24

osmosis

Question 25

how are Urea and small proteins reabsorbed

Answer 25

facilitated defusion

Question 26

Cotransport

Answer 26

transport of molecules or ions together through the same transport protein

Question 27

Secondary active transport

Answer 27

coupling of diffusion, down an electrochemical gradient, providing energy for active transport

Question 28

is the descending loop[ of henle permeable to water

Answer 28

yes

Question 29

is the ascending loop[ of henle permeable to water

Answer 29

no

Question 30

what is the loop of Henle called

Answer 30

a counter current multiplier

Question 31

counter current multiplier

Answer 31

filtrate flows in opposite directions, and the concentration of solutes in the filtrate increases towards the apex

Question 32

where do Animals with long loops of Henle live

Answer 32

dry environments

Question 33

Osmoregulation

Answer 33

control of body fluid water potential by negative feedback

Question 34

control of body fluid water potential by negative feedback

Answer 34

Osmoregulation

Question 35

filtrate flows in opposite directions, and the concentration of solutes in the filtrate increases towards the apex

Answer 35

counter current multiplier

Question 36

coupling of diffusion, down an electrochemical gradient, providing energy for active transport

Answer 36

Secondary active transport

Question 37

where are the highly specialised cuboidal epithelial cells

Answer 37

lining in the proximal convoluted tubule

Question 38

-the capillary walls -the basement membrane - Squamous epithelial cell layer (Podocytes) are layers from where?

Answer 38

layers separate the glomerulus form the bowman space

Question 39

removal of wastes produced by the body due to metabolism. The mammalian body

Answer 39

Excretion

Question 40

filtration under high pressure in the Glomerulus from High hydrostatic pressure

Answer 40

ultrafiltration

Question 41

* microvilli- surface area * many mitochondria - ATP for active transport * Tight junctions between cells - prevent molecules diffusing between adjacent cells *Basal channels-surface area are adaption of what in the nephon?

Answer 41

specialised cuboidal epithelium cell

Question 42

where are Osmoreceptors

Answer 42

in the hypothalamus

Question 43

what do Osmoreceptors (detectors) in the hypothalamus do?

Answer 43

*detect a decrease in blood plasma water potential *signal is sent to the posterior lobe of the pituitary gland *which releases the hormone ADH into the bloodstream

Question 44

what is produced in the hypothalamus, secreted by the posterior lobe of the pituitary gland

Answer 44

Antidiuretic hormone

Question 45

what does ADH do

Answer 45

increases the permeability of cells of the collecting duct and distal convoluted tubule to water, allowing more water to be reabsorbed by osmosis.

Question 46

ransport water across the phospholipid bilayer during osmosis.

Answer 46

Aquaporins