B3.3 - Maintaining Internal Environments

Question 1

When happens when you get too hot

Answer 1

• body hair lie flat on skin, prevents trapping of insulating air around body
• sweat glands produce sweat, as water evaporates energy transferred by heating to environment
• vasodilation: blood vessels supplying capillaries near surface of skin widen, increases blood flow through capillaries, increases heat loss by radiation

Question 2

What happens when you get too cold

Answer 2

• body hair rise, trap layer of insulating air close to skin
• sweat glands stop producing sweat
• shivering: muscles contract/relax, makes cells respire more quickly, transferring energy by heating
• vasconstriction: blood vessels supplying capillaries near surface of skin narrow, reduces blood flow through capillaries, reduces heat loss by radiation

Question 3

What is sweat/urine made of

Answer 3

• mainly water
• excess salt
• urea

Question 4

Type 1 diabetes

Answer 4

• can’t produce insulin
• immune system destroyed pancreatic cells that make insulin
• begins in childhood
• controlled by regular injections of insulin
• eat balanced diet, exercise regularly

Question 5

Type 2 diabetes

Answer 5

• can’t effectively use insulin
• cells don’t produce enough insulin or don’t respond properly to insulin
• occurs later in life, linked to obesity
• controlled by regulating carbs intake through diet, regular exercise
• sometimes, drugs used to stimulate insulin produced/insulin injections given

Question 6

How does water leave the body

Answer 6

• sweating
• urine
• as water vapour as you exhale

Question 7

What happens if there’s too much/little water in blood plasma

Answer 7

OSMOSIS

Question 8

Parts of kidney

Answer 8

• cortex
• medulla
• capsule
• renal artery
• renal vein
• ureter

Question 9

Ureter

Answer 9

Tube through which urine passes from kidney to bladder

Question 10

Urethra

Answer 10

Tube though which urine passes to outside of body

Question 11

Capsule:

Answer 11

• Outer membrane of kidney

- helps maintain kidneys shape & protect it from damage

Question 12

Cortex:

Answer 12

• outer part of kidney

- where top of nephron found

Question 13

Medulla

Answer 13

• inner part of kidney

- where lower section of nephron (loop of Henle) found

Question 14

Symptoms of dehydration

Answer 14

• passing of dark, concentrated urine
• headaches & dizziness
• lack of energy

Question 15

What happens if too much water is consumed rapidly

Answer 15

• water moves into cells by osmosis, may burst
• if water moves into brain cells by osmosis, can lead to death
• concentration of sodium in blood plasma drops = leads to muscle cramps, confusion, seizures

Question 16

Types of sports drinks

Answer 16

• Hypertonic = contain high levels of glucose & salts
• Hypotonic = contain low levels of glucose & salts
• Isotonic = contain ion concentrations equal to those in blood plasma