B5

Question 1

Homeostasis- stable enteral environment

Answer 1

Cells need right conditions to function eg enzyme action

Response to changes in internal and external conditions

Automatic control systems- INTERNAL Environment- nervous and hormonal communication eg body temp, blood glucose, water content

3 components- receptors, coordination centres and effector

Question 2

Negative feedback

Answer 2

Level of something is too high or low so body uses negative feedback to bring it back to normal.

Question 3

Nervous system

Answer 3

Organisms respond to stimulating survive

A single cell can respond to its environment but multicellular need to communicate first so they’re evolved and develop nervous and hormonal communication systems

Question 4

CNS

Answer 4

In vertebrates consists of brain spinal cord only and in mammals connected to body by sensory and motor neurones

Question 5

Sensory neurone

Answer 5

Carry info as electrical impulses from CNS to effectors

Question 6

Motor neurone

Answer 6

Also carry electrical impulses from CNS to effectors

Question 7

Effectors

Answer 7

Muscles and glands responding to nervous Imulses

Question 8

Complex organs

Answer 8

Receptors detect stimuli
Many types such as taste in the tongue and sound in the ears
Can form part of a larger complex organs retina in eyes covered in light receptors

Question 9

CNS is coordination centre

Answer 9

Receives info from from receptors and coordinates a response

Stimulus-receptor-sensory neuron-CNS-motor neurone-effector-response

Question 10

Synapse

Answer 10

Connection between two neurones

Nerve signal is transferred but chemicals which diffuse across the gap

Chemicals set off a new electrical signal in next neurone

Question 11

Reflex prevent injury

Answer 11

Don’t involve a conscious part of the brain

Eg bright light in your pupils automatically get smaller so less light gets into the eye

Passage of information in a reflex is called a reflex arc

Question 12

Endocrine

Answer 12

Hormones are released in blood and go around the body but only affect particular organs (target organs)
They control things in the organs and cells that need constant adjustment
Made in endocrine glands which make up the endocrine system

Question 13

Pituitary gland

Answer 13

Produces many hormones that regulate body conditions
Aka MASTER GLAND
As these hormones act on other glands directing them to relapse hormones that bring change

Question 14

Ovaries

Answer 14

Produces oestrogen

Question 15

Testes

Answer 15

Produce testosterone which controls puppetry and sperm production

Question 16

Thyroid

Answer 16

Produces thyroxine

Regulates rate of metabolism heart rate and temp

Question 17

Adrenal gland

Answer 17

Produces adrenaline to prepare body for fight or flight response

Question 18

Pancreas

Answer 18

Produces insulin which regulates blood glucose level

Question 19

Nerves

Answer 19

Fast and act for short time on a precise area

Question 20

Hormones

Answer 20

Slower action for a long time in a general way

Question 21

Insulin and glucagon

Answer 21

Carbs put glucose into the blood form the gut
Normal metabolism removes glucose form blood
Lots of exercise removes much more glucose from blood
Excess will be stored as glycogen in liver and muscles
Level of glucose in blood must be steady changes are monitored by pancreas using insulin and glucagon in negative feedback

Question 22

Blood glucose too HiGH

Answer 22

Insulin separated from blood by pancreas
Glucose moves from blood into liver and muscle cells
And insulin makes insulin change glucose into glycogen
So blood glucose reduced

Question 23

Blood glucose to LOW

Answer 23

Glucagon separated buy pancreas from blood

Glucagon makes liver turn glycogen into glucose and it’s real eased into the blood

Question 24

Type one diabetes

Answer 24

Pancreas produces little or no insulin meaning glucose level can rise to a level and kill them so they need insulin therapy which makes sure glucose is removed form blood quickly once food is digested.
The amount of insulin needed depends on how active and the diet of of a person.
They might also try and limit the amount of rich foods such as carbs the intake

Question 25

Type 2

Answer 25

Person is resistant to their own insulin (bodies cell don’t respond properly). Can cause blood sugar level to rise to a dangerous level. Being over weight can increase the chance of developing this.
Can be controlled but regular exercise and carb controlled diet

Question 26

Puberty and menstrual cycle

Answer 26

Puberty realises sex hormones
Men- testosterone produced by testes and stimulates sperm production

Women- oestrogen in ovaries brings physical change and involved in menstrual cycle

Question 27

4 stages

Answer 27

Stage1 - menstruation starts / uterus lining breaks down for 4 days

Stage2- uterus lining builds back up / from day 4-14 into a think spongy layer full of blood vessels ready to receive a fertilised egg

Stage3-egg develops and is released / at day 14 it’s called ovulation

Stage4- wall maintained / no fertilised egg by day 28 spongy layer breaks down and cycle starts again

Question 28

4 hormones

Answer 28

FSH.
pituitary gland caused an egg to mature in one of the overuse in structure called follicle. Stimulates overuse to produce oestrogen

Oestrogen.
Produced in ovaries causes lining of uterus to grow. Stimulates release of LH which causes release of egg and inhibits release of FSH

LH.
Produced by pituitary gland. Stimulates realise of egg at day 14

Progesterone.
Produced in ovaries by remains of the follicle after ovulation. When level of this falls the lining breaks down. Inhibits release is LH and FSH