Homeostasis and response

Question 1

Fill in the gaps:

Homeostasis is the ___________ of ________ conditions to maintain ________ conditions for ___________ activity and cell ____________.

Answer 1

-regulation
-internal
-optimal
-enzyme
-functions

Question 2

What things need to be regulated in our body? (name 4)

Answer 2

-temperature
-blood glucose levels
-water levels
-ion content

Question 3

What is the central nervous system made up of?

Answer 3

brain and spinal cord

Question 4

What is the peripheral nervous system made up of?

Answer 4

the nerves that branch out from the brain and spinal cord to the rest of the body

Question 5

Fill in the gaps:

a bundle of neurons is called a _____

Answer 5

nerve

Question 6

How is a neuron adapted to its function? (3 ways)

Answer 6

-long fibre axon so they can carry messages up and down the body over long distances
- insulating fatty myelin sheath increases the speed of nerve impulses along the neuron
- dendrons and dendrite branches recieve many nerve impulses from other neurons.

Question 7

What is the function of a sensory neuron?

Answer 7

takes information from the receptor to the central nervous system

Question 8

What is the function of the motor neuron?

Answer 8

takes information from the central nervouse system to the effector

Question 9

Fill in the blank:

When the electrical impulses reach the nerve ending it stimulates the release of chemicals called ___________________.
these diffuse across the _________ and bind to receptors on the surface of the second neuron.
an electrical triggered in the second neuron passes down the _____

Answer 9

-neurotransmitters
- synapse
-axon

Question 10

What is thermoregulation?

Answer 10

the proccess of controlling body temperature

Question 11

Fill in the blank:

Temperature is regulateed by the ________________ _________ in the brain (______________)

Answer 11

• thermoregulatory centre
• hypothalamus

Question 12

Body temperature is detected by:

Answer 12

• receptors in the thermoregulatory centre detect temperature of blood
• temperature receptors in the skin

Question 13

Name the steps of a conscious response

Answer 13

1, change in environment (stimulus)
2. change detected by receptor cells
3. impulses sent along the sensory neuron to the central nervous system
4. central nervous system decides how to respond to this information (co-ordinator)
5. impulses sent down the motor neuron to the effector (muscle or gland)
6. effector brings about the response to the stimuli

Question 14

What is the function of the retina?

Answer 14

contains light receptors

Question 15

What is the function of the cornea?

Answer 15

refracts light, bends it as it enters the eye

Question 16

What is the function of the iris?

Answer 16

controls how much light enters the pupil

Question 17

What is the function of the lens?

Answer 17

Further refracts light to focus it onto the retina

Question 18

What is the function of the sclera?

Answer 18

tought white outer layer of the eye helps to protect the eye from injury

Question 19

What is the function of the opric nerve?

Answer 19

Carries impulses between the eye and the brain

Question 20

What is the function of the pupil?

Answer 20

small hole at the centre of the iris through which light enters the eye

Question 21

What is the function of the ciliary muscles?

Answer 21

controls the shape of the lens to help focus on an image

Question 22

What is the function of the suspensory ligament?

Answer 22

holds the lens in place

Question 23

Fill in the blank:

In dim light the muscles in the iris ______ to make the pupil __________ so that more light can enter the eye. in bright light, the muscles ____________ to make the pupil ________ so that less light can enter the eye.

Answer 23

• relax
• larger
• contract
• smaller

Question 24

What is the proccess of accomodation?

Answer 24

the proccess by which the lens changes shape in order to focus on an object

Question 25

What is long sightedness also known as?

Answer 25

hypermetropia

Question 26

What is short sightedness also known as?

Answer 26

myopia

Question 27

How can long sightedness be corrected?

Answer 27

a convex lens causes the light to be refracted more ensuring the image is focused on the retina rather than behind it

Question 28

How can short sightedness be corrected?

Answer 28

concave lens which causes light to be refracted less so that the image is focussed on the image rather than ahead of it

Question 29

What is the medulla responsible for (brain)

Answer 29

unconscious activities such as heart rate and breathing rate

Question 30

what is the cerebral cortex responsible for (brain)

Answer 30

concerned with intelligence, personality, conscious thoughts, memory and language

Question 31

what is the cerebellum responsible for (brain)

Answer 31

balance, co-ordination of movement and muscular activity

Question 32

What is the hypothalamus responsible for? (brain)

Answer 32

near the pituitary gland, helps regulate the body including water levels, temperature and appetite

Question 33

How have neuroscientists been able to discover parts of the brain and its functions? (3 ways)

Answer 33

- studying patients with brain damage and corelating the area damaged to the skill or function lost - electrically stimulating different parts of the brain and seeing what happens - using scanning techniques such as MRI or PET scans

Question 34

Fill in the blanks: The endocrine system is made up of a collection of _______ which release _______________ to bring about a response to a stimulus.

Answer 34

- glands - hormones

Question 35

what are hormones?

Answer 35

chemical messengers that travel around the body in the blood

Question 36

What hormone does the pituitary gland release?

Answer 36

ADH

Question 37

What does ADH do? and what does it target ?

Answer 37

controls the water content of the blood by increasing reabsorption of water by the collecting ducts (targets kidneys)

Question 38

to look at near objects the cilliary muscles ________ which slackens the _______ ligaments the lens becomes ___ this increases the amount by which it ______ light

Answer 38

contract suspensory fat refracts

Question 39

to look at distant objects , the ciliary muscles _____ which allows the suspensory ligaments to _____ tight this make the lens go ____

Answer 39

relax pull thin