Animal Responses

Question 1

what do receptors and effectors do?

Answer 1

receptors: detect stimuli
effectors: bring about a response to the stiumuld

Question 2

receptors communicate with eachother through?

Answer 2

nervous system, hormonal system or both.

Question 3

the nervous system is split into:

Answer 3

the central NS and the peripheral NS

Question 4

CNS is made up of

Answer 4

brain and the spinal cord

Question 5

the PNS is made up of

Answer 5

the neurones that connect the CNS to the rest of the body.

Question 6

the PNS is split into

Answer 6

the somatic NS and the autonomic NS

Question 7

somatic NS function

Answer 7

controls conscious activities

Question 8

autonomic NS functions

Answer 8

controls unconscious activites like digestion

Question 9

autonomic NS is divided into

Answer 9

sympathetic NS and the parasympathetic NS

Question 10

sympathetic NS function

Answer 10

controls fight or flight response by releasing noradrenaline

Question 11

parasympathetic NS funciton

Answer 11

controls rest and digest response and release acetylcholine

Question 12

location and function of the hypothalamus?

Answer 12

beneath the middle part of the brain
maintains body temperature at the normal level

Question 13

pituitary gland location and function

Answer 13

beneath the hypothalamus
controlled by the hypothalamus - stimulates other glands to release hormones and releases 6 different hormones.

Question 14

cerebrum structure and function

Answer 14

largest part of brain that is divided into 2 hemispheres
has a thin outer layer called the cerebral cortex
involved in vision, hearing, learning and thinking

Question 15

medulla oblongata location and function

Answer 15

base of brain top of the spinal cord
automatically controls heart and breathing rate

Question 16

cerebellum location and function

Answer 16

underneath the cerebrum abck of head
muscle coordination, posture and coordination of balance

Question 17

what is a reflex

Answer 17

where the body responds to a stimulus without making a conscious decision to respond.

Question 18

rexlexes help organisms to

Answer 18

avoid damage to the body because they are rapid.

Question 19

blinking reflex - how does it work?

4 parts

Answer 19

• sensory nerve endings in the cornea are stimulated by touch
• a nerve impulse is sent along the sensory neurone to a relay neruone in the CNS
• the impulse is then passed from the relay to motor neurones.
• the motor neurones send impulses to effectors (orbicularis oculi muscles) that move the eyelids contract causing them to close quickly and prevents the eye from being damaged.

Question 20

knee jerk relex - how does it work?

3 points

Answer 20

• stretch receptors in the quadriceps muscle detect that the muscle is being stretched.
• a nerve imoulse is passed along a sensory neurone which communicates directly with a motor neurone in the spinal cord
• the motor neurone carries the nerve impulse ot the effector causing it to contract so the lower leg moves forward quickly.

Question 21

FIGHT OR FLIGHT

when an organism is threathened it responds by

Answer 21

preparing the body for action - fight or flight.

Question 22

FIGHT OR FLIGHT

nerve impulses from the sensory neurones arrive at?

Answer 22

the hypothalamus which activates both hormonal and nervous systems.

Question 23

FIGHT OR FLIGHT

the pituitary gland is stimulated to release

Answer 23

the hormone ACTH which causes the cortex of the adrenal gland to release steroidal hormones.

Question 24

FIGHT OR FLIGHT

the sympathetic nervous system is activated and triggers the release of

Answer 24

adrenaline from the adrenal medulla

Question 25

# FIGHT OR FLIGHT adrenaline has the 5 following effects:

Answer 25

* heart rate increases - blood is pumped around the body faster * muscles around the bronchiole relax - deeper breaths * glycogen converted into glucose - more available for muscles to respire * muscles in the artrioles supplying the skin and gut constrict so arterioles supporting the heart and lungs dilate for more oxygen. * erector pili muscles in the skin contract to make hairs stand - animal looks bigger.

Question 26

# HEART RATE the NS helps to control the heart rate: first step?

Answer 26

SAN generates electrical impulses that cause the cardiac muscles to contract

Question 27

# HEART RATE the rate at which the SAN fires is controlled by

Answer 27

the medulla oblongata in the brain (unconscious)

Question 28

# HEART RATE animals need to alter their heart rate to?

Answer 28

respond to internal stimuli

Question 29

# HEART RATE stimuli are detected by?

Answer 29

pressure and chemical receptors

Question 30

# HEART RATE what are baroreceptors

Answer 30

pressure receptors in the aorta and vena cava which are stimulated by high and low blood pressure

Question 31

# HEART RATE what are chemoreceptors?

Answer 31

chemical receptors in the aorta, carotid artery and themedulla which monitor oxygen, carbon diocide and pH levels in the blood.

Question 32

# HEART RATE final step?

Answer 32

electrical impulses from receptors are sent to the medulla along the sensory neurones - the medulla processes the information and sends impulses to the SAN along the motor neurones.

Question 33

# HEART RATE what happens when there is high blood pressure?

Answer 33

baroreceptors detect high blood pressure - impulses are sent to the medulla which sends impulses along the vagus nerve, which secretes acetylcholine and binds to the receptors on the SAN. cardiac muscles slow heart rate down to reduce pressure back to normal.

Question 34

# HEART RATE what happends when there is low blood pressure?

Answer 34

baroreceptors detect low blood pressure - impulses are sent to the medulla which sends impulses along the accelerator nerve, which secretes noradrenaline and binds to the receptors on the SAN. cardiac muscles increase heart rate down to increase pressure back to normal.

Question 35

# HEART RATE what happends when there is high blood o2 / low co2 / high pH

Answer 35

chemoreceptors detect chemical changes in blood - impulses are sent to the medulla, which sends impulses along the vagus nerve, secretes acetylcholine which binds to the receptors on the SAN.

Question 36

# HEART RATE what happends when there is low blood o2 / high co2 / low pH

Answer 36

chemoreceptors detect chemical changes in blood - impulses are sent to the medulla, which sends impulses along the accelerator nerve, secretes noradrenaline which binds to te receptors on the SAN.

Question 37

# HEART RATE the hormonal system also helps to control heart rate by

Answer 37

releasing adrenaline - binds to specific receptors in the heart and causes the cardiac muscles to contract more frequently and with more force so heart rate increases and heart pumps more blood.