5.5 ANIMAL RESPONSE

Question 1

Draw the organisation of the mammalian nervous system

Answer 1

Question 2

Define central nervous system

Answer 2

• The brain and spinal cord

Question 3

Define peripheral nervous system

Answer 3

• The motor and sensory neurons connecting the sensory receptors and effectors to the CNS

Question 4

Define somatic nervous system

Answer 4

• The motor neurones under conscious control

Question 5

Define autonomic nervous system

Answer 5

• The motor neurones under the control of the involuntary motor activities of the body

Question 6

State the neurone(s) that make us the central nervous system

Answer 6

1) Relay neurones

Question 7

State the neurone(s) that make us the peripheral nervous system

Answer 7

1) Sensory neurones
2) Motor neurones

Question 8

Which type of neurone is mainly un-myelinated

Answer 8

• Relay neurones

Question 9

State the role of myelinated neurones

Answer 9

• They carry action potentials up and down the spinal cord for rapid communication over long distances

Question 10

Describe the sensory nervous system

Answer 10

• The sensory neurones that conduct action potentials from the sensory receptors to the CNS

Question 11

Describe the motor nervous system

Answer 11

• Conducts action potentials form the CNS to effectors

Question 12

Describe somatic nervous system

Answer 12

• Motor neurones that conduct action potentials from CNS to effector under conscious/voluntary control (e.g skeletal muscles)
• The neurones are myelinated for rapid response
• Always one motor neurone connects the CNS to the effector

Question 13

Describe autonomic nervous system

Answer 13

• Motor neurones that conduct action potentials from CNS to effector under involuntary control (e.g glands, cardiac muscle/smooth muscle of the heart, the airways)
• Most neurones are un-myelinated as not a rapid response
• Are atleast two motor neurones connects the CNS to the effector (ganglia)

Question 14

Compare in detail the sympathetic and parasympathetic system

Answer 14

Question 15

Draw the human brain

Answer 15

Question 16

Define cerebellum

Answer 16

• Region that co-ordinates balance and controls fine movements

Question 17

Define cerebrum

Answer 17

• Divided into two cerebral hemispheres
• Organises conscious thought and memory

Question 18

Define hypothalamus

Answer 18

• Co-ordinates homeostatic responses

Question 19

Define medulla oblongata

Answer 19

• Controls autonomic responses/psycological processes

Question 20

Define pituatry gland

Answer 20

• Endocrine gland at the base of the brain, attached to the hypothalamus
• The anterior lobe secretes hormones
• The posterior lobe stores and releases hormones made in the hypothalamus

Question 21

Describe the cerebrum

Answer 21

• Controls: conscious thought, conscious actions, emotions, intelligence/decision making, factual memory
• Divided into two hemispheres
• Subdivided into sensory, association and motor areas

Question 22

Describe the cerebellum

Answer 22

• Receives information from the sensory receptors
• Controls: maintanance of body position/balance, judging position of objects, contraction/relaxation of antagonistic skeletal muscles

Question 23

Describe the hypothalamus/pituatry gland complex

Answer 23

Hypothalamus:
1) Temperature regulation - detects changes in body temp and also receives sensory input from temperature recptors in the skin, then initiates response via either the neuronal or hormonal system
2) Osmoregulation - contains osmoreceptors that monitor wtaer potential of the blood, the pituatry gland then initiates response via the hormonal system

Pituatry gland: (two lobes)
1) Posterior lobe is connected to the hypothalamus via specialised neurosecretory cells, hormones like ADH are manufactured by hypothalamus, pass down the neurosecretory cells and released into the blood by the pituatry gland
2) Anterior lobe produces its own hormones which are released into blood in response to releasing factors produced by hypothalamus (anterior lobe responds to stress/growth/reproduction)

Question 24

Describe the medulla oblongata

Answer 24

• Controls the non-skeletal muscles (cardiac muscles and involuntary smooth muscles) by sending action potentails throughout the autonomic nervous system
  1) Cardiac centre - which regulates heart rate
  2) Vasmotor centre - which regulates circulation and blood pressure
  3) Respiratory centre - which regulates rate and depth of breathing

Question 25

Define reflex action

Answer 25

• Responses to chnages in the external environment WITHOUT brain processing
• For survival/ to get out of danger/ avoid damage/ maintain balance

Question 26

State the pathway of reflex actions

Answer 26

1) Sensory neurone
2) Relay neurone
3) Motor neurone

Question 27

State the two types of blinking relfex

Answer 27

• Can be corneal reflex
• Can be optical reflex

Question 28

Define knee jerk reflex

Answer 28

• Straightens the leg when the tendon below the knee cap is tapped

Question 29

Describe the optical reflex

Answer 29

• Slower than the corneal reflex
• Protects the light-sensitive retina cells from damage
• Stimulus is detected by the retina
• Reflex is meditated by the optical centre at the cerebral cortex

Question 30

Describe the corneal reflex

Answer 30

1:
- Action potential from the cornea is carried by a sensory neurone which enters the pons
- This passes the action potential to a relay neurone then to a motor neurone
- The motor neurone then passes the action potential to facial muscles
- Causes both eyes to blink

2:
- The sensory neurone also passes the action potential to myelinated sensory neurones which go to the cerebral cortex
- This can send inhibitory signals to the motor centre in the pons
- This can override the reflex as these sensory neurones are myelinated, so more rapid than non-myelinated relay neurones
- Causes both eyes to blink

Question 31

Describe