Biopsychology: Biochemistry (L1-5)

Question 1

What does the CNS (central nervous system) consist of?

Answer 1

• the brain and spinal cord

Question 2

What are the 2 main functions of the CNS?

Answer 2

• control of behaviour
• regulation of the body’s physiological processes
• in order to do this the brain must be able to receive information from sensory receptions and send messages to the muscles and glands in response

Question 3

What 4 main areas is the brain split into?

Answer 3

• cerebrum
• cerebellum
• deincephalon
• brain stem

Question 4

Cerebrum (brain)?

Answer 4

• largest part of the brain
• has 4 lobes
• split down the middle into 2 halves, called the right and left hemisphere

Question 5

Cerebellum (brain)?

Answer 5

• responsible for motor skills, balance and coordinating muscles to allow precise movements

Question 6

Diencephalon (brain)?

Answer 6

• contains the thalamus, regulates consciousness, sleep and alertness
• and the hypothalamus, regulates body temp, stress response, hunger and thirst

Question 7

Brain stem?

Answer 7

• regulates breathing and heart rate

Question 8

What is the main function of the spinal cord?

Answer 8

• to relay information between the brain and the rest of the body
• allows the brain to monitor and regulate bodily
  processes
• such as digestion and breathing, and co-ordinate voluntary movement

Question 9

How is the spinal cord connected to the body?

Answer 9

• spinal cord is connected to different parts of the body by pairs of spinal nerves, which connect to specific muscles and glands
• if the spinal cord is damaged, body areas connected to it by nerves below the damage will be cut off and stop functioning

Question 10

What does the PNS (peripheral nervous system) consist of?

Answer 10

• the nervous system throughout the rest of the body
• not the brain or spinal cord

Question 11

What does the PNS do?

Answer 11

• transmits messages via neurons (nerve cells) to and from the CNS

Question 12

What are the 2 divisions of the PNS?

Answer 12

• somatic nervous system
• autonomic nervous system

Question 13

Somatic nervous system?

Answer 13

• controls voluntary movements and is under
  conscious control
• connects the senses with the CNS and has sensory pathways AND motor pathways
• controls skeletal muscles
• somatic nervous system is controlled by the motor cortex

Question 14

ANS (autonomic nervous system)?

Answer 14

• involuntary movements, not under conscious control
• ONLY has motor pathways
• controls smooth muscles and the internal organs and glands of the body
• ANS is controlled by the brain stem

Question 15

What is the ANS split into?

Answer 15

• SNS, sympathetic nervous system
• PNS, parasympathetic nervous system

Question 16

When is the SNS (ANS) activated and what happens?

Answer 16

• when a person is stressed
• heart rate and breathing increase, digestion stops, salivation reduces, pupils dilate, and the flow of blood is diverted from the surface on the skin
• fight or flight response

Question 17

When is the PNS (ANS) activated and what happens?

Answer 17

• when the body is relaxing and so conserving energy
• heart rate and breathing reduce, digestion starts, salivation increases, and pupils constrict

Question 18

What are neurons?

Answer 18

• specialised nerve cells that move electrical impulses to and from the CNS

Question 19

What are the parts to a neuron (7)?

Answer 19

• cell body
• nucleus
• dendrites
• axon
• myelin sheath
• Schwann cells
• nodes of Ranvier

Question 20

What is the cell body (neuron)?

Answer 20

• control centre of the neuron

Question 21

What is the nucleus (neuron)?

Answer 21

• contains genetic material

Question 22

What are dendrites (neuron)?

Answer 22

• receives an electrical impulse (action potential) from other neurons or sensory receptors
• e.g. eyes, ears, tongue and skin

Question 23

What is the axon (neuron)?

Answer 23

• a long fibre that carries the electrical impulse from the cell body to the axon terminal

Question 24

What is the myelin sheath (neuron)?

Answer 24

• insulating layer that protects the axon and speeds up the transmission of the electrical impulse

Question 25

What are Schwann cells (neuron)?

Answer 25

• make up the myelin sheath

Question 26

What are the nodes of Ranvier (neuron):

Answer 26

• gaps in the myelin sheath
• they speed up the electrical impulse along the axon

Question 27

Where are sensory neurons found?

Answer 27

• sensory receptors

Question 28

Function of sensory neurons?

Answer 28

• carry electrical impulses from the sensory receptors to the CNS (spinal cord and brain) via the Peripheral Nervous System (PNS)
• sensory neurons convert information from
  sensory receptors into electrical impulses
• when these impulses reach the brain they are converted into sensations, such as heat, pain etc.
• so that the body can react appropriately
• some sensory impulses terminate at the spinal
  cord
• this allows reflexes to occur quickly without the delay of waiting for the
  brain to respond.

Question 29

Where are motor neurons found?

Answer 29

• in the CNS
• but protect their axons outside of the CNS

Question 30

Function of motor neurons?

Answer 30

• send electrical impulses via long axons to the glands and muscles so they can respond
• glands and muscles are called effectors
• when motor neurons are stimulated they release neurotransmitters that bind to the
  receptors on muscles to trigger a response
• leads to movement

Question 31

Where are relay neurons found?

Answer 31

• found in the CNS

Question 32

Function of relay neurons?

Answer 32

• connect sensory neurons to motor neurons so that they can communicate with one another
• during a reflex arc (e.g. you put your hand on a hot hob) the relay neurons in the spinal cord are involved in an analysis of the sensation and decide how to respond
• (e.g. to lift your hand) without waiting for the brain to process the pain