Topic 2 -Mechanisms of Behaviour

Question 1

Stimuli from the internal/external environment may be acted upon by…?

Answer 1

Nervous system, endocrine system, or a combination of both

Question 2

Sensory system contains?

Answer 2

inputs, receptor cells, sensory organs

Question 3

CNS contains?

Answer 3

data processing, brain, spinal chord

Question 4

Motor system contains?

Answer 4

outputs, autonomic and somatic motor systems

Question 5

What is stimuli? What are the different types? How is it detected?

Answer 5

Stimuli -a trigger for a nerve impulse.
Can be chemical, mechanical, photic or electric; and either internal or external.
Detected by specialised receptor cells which are designed to respond to a particular type of stimulus.

Question 6

Name the 3 broad groups of receptors

Answer 6

Interoroceptors
Exteroceptors
Proprioceptors (a sense of where you are in space)

Question 7

Name the 3 kinds of exteroceptors

Answer 7

thermoreceptors
mechanoreceptors
nocioreceptors

Question 8

Receptors can be…?

Answer 8

desensitised or habituated to a stimuli. Different areas of skin have different levels of sensitivity.

Question 9

Explain the physiology of nerve impulses

Answer 9

Nerves transmit an electrical impulse throughout its length. Energy from nerve cell metabolism and nerve cell membrane properties allow the nerve cell to conduct the impulse.

Question 10

Describe resting potential and how it works.

Answer 10

RP -the negative electrical difference b/w the inside and outside of the nerve cell.
The unequal distribution of charges creates a measurable voltage difference across the membrane.
Plasma membrane when resting is very permeable to K+ & Cl- ions.
Na+ are transported outside the membrane building up the + charges

Question 11

A bit about action potential (AP)

Answer 11

Nerve fibre is capable of converting mechanical, chemical energy to electrical energy. Only nerve & muscle cells can have membrane permeability to Na+ & K+ change rapidly to form an AP.
AP results from a reversal of polarity of the plasma membrane. Operates on an “all or none” principle.

Question 12

Describe a neuronal synapse (& a bit about)

Answer 12

Site where electrical charge is transferred across a gap to its target. Ca++ is main ion involved.
Changes in/around synapse can affect transmission of impulses.

Question 13

Autonomic & somatic NS are…? and share?

Answer 13

are the two types of output from the NS. Share sensory nerves but utilise different motor systems

Question 14

A bit about the autonomic NS

Answer 14

Controls smooth/cardiac muscle

• Parasympathetic: general body maintenance, utilises acteylcholine in synapses.
• Sympathetic: gets body ready for action, activates when body is stressed. Utilises noradrenalin.

Question 15

A bit about the somatic NS

Answer 15

Parts of the NS responsible for activity of skeletal muscle. Some responses are initiated at spinal chord/others in brain.