PSYCHOLOGY - biopsychology

the key assumptions made by biopsychologists

• behaviour and experiences are caused by activity in the nervous system

• the nervous system transmits signals for communication via billions of neurons

what is a neuron

nerve cells in the human nervous system,

80% in the brain

send signals electrically and chemically

used for communication

what are the three types of neurons

sensory

relay

motor

what do these neurons look like

what is the dendrite

branch-like structures that receive the nerve impulses from adjacent neurons.

what is the axon

where the impulses travel along

what is the myelin sheath

protects the axon from external influences - so transmission is not affected.

what are the nodes of ranvier

these speed up the transmission of nerve impulses by forcing them to jump between myelin sheath segments.

what are terminal buttons

send signals to the adjacent cell/neuron

function and structure of motor neuron

• carries messages from the CNS to effectors like muscles or glands

• short dendrites

• long axons

function and structure of relay neuron

• transfers messages from sensory neurons to other relay or motor neurons

• short dendrites

• short axons

function and structure of sensory neuron

• carries messages from the PNS to the brain and spinal chord

• long dendrites

• short axons

what is a knee jerk reaction, as a reflex arc

• stimulus is detected by sense organs in the peripheral nervous system

• this conveys a message along a sensory neuron

• when the message reaches the central nervous system it connects with a relay neuron

• this then transfers the message to a motor neuron

• which triggers a response in the effector muscle, resulting in a quick, involuntary movement.

excitation vs inhibition

excitatory - make neurons more likely to fire

inhibitory - make it less likely that the neuron will fire

what is summation

The process by which multiple signals combine to influence a neuron's likelihood of firing. Summation can be either

spatial, where signals from different neurons are received at the same time

temporal, where signals from the same neuron are received in quick succession.

what are the two different nervous systems

central nervous system (CNS), the brain and spinal cord

peripheral nervous system (PNS), CNS to the rest of the body.

how can the PNS be subdivided

somatic nervous system - controls muscle movement and receives information from sensory receptors

autonomic nervous system - regulates involuntary bodily functions, such as heart rate, digestion, sexual arousal and stress responses.

what makes up the endocrine system

glands and hormones that regulate various bodily functions such as metabolism, growth, and mood. In addition to the glands, such as the pituitary, thyroid, and adrenal glands, hormones are released into the bloodstream to target organs.

how does the flight or fight reaction occur

1. the stressor is perceived

2. the hypothalamus activates the pituitary gland and triggers activity in the sympathetic branch of the ANS

3. the ANS transfers from the resting state (parasympathetic) to its aroused state (sympathetic)

4. the stress hormone adrenaline is released into the blood stream

5. this stimulates reactions in the body such as an elevated heart rate

this response is immediate and automatic

6. once the threat has passed, the body returns to the parasympathetic state.