Biopsych Flashcards
2 main divisions of nervous system
Peripheral nervous system and central nervous system
Peripheral nervous system
Does not involve brain and spinal cord.
Central nervous system
Brain and spinal cord
Control of behaviour and regulation of physiological functions
The PNS is further subdivided into two divisions
Autonomic nervous system
Somatic nervous system
Autonomic NS
Operate involuntary.
transmits info from and to internal body organs responsible for vital functions e.g. heartbeats, breathing.
Somatic NS
Controls muscle movement and receives information from senses and transmits it to CNS
Autonomic nervous system is divided into
Sympathetic and parasympathetic
Sympathetic NS
Prepare the body for action, e.g. fight or flight
Increases our HR, blood pressure, dilates the blood vessels
Slows less important functions when under threat e.g. digestion (to conserve energy)
Parasympathetic NS
Conserves/stores energy
Relaxes individual when threat has passed
Slows HR and reduce BP
Structure of a neuron
Dendrites
Dendrites - carry nerve impulses from previous neuron to cell body
Structure of neuron
Cell body
Contains genetic material within nucleus
Structure of neuron
Nodes of ranvier
Speeds up impulse transmission by forcing it to jump across gaps
Structure of neuron
Terminal buttons
Communicates with dendrites of next neuron via synaptic transmission
Structure of neuron
Myelin sheath
Protects axon and speeds up impulse transmission
Structure of neuron
Axon
Carries impulse away from cell body
Motor neuron
Connect the CNS to muscles and glands. they have short dendrites and long axons
Sensory neuron
Carry messages from PNS to CNS
Long dendrites and short axons
Relay neuron
Connect sensory neurons to motor neurons.
Short axons and short dendrites.
Process of synaptic transmission
electrical impulse in the pre-synaptic neuron causes neurotransmitters stored in vesicles to be released into the synapse. Neurotransmitter diffuses across the synapse.
It then binds to receptor sites on post synaptic neuron.
depending on which neurotransmitter is released it will either have an excitatory or inhibitory effect on the neighbouring neuron.
Neurotransmitters
Chemical messengers in the brain that transmits nerve impulses across a synapse, e.g. dopamine/serotonin. either have an excitatory or inhibitory effect on the next neuron.
Excitation
When a neurotransmitter increases the positive charge of the post synaptic neuron.
More likely to fire and pass on electrical impulse.
Inhibition
When a neurotransmitter increases negative charge of post synaptic neuron.
Decreases likelihood that the neuron will fire and pass on electrical impulse.
Endocrine system
Works alongside the nervous system to control vital functions in the body functions more slowly than NS.
has a series of glands throughout the body that release hormones
Hormones
Chemical messengers
Influence behaviour
Eg adrenaline
Pituitary gland
Releases ACTH, growth hormone etc.
Controls release of hormones from all other glands in the body.
Adrenal gland
Releases adrenaline.
Fight/flight response
Ovaries
Release oestrogen and progesterone
- female puberty, emotional disregulation.
Testes
Release testosterone – male puberty
Pineal gland
Releases melatonin - sleep
Body’s response to sudden stressors -
silly harry potter always acts aroused around sexy females
Body detects stressor and prepares for fight or flight
Hypothalamus detects stressor and stimulates pituitary gland.
Pituitary gland releases ACTH adrenocorticotrophic hormone to stimulate adrenal glands.
They release adrenaline and stimulate Autonomic NS
ANS stimulates sympathetic NS
Fight or flight initiated
