biopsychology Flashcards
the nervous system
• the body’s main communication system which is very fast acting
• it is a complex network of specialised nerve cells which passes information around the body
•it passes messages using electrical signals and chemicals using neurones and neurotransmitters
what is the CNS made up of
brain and spinal cord
what is the function of the CNS
pass messages from the brain to other parts of the body along with receiving information from PNS.
what is special about the brain
the brain is the centre of conscious awareness. the cerebral cortex is highly developed in humans and distinguishes out higher mental functions from other animals.
what is the spinal cord
the spinal cord is an extension of the brain. It is responsible for reflex actions
what is the peripheral nervous system
send information to the CNS from the outside world and transmits messages from the CNS to muscle ls and glands in the body
what’s the PNS made up of
nerve fibres (axons) which are connected to the CNS
what is the somatic nervous system
•revives instructions from the CNS for muscle movement.
•controls conscious movement.
•transmits information from receptor cells in sense organs to the CNS.
what type of neurones is the somatic nervous system made up of
myelinated neurones
what is the automatic nervous system
• responsible for control of the bodily functions unconsciously directed
•transmits information to and from internal bodily organs
what is the autonomic nervous system made up of
•unmyelinated nerve fibres
• two main division : sympathetic nervous system and parasympathetic nervous system.
sympathetic nervous system
gets body prepared for fight or flight
parasympathetic nervous system
returns body to its normal resting state
what is a neuron
nerve cells which are part of the nervous system
how do neurones transit information
they transmit signals two ways:
•electrically (though action potential)
•chemically (using neurotransmitters)
what do all neurones consist of
cell body, dendrites and an axon
what are dendrites and what do they do
dendrites at one end of the neuron receives signals from other neurons or from sensory receptors. dendrites are connected to the cell body
what is the function of the cell body
the control centre of the neuron which contains all the genetic information of the cell.
what is the axon
the impulse is carried along the axon where it terminates at the axon terminal
what is the axon terminal
the end of the axon where neurotransmitters are found
what is a myelin sheath
a fatty coating that surrounds the neuron, allows nerve impulses to transmit more rapidly along the axon. If damaged they slow down.
function of sensory neuron
carry messages from the sense receptors in the PNS to the CNS
what size dendrites and axons do sensory neurons have
•long dendrites
•short axons
what is the function of a relay neuron
•connect the sensory neurons to the motor or other relay neurons. allowing motor and sensory neurons to communicate with each other
•they are found only in the brain and spinal cord
what size dendrites and axons do relay neurons what
• short dendrites
• short axons
what is the function of a motor neuron
•connect the CNS to effectors such as muscle glands
what size dendrites and axons do motor neurons have
• short dendrites
• long axons
where is the motor neurons cell body and axon located
the cell body is in the spinal cord the fibre (axon) projects outside the spinal cord to directly or indirectly control effector organs.
synaptic transmission
the process in which one neuron communicates with another by releasing neurotransmitters to diffuse across the synapse.
synapse
- the gap of the end of the axon of one neurone and the dendrite or cell body of another.
- the signal needs to cross the gap to pass on its message. this is done using neurotransmitters that diffuse across the gap between the two neurones.
action potential
electrical impulse. when a neurone is in a resting state it is negatively charged compared to the outside. when a neurone is activated by a stimuli it becomes positively charged for a split second causing an action potential to travel down the axon.
stages of synaptic transmission
- an action potential travels down the axon of the pre-synaptic neuron
- when it reaches the terminal buttons it causes vesicles to migrate and bind with the pre-synaptic membrane triggering the release of a neurotransmitter.
- neurotransmitters diffuse across the synapse and bind with postsynaptic receptors like a lock and key.
- once activated the receptors produce either excitatory or inhibitory effects on the postsynaptic neurone
- Neurotransmitters are then released back into the synapse and go through the process of re-uptake or get metabolised.
What is the Endocrine system
-It is a communication system that instructs glands to release hormones directly into the bloodstream.
-These hormones are carried in the blood towards target organs in the body.
-It works alongside the NS to control vital functions in the body.
What speed does the endocrine system send messages compared to nervous system
It acts much more slowly than the NS but still has powerful effects.
Hormone
•A chemical substance that circulates in the bloodstream and affects target organs.
•Hormones can affect cells in several organs leading to a diverse range of responses
What does the hypothalamus do
•Thehypothalamusis a brain region which is connected to thepituitary gland. is responsible for stimulating or controlling the release of hormones from the pituitary gland.
•regulates the endocrine system.
Pineal gland
- releases melatonin
- responsible for important biological rhythms, including the sleep-wake cycle
Thyroid gland
- releases thyroxine
- responsible for regulating metabolism
Pituitary gland
•master gland
•the hormones released by this gland control and stimulate the release of hormones from other glands
Ovaries
- releases oestrogen
- controls the regulation of the female reproductive system, including the menstrual cycle and pregnancy.
Testes
- releases testosterone
- responsible for the development of make sex characteristics during puberty while also promoting muscle growth