Biological Psychology Flashcards
Structural organisation
Subsections of the nervous system
The central nervous system
The peripheral nervous system
The central nervous system
Spinal cord
Brain
Co-ordination
Integration
Peripheral nervous system
Nerves (outside the brain and spinal cord)
Somatic and autonomic
Motor and sensory
Sympathetic and parasympathetic
Transmission of neurons
The nervous system
- Highly complex part of an animal- co-ordinates its actions and sensory information, -transmitting signals to and from parts of the body.
- The nervous system detects environmental changes that impact the body, then works in tandem with the endocrine system to respond to such events
-produces and relays messages between the brain, spinal cord and a network of neurons.
Subsections of the peripheral nervous system
Somatic
Autonomic
Somatic Nervous System
Voluntary movement of muscles
Have to think about
Stimulatory only
Controls skeletal muscle movement(reflex responses)
Autonomic Nervous System
Involuntary - automatic, subconscious, without thinking, cannot control
Can be stimulatory or inhibitory
Controls muscle movement (not skeletal muscles)
(Internal organs and glands)
Eg.
Heart rate
Blood pressure
Respiration
Digestion
Sexual arousal
Subsections of the somatic nervous system
Sensory
Motor
Subsections of the autonomic nervous system
Parasympathetic
Sympathetic
Central nervous system explained
- carries sensory info up the spinal cord (sensory neurons)
- carries motor messages to the PNS (motor neurons)
Spinal cord
Cable of nerve fibres that runs from the base of the brain to the lower back and connects the brain to the PNS
Peripheral nervous system explained
- carries sensory info to CNS from the body
- carries motor info from the brain to organs and muscles in the body
Autonomic nervous system explained
- carries motor messages from the brain to internal glands and organs - motor neurons
- carries sensory messages to the brain about the activity level of glands and organs - sensory neurons
Somatic Nervous system explained
- carries sensory info received by sensory receptor cells to the CNS - sensory neurons
- carries motor messages from the CNS to skeletal muscles - motor neurons
Parasympathetic
Rest and digest (calming)
- pupils contrict
- salivation
- airways constrict
- heart rate slows
- stomach digests
- intestines digest
- bladder constricts
- reproductive system increases blood flow
Sympathetic
Fight or flight (arousing)
- regulates the glands and internal organs function to physically prepare the body
- pupils dilate
- saliva inhibited
- airways dilate
- heart rate increases
- stomach inhibits digestion
- liver releases glucose
- intestines inhibit digestion
- kidneys release adrenaline
- bladder relaxes
- reproductive system decreases blood flow
Sensory (afferent)
- transmit info to the CNS from sensory organs and receptors within muscles
Eg.
-muscle tension
- pain
- joint angle
- damaging stimuli eg heat or toxins
- adapted or special receptors as hearing and vision
Motor (efferent)
Transmit info from the CNS to cause muscles to contract
Features of a neuron
Dendrites, Soma, axon, myelin, axon terminal
Dendrites
Fibres that receive and convey messages to cell body
Soma (cell body)
Metabolic centre of the cell (contains the nucleus)
Axon
Fibres that conduct electrical impulses away from the cell body
Axon terminal
- Branching fibres at the end of the axon, contains vesicles filled with neurotransmitters.
- Axons branch into hundreds/thousands of axon terminals, which contain vesicles (sacks) of neurotransmitters.
- when a nerve impulse reaches the axon terminals, it stimulates the release of neurotransmitters
Myelin sheath
whitish fatty material called myelin, which insulates the nerve fibre and increases the rate of transmission of the nerve impulse
Synapse
- neurons don’t actually touch each other. The gap between them is called the synapse. (Synaptic cleft)
- Neurotransmitters diffuse across the synapse to continue cell to cell communication.
- Synapses connect neurons and help transmit information from one neuron to the next.
- Places where neurons connect and communicate with each other.
- Is a small gap at the end of a neuron that allows a signal to pass from one neuron to the next.
Three types of neurons
Sensory neuron (unipolar)
Interneuron (bipolar)
Motor neuron (multipolar)
Sensory neuron
Sensory neurons, unipolar.
- process sensory information from the sense organs and carry the sensory messages to the spinal cord ad brain (CNS)
Motor neurons
Motor neurons, multipolar
- carry motor messages from the spinal cord and brain (CNS) to the muscles, glands and organs of the body
Interneurons
Interneurons, bipolar
- act as the connection between sensory neurons and motor neurons and transfers messages from sensory neurons and motor neurons within the CNS.
- Integrate and co-ordinate motor and sensory neurons
- belong in the brain and spinal cord
Direction of transmission
- from the dendrites, to the cell body, then along the the axon to the axon terminals.
- when the action potential reaches the axon terminals, it causes the release of neurotransmitters into the synaptic cleft.
What effects the speed of the action potential in the neuron
The speed of the action potential through neurons depends on the thickness of myelin sheath that covers the axon.
Action potential
‘The electrical impulse’
The electrical impulse that travels along the axon of neurons towards the axon terminals where it causes the release of neurotransmitters into the synaptic cleft.
Electro-chemical signals
- Neurons carry electro-chemical signals, as an electrical nerve impulse travels through the neuron (axon) and neurotransmitters travels between the synapse of neurons.
- the electrical nerve impulse are the ‘electro’ component and the neurotransmitters are the ‘chemical’ component of the signal.