UNIT 3 Flashcards
State the function of the central nervous system (CNS)?
It Processes and coordinates sensory information
Name the structures which make up the CNS?
brain and spinal cord
State the function of the peripheral nervous system (PNS)
Carry information to and from the CNS
Name the structures which make up the PNS?
Nerves outside brain and spinal cord
Name the two branches of the PNS?
Somatic and autonomic nervous systems
Name the part of the brain which sends impulses along the autonomic nervous system (ANS)?
medulla
List the effects of the sympathetic and parasympathetic systems on the body
Sympathetic:
increase :heart rate, breathing rate
Decrease: peristalsis and intestinal secretions
- Parasympathetic:
Increase: peristalsis and intestinal secretion
Decrease: heart rate and breathing rate
Explain the term antagonistic?
Have opposite actions/effects
Describe the role of sensory and motor neurons?
- Sensory: take impulses from sense organs to CNS
- Motor : take impulses from CNS to muscle and glands
Describe how the nervous system is divided into branches?
CNS and PNS
Identify converging, diverging and reverberating neural pathways?
- Converging: Impulses from several neurons travel to one
neuron - Diverging: Diverging:
Impulses from one neuron travel to several
neuron so affecting more than one destination
at the same time. - Reverberating: neurons later in the pathway can link with earlier neurons which allows the impulse to travel through the pathway again
Name and identify the parts of a neuron? And their function?
- Dendrites : receive impulses and send them to cell body
- Cell body: Expresses proteins required
for nerve transmission
Contain nucleus and mitochondria for ATP - Axon:Carries impulses away from cell body towards synapse and the next neuron
- Myelin sheath: insulates the axon and increases the speed of impulse conduction
Describe the movement of an impulse through a neuron?
An electrical nerve impulse travels along the axon. of the first neuron
Describe the process of myelination?
The process of forming myelin sheath around an axon
Explain why individuals under 2 years old are not as coordinated as older individuals?
myelination is not complete till they reach adolescense
Explain why multiple sclerosis can cause loss of coordination?
They cause the coordination loss by damaging the myelin sheath
State two functions of glial cells?
1- physically support neuron
2- produce myelin sheath
Name the point where neurons connect with other neurons or muscle fibres?
Synaptic cleft
Describe the role of neurotransmitters?
are chemical messengers that transfer signals across synapses between neurons
Identify the parts of a synapse?
Presynaptic neuron, synaptic cleft , postsynaptic membrane
Name the structures which store neurotransmitters?
Vesicles
Describe what happens to the vesicles upon arrival of an impulse?
They release neurotransmitters into the synaptic cleft
Describe how neurotransmitters travel across the synaptic cleft?
Through diffusion
Name the structures which the neurotransmitters bind to?
Specific receptors on the postsynaptic membrane