Nervous system Flashcards
Name the two divisions of the nervous system
Central nervous system [CNS]
Peripheral nervous system [PNS]
Name the two components of the Central Nervous System (CNS)
Brain and spinal cord
What is the peripheral nervous system (PNS) made up of?
Nervous tissue outside the CNS
What are the subdivisions of the PNS?
1) Somatic nervous system (SNS)
2) Enteric nervous system (ENS)
3) Autonomic nervous system (ANS)
[ANS consists: sympathetic and parasympathetic]
Nervous tissue is composed of 2 types of cells. Name them and their overall function.
1) Neurons (nerve cells): convert stimuli into nerve impulses and conduct nerve impulses to other neurons, muscle fibres or glands (action potential)
2) Neuroglia: protective and supporting cells
Name the overall functions of the nervous system
Control and integrate all body activities within limits that maintain life
What are the 3 basic functions of the nervous system?
Sensory (receptors detect stimuli)
Integrative (process sensory information)
Motor (response)
A neuron possesses electrical excitability. Explain what this term means.
The ability to respond to stimuli and convert it into an action
As a result of specialisation, what have neurons lost the ability to do?
Mitosis
Function of dendrites
Receptor sites
What is a collection of cell bodies in the CNS called?
Nucleus
What is a collection of cell bodies in the PNS called?
Gangelion
Name the three (3) functional classifications of neurons and describe which direction the nerve impulse is conveyed.
Sensory: action potential conveyed into the CNS through cranial or spinal nerves
Motor: away from CNS
Interneurons: integrate (process) incoming sensory info and elicit a response
What is white matter composed of?
Myelinated axons
What is grey matter composed of?
Neuronal cell bodies, dendrites, unmyelinated axons, axon terminals and neuroglia
Describe two (2) functions of the myelin sheath.
Electrically insulates the axon of a neuron
Increases speed of nerve impulse conduction
What are the two types of electrical signals that neurons communicate through?
Graded potential
Action potential
How do graded and action potentials differ according to the distance travelled?
Graded = local
Action = long distance
Name the four different ions channels that can change the membrane potential of a neuron.
1) Leak channels: Randomly open and closed
2) Ligand-gated channel: Responds to ligand (chemical) stimulus
3) Mechanically gated channel: Responds to mechanical stimulation (vibration, touch, pressure)
4) Voltage-gated channel: Responds to change in membrane potential In axons of all neurons
What is the typical value of the resting potential in a neuron?
-70mV
