Module 3 Overview Flashcards
Nervous system functions
- sensory input
- interpretive and integrative functions
- Motor output
- higher mental functioning and emotional responsiveness
Nervous system is split into… (2)
Central nervous system and peripheral nervous system
Central nervous system includes… (4)
- brain
- meninges
- cerebrospinal fluid (CFS)
- spinal cord
2 divisions of Peripheral nervous system (PNS)
- somatic nervous system ( consciously controlled )
- autonomic nervous system
2 divisions of autonomic nervous system
Parasympathetic (rest & digest)
Sympathetic (fight or flight)
The peripheral nervous system has __ pairs of nerves: ___ cranial and ___ spinal
43 pairs, 12 cranial, 31 spinal
Major regions of brain (4)
- cerebrum
- diencephalon
- cerebellum
- brain stem
There are 2 types of cells in the nervous system: neurons and neuroglia (glial cells). What are key differences between them?
Neurons conduct nerve impulses. Neuroglia cannot.
Neuroglia never lose their ability to divide.
Neuroglia cells support, nourish, protect, insulate, and organize neurons.
Neuroglia:
_________ produce myelin around axons in the CNS
_________ produce myelin around axons in the PNS
Oligodendrocytes (CNS)
Schwann Cells (PNS)
3 parts of a neuron
Dendrites (transmit impulse —> toward —> cell body)
Cell body
Axon ( carry the nerve impulse AWAY from cell body)
The gaps in the myelin sheath are called _______
Nodes of ranvier
The functional unit of the nervous system is called…
Reflex arc
A reflex arc consists of these 3 neurons
- afferent
- interneuron
- efferent
What is an afferent nerve?
A sensory nerve that carries impulses/signals to brain or spinal cord and UP the spinal column
What is an efferent neuron?
Carry message from brain to spinal cord to muscle or gland. Signals travel DOWN the spinal column
What is the function of an interneuron?
Process information
Connective tissue components of nerves:
- _________ surrounds each nerve fibre (SMALLEST)
- _________ surrounds groups of fibres (fascicles)
- _________ surrounds groups of fascicles, forming a nerve
- Endoneurium (Endo = inside, within)
- Perineurium (Peri = around, near)
- Epineurium (Epi = over, above)
Define summation
The amount of stimuli needed to reach threshold stimulus
Define threshold
The minimum level of intensity a stimulus must reach to generate a nerve impulse
What is myelin?
A white layer of cells that surrounds axons to insulate and increase the speed of impulses
Continuous conduction: nerve impulses travel along _______ axons and is ________ than saltatory conduction
Unmyelinated axons; slower
Saltatory conduction: nerve impulses travel along ________ axons and is ______ than continuous conduction
Myelinated; faster
The sodium potassium pump exchanges sodium and potassium at a ratio of ____
3:2
Meninges are connective tissue covering the brain and spinal cord. Name the 6 layers and spaces from INNER to OUTER.
INNER (DEEPEST LAYER)
Pia Mater
Subarachnoid space
Arachnoid
Subdural space
Dura mater
Epidural space
OUTER (MOST SUPERFICIAL)
