Chapter 5: Nervous System Flashcards
Nervous system 3 functions
Sensory
Integration
Motor output
Sensory input
Gathering information from receptors
Integration
Processing of info and decision making
Motor output
Signal to cause a response
Central nervous system
The brain and spinal cord, the integration centers
Peripheral nervous system
Outside the CNS, cranial nerves and spinal nerves
2 divisions: sensory and motor
Sensory division
Conveys info to the CNS from muscles and skin and organs
Motor division & parts
Conveys impulses from the CNS to muscles and glands
Autonomic nervous system
Part of motor division
motor neurons controlling smooth and cardiac muscles and glands ( involuntary )
-sympathetic: fight or flight
-parasympathetic: rest or digest
Cells of nervous tissue
- Neurons: excitable cels that carry nerve impulses
2. Neuroglia: the supporting cells
Neuroglia of the CNS
- Astrocytes
- microglia
- Ependymal cells
- Oligodendrocytes
Astrocytes
Attach neurons to capillaries and regulate the chemical environment
Microglia
Act as phagocytes
Ependymal
Line fluid filled spaces of CNS and circulate fluids via cilia
Oligodendrocytes
Form the myelin sheath insulations if CNS neurons
Neuroglia of the PSN
Satellite cells: surround neuron cell bodies, function unknown
Schwann cells: form the myelin sheath insulation’s of PNS neurons
Neuron
The functional units of nervous tissue, having the ability to conduct impulses
Neuron characteristics
Longetivity
Amitotic
High metabolic rate
Parts of a neuron
Soma Dendrites Axon Terminal branches Axon terminal Nucleus Ganglion Tract Nerve
Soma function
Contains cytoplasm, nucleus, and organelles
Dendrites
Many
short processes that rely input toward the soma
Terminal branches
Divisions at end of axon
Axon terminal
Bulbous ends of axons containing neurotransmitters
Nucleus
A cluster of neuron cell bodies in the CNS
Ganglion
A cluster of neuron cell bodies in the PNS
Tract
A cluster of axons in the CNS
Nerve
A cluster of axons in the PNS
Myelin sheath
White fatty wrapping of nerve fibers
Insulate the fiber
Formed by Schwann cells
Multipolar neurons
Most common type, many dendrites and one axon
Bipolar neurons
Very rare, one dendrite and one axon
Unipolar neurons
Only one process (an axon) with receptive and secretory ends
Sensory (afferent) neurons
Relay impulses to the CNS
Motor (efferent) neurons
Relay impulses from the CNS to muscles and glands
Interneurons
Found between sensory and motor, located within the CNS
