Chapter 11 Flashcards
How fast is the major control system?
100 m/second
What does the central nervous system consist of?
all of the neurons and support cells in the brain and spinal cord
What does the peripheral nervous system consist of?
- All nervous tissue outside of the CNS/brain and spinal cord
- Cranial nerves from brain and spinal nerves from spinal cord
Describe the 2 types of cells in the PNS.
- sensory- inputs from various receptors
- motor- output to effectors
Describe the somatic nervous system.
It gives conscious and voluntary control of skeletal muscle
Describe the autonomic nervous system
It is involuntary control of viscera (GI, blood vessels, heart, lungs)
Describe the parasympathetic and sympathetic parts of the autonomic nervous system.
Parasympathetic: homeostasis, steady state, “rest and digest”
Sympathetic: “fight or flight:, wants change
Describe sensory neurons
- detect changes through stimuli both outside and inside body
- PNS input carried to CNS via sensory or afferent neurons
Describe integration neurons
- they interpret sensory information, storage and decision making
- they use inter or association neurons of CNS
Describe motor neurons
- response and action due to stimulus and/or integration commands
- use motor of efferent neurons to communicate to target effectors (muscles and glands)
Describe neuroglial cells
- supportive
- about 50:1 neuroglial cell to neuron ratio
Describe astrocytes
- between nervous tissue and blood vessels
- structural support
- regulates CNS ion concentrations (suck up sodium, release potassium if necessary)
- forms scar tissue after injury
Describe ogliodendrocytes
- rows between neurons
- form myelin sheath for insulation
Describe ependymal cells
- epithelial-like/sheet membrane
- enclose fluid filled spaces in CNS such as ventricles of brain and central canal of spinal cord
- make cerebrospinal fluid
Describe Schwann cells
- PNS only
- cells form lipid and protein myelin insulation
- wrapped
- similar oligodendrocytes
Describe satellite cells
- support cluster of neuron cell bodies called ganglia
Describe neurons/nerve cells
- high metabolic rate and will die without O2
- growth and development regulated by trophic factors like nerve growth factor and brain-derived neurotrophic factor
Describe the cell body (soma or perikaryon)
cytoplasm, nucleus, and organelles
Neurofibrils
- threadlike proteins that extend into axon
- provide support and shape
Nissil bodies
- same arrangement of rough ER
- synthesize proteins for repair and growth
Dendrites
- many short, highly branched
- receptive (input) surface, conducts toward cell body
Axon
- carries signal away from cell body
- only 1 per neuron
- arises from axon billock which is a cone-shaped elevation where nerve impulses leave cell body at trigger zi
Nodes of Raniver
gaps between Schwann cells that allow fast saltatory conduction ( gap to gap )
Myelinated Matter vs Unmyelinated Matter
White matter is myelinated
Gray Matter is unmyelinated
Myelinated axons conduct faster than unmyelinated
