N2 PNS CNS and cells

What is the central nervous system and function?

-Brain and spinal cord
-Integrative and control centers

What is peripheral nervous system and function?

-Cranial nerves and spinal nerves
-communication lies between CNS and the body

how many pairs of cranial nerves and spinal nerves in human body?

12, 31 pairs

Nervous system from primary to respond

sense(sensory), integrate(integration), respond(motor output)

Example for sense, integrate, respond

see red light, process info, hits brake

What is the efferent division of the peripheral nervous system?

Motor division

What is the afferent division of the peripheral nervous system?

sensory division

What is the sensory division

-Somatic and visceral nerve fibers

-conduct impulses from receptors to CNS

What is motor division?

-motor nervous fibers
-conducts impulses from CNS to muscle

What are the systems of Motor division?

Somatic nervous system, autonomic nervous system

What is the somatic nervous system?

-somatic motor nerve fibers (voluntary)
-conducts impulses from CNS to skeletal muscles

What is autonomic nervous system?

-visceral motor nerve fibers(involuntary)
-conducts impulses from CNS to smooth muscle, cardiac muscle, and glands

What are the division in autonomic nervous system?

sympathetic , parasympathetic

What is the sympathetic division?

-flight or fight
-mobilizes body systems during activities
-only goes from T1 to L2 (thoraco-lumbar)
-heart rate increase

What is parasympathetic division?

-conserves energy

-promotes housekeeping function during rest
-contains the brain, cranial, and sacrum (Cranial-sacral)
-heart rate decrease

What is neuroglia also called?

glial cells

What are the three parts?

nuclei of supporting cells, cell body of a neuron, neuron process(dendrites and axon)

What is the neuroglia?

support and maintain neurons

how many types of neurogila are in CNS and PNS

four and two?

What neuroglia cells are in the CNS?

astrocytes, microglial cells, ependymal cells, and oligodendrocytes

What neuroglia cells are in the PNS?

satellite cells and schwann cells

Which cells make the myelin sheath in the CNS or PNS?

CNS: oligodendrocytes
PNS: Schwann cells

What is astrocytes?

-star-shaped cells
-maintain the blood-brain barrier
-most abundant CNS neuroglia
-helps regulate chemical envrionment

What is microglia cells?

-immune cells in CNS
-perform phagocytosis
-brain’s defense system

What are ependymal cells?

-line cerebrospinal fluid-filled CNS cavities
-some have cilia that help circulate CSF

What are satellite cells?

-physical support
-regulate chemical/ionic environment

What is function of dendrites?

receptive regions

What is the function of Cell body?

biosynthetic center and receptive region

What is the function of axon?

impulse-generating and conducting region

What is neuron cell body also called?

perikaryon and soma

What does a neuron cell body consist of?

spherical nucleus(with a conspicuous nucleolus) surrounded by cytoplasm

What is the nuclei in neuron cell body?

clusters of cell bodies in the CNS

What is the ganglia in neuron cell body?

cluster of cell bodies that lies along the nerve of the PNS

What does the CNS mainly contain?

neuron cell bodies and their processes

What does the PNS mainly contain?

neuron process(who cell bodies are in the CNS)

What do the neuron processes contain?

dendrites and axons

What are the structures and function of dendrites?

-short tapering extensions
-main receptive and input regions, large surface area for receiving signals from other neurons to the cell body

What is the dendritic spine?

represent the point of close contact (synapses)

What is the axon hillock?

cone-shaped area of the cell bodies

What are the axon collaterals?

occasional branches along its length

What are the terminal branches?

the axon’s end

What is the axon terminal?

the knob-like endings of the terminal branches

What is the main function of the axon?

transmit impulses away from the cell body

What is the trigger zone of the axon?

the impulse at the initial segment of the axon

What is the secretory region of the axon?

impulses from axon and axon terminal

What are the tracts?

bundle of axons in CNS

What are the nerves?

bundle of axon in PNS

What are the three neuron types?

multipolar, bipolar, unipolar

What is the difference between structural class and functional class?

structural class separates neuron type by the number of processes extending from the cell body, functional class seperates neuron type by the direction of impulse conduction

What is the structure and function of a multipolar neuron?

Structure:
- many processes, all are dendrites and except single axon

Function:
-Most are interneurons in the CNS, one chain of CNS/single neuron connecting sensory and motor neurons

-Some motor neurons: efferent pathways to effectors

What is the structure and function of a bipolar neuron?

Structure:
-Two processes, including a fused dendrite and an axon
Function:
-Most are sensory neurons in special sense organs
-Retina transmits visual inputs from the eye to the brain (intermediate chain of neurons)

What is the structure and function of unipolar neuron?

Structure:
-One process that extends from the cell body, forming an axon from the central and processes
Function:
-Most are sensory neurons
-Afferent pathway for interpretation(primary or first order sensory neurons)

What does myelin do?

-protects and electrically insulates fibers
-increases transmission speed
-covers nerve fiber with large diameters

What do oligodendrocytes have?

- flat process that can coil around 60 axons at the same time
-have nodes of Ranvier to seperate myelin sheath

What do Schwann cells have?

-wraps themselves like a jelly roll
-have nodes of Ranvier to seperate myelin sheath