Chapter 14 Self Study
A nerve is...
A bundle of parallel axons
Factors that affect PNS regeneration
Amount of damage Distance btwn injury and effector organ
Endoneurium is made of
Areolar connective tissue
What functional division of the nervous system provides involuntary control of smooth muscle?
Autonomic motor
What helps connect the axon to the soma?
Axon hillock
What are the reasons for very limited regeneration of damaged axons in CNS?
Axons are crowded in the CNS Astrocytes create scar tissue inhibiting growth
The neurons in the retina of the eye are...?
Bipolar
fascicle
Bundle of axons
Satellite cells are found surrounding ..?
Cell bodies
Ependymal cells help produce?
Cerebrospinal fluid
Two primary functions of the nervous system
Control and communication
The neural plate is a thickened region of the:
Ectoderm
The muscle and gland cells that receive nerve impulses from motor neurons are called...
Effectors
Synapses are classified as:
Electrical and chemical
Order the connective tissue wrappings of a nerve from deep to superficial
Endoneurium Perineurium Epineurium
True or false: neurons far outnumber glial cells
False
Myelin sheath is made of a large portion of...
Fats
How are neurons classified depending on the direction the nerve impulse travels?
Functionally
Peripheral nervous system is composed of what structures?
Ganglia Spinal nerves Cranial nerves
Unipolar neurons
Have a single process that emerges from the cell body and branches like a T
Function of Astrocytes
Help form the blood brain barrier Replaces damaged neurons Regulates composition of tissue fluid
Basic characteristics of a neuron
High metabolic rate Depend on high levels of oxygen and glucose Respond to stimuli
Glial cells are found...
In both the central and peripheral nervous systems
The visceral sensory division is under _________ control
Involuntary
Which glial cell acts as a phagocyte?
Microglial cell
Three diseases caused by destruction of myelin sheath
Multi focal motor neuropathy MS Gullain-Barre syndrome
Function of oligodendrocyte
Myelinated axons in the CNS
Function of neurolemmocytes
Myelinated axons in the PNS
What has several neurons processing the same info at one time?
Parallel-after-discharge circuits
Function of microglial cells
Phagocytize waste
A tumor that originated within the organ it is found is called a ...
Primary tumor
Function of satellite cells
Protects cell bodies in PNS ganglia
Neurofibrils
Provide tensile strength for the axons and dendrites
Do dendrites send or receive messages?
Receive
A ____________ neuron transmits stimuli to the interneuron.
Sensory
If a(n) ___________ detects a painful stimulus, it will send a signal to a(n) ____________ in the CNS for processing. This may result in a(n) ___________ stimulating muscle contraction, moving the body away from the painful stimulus.
Sensory neuron, interneuron, motor neuron
Divisions of the motor nervous system
Somatic and autonomic
Divisions of the sensory nervous system
Somatic and visceral
Stimulus of itchy nose was detected by the _________ division of the sensory nervous system and the command to scratch was carried out by the ________ division of the motor nervous system
Somatic sensory, somatic motor
The cell bodies of most motor neurons lie in the:
Spinal cord
Central nervous system is composed of what structures?
Spinal cord Brain
What is the name of the slightly expanded region at the tip of the terminal arborizations?
Synaptic knobs
What helps create the gray color in parts of the brain and spinal cord?
The chromatophilic substance
What helps circulate the CSF?
The cilia of ependymal cells
What is responsible for OUTPUT of info from the CNS?
The motor nervous system
What division of the nervous system receives info from the eyes, ears and skin?
The somatic sensory
The blood brain barrier helps protect the brain from ...
Toxins
Where do synapses occur?
Where axons contact muscles, glands, and other neurons
Bipolar neurons
neurons with two processes, an axon and a dendrite
