A CH 16 Nervous tissue

Question 0

Peripheral nervous system

Answer 0

All nervous structures outside the cns (cranial nerves with their branches, spinal nerves and their branches, ganglia, enteric plexuses, and sensory receptors.
These link the body to the cns

Question 1

Central nervous system

Answer 1

Composed of brain and spinal cord which are continuous with one another through the foramen magnum of the occipital bone
Source of thoughts, emotions, and memories
Most nerves impulses that stimulate muscles to contract and glands to secrete are here

Question 2

Nerve

And cranial nerves

Answer 2

A nerve is a bundle of hundreds to thousands of axons and associated blood vessels and connective tissue

12 pairs of cranial nerves emerge from the base of the brain

Question 3

How many pairs of spinal nerves are there

Answer 3

31

Question 4

Ganglia

Answer 4

Small masses of nervous tissue consisting primarily of neuron cell bodies that are located outside the brain and spinal cord.

They are closely associated with cranial and spinal nerves

Question 5

Name the functions of the nervous system

Answer 5

Sensory
Integrative
Motor function

Question 6

Sensory

Answer 6

External and internal environment
Neurons called sensory or afferent neurons carry this information into the brain and spinal cord through cranial and spinal nerves

Question 7

Integrative function

Answer 7

Analysis and decision making

Processes sensory info by analyzing and storing some o fit by making decisions for appropriate responses, this is know as integration
Another important function is perception which is the conscious awareness of sensory stimuli

Question 8

What neurons participate in integration?

Answer 8

Interneurons with short axons that contact nearby neurons in the brain or spinal cord
These set up complex circuit boards of the cns and make up majority of the cns

Question 9

Motor function

Answer 9

Stimulates effectors to create a response

• muscle contraction
• glandular secretion

Response after info is integrated
The neurons that stimulate the response are called efferent neurons

Question 10

Somatic nervous system

Answer 10

Part of the pns
Consists of somatic sensory neurons that convey info to the cns from sensory receptors in the skin, skeletal muscles, and joint and from special senses
Involved in input of info to the cns for integration (processing)

Question 10

Somatic nervous system

Answer 10

Part of the pns

Question 11

Somatic motor neurons

Answer 11

Part of the sns
Conveys info from the cns to skeletal muscles only
These somatic pathways are involved in the output of info from the cns that results in muscular contraction
The actions of the sns are voluntary

Question 12

Autonomic nervous system

Answer 12

Part of pns
Involuntary
Has sympathetic division and parasympathetic division
Has autonomic sensory neurons and autonomic motor neurons

Question 14

Sympathetic vs parSympathetic divisions

Answer 14

Sympathetic is fight or flight

Parasympathetic is rest and digest

Question 15

Enteric nervous system

Answer 15

Part of pns
Called the brain of the gut
Consists of over 100 million neurons that occur throughout most of the length of the gastrointestinal tract
Has sensory and motor components and can operate independently from the cns
Involuntary

Question 16

Neuroglia

Answer 16

Or glia or glial cells
Smaller than neurons and more numerous
In case of injury or disease neuroglia multiply to fill in the spaces formerly occupies by neurons

Question 17

Gliomas

Answer 17

Brain tumors derived from glia

Tend to be highly malignant and rapidly growin

Question 18

Astrocytes

Answer 18

BBB- blood brain barrier
Star shaped with armlike projections
Two types protoplasmic found on gray matter and fibrous in white matter
Support neurons, selectively permeable to protect the brain, help maintain appropriate chemicals for generation of nerve impulses, play a role in learning and memory

Question 19

Oligodendrocytes

Answer 19

Responsible for Myelin sheath in the cns

Question 20

Microglial

Answer 20

Originate in red bone marrow and migrate to the cns as it develops
Function as phagocytes

Question 21

Ependymal

Answer 21

Have microvilli and cilia

Produce cerebral spinal fluid

Question 22

Schwann cells

Answer 22

Flat cells that incircle the pns
Form myelin sheath around axons
Only Myelinates a single axon
Participate in axon regeneration

Question 23

Satellite cells

Answer 23

In pns
Support ganglia
Flat cells that surround the cell bodies of neurons of pns ganglia
Provide support

Question 24

Myelin sheath

Answer 24

A multilayered lipid and protein covering surrounding an axon
The sheath electrically insulates the axon of a neuron and increases the speed of the nerve impulse conduction

Question 25

What neuroglia produce myelin sheaths

Answer 25

Schwann cells

Oligodendrocytes

Question 26

Nodes of Ranvier

Answer 26

Gaps in myelin sheath
Speeds up nerve impulses because it can jump the gap instead of slowly through every part of the membrane in unmyelinated axons

Question 27

Neurolemma

Answer 27

Plasma membrane of axons

Question 28

Demyelination

Answer 28

Refers to the loss or destruction of myelin sheaths around axons

Question 29

Neurons

Answer 29

Electrically excitable and conduct nerve impulses or action potentials
Cell body which has mostly organelles and nucleus
Nerve fibers which are the dendrites and axons

Question 30

Neuron

Answer 30

Single nerve cell

Question 31

Nerve

Answer 31

Bundle of axons

Question 32

Ganglia

Answer 32

Cluster of nerve cell bodies outside the cns

Question 33

Nucleus

Answer 33

Cluster of nerve cell bodies inside the cns

Question 34

Nissl bodies

Answer 34

Clusters of rough endoplasmic reticulum

These are responsible for high levels of protein synthesis

Question 35

Dendrites

Answer 35

Receiving or input portions of a neuron
Short and highly branched, extend from cell body
Each type of neuron has a similar branching pattern
Cytoplasm of dendrites contains nissl bodies, mitochondria, and other organelles

Question 36

Axon

Answer 36

Is the other type of nerve fiber besides a dendrite
Very in length and communicate with neighboring cells
Carries nerve impulses toward another neuron, a muscle fiber, or gland cell

Question 37

Axoplasm

Answer 37

Cytoplasm of an axon

Question 38

Axolemma

Answer 38

Plasma membrane of axon

Question 39

Synaptic end bulbs

Answer 39

Tips of axon terminals

Contain many tiny membrane enclosed sacs called synaptic vesicles that store neurotransmitter

Question 40

Multipolar neuron

Answer 40

Have several dendrites and one axon

Most neurons in the brain and spinal cord (interneurons) are multipolar, as are all motor (efferent) neurons

Question 41

Bipolar neurons

Answer 41

Have one main dendrite and one axon

They are found in the retina of the eye in the inner ear and in the olfactory area of the brain

Question 42

Unipolar neurons

Answer 42

Sensory neurons that begin in the embryo as bipolar neurons

Cell body is off to the side and there is a gap between the peripheral process and dendrites

Question 43

White matter

Answer 43

Bundles of myelinated axons

Question 44

Gray matter

Answer 44

Contains neuronal cell bodies, dendrites, unmyelinated axons, axon terminals and glial cells
Nissl bodies cause the gray color

Question 45

Diverging circuit

Answer 45

The nerve impulses from a single presynaptic neuron causes the stimulation of increasing numbers of cells along the circuit

A single presynaptic neuron may synapse with several postsynaptic neurons, it premits one presynaptic neuron to influence several postsynaptic neurons

(Looks like a tree, with one leading to two, and those two having two more)

Question 46

Converging circuit

Answer 46

Several presynaptic neurons synapse with a single postsynaptic neuron
Arrangement allows for effective stimulation of the postsynaptic neuron
It receives nerve impulses from several different sources

Question 47

Reverberating circuit

Answer 47

Causes a series of nerve impulses
The incoming impulse stimulates the first neuron, which stimulates the second, which stimulates the third, and so on.
Branches from later neuron synapse with earlier ones
Breathing, coordinated muscular activities, waking up, sleeping and short term memory

Question 48

Parallel after discharge circuit

Answer 48

A single presynaptic cell stimulates a group of neurons each of which synapses with a common post synaptic cell
One long one with two other coming off the sides