Chapter 12: Neural Tissues Anatomy

Question 1

Central Nervous System (CNS)

Answer 1

Brain and Spinal Cord - INTEGRATION

Question 2

Peripheral Nervous System (PNS)

Answer 2

Neural Tissues outsides the CNS. (Cranial nerves, spinal nerves, peripheral nerves, and receptors.)

Question 3

Nervous System Overview

Answer 3

1. Provides quick responses to stimuli
2. Maintains Homeostasis

Question 4

Nervous System Functions

Answer 4

1. Sensory Input
   - monitor stimuli
2. Integration
   - process stimuli
3. Motor Output
   - send reaction to stimuli

Question 5

Classification of the PNS

Answer 5

1. Sensory - Afferent division
2. Motor - Efferent division

Question 6

Collaterals

Answer 6

Branches

Question 7

Sensory division of the PNS

Answer 7

Carries information to the CNS from sense receptors (input)
1. Somatic - from sense receptors in skin/muscle
2. Visceral - from sense receptors in organs

Question 8

Somatic Nervous System (Motor)

Answer 8

Voluntary, towards skeletal muscles

Question 9

Motor division of the PNS

Answer 9

Carries impulses away from the CNS towards effectors (Muscles and Glands) OUTPUT

Question 10

Autonomic Nervous System (Motor)

Answer 10

Involuntary; towards smooth muscles, glands, and cardiac muscles.

Question 11

Neuron Function

Answer 11

1. Respond to stimuli
   2.Conduct nerve impulses

Question 12

Dendrites

Answer 12

Receive stimuli; receptive function

Question 13

Axon

Answer 13

Conduct impulses; conductive function

Question 14

Neurons Characteristics

Answer 14

1. Amitotic
2. High demand for o2 (only o2)
3. Extreme longevity

Question 15

Neuron Cell Body

Answer 15

Contains the nucleus
1. Biosynthetic system: rough ER, Mitochondria.
2. Ribosomes, neurofibrils

Question 16

Axon Hillock

Answer 16

Initial segment; connection to cell body

Question 17

Structural Classification of Neurons

Answer 17

1. Anaxonic
   2.Bipolar
2. Unipolar
3. Multipolar

Question 18

Axoplasmic Transport

Answer 18

Trasnport of substances in axon between synaptic terminals and cell body

Question 19

Telodendria

Answer 19

Fine extensions; excretory function

Question 20

Anaxonic Neuron

Answer 20

1. No distinction between axon and dendrites
2. Brain and special sense organs
3. Function is poorly understood

Question 21

Bipolar Neurons

Answer 21

1 Two processes: Axon and Dendrites
2. Rare

Question 22

Unipolar Neurons

Answer 22

1. Dendrites and axon are continuous
2. Makes up most sensory neurons in the PNS

Question 23

Multipolar Neurons

Answer 23

1. Many dendrites and one axon
2. Most common
3. Makes up motor and some interneurons

Question 24

Sensory Neurons (Afferent)

Answer 24

Deliver information from sense receptors towards CNS

Question 25

Exteroceptors (Sensory)

Answer 25

info. about external environment; touch, temp, sight, hearing, taste, smell

Question 26

Interoceptors (Sensory)

Answer 26

monitor viscera; deep pressure, pain, distention

Question 27

Proprioceptors (Sensory)

Answer 27

Position and movement of joints and muscles

Question 28

Motor Neurons (Efferent)

Answer 28

1. Deliver information to muscles and glands 2. Form the efferent division of the PNS (Somatic and Autonomic)

Question 29

Interneurons (Associated)

Answer 29

1. Most within the CNS 2. Higher functions; Integrate (process and analyze) 3. Distribute sensory input and coordinate motor output 4. 99% of neurons in body

Question 30

Neuroglia

Answer 30

Mitotically active supportive Cells

Question 31

Ependymal Cells (CNS Neuroglia)

Answer 31

1. Lines fluid filled cavities of the CNS 2. Assist in producing, circulating, and monitoring cerebrospinal fluid

Question 32

Astrocytes (CNS Neuroglia)

Answer 32

1. Maintain Blood –Brain barrier 2. Isolation of CNS from general circulation 3. Regulate composition of interstitial fluid of CNS 4. Structural support 5. Form scar tissue

Question 33

Microglia (CNS Neuroglia)

Answer 33

Phagocytic Cells

Question 34

Oligodendrocytes

Answer 34

1. Myelination of CNS axons; one cells wraps around many axons 2. NO Neurilemma

Question 35

Myelination

Answer 35

The process of acquiring a myelin sheath

Question 36

Satellite Cells (Neuroglia PNS)

Answer 36

1. Surround neuron cell bodies within ganglia 2. Regulate exchange with interstitial fluid

Question 37

Schwann Cells

Answer 37

Myelinating cells of the PNS; wrap around the axon

Question 38

Myelin Sheath

Answer 38

1. Fatty wrapping around axon 2. Electrically insulates and protects 3. Increases speed of transmission of signal (150x) 4. Loss of myelin = loss of function ! Cell membrane of Schwann Cell !

Question 39

Neurilemma (PNS)

Answer 39

Outer layer with cytoplasm and nucleus of Schwann cell

Question 40

Nodes of Ranvier

Answer 40

1. Gaps between cells 2. Important in sending the signal

Question 41

White Matter of CNS

Answer 41

Myelinated fibers

Question 42

Gray Matter of CNS

Answer 42

Unmyelinated fibers and cell bodies

Question 43

PNS Axon Repair

Answer 43

1. Schwann cells have neurilemma 2. Form a guiding canal 3. Can regrow damaged axons

Question 44

CNS Axon Repair

Answer 44

1. Oligodendrocytes have no neurilemma 2. Can not reconnect 3. Astrocytes secrete chemicals that block regrowth and they form scar tissue