Chapter 12 - Nervous tissue and Nervous system

Question 1

Nervous System

Answer 1

THE master control and communications center in the body
Communication occurs via electrical signals
Three overlapping functions

Question 2

Three overlapping functions of the Nervous System

Answer 2

Sensory receptors monitor changes
Integration (processing and interpreting)
Response (motor output)

Question 3

Central Nervous System (CNS)

Answer 3

Brain and spinal cord

Integrative and control centers

Question 4

Peripheral Nervous system (PNS)

Answer 4

Cranial nerves and spinal nerves
Communication lines between the CNS and the rest of the body
2 Divisions: Sensory and Motor

Question 5

Sensory (afferent) division

Answer 5

Carry signals TO brain/spinal cord
Somatic and visceral sensory nerve fibers
Conducts impulses from receptors to the CNS

Question 6

Motor (efferent) division

Answer 6

Carry signals FROM brain/spinal cord
Motor nerve fibers
Conducts impulses from the CNS to effectors (muscles and glands)
2 systems: Somatic nervous system & autonomic nervous system

Question 7

Somatic nervous system

Answer 7

Structures external to visceral cavity
Somatic motor (voluntary)
Conducts impulses from the CNS to skeletal muscles

Question 8

Autonomic nervous system (ANS)

Answer 8

Visceral motor (involuntary)
Conducts impulses from the CNS to cardiac muscles, smooth muscles, and glands
2 divisions: Sympathetic division & Parasympathetic division

Question 9

Sympathetic division

Answer 9

Mobilizes body systems during activity

Question 10

Parasympathetic division

Answer 10

Conserves energy

Promotes house-keeping functions during rest

Question 11

Visceral

Answer 11

Organs

Question 12

4 combinations of Basic Divisions of Nervous System

Answer 12

Somatic snsory
Somatic motor (voluntary)
Visceral sensory
Visceral motor (involuntary ANS)

Question 13

Basic Divisions of the Nervous System

Answer 13

Sensory
Motor
Somatic
Visceral

Question 14

Neurons comprised of…

Answer 14

Cell body
Dendrites
Axons

Question 15

Cell body

Answer 15

Contains one nucleus
Group of cell bodies in CNS = nucleus
Group of cell bodies in PNS = ganglia
Metabolic center of neuron (contains organelles)

Question 16

Group of cell bodies in CNS

Answer 16

nucleus

Question 17

Group of cell bodies in PNS

Answer 17

ganglis

Question 18

Dendrites

Answer 18

Branched processes that extend from cytoplasm of cell body

RECEIVE stimuli and conduct impulses TO CELL BODY

Question 19

Axons

Answer 19

Conduct impulses AWAY FROM CELL BODY
If myelinated or large, have increased electrical conduction speed
Lengths vary; have axon terminals at end (bulbs)
Is a cytoplasmic extension from cell body

Question 20

Synapses

Answer 20

Junction that controls information transfer from one neuron to the next
Can be excitatory or inhibitory

Question 21

Presynaptic neuron

Answer 21

Conducts signal towards synapse

Question 22

Postsynaptic neuron

Answer 22

Conducts signal away from synapse

Question 23

Neurons structure

Answer 23

Multipolar
Bipolar
Unipolar

Question 24

Multipolar neuron

Answer 24

Most of body’s neurons
Many dendrites and an axon
Motor neurons, most interneurons

Question 25

Bipolar neuron

Answer 25

Processes extend from two sides of body | Rare, sensory

Question 26

Unipolar neuron

Answer 26

One process that divides like a "T" | sensory neurons

Question 27

Neuron function

Answer 27

Sensory Motor Interneuron

Question 28

Sensory (afferent) neurons

Answer 28

carry signal TO CNS

Question 29

Motor (efferent) neurons

Answer 29

Carry signal AWAY from CNS

Question 30

Interneurons (association neurons)

Answer 30

Between sensory and motor neurons | Located ONLY in CNS

Question 31

Neuroglia

Answer 31

Support cells Have central cell body and branching processes, are smaller than neurons Outnumber neurons 10-1 in CNS Consist of half of brain's mass Can divide throughout life Provide scaffold of support for neurons and cover non-synaptic parts (insulate and keep them from interfering with each other)

Question 32

Types of CNS Neuroglia

Answer 32

Astrocytes Microglia Ependymal cells Oligodendrocytes

Question 33

Types of PNS Neuroglia

Answer 33

Satellite cells | Schwann cells

Question 34

Astrocytes

Answer 34

Most abundant neuroglia Key component of blood brain barrier -regulate passage of molecules from blood to brain -only allow small molecules through to brain

Question 35

Microglia

Answer 35

Smallest and least abundant neuroglia | Phagocytes, thorny-looking

Question 36

Ependymal cells

Answer 36

Form simple epithelial layer that lines central cavity of brain and spinal cord

Question 37

Oligodendrocytes

Answer 37

Produce myelin sheath around nerve cell axons | Fewer branches than astrocytes

Question 38

Satellite cells

Answer 38

Surround cell bodies in ganglia

Question 39

Schwann cells (neurolemmocytes)

Answer 39

surround all axons in PNS | produce myelin sheath (gaps=nodes of Ranvier)

Question 40

Nerves

Answer 40

Collection (bundle) of neurons outside CNS Naked eye can see a nerve, but not a neuron Composed of many axons Nerves often contain both sensory and motor neurons (mixed nerves) Some are sensory or motor only though (cranial nerves) Neurons are held together by CT

Question 41

Endoneurium

Answer 41

Surrounds each axon | loose CT

Question 42

Perineurium

Answer 42

Surrounds bundle of axons | fascicle

Question 43

Epineurium

Answer 43

Surrounds entire nerve | bunch of fascicles

Question 44

Reflex Arcs

Answer 44

Chains of neurons that create reflexes Unlearned and involuntary Somatic or visceral Monosynaptic or Polysynaptic

Question 45

Reflex

Answer 45

rapid, automatic, motor response to a stimulus

Question 46

5 components of reflex arcs

Answer 46

``` Receptor Sensory neuron Integration center Motor neuron Effector ```

Question 47

Receptor

Answer 47

site where stimulus acts

Question 48

Sensory neuron

Answer 48

transmits signal to CNS

Question 49

Integration center

Answer 49

one or more synapses

Question 50

Motor neuron

Answer 50

Conducts impulse from integration center

Question 51

Effector

Answer 51

muscle or gland that responds

Question 52

Polysynaptic

Answer 52

one or more interneurons are part of reflex pathway | most contain one interneuron (are 3-neuron reflexes)

Question 53

monosynaptic

Answer 53

one synapse is involved fastest of all reflexes classic example is knee jerk

Question 54

Gray matter

Answer 54

cell bodies H-shaped in spinal cord -dorsal half has bodies of interneurons and venral half has bodies of motor neurons

Question 55

White matter

Answer 55

axons | often myelinated

Question 56

tracts

Answer 56

bundles of axons

Question 57

multiple sclerosis (MS)

Answer 57

Most common neural disability in young adults progressive, destroys patches of myelin cause is not well understood-autoimmune