Module 2 - Muscle and Nervous Tissues

Question 1

What type of muscle has: very long muscle fibers, under voluntary control, striated, located in the muscles that move our arms, legs, head, neck, and trunk, cannot divide but has other cells that can regenerate new cells of its kind

Answer 1

Skeletal Muscle

Question 2

What type of muscle has: striated, under involuntary control, located in the heart, contains intercalated discs and gap junctions, muscle cells branch, CANNOT divide or generate new cells

Answer 2

Cardiac Muscle

Question 3

What type of muscle has: small cells with tapering ends, under involuntary control, located in the walls of blood vessels and hollow organs, capable of dividing and generating new cells

Answer 3

Smooth Muscle

Question 4

Contractility

Answer 4

Ability to exert tension by actively shortening

Question 5

Elasticity

Answer 5

Muscles ability to return to its original length after contraction

Question 6

Excitability

Answer 6

Ability to respond to stimulation

Question 7

Extensibility

Answer 7

Ability to stretch over a range of resting lengths

Question 8

What are functions of skeletal muscle?

Answer 8

-Maintain posture
-Produce skeletal movement
-Generate heat
-Protect internal organs

Question 9

Cell Body (Soma)

Answer 9

Processing or “thinking” part of the neuron

Question 10

Dendrite

Answer 10

Receives input from other neurons and carries it to the cell body

Question 11

Axon

Answer 11

Single fiber that emerges from the cell body and propagates the nerve impulse, which is communicated to one or more cells

Question 12

Astrocytes

Answer 12

-Regulate the environment around the neurons
-Contribute to the blood-brain barrier
-Regulate the inflammatory response to damage

Question 13

Microglia

Answer 13

-Patrol the CNS, extending and retracting processes looking for areas of damaged, dead, or dying cells
-Phagocytize debris from the dead or dying cells and invading microorganisms

Question 14

Oligodendrocytes

Answer 14

Myelinate axons in the CNS

Question 15

Ependymal Cells

Answer 15

Have cilia that help move cerebrospinal fluid through the CNS
-Filter blood to make cerebrospinal fluid

Question 16

Satellite Cells

Answer 16

Surround the cell bodies of neurons in the PNS, isolating them and protecting them from the surrounding tissue

Question 17

Schwann Cells

Answer 17

Myelinate axons in the PNS

Question 18

After a head injury, which glial cells would try to repair the damaged area?

Answer 18

Astrocytes & Microglia

Question 19

Collections of neuronal cell bodies in the PNS are called _____, while collections of neuronal cell bodies in the CNS are called ______

Answer 19

ganglia; nuclei

Question 20

What do the intercalated discs and gap junctions in cardiac muscle do?

Answer 20

form communication channels between adjacent cardiomyocytes, allowing cardiac muscle cells to contract in a wave-like pattern so the heart can work as a coordinated pump.

Question 21

Fascicles

Answer 21

In the muscle: muscle fibers are organized into individual bundles in EACH skeletal muscle; sheath of connective tissue surrounds each individual fascicle called perimysium (mysium=muscle)
In the nerves: what axons are further bundled into within the nerve; surrounded by their own layer of fibrous connective tissue called perineurium (neurium=nerve)

Question 22

Muscle fiber

Answer 22

a muscle cell, long and cylindrical, spans the entire length of the muscle within the fascicle; surrounded by a sheath of connective tissue the endomysium

Question 23

Myofibrils

Answer 23

embedded in the muscle fiber; cylindrical structures extending the entire length of the muscle fiber

Question 24

Epimysium

Answer 24

a sheath of dense, irregular connective tissue that surrounds each muscle

Question 25

Perimysium

Answer 25

a sheath of connective tissue surrounding each individual fascicle

Question 26

Endomysium

Answer 26

a sheath of connective tissue surrounding each individual muscle fiber

Question 27

Myofilaments

Answer 27

-actin and myosin proteins organized into repetitive groupings that results in striations Actin: thin filament Myosin: thick filament

Question 28

Sarcomere

Answer 28

actin and myosin are organized into repetitive groupings, and each unique grouping is called a sarcomere (the functional unit of the muscle fiber)

Question 29

Neuromuscular junction

Answer 29

Where the motor neuron meets the muscle fiber; every skeletal muscle fiber must be innervated by a motor neuron in order to contract.

Question 30

Motor unit

Answer 30

Single motor neuron and the muscle fibers it controls

Question 31

All-or-none principle

Answer 31

when a motor neuron is stimulated, all muscle fibers in its motor unit will contract.

Question 32

Slow oxidative fibers

Answer 32

A type of skeletal muscle fiber; Aerobic, endurance

Question 33

Fast oxidative fibers

Answer 33

A type of skeletal muscle fiber; Anaerobic, instantaneous power

Question 34

Atrophy

Answer 34

-reduction of muscle size, tone, and power -can be caused by a lack of stimulation -occurs with aging

Question 35

Hypertrophy

Answer 35

-increase in muscle fiber size -Results from repetitive stimulation of muscle fibers -Both myofibrils and myofilaments increase in number, all resulting in the muscle increasing in size

Question 36

Central Nervous System (CNS)

Answer 36

-consists of brain and spinal cord -Nucleus, center -Tract, column, etc...

Question 37

Peripheral Nervous System (PNS)

Answer 37

-consists of all nervous tissue outside of the brain and spinal cord. -Ganglion -Nerve

Question 38

Ganglion

Answer 38

collection of nerve cell bodies in the peripheral nervous system

Question 39

Nucleus

Answer 39

a collection of neuronal cell bodies within the CNS

Question 40

Nerve

Answer 40

bundle of axons in PNS

Question 41

Tract

Answer 41

bundle of axons in CNS

Question 42

Afferent

Answer 42

fibers that carry sensory information

Question 43

Efferent

Answer 43

fibers that carry outgoing motor information

Question 44

Sensory

Answer 44

carry signals from the outer parts of your body (periphery) into the central nervous system

Question 45

Motor

Answer 45

carry signals from the central nervous system to the outer parts (muscles, skin, glands) of your body.

Question 46

General somatic sensory

Answer 46

our sense of touch, pressure, pain, temperature, and proprioception

Question 47

General somatic motor

Answer 47

voluntary movement by skeletal muscles

Question 48

General visceral sensory

Answer 48

monitoring and sensing unconscious information primarily coming from our organs and glands

Question 49

General visceral motor

Answer 49

involuntary movement of our cardiac and smooth muscle and secretion from glands

Question 50

Synapse

Answer 50

the gap between two neurons; where neuronal communication occurs

Question 51

Pseudounipolar neuron

Answer 51

have an axon that emerges from the cell body, but it splits so that the axon can extend along a very long distance. At one end of the axon are dendrites, and at the other end, the axon forms synaptic connections with a target

Question 52

Bipolar neuron

Answer 52

These neurons have two processes, which extend from each end of the cell body, opposite to each other. One is the axon and one the dendrite. Bipolar cells are not very common.

Question 53

Multipolar neuron

Answer 53

Multipolar neurons are all of the neurons that are not unipolar or bipolar. They are by far the most common neurons in the body. They have one axon and two or more dendrites (usually many more).

Question 54

Converging circuit

Answer 54

postsynaptic neuron receives nerve impulses from several different sources; many inputs, one output

Question 55

Diverging circuit

Answer 55

one nerve fiber branches and synapses with several postsynaptic cells

Question 56

Myelin (sheath)

Answer 56

-a lipid-rich sheath that surrounds the axon and creates a myelin sheath that facilitates the transmission of electrical signals along the axon -acts as insulation

Question 57

Myelination

Answer 57

Process of wrapping an axon with a myelin sheath; Schwan cell wraps around the axon in layers

Question 58

Node of Ranvier

Answer 58

gaps in the myelin covering of an axon

Question 59

Endoneurium

Answer 59

the loose CT that surrounds each individual axon

Question 60

Perineurium

Answer 60

layer of fibrous connective tissue around individual fascicles (small groups of axons)

Question 61

Epineurium

Answer 61

layer of fibrous connective tissue around the entire nerve

Question 62

Fascicle

Answer 62

what axons are further bundled into within the nerve

Question 63

Wallerian degeneration

Answer 63

process where a nerve fiber, when cut or damaged, begins to break down and deteriorate in the part of the axon that is furthest away from the cell body

Question 64

Axon regeneration

Answer 64

After traumatic injuries, PNS axons can regenerate. Regeneration is possible if: Neuron cell body is intact, enough neurilemma remains, regeneration success is more likely if amount of damage is less extensive, distance between site of damage and structure it innervates is shorter

Question 65

Skeletal muslce

Answer 65

an organ that consists of skeletal muscle fibers, blood vessels, nerve fibers, and connective tissue; sheathed in the epimysium

Question 66

Small vs. Large motor unit

Answer 66

Small: one motor neuron supplies a small number of fibers in a muscle; this permits very fine motor control of the muscle Large: one motor neuron supplies a large number of muscle fibers in a muscle; concerned with simple, or “gross” (large), movements.