Ch. 9&10 - Nerve Tissue & Muscle Tissue Flashcards Preview

Histology > Ch. 9&10 - Nerve Tissue & Muscle Tissue > Flashcards

Flashcards in Ch. 9&10 - Nerve Tissue & Muscle Tissue Deck (78):
1

Nerve tissue

Made up of neurons and glial cells

2

Neuron

Very Labile nerve cells
No CT, rely on glial cells

3

Glial cells

Cells of the nervous tissue that support the neurons
Aka neuroglia
~90% of the cell population
Maintain the nervous system
Support neurons physically and metabolically
Homeostatically maintain the environment around neuron so they aren't affected by sudden changes
Secrete neurosteroids that act locally

4

Astrocytes

Glial cells found in the CNS
Regulate movement between the CNS and the blood
Anatomically and physiologically protect the blood-brain barrier
Derived from the ectoderm

5

Oligodendrocytes

Glial cells found in the CNS that lay down the myelin onto axons
Derived from the ectoderm

6

Ependymal cells

Glial cells found in the CNS that line the brain ventricles ad the central canal of the spinal cord
Some have cilia that are used for movement of CSF
Derived from the ectoderm

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Microglia

Ag-presenting glial cells found in the gray and white matter of the CNS
Highly phagocytic immune cells of the CNS
Only glial cells that are derived from the mesoderm

8

Schwann cells

Glial cells found in the PNS
Deposit myelin onto axons
Derived from the ectoderm

9

What are the five types of glial cells?

Astrocytes, oligodendrocytes, ependymal cells, microglia, and Schwann cells

10

Nervous system

Deciphers, analyzes, and integrates information
Regulates and controls output and therefore behavior
Bp regulation, pH, glucose levels, etc.

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Perikaryon

Area surrounding the nucleus
Don't use interchangeably with the word "cyton"

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Cyton

Cell body of a neuron

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Nissl bodies/substance

Very basic ribonuclear proteins found in the cytoplasm of the neuron

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Myelin

Schwann cells (PNS) or oligodendrocytes (CNS) wrapped around the axon of a neuron at regular intervals
Provides insulation and saltatory conduction

15

Saltatory conduction

Nerve impulses jump form node to node

16

Neurons can be classified based on _______ and _______.

structure; function

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Classification of neurons based on structure is based on what?

The number of processes coming off of the cell
Unipolar/pseudounipolar, bipolar, multipolar

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Unipolar/Pseudounipolar neuron

Have only one process
Sensory neurons

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Bipolar neuron

Have two processes
Found in the retina of the eye and the olfactory region of the nose
Rarest of the three types of neurons based on structure

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Multipolar neuron

Many processes
Motor neuron

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Classification of neurons based on function is based on what?

How the impulse is transmitted

22

Neurons are _______ cells that exhibit a change in membrane _______ upon stimuli.

excitable; potential

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Action potential

Quick depolarization and depolarization of a cell

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CNS

Central nervous system
Consists of the brain and spinal cord, which are continuous with one another
Consists of white matter and gray matter

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White matter

Makes up tracts of the CNS
Also has glial cells

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Tracts

Collection/aggregation/bundle of axons in the CNS
Made up of white matter
Ascending and descending tracts

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Ascending tract

Afferent, sensory tracts of the CNS
Carry impulses up from the brain to the spinal cord

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Descending tract

Efferent, motor tracts of the CNS
Carry impulses down from the spinal cord to the brain

29

Gray matter

Made up of cell bodies of motor neurons, interneurons, glial cells, and axons of sensory fibers
CNS

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Ganglion

Aggregation/collection of cell bodies located in the PNS

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Nerve

Bundle of axons in the PNS
Analagous to a tract in the CNS

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Mixed nerve

Nerve made up of both sensory and motor fibers

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Dorsal root ganglion

True CT structure in the PNS

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Fasciculus

Bundle of axons

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Perineurium

True CT that separates fascuculi

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Nucleus

Cluster of nerve cell bodies
No CT encapsulation
Equivalent CNS structure to ganglion in PNS

37

Nerves are found in the _______ and tracts are found in the _______.

PNS; CNS

38

A nucleus is found in the _______ and a ganglion is found in the _______.

CNS; PNS

39

Meninges

Singular form is menyx
Fibrous CT surrounding and protecting the spinal cord and brain
Dura mata, arachnoid, and pia mata

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Pia mata

Innermost menyx
Thinnest layer of CT covered with simple squamous epithelium
there is a very thin layer of glial cells between the pia mata and the spinal cord, so there isn't direct contact between the two

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Subarachnoid space

Space between the pia mata and the arachnoid
Contains CSF

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Arachnoid

Thinner layer of fibrous CT encapsulated with simple squamous epithelium
Has anchoring projections called arachnoid trabeculae that are continuous with the pia mata

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Subdural space

Space between the arachnoid and the dura mata

44

Dura mata

Thick external menyx
Consists of dense, fibroelastic CT that is continuous with the periosteum of the skull
Simple squamous epithelium on the outside

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Epidural space

Space outside the dura mata, separating it from the vertebrae

46

The brain has the brain layers of _______ as the spinal cord, only with less _______.

meninges; space

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PNS

Peripheral nervous system
Everything except for the brain and spinal cord
Ganglia and nerves

48

Axolemma

Cell membrane of an axon
Produces neuroregulin that regulates thickness of myelin

49

P-zero protein

Protein that tightens up myelin around axons

50

Nerves won't function if myelin is too _______.

loose

51

Dentate gyrus

Area of the hippocampus that can generate new neurons daily due to its population of stem cells

52

Muscle cells are _______; stimulus causes a _______ or contraction of the fiber.

excitable; shortening

53

There are three types of muscle, _______, _______, and _______.

smooth; skeletal; cardiac

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Skeletal muscle

Consciously controlled muscle
Long, cylindrical cells with striations/banding patterns and multiple nuclei
Building blocks are called myofibrils

55

Myofibrils

Building blocks of muscle cells
Stacked on top of one another, perfectly aligned

56

Myofibrils consist of what components?

Sarcomeres

57

The terms muscle cell and _______ are interchangeable.

muscle fiber

58

How do muscle cells gain their many nuclei? What is it called when a cell has many nuclei?

Several early embryonic muscle cells called myoblasts fuse together to form one large muscle cell. This is called a syncitial cell.

59

How can you tell the difference between skeletal and cardiac muscle cells?

Both are striated, but skeletal muscle cells have their nuclei pushed all the way up near the cell membrane

60

Myofilaments have _______ and _______ filaments.

thick; thin

61

What are the three proteins that are linked together of the thin myofilaments of muscle cells?

Troponin, tropomyosin, and F-actin

62

F-actin

One of the three proteins of thin myofilaments
Homopolymer of G-actin

63

Homopolymer

Polymer of one repeating unit

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Connectin

Z-line anchoring protein

65

H band contains _______ filaments, so it shows up as a _______ band.

only thick; light

66

I band contains _______ filaments, so it shows up as a _______ band.

only thin; light

67

A band contains _______ filaments, so it shows up as a _______ band.

both thick and thin; dark

68

Motor unit

One neuron stimulates multiple muscle cells
Each terminal innervates one muscle cell

69

The neuron of a motor unit has _______ branches.

collateral

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NMJ

Neuromuscular junction
A synapse between the neuron and muscle cell

71

Vesicles with _______ diffuse from the terminal to the _______.

NTM; end plate

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The only place to find receptors in the NMJ is the _______.

end plate

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Ionotropic

Very quick ion flow; not delayed

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Perimysium

Thin CT layer surrounding fasciculus
Contains bv, lv, and nerves

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Fasciculi

Bundle of muscle fibers packed together

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Epimysium

Thin CT layer surrounding groups of fasciculi
Contains bv, lv, and nerve fibers

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Endomysium

Thin CT layer surrounding individual muscle fibers

78

Smooth muscle

Involuntary, subconscious muscle