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Histology > Nervous Tissue > Flashcards

Flashcards in Nervous Tissue Deck (71):
1

Consists of the brain and spinal cord

CNS

2

Composed of cranial, spinal, and peripheral nerves conducting impulses to and from the CNS and ganglia that are small aggregates of nerve cells outside the CNS

PNS

3

Small aggregates of nerve cells outside the CNS

Ganglia

4

Cells in both PNS and CNS are of two kinds ___ and __

neurons and glials

5

Collectively, 2 functions of the nervous system, ___ and ___

stabilizes intrinsic conditions of the body and maintains behavioral patterns

6

Nerous system develops from the ____of the three early embryonic layers

ectoderm, outermost layer

7

The folding of the neural plate forms the ___which gives rise to the entire CNS including neurons and most glial cells

Neural Tube

8

As the folds fuse and the neural tube separates from the overlying surface, a large population of developmentally important cells called___separate and migrate extensively to differentiast as all the cells of the PNS

Neural Crest

9

where does the CNS and PNS coem from embryonically

CNS- neural tube cells
PNS- neural crest cells

10

___is the portion of the neuron that receives stimuli from other neurons at synapses

Dendrites

11

___is a single process extending from a neuron that generates and conducts nerve impules to other cells

Axons

12

___neurons each have one axon with two or more dendirts and are the most common neurons

Multipolar Neurons

13

___neurons have one dendrite and one axon, these types of neurons comprise the sensory neurons of the retina, olfactory epithelium and inner ear

Bipolar Neuron

14

____neurons have a single process that bifurcates close to the cell body with long branch extending to peripheral end and the other to the CNS

unipolar or pseudounipolar neurons

15

___neurons have many dendrites but no true axon, do not produce action potentials but regulat electrical changes of adjacent CNS neurons

Anaxonic neurons

16

___neurons receive stimuli from receptors throughout the body

Sensory or afferent neurons

17

___neurons send impulses to effector organs such as muscle fibers and glands

Motor neurons or efferent neurons

18

____motor nerves are under voluntary control and innervate skeletal muscle

Somatic motor nerves

19

____motor nerves control the involuntary or unconscious activities of glands, cardiac muscle, and most smooth muscle

Autonomic motor nerves

20

___establish relationships among other neurons forming complex functional networks or circuits in the CNS they are iehter multipolar or anaxonic and comprise 99% of ALL neurons in adults

Interneurons

21

In CNS most cell bodies are in____ and axons are concentrated in the ___

grey matter ; white matter

22

In PNS cell bodies are found in___ and axons are bundled in __

ganglia, nerves

23

____are found only in the PNS and differentiat from precursors of the neural crest. they are the counterparts of oligodendrocytes of the CNS

Schwann Cells

24

____cells are columnar or cuboidal cells that line the fluid-filled ventricles of the brain and the central canal of the spinal cord

Ependymal cells

25

What is the purpose of cilia on ependymal cells?

The cilia on ependymal cells facilitates the movement of cerebrospinal fluid and long microvilli possible absorption purposes

26

Like neuron, most glial cells develop from progenitor cells of___

the embryonic neural plate

27

___electrically insulates the axon and vacilitatees rapid transmission of nerve impulses

myelin sheath

28

___is the predominant glial cell in white matter CNS

Oligodendrocytes

29

___are the most numerous glial cells of the brain

Astrocytes

30

__ form a thin, intimate glial layer around each large neuronal cell body in the ganglia of the PNS

Satellite cells

31

___exert a trophic or supportive effect on neurons in the PNS, insulating, nourishing, and regulating their microenvironments

Satellite Cells

32

The major structures comprising the CNS are the ___,___,and___

Cerebrum, cerebellum, and spinal cord

33

The main components of white matter are myelinated axons often grouped togehter as__

tracts

34

Gray matter in the CNS contains the ___

abundance of neuronal cell bodies unlike white matter in the CNS

35

Gray matter makes up the ___of both the cerebrum and the cerebellum; most white matter is found in the deeper regions

thick cortex or surface layer

36

Deep within the brain are localized, variously shaped darker areas called ___

cerebral nuclei

37

What is the function of neurons of the cerebral cortex?

Integration of sensory information and the initiation of voluntary motor responses

38

What are the 3 layers of the cerebellar cortex?

-Thick outer molecular layer
-Thin middle layer consisting of purkinje cells
-Thick inner granular layer

39

____coordinates muscular activity throughout the body and is organized with three layer

cerebellar cortex

40

The anterior horns of the spinal cord contain ___

cell bodie of very large motor neurons that make up the vental roots of the spinal nerves

41

The ___of the spinal cord is continuous with the ventricles of the brain and is lined by ependymal cells and contains CSF

central canal

42

The two posterior horns of the spinal cord contain the ___ which receive sensory fibers from the neurons in the spinal (dorsal root) ganglia

Interneurons

43

The central canal of the spinal cord develops from ___

the neural tube

44

What are the three layers of meninges between bone and nervous tissue

-dura mater
-arachnoid mater
-pia mater

45

The thick dura mater of the meninges are continuous with__

periosteum of the skull and an inner meningeal layer

46

Around the spinal cord, the dura mater is steparated from the periosteum of the vertebrae by the ___

epidural space

47

Surrounding the trabeculae of the arachnoid layer is the ___ filled with CSF

subarachnoid space

48

What is the purpose of CSF

CSF fluid helps cushion and protect the CNS from minor trauma

49

CSF is produced in the ___

ventricles

50

What is the function of the arachnoid villi

It is site for absorption of CSF into the blood of the venous sinuses

51

The innermost meninge layer___ together with a layer of astrocytic end feet forms a physical barrier separating CNS tissue from CSF in the subarahnoid space

Pia mater

52

Blood vessels penetrate CNS tissue through long____

vascular spaces

53

The___is a functional barrier that allows tight control over passages of substances moving from blood into the CNS tissue

Blood brain barrier

54

The main structural component of the blood brain barrier is ____

capillary endothelium

55

There are three places where there is no blood brain barrier

-regions of the hypothalamus where plasma components are monitored
- posterior pituitary which releases hormones
-choroid plexus where CSF is produced

56

___consists of highly vascular tissue, elaborately folded and projecting into the large ventricles of the brain

Choroid Plexus

57

What is the function of the choroid plexus?

-To remove water from blood and release it as the CSF
- provides ions required for CNS neuronal activity
-serves to absorb mechanical shocks in the arachnoid

58

The main components of the peripheral nervous system are ___,___,and_.

nerves, ganglia, and nerve endings

59

Nerve fibers are analagous to___ in the CNS

tracts, containing axons enclosed within sheaths of glial cells specialized to facilitate axonal functions

60

What is a major difference between oligodendrocyte and schwann cell?

Unlike oligodendrocytes of the CNS, a Schwann cell forms myelin around only a portion of one axon

61

Between adjacent Schwann cells on an axon the myelin sheath has gaps called___where the axon is partially covered by interdigitating Schwann cell processes

nodes of Ranvier

62

In the PNS nerve fibers are grouped into bundles to form__

Nerves

63

Immediately around the external lamina of the Schwann cells is a thin layer called the ___ consisting of reticular fibers, scattered fibroblasts, and capillaries

Endoneurium

64

Groups of axons with Schwann cells and endoneurium are bundled together as____by a sleeve of perineurium

fascicles

65

Peripheral nerves have a dense, irregular firbous coat called the __ which extends deeply to fill the space between fascicles

Perineurium

66

___fibers carry information from internal body regions and the environment to the CNS

afferent

67

____fibers carry impulses from the CNS to effector organs

Efferents

68

Nerves carrying only fibers carrying impulses to the effect (source) are called__

motor nerves

69

Nerves possessing only sensory fibers are called __

sensory nerves

70

__are typically ovoid structures containing neuronal cell bodies and satellite cells surrounded by a denser capsule

Ganglia

71

What determines whether the ganglion will be a sensory or an autonomic ganglion?

The direction of the nerve impulse