Nervous Tissue Flashcards Preview

Histology Exam 1 TonyFrim > Nervous Tissue > Flashcards

Flashcards in Nervous Tissue Deck (73):
1

functional unit of the nervous system

Neuron

2

3 basic components of neuron

cell body/soma, axon, dendrites

3

Multipolar neuron

irregularly shaped cell body-more than 2 cell processes-with one the axon and the other dendrites .(Motor and Interneurons)

4

Bipolar neuron

1 dendrite and axon (retina, olfactory receptor neurons)

5

Pseudounipolar neurons

single process close to the cell body divides into 2 branches. One branch extends to the CNS and the other to a peripheral ending

6

Motor neurons

control effector organs and exocrine and endocrine glands

7

Sensory neurons

receive sensory stimuli

8

form links among neurons

interneurons

9

Receiving surfaces of neurons

dendritic and cell body synaptic sites

10

name of the "conducting process" in a neuron

axon

11

Impulse initiating mechanism

the initial segment aka "axon hillock"

12

On a slide what would neuron look like?

Speherical, large, pale staining, centrally located nucleus with prominent nucleolus

13

conduct information away from cell body

axons

14

Plasma membrane of the axon

=the axolemma and cytoplasm = the axoplasm

15

Axoplasm contains abundant _______ and ________

microtubules and neurofilaments (no ribosomes or Golgi)

16

Transport of metabolites in the axon may be _______ or ______ (direction)

orthograde(from cell body to nerve endings) or retrograde (nerve ending to cell body)

17

Cytoplasmic dynein

can transport organelles and vesicles in retrograde direction. Retrograde flow can carry viruses and toxins along the axon into the CNS.

18

Dendrites

branching cell processes-protrude from the cell body

19

Do dendrites have myelin sheath

Dendrites have NO myelin sheath

20

Function of dendrite

transmit information toward cell body

21

Cytoplasm of dendrites lack _____________

Golgi complex

22

Large dendrites may have ____ substance

Nissl

23

Dendritic spines

present on some dendrites with beaded appearance and are specialized for synaptic contact

24

Contact of one axon with the dendrites

axodendritic synapse

25

Contact of one axon with cell body

axosomatic synapse

26

Contact of one axon with another axon

axoaxonic synapse

27

Contact of one axon with dendritic spine

axospinous

28

Contact site between dendrites

dendrodendritic

29

Where are neurotransmitters stored

synaptic vesicles

30

Synaptic vesicle membrane contains vesicular docking proteins that

attach to membrane docking proteins of presynaptic membrane

31

What causes exocytosis of neurotransmitters from vesicle

depolarization of axon terminal

32

Basic function of Neuroglia

function in mechanical and metabolic support of neurons

33

Examples of neuroglia in CNS

astrocytes, oligodendrocytes, microglia, ependymal cells

34

Name of neuroglia in PNS

Schwann cells

35

Name of neuroglia in CNS that contributes to blood brain barrier

astrocytes

36

Largest of the neuroglial cells

astrocytes; have processes that attach to capillary walls

37

Where are astrocytes located?

Localized beneath pia of brain and spinal cord

38

Function of astrocytes

assist in maintenance of electrolyte balance in CNS and nutrient transport to neurons

39

Ependymal cells

line neural tube and ventricles of the brain; bathed in CSF ;many have motile cilia

40

microglia

phagocytic cells derived from bone marrow monocytes. condensed elongated nucleus

41

Oligodendrocytes

In CNS, analogous to Schwann cells of PNS. Produce myelin.(In gray matter-localized close to perikaryons. In white matter-appear in rows among myelinated nerve fibers)

42

What are two specific types of astrocytes

Protoplasmic astrocytes and Fibrous astrocytes

43

Protoplasmic astrocytes

Granular cytoplasm. Processes have many short and thick branches. CNS gray matter

44

Fibrous astrocytes

Long, slender, infrequently branching processes. CNS white matter.

45

What astrocytes are found in CNS white matter

Fibrous astrocytes

46

Choroid plexus

Ependymal cells and associated capillary loops that are modified to produce CSF

47

Schwann cells produce

myelin for myelinated axons in PNS

48

Schwann cells originate from

neural crest cells

49

Myelinated nerve fibers

Schwann cell wraps around and form myelin sheath -(lipoprotein complex)

50

Dark regular lines of myelin

major dense lines

51

Less regular lines of myelin

interperiod lines

52

Nodes of Ranvier

spaces between adjacent Schwann cells that appear as gaps in the myelin sheath

53

Distance between 2 nodes on myelinated nerve fibers

an internode (1 Schwann cell)

54

Schmidt-Lantermann clefts

Small clefts or fissures in the myelin

55

Non-myelinated nerve fibers

Axons containing no myelin sheath but are ensheathed by Schwann cells or oligodendrocytes

56

Schwann cell sheath

neurolemma

57

Peripheral nerves may be ________ or ________

myelinated or nonmyelinated

58

Ganglia on slide

ovoid structures encapsulated by dense connective tissue

59

Nerve ganglion

aggregation of NERVE CELL BODIES outside the CNS

60

Sensory ganglia

1) dorsal root ganglia 2) ganglia of cranial nerves

61

Where are autonomic ganglia located

Sympathetic ganglia occur as segmented chain ganglia (sympathetic trunk) and non-segmental collateral ganglia (pre vertebral)

62

Where are parasympathetic ganglia located?

Scattered throughout body located near organs they innervate

63

Auerbach's plexus

parasympathetic ganglion in walls of lower GI tract

64

Spinal cord

Central mass of gray matter (H-shaped), surrounded by myelinated and non-myelinated nerve fibers

65

Gray matter consists of a broad anterior horn, a narrow posterior horn joined by a

central commissure

66

Where are the lateral horns located?

Lateral horns are present in the thoracic and first 2 lumbar segments

67

The anterior horn contains

large motor neurons which send axons via the ventral spinal roots to skeletal muscles - terminate in motor plates

68

The posterior horn contains

small nerve cells which receive afferent impulses from sensory nerve cells of the spinal ganglion cells via dorsal spinal roots

69

Pacini's corpuscle

nerve ending; lamellated corpuscle with "onion shape". located in subcutaneous tissue-sense organ stimulated by pressure found in deep layers of skin particularly around finger pads. Transducer which responds to vibration, pressure, and tension

70

Meissner's corpuscles

nerve ending; touch receptors numerous in dermal papillae of finger pads. involved in 2-point discrimination

71

Merkel nerve ending

Merkel cell in skin associated with nerve. pressure and texture sensor. Sustained response to pressure. also involved in 2-point discrimination along with Meissner's corpuscle

72

Blood Brain Barrier

Continuous capillaries with occluding junctions + cell processes of astrocytes

73

What kind of drugs cross Blood Brain Barrier

lipid soluble drugs; substance>500 daltons