nervous system - histo lec Flashcards Preview

dHA 2nd year - Botanical medicine > nervous system - histo lec > Flashcards

Flashcards in nervous system - histo lec Deck (61)
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1
Q

receive stimuli from the environment or from different organs of the body
transmit impulses to the brain and spinal cord

A

Nervous tissues

2
Q

Properties of Nervous Tissues:

A
  1. Irritability
    - react to various stimuli
  2. Conductivity
    - transmit impulses
3
Q

A. Anatomical Division

A

CNS – brain and spinal cord
PNS – Peripheral Nervous System
- nerves outside the CNS and their associated ganglia

4
Q

B. Functional Division

A

Sensory component – transmits signal ( electrical impulses) to the CNS
Motor component – transmits impulses from the CNS to various structures of the body
1. somatic
2. autonomic

5
Q

C. Consists of two types of cells

A
Nerve cells (neurons) – conduct electrical impulses 
	glial (neuroglial cells – support, nurture, and protect the neurons
6
Q

2 elements of nervous tissue:

     - structural and functional units
     - receive and transmit impulses
A
  1. Neurons
7
Q

2 elements of nervous tissue:

   - glial cells 
   - specialized type of connective 	tissue
   - non  neuronal cells of the CNS 	and PNS
A
  1. Neuroglia
8
Q

Nucleus – “owl-eye nucleus”

-abundant in ?

A

euchromatin

9
Q

cytoplasmic organelles in neurons

A
Cytoplasmic organelles
	a. Nissl bodies - polysomes and RER
		most abundant in motor neuron
	b. Golgi complex and mitochondria
	c. melanin- containing granules
	d. Lipofuscin- containing granules
	e. lipid droplets
10
Q
  • polysomes and RER most abundant in motor neuron
A

Cytoplasmic organelles

a. Nissl bodies

11
Q
  1. cytoskeletal filaments of neuron
A

a. neurofilaments
b. microtubules
c. actin filaments

12
Q

receive stimuli from sensory cells, axons or other neurons

A

dendrites

13
Q

and convert these signals into action potentials that are transmitted toward the soma

A

dendrites

14
Q

presence of arborized terminals

A

dendrites

15
Q

spines on the surface

A

dendrites

16
Q

cytoplasm lacks Golgi complex

A

dendrites

17
Q
  1. conducts impulses away from the soma to the axon terminals
A

AXONS

18
Q
  1. up to 100 cm length
A

AXONS

19
Q
  1. originates at the axon hillock
A

AXONS

20
Q
  1. with axon collateral
A

AXONS

21
Q
  1. axoplasm with SER, RER, mitochondria
A

AXONS

22
Q
  1. Initial segments for site if various excitatory and inhibitory stimuli
A

AXONS

23
Q
  1. terminates into axon terminals
A

AXONS

24
Q
  1. membrane is called axolemma
A

AXONS

25
Q
  • many dendrites and one axon

ex. neurons in the CNS

A
  1. Multipolar neuron
26
Q
  • one axon and one dendrite

ex. neurons in the retina of the eye and neurons in the nasal cavity

A
  1. Bipolar neuron
27
Q
  • one process extending from the cell body that divides into an
    axon and dendrite
    ex. Spinal and cranial ganglia
A
  1. Unipolar neurons (pseudounipolar)
28
Q

> Protect and support neurons
Do not conduct impulses or form impulses or form synapses
Cell Division
Revealed only in histologic sections by special gold and silver stains

A

neuroglial cells

29
Q

Are the largest of the neuroglial cells

A

astrocytes

30
Q

“perivascular feet” that surround blood vessels and pia matter

A

astrocytes

31
Q

glial cell

Supply energy for metabolism

A

astrocytes

32
Q

Forms a protective sealed barrier between the pia mater and the nervous tissue of the brain and spinal cord

A

astrocytes

33
Q

Scavenge ions or debris from neuronal activity

A

astrocytes

34
Q

glial cell

Structural support

A

astrocytes

35
Q

Form scar tissues after injury to CNS

(e.g cerebral infarct)

A

astrocytes

36
Q

Two types of Astrocytes

gray matter
branched processes envelop blood vessels, neurons and synaptic areas
Blood-brain barrier
With GFAP

A

Protoplasmic

37
Q

Two types of Astrocytes
white matter
Long slender processes

A

fibrous

38
Q

protects the CNS from fluctuating levels of electrolytes,hormones, and tissue metabolites
circulating in the blood vessels

A

The blood–brain barrier

39
Q

Live symbiotically with neurons in the CNS

Located both in gray and white matter

A

Oligodendrocytes

40
Q

Produces myelin that insulates and protects axons

A

Oligodendrocytes

41
Q

increases the speed of transmission of the action potential down the axon.

A

Myelin sheath:

42
Q

decreases the metabolic needs of the neuron by reducing the total amount of ion exchange that happens during an action potential.

A

Myelin sheath:

43
Q

Flat cells, few mitochondria and GA

From neural crest cells

A

Schwann Cells

44
Q

For regeneration of nerve fiber

A

Schwann Cells

45
Q

Protect and insulate neuron in PNS

A

Schwann Cells

46
Q
  • phagocytic
    • remove bacteria and cell debris from the CNS
    • distributed in GM and WM
    • secrete cytokines
A
  1. Microglia
47
Q

line the neural tube and ventricles of the brain and spinal cord

A

Ependymal cells

48
Q

transport and circulation of the CSF

A

Ependymal cells

49
Q

no basal lamina

A

Ependymal cells

50
Q

low columnar/cuboidal GLIAL CELL

A

Ependymal cells

51
Q

Contribute to formation of choroid plexus

A

Ependymal cells

52
Q

Functional apposition where signals are transmitted from one neuron to another or from neuron to other type of cell (e.g. muscle)

A

synapse

53
Q
  • enclosed by myelin sheath
    - prevents loss of nerve impulse
    - circular constrictions (Nodes of Ranvier)
    - internodal segments or Schwann segments
A

Myelinated nerve fibers

54
Q
  • naked axons
    • devoid of myelin sheath
    • neurolemma
A

Unmyelinated nerve fibers

55
Q

classification of peripheral nerves as to function

A

Sensory – contain afferent fibers (to the CNS)

Motor – contain efferent fibers (from the CNS)

Mixed – contain both afferent and efferent fibers

56
Q

Are encapsulated aggregations of neuronal cell bodies (soma) outside the CNS

A

GANGLIA

57
Q

Two types of ganglia

A

Autonomic ganglia

Craniospinal ganglia

58
Q

mostly myelinated nerve fibers, some unmyellinated and glial cells

A

White matter –

59
Q

– mostly neuronal cell bodies, unmyelinated

fibers, and neuroglial cells

A

Gray matter

60
Q

Degeneration of distal axonal segment

(anterograde changes)

A

“Wallerian degeneration”

61
Q
  1. Regeneration of proximal axonal segment
A

(retrograde changes)