Nervous Tissue

Question 1

what is nervous tissue

Answer 1

-relays signals
-formed by neurons
-divided into CNS and PNS

Question 2

what is the CNS made up of

Answer 2

-brain and spinal cord (neurons)

Question 3

what is the PNS made up of

Answer 3

-nerves and ganglia
-outside of the brain - nerves

Question 4

what are neurons

Answer 4

-functional unit of the nervous system
-receive, process , store, transmit info to and from other neurons, muscle cells or glands in the body

-dendrites receive the signal
-axon sends signal

Question 5

neuroglia

Answer 5

support cells
-do not conduct impluses
-support myelin sheath

like astro,oligeio

they are self generating and susceptible to mutation

Question 6

astrocyte

Answer 6

-largest
-in CNS
connect neuron and capillaries
-feeds the brain - transfers nutrients from blood to the brain
-form blood brain barrier
-keep brain healthy

Question 7

microglia

Answer 7

-CNS
-phagocytic function
-

Question 8

ependymal cells

Answer 8

cns
-line fluid filled cavities of the brain and spinal cord
-resemble epithelial cells
-they have cilia to move the CSF

Question 9

oligodendrocytes

Answer 9

-CNS
-membrane tipped arms
-hold axons together
-produce myelin sheath
-move info faster

look like criss crosses

Question 10

Schwann cells

Answer 10

-pns
satellite cells - schwann cells that surround the cell body of the neuron

-form SPIRALS (not arms like oligo) around the axons
-myelin sheath around axon
-like oligio but in PNS

-look like straight line

Question 11

what is the myelin sheath

Answer 11

• lipid rich layer around the axon fibers
  -insulation and increases speed of conduction
  –not continuous like the nodes of Ranvier

Question 12

what are non myelinated axons

Answer 12

-small diametric axons in the cytoplasm of the neuroglial cells
-not wrapped around axons
-slow conductions

Question 13

white matter and gray matter in brain vs the spinal cord

Answer 13

-it is reversed
in the brain the grey matter is on the outside and white inside
-in the spinal cord white on the outside and grey on the inside

GM - Cortex of the brain – controlled by neurons
WM Tract – allows communication to and from grey matter

Question 14

what is the cerebrum

Answer 14

-largest part of the brain
- sensory motor
-grey outer STAINS LIGHTER
-the outer layer has:
neurons - large cells dendrites and axons (on the slide itll look like a little tail is coming from it -dendrites)
-neuroglial cells All 4 types – no Schwann cells
-unmyelinated axons ONLY

white matter STAINS DARKER
-inner layer
- all neuroglial cells and non and myelinated cells

All 4 types of neuroglial cells are present in both WM and GM – no Schwann cells

Question 15

what is the cerebellum

Answer 15

2nds largest
under the lobe
movement and coordination
outer- grey - neurons, glial cells non mye ONLY, (looks more dense)
3 components in the grey matter :
1Granular layer - neuroglial cells.
2. Molecular layer – neuroglial cells.
3. Purkinje cells - specialized neurons. in-between granular and molecular layer

inner white STAINS DARKER- contains NO NEURONS does contain neuroglial, mye and non mye
looks like a cauliflower

All 4 types of neuroglial cells are present in both WM and GM – no Schwann cells

Question 16

the spinal cord has

Answer 16

is in the spinal cavity
-carries signals from brain to spinal cord

-white matter -outer
-grey matter - inner (dorsal/post horn and ventral/ante horn)

central canal -the middle of the cord in H shape is lined by ependymal cells

Dorsal and ventral fissures are the indentations (divided into halves)

All 4 types of neuroglial cells are present in both WM and GM – no Schwann cells

Question 17

sPINAL CORD – GREY MATTER

Answer 17

Inner layer; H-shaped.
* Composed of:
* Anterior horn cells (AHC).
* Large neurons.
* Motor neurons - voluntary skeletal muscle control.
* Located in anterior horn.
* Neuroglial cells.
* Non-myelinated axons

Question 18

white matter in spinal cord

Answer 18

• surround the H shape
  -contains NO NEURONS neuroglial cells, mye and non mye

-large bundles of axons are called tracts

Special stain – Luxol fast blue.
* Stains myelin sheaths dark blue

Question 19

what does the PNS consists of

Answer 19

-nervous tissue outside the brain
-have relay nerve stations called ganglia
-12 pairs of carnial nerves
made of bundles of axons, mixed, sensory + motor cranial nerves , comes from the brain

-31 pairs of spinal cord nerves all mixed
DORSAL ROOT GANGLION - IS THE SWELLING IN THE DORSAL ROOT

Question 20

What are ganglia

Answer 20

relay stations of the bodies nervous system - have afferent (sensory) and efferent (motor) fibers

cell body neurons - larger in the PNS

Question 21

Nervous tissue outside of the CNS is what

Answer 21

Peripheral nerves (HAVE A WAVY CUT)
-afferent and efferent nerve fibers
-composed of fascicles with each fiber having Schwann cell
-somatic or autonomic

Question 22

types of connective tissue support

Answer 22

endo NEURIUM - CT fibers around EACH individual axon
peri - Connective tissue fibers surrounding a nerve fascicle.
epi -Outermost layer of dense connective tissue fibers surrounding the ENTIRE nervous tissue.
* In the brain, this layer is also known as the meninges

(DENSE IRREGULAR CONNECTIVE TISSUE)

SKELETAL FIBRES LOOK LONG

Question 23

GLANDULAR EPI

Answer 23

LOOK LIKE CLOUDS OR BUBBLES ALL TOGETHER