Nervous System

Front 1

Development of Nerve Tissue

Back 1

1. Ectoderm
2. Chordamesoderm (axial mesoderm, notochord) induces ectoderm to form Neural Tube. Neural Plate --> Neural Groove --> Neural Tube --> Spinal Cord and Brain

Front 2

Nissl Substance

Back 2

RER of Cell Body

Front 3

Unipolar Dendrite

Back 3

Does not have dendrites (sensory)

Front 4

Bipolar

Back 4

Single Dendrite

Front 5

Multipolar

Back 5

more than one dendrite

Front 6

Axon Hillock

Back 6

Sums up all incoming depolarizaitons. Connects cell body to axon

Front 7

Schwann Cells

Back 7

1. PNS
2. Myelinate Nerves
3. Make 'em appear white.
4. Lots of 'em

Front 8

Oligodenrocytes

Back 8

1. CNS
2. Make it appear white
3. One Cell to several axons.

Front 9

Non-Myelinated Nerve Fibers

Back 9

1. Smaller in diameter.
2. Post Ganlionic Fibers of ANS
3. Lie in a Schwann Cell groove, no myelin wrappings

Front 10

Supporting Cells = Glial Cells = Neuroglial Cells

Back 10

1. Astrocytes
2. Oligodenrocytes & Schwann Cells
3. Microglia
4. Ependymal

Front 11

Astrocytes

Back 11

1. Only found in CNS
2. Largest
3. Anchor Neurons to blood supply, important in blood-brain barrier.
4. Provides structural support, regulate external chemical environment by removing ions, regulate capillary blood flow, supply glucose
5. Gap Junctions to pass metabolites
~~Protoplasmic Astrocytes -- Have thick processes and are found in gray matter.
~~Fibrous Astrocytes -- Thinner processes, found in white matter

Front 12

Microglia

Back 12

1. Specialized brain macrophages immigrated from blood born monocytes.
2. Found in all regions of gray and white matter of brain and spinal cord.

Front 13

Ependymal Cells

Back 13

1. Cuboidal or low-columner cells that form single layer lining of internal cavities (ventricles of brain and central canal.)
2. Bathed in cerebrospinal fluid
3. Apical surfaces have cilia to circulate CSF around CNS

Front 14

Choroid Plexus

Back 14

Made up of modified ependymal cells, loose connective tissue and capillaries. Produce CSF

Front 15

Meninges

Back 15

~System of membranes that envelops CNS, secretes CSF and protects brain.
1. Dura Mater -- Outermost layer, dense fibrous connective tissue. Impermeable and tough.
2. Arachnoid -- Loos connective Tissue, CSF occupies.
3. Pia Mater -- innermost layer, delicate layer of collagen and Fibroblast like cells

Front 16

Gray Matter in CNS

Back 16

Groups of nerve Cell Bodies

Front 17

Ganglia in PNS

Back 17

Groups of Nerve Cell Bodies

Front 18

White Matter in CNS

Back 18

Grops of Nerve Cell Processes

Front 19

Fibers or Bundles in PNS

Back 19

Groups of nerve cell processes

Front 20

Spinal Ganglia or Dorsal Ganglia

Back 20

1. Found in Dorsal Roots
2. Carry Afferent Sensory (sensory)
3. Cell bodies are unipolar
4. Not involved in nerve transmission

Front 21

Autonomic Ganglia

Back 21

1. Made up of clusters of neuronal cell bodies and dendrites, located in PNS
2. Junction between autonomic nerves originating from CNS and autonomic nerves innervating target organs.
3. Categories: sympathetic and parasympathetic ganglia

Front 22

Fascicle

Back 22

Grouping of axons

Front 23

Endoneurium

Back 23

Surrounds Nerve Fiber

Front 24

Perineurium

Back 24

Surrounds groups of nerve fibers

Front 25

Gyri

Back 25

up folds surrounded by sulic in the cerebral cortext

Front 26

Sulci

Back 26

Depression or fissure in cerebral cortex. Surrounds gyri.

Front 27

Pyramidal Cells

Back 27

1. Majority of Neurons in at least 3 layers of Cerebral Cortex
2. Multipolar Neurons with triangular shape soma, single apical dendrite that extends into higher levels of the cortex.
3. Release glutamate (neurotransmitter) which makes them the major excitatory component of cortex.
4. Output neurons and transmit signals to other parts of CNS.

Front 28

Cerebral Cortex Layers

Back 28

1. Molecular -- Very few neurons. Composed of Axons and dendrites from cells in other layers.
2. External Granular Layer
3. External Pyramidal Layer
4. Internal Granular Layer -- Devoid of pyramidal Cells. Contains fusiform, stellate, and granule cells.
5. Internal Pyramidal Layer
6. Fusiform Layer (multiform layer)

Front 29

Cerebellum function and layers

Back 29

~~Responsible for coordination of voluntary motor movement, balance, equilibrium, and muscle tone.
1. Molecular Layer -- Filled with very fine axons and dendrites from cells below.
2. Purkinje Layer -- Has gian Neurons that send dendrites into molecular Layer and axons into white matter. Contain Purkinje Cells (huge)
3. Granule Cell Layer --- (out line white matter). Granule cells are small neurons with nuclei, axons extend into upper molecular layer.