Anatomy - Nervous System

Front 1

Nerve tissue is distributed throughout the body as an integrated communications network:

Back 1

Sensory - Discriminative (Afferent)
Motofacient - Secretory (Efferent)
Cognative - Affective

Front 2

What are the two cell types in nervous tissue?

Back 2

Neurons and Glial Cells

Front 3

How is the nervous system topographically divided?

Back 3

CNS - Brain, spinal cord
PNS - Peripheral nerves, ganglia, cranial and spinal nerves

Front 4

______________ are specialized for transmitting nerve impulses

Back 4

Neurons

Front 5

supporting cells, called _____________ provide for the maintenance of the chemical environment around neurons, and produce an insulating material called _________________.

Back 5

glia,
myelin

Front 6

Name structure and function:
***Neuron

Back 6

***Neuron - answer

Front 7

Functional classifications of neurons:

Back 7

Efferent or motor neurons carry commands to muscles and glands.
Afferent or sensory neurons are involved in the reception of sensory stimuli.
Interneurons, which constitute the largest class, establish connections among other neurons.

Front 8

Shape classification of neurons:

Back 8

Multipolar neurons - one axon and many dendrites.
Bipolar neurons (retina and olfactory) - a dendrite that carries information from the periphery, and an axon that conveys information toward the CNS.
Pseudounipolar neurons (spinal and cranial ganglia) - single axon that branches to send one process to the CNS and one process to the periphery.

Front 9

What is Nissl substance?

Back 9

within nerve cell, aggragates of ribosomal RNA

Front 10

What is the plasma membrane of a nerve called?

Back 10

axolemma

Front 11

Are ribosomes present within the axon?

Back 11

No, they are absent and therefore rely on the cell body for metabolic needs and neurotransmitter manufacturing

Front 12

What are the characteristics of the axon hillock?

Back 12

The axon hillock is characterized by the absence of Nissl substance and the presence of large numbers of microtubules and neurofilaments.

Front 13

What are axons' main functions?

Back 13

They conduct action potentials

They transport materials by a process called axoplasmic transport

Front 14

What is axoplasmic transport?

Back 14

involves mechanisms by which selected organelles and certain chemical substances are moved along the axon in both directions

Front 15

Define anterograde vs. retrograde transport:

Back 15

Anterograde - Cell body along axon

Retrograde - Axon to cell body

Front 16

What are the main functions of glia?

Back 16

To serve as supporting elements in the brain.

To form myelin (oligodendrocytes in the CNS and Schwann cells in the PNS), the insulating sheath that covers most large axons

To function as scavengers (microglia), removing debris after injury or cell death

To buffer the extracellular space and take up some neurotransmitters released by neurons during synaptic transmission.

To form part of the blood-brain barrier.

Front 17

What are the two classifications of glial cells and where are they located?

Back 17

Microglia - bone marrow-derived macrophages that are scattered throughout the CNS. These cells become phagocytic, cleaning up cellular debris and ingesting damaged myelin.

Macroglia - consist of Schwann cells and satellite cells (PNS), and oligodendrocytes and astrocytes (CNS).

Front 18

What type of cells do schwann cells cover?

Back 18

Both myelinated and unmyelinated nerve cells

Front 19

How many axons can a schwann cell cover?

Back 19

Although a schwann cell may envelope many axons, it will only myelinate one axon

Front 20

What does myelination do for a cell?

Back 20

Increases the speed of conduction

Front 21

What exists between schwann cells?

Back 21

Nodes of Ranvier

Front 22

How many axons can an oligodendrocyte myelinate?

Back 22

Unlike the schwann cells in the PNS, the oligodendrocytes have multiple processes and are capable of myelinating multiple axons

Front 23

Where are satellite cells located in nerve cells?

Back 23

The satellite cells surround nerve cell bodies in both autonomic and sensory ganglia

Front 24

Describe how astrocytes look:

Back 24

Star shaped
Many cell processes

Front 25

What do astrocytes do?

Back 25

Astrocytes form most of the supporting cells of the CNS.

They participate in:
*The regulation of ionic balance in the extracellular space during the generation of action potentials.

*Aid in the repair of damaged neural tissue

*They participte in the formation of the blood-brain barrier.

Front 26

Connective tissue is a component of nerve bundles. What are the layers from superficial to deep?

Back 26

Epineurium
Perineurium
Endoneurium

Front 27

What is the epineurium?

Back 27

Loose connective tissue with axon bunndles embedded within

Front 28

What is the perineurium?

Back 28

Bundles of axons (bounded by endoneurium) are then bundled into perineurium

Front 29

What is endoneurium?

Back 29

Connective tissue that surrounds each axon

Front 30

The meninges of the brain have extensions into the PNS, what are they?

Back 30

Dura Mater --> Epineurium
Arachnoid --> Perineurium
Pia Mater --> Endoneurium

Front 31

What are the two types of tissue within the CNS and describe their topographical relationship with each other:

Back 31

Dark Matter - Cortex of brain, center of spinal cord

White Matter - Bulk of central brain, exterior portions of spinal cord

Front 32

What is grey matter composed of?

Back 32

neuron cell bodies, their dendrites and axons, glial cells and blood vessels. Aggregates of neuronal cell bodies are called "nuclei"

Front 33

What is white matter composed of?

Back 33

mainly of myelinated axons and glial cells, and provides the routes (nerve tracts) that connect one part of the brain to another

Front 34

How much of the brain's total volume is devoted to the cerebrum?

Back 34

~80%

Front 35

Histologically, how is the cerebral cortex (grey matter) arranged?

Back 35

In layers that follow the contours of the cerebral cortex

Front 36

The layers of cerebral cortex (grey matter) tend to have different purposes, ie, regions tend to be receivers or senders.

What is it?

Back 36

Histologically, the cerebral cortex (gray matter) is organized in several layers parallel to the outer surface. The outer layers receive afferent input from other regions of the cerebral cortex and brainstem, while the inner layers send efferent fibers into the white matter.

Front 37

Within the cerebrum, what type of neurons are mostly present?

Back 37

Pyramidal (motor) cells

Interneurons (stellate cells)

Front 38

What is the thalamic nuclei?

Back 38

integrates information for the cortex, and is involved in maintaining consciousness

Front 39

What is the basal ganglia?

Back 39

involved in coordinating muscle action and tone

Front 40

How is the gray matter of the spinal cord divided?

Back 40

Divided in concentric laminae (I-X)

Front 41

What is within the white matter of the spinal cord?

Back 41

Ascending and descending tracts

Front 42

What are the horns of the spinal cord for?

Back 42

posterior or dorsal horn - is associated with afferent (sensory) functions

anterior or ventral horn - contains large motor neurons

Front 43

What are the two components of the blood-brain barrier?

Back 43

*Tight surround layer of astrocytes

*Impermeable endothelial cells of the endoneurial capillaries

Front 44

Where is the blood-nerve barrier not well-developed?

Back 44

blood-nerve barrier is not well-developed in sensory and autonomic ganglia