43

12 pair cranial

31 pair spinal

Somatic Nervous System

(part of the PNS)

Autonomic Nervous System

(part of the PNS)

Sympathetic (fight or flight)

Parasympathetic (rest and digest)

aka. glia

connective tissue that supports, nourishes, insulates, and organizes neurons.

4 types exist in CNS:

astrocytes, ependymoctyes, microglia, oligodendrocytes

2 types exist in PNS:

satellite cells, Schwann cells (neurolemmoctyes)

Excitability: converts stimulus into impulse

Conductability: transmit impulses

Synaptic bulb (axon terminate into)

Telodendria (distal end of axon)

Synaptic vesicles (within synaptic bulb, store neurotransmitters--chemicals facilitating or inhibiting transmission of impulses)

Myelin Sheath (white matter--prevents signal leakage, increases impulse speed--are formed by Schwann cells

Nodes of Ranvier: gaps at intervals between Schwann cells along axon.  Impulses jump over gap, increasing speed)

afferent carry impulses away from the PNS (to CNS)

called sensory nerves

efferent carry impulses from brain(CNS) to the body (PNS) Impulses effect the body systems,

called motor nerves

Caused by increased stimuli or amount of afferent impulses entering sp. cord. 

Could be a result of accident or emotional stress, etc.

Vasoconstriction occurs, starving m. of oxygen and nutrients due to lack of bl. supply.

Cellular waste is produced and accumulates in m. causing pain and trigger points

TrP pain is referred to other m., causing a cycle

neurons are held together by endoneurium

bundles of neurons (nerve fascicles) wrapped by perineurium

Nerves bound together by epineurium

The method that produces and maintains resting potential

Na and K is transported inside and outside the neuron at unequal rates (3 Na to 2 K), producing a negative charge

Because so little sodium enters the cell, this helps maintain an imbalance or resting potential.

Stimulus is added

Na channels open.  Other channels sense the change in electrical charge and respond by moving more Na into cell.

Now the cell is positively charged and is conducted all along the entire neuron and onto the next neuron.

Sodium-potassium pump reinstates behind the impulse, causing a resting potential once again.

Occurs in myelinated fibers only

insulation properties resist ionic mvmt

impulses occur only at gaps (Nodes of Ranvier)

Action potential seems to leap from node to node, increasing speed of impulse

The amount of stimuli in both frequency and number of fibers stimulated needed to reach threshold stimulus

Pia mater

Arachnoid

Dura mater

filum terminale

cauda equina

lower end of sp cord, marked by threadlike fibrous extension anchored to coccyx

end of sp. cord fan out, resembling a horse's tail

cerebrum

Frontal

Parietal

Temporal

Occipital

Insula

Beta: wakeful consciousness and mental activity--busy waves, associated with extreme stress

Alpha:  awake but relaxed waves, associated with self-healing, creativity, meditation

Theta: Drowsiness, out of body experiences--used to access deep-rooted memories.  Drowsy waves

Delta:  Deep sleep

Which hemisphere specializes in language and hand movements

Which hemisphere specializes in spatial relationships, nonspeech auditory sounds

Left

Right

regulates ANS and endocrine system by governing the pituitary gland.

Controls circadian rhythm and ANS functions such as hunger, thirst, sexual behavior, temperature, sleep patterns and maintains conciousness

posterior, inferior brain--2nd largest part

regulates posture, balance, complex m. movements

midbrain

pons

medulla oblongata

Within brainstem, considered most vital part of brain, controlling respiratory, cardiovascular, vasomotor, gastric secretions and reflexes (sweating, sneezing, swallowing, vomiting)

Allows right brain and left brain to associate with each other

the great flexor

(within forearm)

malleus (hammer), incus (anvil), stapes (stirrup)

are within middle ear

In nose, tongue, brain, activated by smells, tastes and changes in blood chemistry.

Stimulate medulla oblongata to increase respiration rate if oxygen or carbon dioxide levels are off.

Touch receptors

Include Meissner, Ruffini, Pacinian and Krause end bulbs.

Also, stretch receptors (m. spindles and GTO's)

Also, baroreceptors--detecting bl. pressure within carotid arteries and aortic arch.

Sensitive to light--two types are:

rods: sense dim light, black, white and gray

cones: color vision

Free nerve endings--detect pain and located in almost every tissue of body, especially near surface.

Detect heat and cold.  10 x's more heat receptors than cold ones.

When temps fall below 50 degrees or rise above 113 degrees, nociceptors activate