A. Sensory Division - Into CNS

B. Motor Division - From CNS

1. Somatic NS - Voluntary eg. skeletal muscles

2. Autonomic NS - Involuntary eg. organs 

a. Sympathetic - Fight or Flight eg. heart rate, pupil size, blood pressure dilate

b. Parasympathetic - Resting and Digesting eg. decrease all above

Definition - Main cell in the nervous system

Properties - 1. High metabolic rate -supplies w/ glucose O2,etc.

2. Amitotic - Doesn't Divide

3. Longevity - Most live as long as organism

4. Sends signals

Sensory Neurons - Brings signals to CNS from PNS

Motor Neurons - Sends signals from CNS to PNS

Interneurons - Located between sensory and motor neurons eg. Reflex loop

1. Astrocytes - Form blood brain barrier

2. Microglia - Macrophages "big eater, immune system

component

3. Ependymal Cells - Have cilia, move cerebral spinal fluid

4. Oligodendrocytes - wrap myelin around axons "white matter", increaes speed of transmission, doesn't regenerate axons and scars form

 -Nodes of Ranvier - signal jumps to bare patches on axon 

Schwann Cells - wrap myelin around axons, increases speed of transmission, help to regenerate axons after damage

-Nodes of Ranvier - signal jumps to bare patches on axon  

-Motor Area

-Broca's Area (motor speech area)

-Prefrontal Cortex

1. Long term planning
2. Goal Oriented Behavior
3. Ethical Decision Making

- Primary Somatosensory Area

-sensations from skin, muscles, joints

1. Visual Area
2. Visual Association Area

Anterior Assocation Area

&

Posterior Assocation Area

Affective Language

&

Sends signals to motor area

Left - Analytical

Right - Visual / Artistic

1. "Emotional Brain"
2. All lobes work together
3. Constantly connecting to cerebrum and hypothalamus
4. Fear/Aggression - Primal instinctual emotions 

Short Term Memory 

-Hippocampus, lower brain  >>>>>>>

Emotion plays a big role

<<<<<Long Term Memory

-Cerebral Cortex

1. Edits info
2. Allows brain to filter information that is coming in

1. Hunger/Satiety
2. Thirst
3. Body Temperature
4. Biologic Clock
5. Emotions
6. Endocrine System Reg.
7. Autonomic N.S. Regulation - Heartbeat, Blood Pressure, Respiration

1. Pineal Gland - melatonin release

- Preganglionic Neuron reside in CNS

- Postganglionic Neuron resides outside of PNS

- Sympathetic: Chain Ganglia

- Parasympathetic: Head, Neck, Abdomen

1. Fight or Flight - Increases pupil size, respiration, and heart rate
2. Releases epinephrine and norepinephrine
3. Adrenergic Receptors

       - A (Alpha): Puplis Dilate

       - B (Beta): Increased Heart Rate

1. Resting and Digesting - Decreases pupil size, respiration and heart rate
2. Acetylcholine
3. Cholinergic

1. Prevalent in most organs
2. Involves both sympathetic and parasympathetic innervation
3. Eg. H.R. increased by symp decreased by para

Eg. Blood Vessels

-Increase in Symp stimulation = vasoconstriction

-Decrease in Symp stimulation = vasodilation

1. Medulla Oblongata
2. Hypothalamus - main regulatory center
3. Limbic System -  visceral responses
4. Cerebrum - biofeedback training (conscious control of Autonomic NS)

1. Mechanoreceptors -  detect movement
2. Chemoreceptors - detect chemicals, eg. smell
3. Photoreceptors - detect light
4. Thermoreceptors - detect temperature
5. Propioreceptors - detect stretching of ligaments and flexibility
6. Nocireceptors - detect pain

• Tonic Receptors - maintain firing of neuron eg. pain
• Phasic Receptors - adapt & decrease to sensation eg. smell of gasoline
• Cutaneous Receptors - skin, 
• Touch, pressure
• Face, hair follicles, nerve endings
• Meissner's corpuscles & pacinian corpuscles
• Cold - cold & menthol
• Heat - warm & capsaicin
• Pain - tissue damage released
• chemicals - prostaglandins, histamines
• endorphines - decrease pain(mimic morphine)

• Located on tongue, cheek and palate
• Types include:
• Fungi Form - most common
• Vallate ( or circumvallate)
• Filiform - textured

- Takes place on Olfactory Epithelium

- Must be in a solution (mucus in nasal cavity)

- Limbic System (emotional response to smells)

1. Pinna( Auricle) - Funnel the sound into >
2. External Auditory Canal - Ceruminous glands that produce ear wax > Attached to Middle Ear
• Trap Particles, Insects, Water) 

1. Tympanic Membrane >
2. Malleus (Hammer) Muscle Tensor Tympani >
3. Incus (Anvil) >
4. Stapes (Stirrup) Muscle Stapedius > Attached to Inner Ear
• Tensor Tympani & Stapedius - Dampens vibration during contraction

1. Cochlea - Fluid, Hearing
2. Organ of Corti - Membrane w/ stereocilia - bend when fluid moves > signal > vestibulocochlear nerve
3. Eustachian Tube - Pharynotympanic tube - equalize air pressure
4. Vestibulocochlear apparatus - hairs > bend > signal > vestibulocochlear nerve
• Semicircular canal - rotational
• Utricle and Saccule - linear (otoliths)

1. Eyebrows, lids, lashes -  protect from dust etc.
2. Lacrimal Glands - tears
3. Extrinsic eye muscles 
• rectus - direct innervation: up, down, left, right
• oblique - rotation
4. Conjunctiva - film on surface of eye

Vascular Tunic

Middle Layer

1. Iris - colored portion, smooth muscle, constricts/dilates pupil
2. Ciliary Body - encircles lens
• Lens - focuses light to retina, gets flatter and thicker by pulling of attached ligaments
• Accomodation
• Close objects - lens gets thicker
• Far objects - lens gets flatter
• Produces Aqueous Humor - which brings nutrients, oxygen, to lens/cornea
• Canal of Schlemm (scleral venous sinus) - Drains aqueous humor

Inner Layer

1. Retina
2. Rods - Black and White Vision
3. Cones - Color, Brights
• Red, Blue, Green
4. Macula Lutea - highly packed w/ rods & cones
• Fovea Centralis - sharpest vision, cones only
5. Blind Spot - optic nerve

1. - Nearsightedness
2. - Lens is too thick 
3. - Light converges in front of retina

• Treated with concave lenses - glasses or contacts
• Light rays seperate more

1. Far Sightedness
2. Lens is too thin

• Treated with convex lens - glasses

1. Presbyopia - caused by old age, lens loses elasticity.
2. Astigmatism - uneven curvature of cornea or lens
3. Cataract - Lens cloudy, caused by age
4. Glaucoma - Aqueous Humor isn't draining through Canal of Schlemm