Nervous System

• 1. Reception- recieve stimuli/ sense a change
• 2. Conduction- info is carried as impulses to and from the brain and spinal cord
• 3. Response- Reaction to the stimulus/stimuli

nerve cells that enabel humans to be aware of their environment (eyes, nose, skin, etc)

• CNS (Central Nervous System)- control center in the middle of your body (brain and spinal cord)
• PNS (Peripheral Nervous System)- outside the brain and spinal cord (sensory nerves and motor nerves)

• Afferent Fibers
• carry impulses to the CNS
• reception

• Efferent Fibers
• Carry out of the CNS (movement and action)

• a nerve cell
• highly modified

• 1. Cell Body- controls impulses; nucleus and mitochondria; main portion of the cell
• 2. Dendrites- also called afferent process. one or more branches that carry the impulse into the cell body.
• 3. Axon- also called the efferent process. one extra long branch that carries the impulse away from the cell body

cell bodies outside the CNS

the message comming into a cell body

the message leaving the cell bodyp

• increses the speed of an impulse
• only in some neurons

Schwan cells that wrab around the axon

• located between the myelin sheath
• help in speeding up reactions
• in a myelinated cell the Na+ come in at the nodes of ranvier

• also called Impulse
• deals with electricity and chemicals

• K+ and mostly negative ions inside axon, positive Na+ on the outside
• fewer positive ions sitting on the inner face of the neurons plasma membrane than
• there are on its outer face in the tissue fluid that surrounds it
• the stimulus is inactive
• 

• Resting potential decreased and after sodium gates open, Na+ ions diffuse into the axon, making the inside more positive and the outside more negative
• 

the axon teminals open and neurotransmitters travel through the synapse and deliver the impulse to the dendtrites of the next neuron

The space between the axon terminals and the dendrites of the next neuron.

• The membrane of the axon becomes impermeable to sodium and K+ ions exit the axon making the inside negative again and the outside positive.
• 

• In a myelinated cell the Na+ can come in at each node of ranvier rather than come in at every opening, which is what it does in an unmeylinated cell. Myelinated cells complete the same task faster and are usually used for vital functions such as heartbeat.
• 

the coordinated transmission of an impulse over sensory, inter and motor neurons involved in reflexes

• 1. Receptor must be stimulated (sensory receptor)
• 2. Impulse travels over a sensory neuron to the CNS
• 3. Inter neurons in the CNS transfer imoulses to the motor neurons
• 4. Impulses tracel through the motor neurons to the muscles/glands for a reaction

The space between the ason terminals of once neuron and the dendrites of the next neuron

• the response to an impulse over a reflex arc.
• ex: blinking, sneezing, coughing

• the time it takes for an impulse to travel over a reflex arc.
• can be faster or slower depending on the person

• the minimum level required to generate an impulse
• Where the axon fires

• not enough stimuli to create an impulse
• below the threshold

• also called nerve impulse or action potential
• says that if the threshold is met, it will generate an impulse all the way through even if the pressure, smell, etc stops.
• If the threshold is not hit, no impulse will be generated.

Approx. 3lbs

• the skull
• 3 membrane layers

• 1. Dura Mater- outermost membrane protecting the brain
• 2. Arachnoid- middle membrane, looks like a spiderweb
• 3. Pia Mater- innermost membrane

spinal cord

• looks like a mushroom
• connects brain to spinal cord

• 1. Medulla Oblongata- lowest part of the brain stem; attaches to the spinal cord; has reflex centers for heart & lungs
• 2. Pons- above the medulla oblongata. controls breathing; has many tracks/axons running through it.
• 3. Midbrain- tracks for hearing and vision; cirucular part inside of actual brain

sensory nerves that conduct impulses to higher parts of the brain and motor nerves that conduct impulses from higher parts of the brain to the spinal cord

Myelinated Axons

cell bodies

• Grey Matter: Outside
• White Matter: Inside

• Grey Matter: Inside
• White Matter: Oustide

right after the period of repolarization

period when a neuron can't be restimulated because its sodium gates are open

Codes for intensity of the stimulus

largest, uppermost and outermost part of the brain

more complex sensory and motor functions

• the outermost layer of the cerebrum
• functions: ability to reason, memory, judgement, will power, ability to perservere, voluntary muscle contraction, vision, hearing, speech

• 1. Frontal: located under frontal bone in front
• 2. Parietal: top back under parietal bone
• 3. Temporal: sides
• 4. Occipital: lower back

joins the left and right sides of the brain together

hills (bumps that stick up in the brain)

valleys (deep lines in the brain)

Fissure

• also called diencephalon
• located above the midbrain andbelow the cerebrum
• inside the brain, not visible from the outside
• has 2 major structures

• Hypothalmus: lower part deals with alimentary canal (digestive system) controls teperature, sleep, water balance, matabolism, and emotional responses
• Hypothalmus functions through the Pituitary gland:deals w/ hormones
• Thalmus:upper part of the interbrain, deals with emotions of pleasentness unpleasentness in regards to sensation

• underneath occiputal lobe
• below cerebrum
• behind brainstem
• looks like a shell

• balance and percise movements (hand eye coordination)
• affected easily by alcohal

• nerves that come directly off of the brain
• still part of the PNS

• 1. Olfactory
• 2. Optic
• 3. Oculomotor
• 4. Trochlear
• 5. Trigeminal
• 6. Abducens
• 7. Facial
• 8. Vestibulocochlear (Auditory)
• 9. Glossopharyngeal
• 10. Vagas
• 11. Accessory
• 12. Hypoglossal

• 1. Olfactory: sensory nerve
• 2. Optic: sensory nerve
• 3. Oculomotor: motor nerve
• 4. Trochlear: motor nerve
• 5. Trigeminal: sensory & motor nerve
• 6. Abducens: motor nerve
• 7. Facial: sensory & motor nerve
• 8. Vestibulocochlear (Auditory): sensory nerve
• 9. Glossopharyngeal: sensory & motor nerve
• 10. Vagas: sensory & motor
• 11. Accessory: motor nerve
• 12. Hypoglossal: sensory & motor nerve

• 1. Olfactory: sensory nerve; deals w/ sense of smell
• 2. Optic: sensory nerve; sense of sight
• 3. Oculomotor: motor nerve; controls pupil dialation and eyelid
• 4. Trochlear: motor nerve; controls 4 out of 6 eye muscles
• 5. Trigeminal- sensory & motor nerve; sensory of touch on your face deals with chewing and the muscles in your nose
• 6. Abducens: motor nerve: controls other 2 of the 6 eye muscles; deals with eye rolling
• 7. Facial: sensory & motor nerve; controls tears and saliva and deals w/ taste
• 8. Vestibulocochlear (Auditory): sensory nerve: controls hearing
• 9. Glossopharyngeal: sensory & motor nerve; controls swallowing and the back of the tongue, bitter taste.
• 10. Vagas: sensory & motor nerve; vital center; deals with heart and lungs
• 11. Accessory: motor nerve; deals with trapezies muscles (traps) in your back. allows you to shrug and get chills in your spine
• 12. Hypoglossal: sensory & motor nerve; deals with the front of the tongue sweet taste

31 pairs (peripheral nerves)

• Right:1
• Left:2
• Right:3
• Left:4
• Right:5
• Left: 6 7
• Right: 8 9
• Left: 10 11
• Right: 12
• 

• EEG: Electroencephalogram
• measures the electrical activity of the brain

a removal of part of the brain

• CAT Scan: Computed Axial Tomography
• computer assisted x-ray of the brain. Maps out parts of the brain and can take off certian parts so you can see deeper inside

conditioned reflex allows you to create a reflex. Pavlov had dogs and every time he fed them he would ring a bell and eventually, when he rang the bell the dogs would automatically start salivating

manipulating or doing something to create a wanted reaction. ex: training to do things fro rewards, giving kids candy for behaving

• MRI: Magnetic Resonance Imaging
• you go into this tube and a magnet goes around you, pulls up all your ions and then drops them back to map out your body. allows you to see organs and stuff inside the body without cutting someone open
• Restricitons: You can't move in it (takes a long time), you can't weigh over 300lbs, and you can't have any metal in your body.

• CNS: central nervous system; brain and spinal cord
• PNS: peripheral nervous system; spinal nerves, sensory and motor nerves, everything outside brain and spinal cord

• 1. Somativ Nervous System
• 2. Autonomic Nervous Sytem

• made up of special senses: sight, touch, smell, taste, hearing
• controls voluntary funtions

• regulates the body's automatic involuntary functions: heart beat, secretions of glands, body temp, and stomach and intestine contractions
• broken into 2 systems

• 1. Sypathetic Sytem
• 2. Parasymmpathetic system

• originates in the spinal cord so the message is comming out
• acts as an emergency system in times of stress/danger
• called "fight or flight response"- you fight or run away
• increases your heart rate,decreases size of blood vessels, increases blood pressure to move O₂ faster around the body, stimulates adrenaline, decreases blood flow to the digestive system (can cause you to puke)

• Originates in the brain stem (midbrain, pons, medulla oblongata) controls normal everyday activities
• opposing sympathetic: decreases heart rate and blood pressure, decreases respiratory rate, increases parastalsys (movement of food through the GI Tract) increses digestive juices and saliva
• used when your relaxed ex: sleeping