Bio 30 Nervous System

Front 1

Neurons

Back 1

Functional units of nervous system. Consist of Dendrites, cell bodies, axon (myelinated or unmyelinated) and terminal branches.

Front 2

Dendrites

Back 2

Recieve information from either environment or other neurons.

Front 3

Axon

Back 3

Extension of cytoplasm that carries the nerve impluses away from the cell body

Front 4

Myelin Sheath

Back 4

White coat of fatty protien that acts as unsulation for the neurons

Front 5

Schwan Cells

Back 5

Special type of glial cell that produces the Myelin Sheath.

Front 6

Nodes of Ranvier

Back 6

Delicate membrane that surrounds the axon of some nerve cells, promotes the regeneration of damaged axons.

(The CNS lacks neurilema)

Front 7

Glial Cell

Back 7

Non conducting cells, important for structural support and the metabolism of nerve cells. Includes Schwann cells.

Front 8

Central Nervous System

Back 8

Brain and Spinal Chord.

Front 9

Peripheral Nervous System

Back 9

Relays information between CNS and other parts of the body

Front 10

Somatic Neurons

Back 10

Voluntary Nerves. Motor and sensory neurons. Voluntary body nerves.

Front 11

Sensory Neurons

Back 11

Neurons which carry information from a stimlus to the CNS

Front 12

Motor Neurons

Back 12

Neurons which carry information from the CNS to a body tissue, such as a muscle

Front 13

Interneurons

Back 13

A part of the CNS which connects sensory neurons with motor neurons.

Front 14

Autonomic Neurons

Back 14

Involuntary neurons which govern the body's response to stress and homeostasis.

Front 15

Sympathetic Neurons

Back 15

Help the body to deal with stress

Front 16

Parasympatheic Neurons

Back 16

Help the body regain homeostasis

Front 17

The path of a reflex arc (8 steps)

Back 17

1. Stimlus

2. Pain receptor

3. Sensory Neuron

4. Interneuron

5. Spinal chord (or brain)

6. Motor Neuron

7. Muscle

8. Response

Front 18

All-Or-None Response

Back 18

Axons fire maximally or not at all. Once the threshhold level is met the axon will fire maximally, and it will not have a greater response for a greater stimulus.

Front 19

Measure of stimulus intensity

Back 19

When a stimulus is more intense, the neuron will fire with a greater frequency

Front 20

Resting Potential

Back 20

The voltage difference accross a cell membrane when it is not transmitting a nerve impulse.

-70 mV

Front 21

Sodium Potassuim Exchange Pump

Back 21

Actively transports 3 Na+ out of the cell for 2 K+ into the cell. Results in the resting potential

Front 22

Steps of Action Potential (4 steps)

Back 22

1. Depolarization

2. Repolarization

3. Hyperpolerization (refractory period)

4. Resting potential

Front 23

Depolarization

Back 23

The stimulus results in the opening of the Na+ channels, allowing Na+ to flood into the cell, making the inside of the neuron more positive than the intercellular fluid resulting in a charge reversal.

Front 24

Repolarization

Back 24

The posive inside of the cell causes the Na+ channels to close stopping Na+ inflow. K+ channels open and K leaves the cell making the intercellular fluid more positive than the cytoplasm of the neuron

Front 25

Hyperpolarizaton (refractory period)

Back 25

An overshoot in repolarization in which the charge exceedes the charge for a resting potential before K+ channels close, and the Sodium Potassium exchange pump works to restore resting potential

Front 26

Nerve impluse

Back 26

A series of action potentials

Front 27

Saltatory conduction

Back 27

Nerve impulses through a myelinated nerve cell

Front 28

Synaptic cleft

Back 28

The small space between two neurons or a neuron and an effector

Front 29

How the impulse is transmitted accross the Synaptic cleft. (8 steps)

Back 29

1. Action potential reaches presynaptic terminal

2. Ca+ channels open

3. Infulx of Ca+

4. Synaptic vesicles fuse with membrane

5. Neurotransmitters released into synaptic cleft and diffuse to postsynaptic terminal

6. Neurotransmitter binds to postsynaptic memberane

7. If excitatory Na+ channels open into and Na+ enters post synaptic membrane

8. Action potential is initiated and a enzyme breaks down the neuro transmitter.

Front 30

Excitatory Neurotransmitter

Back 30

A neurotrasmitter which initiates a new action potential when it reaches the postsymaptic neuron

Front 31

Inhibitory Neurotransmitter

Back 31

When it reaches the post synaptic neuron, opens K+ channels and does not initiate an action potential, thus ending the nerve impluse.

Front 32

Summation

Back 32

The effect produced by the accumulation of neurotransmitters from two or more neurons

Front 33

Dopamine

Back 33

Pleasure neurotransmitter. Excess= schiziophrenia. Too little= Parkinsons

Front 34

Serotonin

Back 34

Feel good neurotransmitter. Too little= depression

Front 35

Endorphins

Back 35

natural painkillers

Front 36

norepinephrine

Back 36

stress neurotransmitter. Too much= high blood pressure and well... stress. Too little= hunger and exaustion

Front 37

Frontal Lobe

Back 37

Motor control and emotions. Personality and the majority of concious thought.

Front 38

Parietal Lobe

Back 38

Touch and temperature and smell. Language interpretation.

Front 39

Temporal Lobe

Back 39

Process auditory, sound, and hearing information

Front 40

Occipital

Back 40

Interperet visual information

Front 41

Corpus Callosum

Back 41

The fibers connecting the right and left sides of the cerebrum.

Front 42

Cornea

Back 42

Hard layer of the eyeball which directs light toward the lens.

Front 43

Lens

Back 43

Hard clear structure within the eye which bends light toward the retina. Adjusts in shape to change focus.

Front 44

Sclera

Back 44

the hard protective layer around the eyeball

Front 45

Choroid layer

Back 45

The fleshy layer between the sclera and the retina containing bloodvessel. Provides nutrients to the rest of the eye.

Front 46

Retina

Back 46

Layer at the back of the eyeball containing photoreceptors

Front 47

Rods

Back 47

Photoreceptors, sensitive to light and good for seeing in dim light and peripheral vision

Front 48

Cones

Back 48

Photoreceptors, sensitive to colour and detail, and require a lot of life, create high definition images.

Front 49

Fovea centralis

Back 49

Point on the eyeball across from the pupil, packed with cones for the best focus.

Front 50

Iris

Back 50

Coloured muscle which changes the size of the pupil with ciliary muscles.

Front 51

Pupil

Back 51

Whole which allows light to pass through from the cornea to the lens and the rest of the eyeball. The iris controls the size of the pupil

Front 52

Vitreous Humor

Back 52

The jelly like substance within the eyeball.

Front 53

Aqueus Humor

Back 53

The jelly like substance within the cornea of the eye.

Front 54

Optic Nerve

Back 54

The nerve in the back f the eyeball which connects the photorecptors of the retina to the occipital lobe of the brain.

Front 55

Pathway of Light through the eye (8 structures)

Back 55

1. Cornea

2. Aqueous humor

3. Pupil

4. Lens

5. Virteous humor

6. Retina

7.Photoreceptors

8. Optic Nerve

Front 56

Blind Spot

Back 56

The point at which the optic nerve connects to the retina. There are no photoreceptors on this part of the retina, making it a blindspot.

Front 57

Astigmatism

Back 57

irregular shape of the cornea. Changes the way light bends on it's way into the eye.

Front 58

Myopia

Back 58

Nearsightedness. Light converges before it gets the chance to reach the back of the eyeball.

Front 59

Hyperopia

Back 59

Farsightedness. Light has not yet converged by the time it reaches the back of the eyeball.

Front 60

Sensory accomodation

Back 60

"Can you feel your clothes? Now you can." The dismissal of unimportant sensory information such as background noise and the constant feeling of clothes.

Front 61

Pinna

Back 61

The ouside of the ear, herds sound waves into the ear.

Front 62

Auditory canal

Back 62

Tube between the pinna and the tympanic membrane

Front 63

Tympanic membrane

Back 63

The eardrum, recieves soundwaves from outer ear.

Front 64

Ossicles

Back 64

Malles- The mallet

Incus- The anvil

Stapes- The stirrup.

Three tiny bones which amplify the soundwave as it passes through the middle ear

Front 65

Oval window

Back 65

The soundwaves passes through the oval window on it's way to the inner ear from the ossicles

Front 66

Cochlea

Back 66

Converts sounds to nerve impulses to be sent to the brain

Front 67

Organ of Corti

Back 67

The organ contained within the cochlea in which sound waves are converted to nerve impulses. Consists of stereocilia hairs which on a basilar membrane which determine the pitch of a sound wave.

Front 68

Vestibule

Back 68

For ballance in two dimensions (Up vs. Down) Uses cilia.

Front 69

Semi circular canals

Back 69

For ballance in three dimensions. Uses cilia and saccules (rocks)

Front 70

Auditory nerve

Back 70

Carries nerve impulses from the Cochlea to the temporal lobe of the brain

Front 71

Eustachian tube

Back 71

Maintains ballance within the middle ear. Connects middle ear, and mouth and nose.