The Nervous System

Front 1

Brain

Back 1

Nervous tissue inside the cranium

Front 2

Spinal cord

Back 2

Extension of nervous tissue within vertebral column

Front 3

Central nervous system

Back 3

Brain and spinal cord

Front 4

Peripheral nervous system

Back 4

Everything else beyond brain and spinal cord

Front 5

Glial cell

Back 5

neuroglial cells that provide a framework of tissue that supports the neurons and their activity

Front 6

Neuron

Back 6

More structurally important due to its communicative function

Front 7

Soma

Back 7

Neuron cellbody

Front 8

Process

Back 8

Extensions from the cell body (ie-axon and dendrite)

Front 9

Gray matter

Back 9

Regions of the brain with cell bodies and dendrites

Front 10

White matter

Back 10

Regions with many axons (white because of myelin around axons)

Front 11

Nucleus -central nervous system

Back 11

Group of neuron cell bodies in

Hint 11

CBS specific

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Ganglion - pns

Back 12

Group of cell neuron cell bodies in PNS

Front 13

Tract

Back 13

bundle of axons in the Central nervous System

Front 14

Nerve

Back 14

bundle of axons in the PNS

Front 15

basic functions of the nervous system

Back 15

sensation, integration and response

Front 16

sensation

Back 16

receiving information about the environment around us

Front 17

5 senses

Back 17

taste

touch

smell

sight

hearing

Front 18

stimulus

Back 18

a particular event in the external or internal environment

Front 19

integration

Back 19

stimuli are compared with or integrated with other stimuli, memories of previous stimuli, or mechanical stimuli

Front 20

response

Back 20

contraction of muscle tissue, neral control of glands

Voluntary and involuntary

Front 21

Somatic Nervous System

Back 21

conscious perception and voluntary motor responses

- skeletal muscle contraction

- can be considered unconscious due to reflexes or because of learned motor skills/habitual or procedural memory

Front 22

Autonomic Nervous System

Back 22

involuntary control of the body for the sake of homeostasis (regulate organ systems of the body)

- smooth muscle, cardiac muscle, and glands

- broken into sympathetic and parasympathetic

Front 23

Enteric Nervous System

Back 23

controls smooth muscle and glandular tissue in the digestive system

Front 24

What is enervous tissue composed of

Back 24

neurons and glial cells

Front 25

neurons

Back 25

electrical signals that communication information about sensations produce movement in response to stimuli and induce thought

Front 26

Purpose of the axon

Back 26

propogate nerve impulse

Front 27

axon hillac

Back 27

where axon emerges from cell body

Front 28

axoplasm

Back 28

the cytoplasm has changed to a solution of limited components

Front 29

myelin

Back 29

wraps around the axon and acts as insulation

Front 30

nodes of Ranvier

Back 30

gaps between the myelin - important for how signals travel b/c potassium channels located here

Front 31

unipolar neuron

Back 31

one process with both the axon and dendrites

Front 32

bipolar

Back 32

2 processes - one axon and one dendrite

Front 33

multipolar

Back 33

- most common

- more than 2 processes - axon and 2 or more dendrites

Front 34

Astrocyte

Back 34

CNS glia that has a support function

Front 35

Satellite Cell

Back 35

PNS glia that has a support function

Front 36

Oligodendrocyte

Back 36

CNS glia

Function: insulation and myelination

Front 37

Schwann Cell

Back 37

PNS Glia

Function: insulation and myelination

Front 38

Microglia

Back 38

CNS Glia

Function: immune surveillance and phagocytosis

Front 39

Ependymal Cell

Back 39

CNS Glia

Function: create cerebrospinal fluid

Front 40

Myelin

Back 40

lipid-rich sheath that surround axon creating a myelin sheath that facilitate the transmission of electrical signals

Front 41

Cerebrum

Back 41

grey mantle which appears to make up most of the brain mass - it's split into the right and left hemisphere

Front 42

cerebral cortex

Back 42

continuous, wrinkled and thin layer of grey matter that wraps both hemispheres

Front 43

gyrus

Back 43

ridge of the wrnkle in the brain

Front 44

sulcus

Back 44

groove between 2 gyri

Front 45

localization of function

Back 45

different regions associated with function - there are 52 regions

Front 46

Lobes of the brain

Back 46

1, Frontal

2. Parietal

3. Temporal

4. Occipital

Front 47

Diencephalon

Back 47

the connection between the cerebrum and the rest of the nervous system

- every sense apart from olfactory travel through this area

- thalamus, hypothalamus, epithalamus (pineal gland), and subthalamus

Front 48

Thalamus

Back 48

collection of nuclei that relay information between the cerebral cortex and the periphery, spinal cord, or stem

processes information

Front 49

Hypothalamus

Back 49

a collection of nuclei largely involved in the regulation of homeostasis, memory and emotion

- ANS and endocrine system through regulation of anterior pituitary gland

Front 50

Brian Stem

Back 50

midbrain and hindbrain (pons and medulla) - a tapering cone that connects brain to spinal cord

Front 51

Function of the hindbrain

Back 51

cardiovascular and respiratory regulation

Front 52

Function of brainstem

Back 52

coordinate sensory representations of visual, auditory, and somatosensory perceptual spaces

Front 53

Pons

Back 53

thick bundle of white matter that acts as the main connection with cerebrum and brain stem

Front 54

inferior colliculus

Back 54

part of the auditory brain stem pathway, sends auditory info to the verebrum for conscious perception of sound

Front 55

superior colliculus

Back 55

combines sensory information about visual space, auditory space, and somatosensory space

(ie. orienting eyes to a sound or touch stimulus)

Front 56

Medulla

Back 56

diffuse region of gray matter through the brain stem (reticular formation) is related to sleep/wakefulness, general brain activity, and attention

Front 57

cerebellum

Back 57

"little brain"

integrates motor commands from cerebral cortex with sensory feedback from periphery allowing for coordination & precise execution of motor activities

Front 58

Spinal Cord Regions

Back 58

Cervical --> thoracic --> lumbar --> sacral

Front 59

Gray Horns

Back 59

1. Posterior horn: sensory processing

2. anterior horn: sends motor signals to skeletal muscles

3. Lateral horns: central component for the sympathetic division of the ANS (found in thoracic, upper lumbar and sacral regions)

Front 60

White Columns

Back 60

ascending tracts carry sensory info up to the brain

descending tracts carry motor commands from the brain

Front 61

The Meninges

Back 61

membrane covering the brain that composed of connective tissue

Front 62

Dura Mater

Back 62

thick fibrous layer and strong protective sheath over the entire brain and spinal cord

Front 63

arachnoid mater

Back 63

the membrane of thin fibrous tissue that forms a loose sac around CNS

Front 64

pia mater

Back 64

thin fibrous membrane that follows the convolutions of gyri and sulci in the cebral cortex

Front 65

Functions of CSF

Back 65

circulates to remove waste from the interstitial fluid of nervous tissue and returns it to the bloodstream

a liquid cushion

Front 66

ventricles

Back 66

open spaces in the brain where CSF circulates

Front 67

choroid plexus function

Back 67

filters the blood

Front 68

subarachnoid space in the circulation of CSF

Back 68

where CSF is reabsorbed into the blood

Front 69

Circulation of CSF

Back 69

lateral ventricles --> 3rd ventricle (more CSF is produced) --> cerebral aqueduct --> 4th ventricle (CSF produced) --> spinal cord

Front 70

Sensory Axons

Back 70

dorsal nerve root

Front 71

motor axons

Back 71

ventral root nerves

Front 72

what does it mean to have mixed (sensory & motor) functions?

Back 72

the axons originate out of sensory ganglia external to cranium or motor nuclei within the brainstem

Front 73

Somatic Nervous System

Back 73

conscious perception of our environment and our voluntary responses to that perception by skeletal muscles

Front 74

Reflex

Back 74

automatic response that nervous system produces in response to stimuli

Front 75

Explain the stretch reflex using the patellar reflex

Back 75

1. tap the patellar tendon causing a stretching of the muscle fiber in the quad stimulating sensory neurons innervating those fibers

2. within the sensory neuron: nerve impulse (a.p.) is generated and travels along the sensory nerve from muscle to dorsal root ganglion to spinal cord

3. sensory neuron stimulates the motor neuron in the ventral horn

4. motor neuron sends action potential along the axon

5. impulse reaches the quad muscle causing contraction and extension of the leg

Front 76

Explain the withdrawal reflex

Back 76

1, sensory neurons in skin sense extreme temperature

2. within sensory neuron: A.P. is generated, travels along the sensory nerve fiber through dorsal root ganglion to spinal cord

3. sensory neuron stimulated the motor neuron in the ventral horn

4. motor neuron sends nerve impulse (A.P) along the axon

5. impulse reaches biceps brachii causing contraction of muscle and flexion of forearm

Front 77

Autonomic Nervous System

Back 77

Sympathetic: Fight or Flight

Parasympathetic: Rest and Digest

Front 78

Sympathetic nervous System - what does it activate system-wise?

Back 78

respiratory, cardiovascular, and musculoskeletal (thoracolumbar system)

Front 79

Fight or Flight Response

Back 79

Adrenaline floods the circulatory system

Cardiovascular: heart rate increase, high B.P., increased capillary permeability

Respiratory: lungs and pupils dilate

Sweat glands activate to help reduce heat

Digestive system shuts off

Front 80

Parasympathetic System

Back 80

the activation decreases activity in the respiratory, cardiovascular, and musculoskeletal system

increases activity in the digestive, urinary, and reproductive systems

"craniosacral"

Front 81

cholinergic

Back 81

Ach (acetylcholine) released at synapse

Front 82

adrenergic

Back 82

norepinephrine released at synapse

Front 83

thermoreceptor

Back 83

sensory receptor sensitive to temperature

Front 84

graded potential

Back 84

amount of change in the electrical state based on strength of the stimulus (if the stimulus is strong, it will change the cytoplasm enough to send electrical sugnal)

Front 85

threshold

Back 85

voltage at which a signal is generated

Front 86

action potential

Back 86

electrical signal nervous tissues generate for communication

Front 87

propagation

Back 87

action potential travelling

Front 88

Path of action potential

Back 88

the signal travels down the axon from hillock to terminals, into synaptic bulbs which causes the release of neurotransmitter

the neurotransmitter diffuses across the synapse to bind to receptor protein causing cell membrane or target neuron to change voltage and new graded potential begins --> thalamus --> cerebral cortex

Front 89

Sodium-potassium pumps

Back 89

sodium ions pumped out of the cell, potassium ions pumped into the cell and regulate concentration on both sides of membrane

- requires ATP

Front 90

ligand-gated channel

Back 90

open because a signalling molecule (ligand) binds to extracellular region of the channel

Front 91

mechanically-gated channel

Back 91

opens because of a physical distortion of the cell membrane (sense of touch)

Front 92

voltage-gated channel

Back 92

channel that responds to changes in the electrical properties of the membrane in which its embedded (voltage needs to be less negative than before)

Front 93

membrane potential

Back 93

electrical state of cell membrane (distribution of the charge across membrane)

Front 94

resting cell membrane potential

Back 94

-70mV

Front 95

Generation of Action Potential

Back 95

1. Channel opens for Na+ leading to an increase in Na+ in the cell and a less negative charge in the cell (depolarization)

2. at +30mV voltage-gated channel is ended --> K+ leaves cell --> membrane potential moves toward resting potential (repolarization)

3. Overshoot -70mV because of K+ channels

4. Return to rest

Front 96

When is action potential generated

Back 96

-55mV

Front 97

when does voltage-gated K+ channel open

Back 97

-50mV

Front 98

refractory period

Back 98

another Action Potential cannot be generated while an action potential is in the process

Front 99

Explain Synaptic Transmission

Back 99

1. An action potential reaches the axon terminal.

The change in voltage causes voltage-gated Ca2+ channels in the membrane of the synaptic end bulb to open.

The concentration of Ca2+ increases inside the end bulb, and Ca2+ ions associate with proteins in the outer surface of neurotransmitter vesicles facilitating the merging of the vesicle with the presynaptic membrane. The neurotransmitter is then released through exocytosis into the small gap between the cells, known as the synaptic cleft.

Once in the synaptic cleft, the neurotransmitter diffuses the short distance to the postsynaptic membrane and can interact with neurotransmitter receptors. Receptors are specific for the neurotransmitter, and the two fit together like a key and lock. One neurotransmitter binds to its receptor and will not bind to receptors for other neurotransmitters, making the binding a specific chemical event.

The interaction of the neurotransmitter with the receptor can result in depolarization or hyperpolarization of the postsynaptic cell membrane, leading to excitation of the postsynaptic cell (and possibly the generation of a new action potential) or inhibition, respectively.

The neurotransmitter is removed from the synaptic cleft by diffusion, due to the action of enzymes that break it down chemically or by transporters in the presynaptic cell membrane.