A&p Nervous System

Front 1

Nervous system (definition)

Back 1

The system in the body that is made up of the brain, brain stem and spinal cord, nerves, ganglia, and parts of the receptor organs and that receives and interprets
stimuli (from the environment &/or the body) and transmits impulses to the body (muscles, organs, glands, other nerves)

Front 2

Nervous system organization

Back 2

Central Nervous System (CNS)
A. Brain
B. Brainstem
C. Spinal cord

Peripheral Nervous System (PNS)
A. Peripheral nerves
1. Somatic
a. Cranial nerves
b. Spinal nerves
2. Autonomic

Front 3

Nerve

Back 3

group of multiple neurons

Front 4

Neuron

Back 4

single nerve cell that acts as a conduit to conduct a signal or impulse in ONLY one direction

Front 5

Neuron (composition)

Back 5

Cell body
Dendrite
Axon

Front 6

Afferent neuron

Back 6

conducts an impulse towards the CNS

Also called sensory neurons

Front 7

Efferent neuron

Back 7

conducts an impulse away from CNS

Also called motor neurons

Front 8

Interneuron

Back 8

Conducts impulses between other neurons

Found only in brain and spinal cord

Front 9

Bipolar neuron

Back 9

2 extensions from the cell body
1 axon
1 dendrite

Front 10

Bipolar neuron - where found

Back 10

Eyes, nose, ears

Afferent, sensory

Front 11

Unipolar neuron

Back 11

One extension from cell body that divides into two branches (1 axon, 1 dendrite)

Front 12

Unipolar neuron - where found

Back 12

sensory neurons

Temp, touch, pain

Front 13

Multipolar neuron

Back 13

Many extensions from the cell body

Only one is an axon

Front 14

Multipolar neuron - where found

Back 14

Everywhere

Front 15

Nervous system function

Back 15

Gather information
Transport the information
Interpret the information

Front 16

Form of signal that nervous system uses

Back 16

Action potential

Front 17

Action potential

Back 17

Wave of electrochemical activity that allows a neuron to carry a signal over a distance

Front 18

Polarity of cell (compared to outside)

Back 18

Negative

Front 19

Polarity of surroundings (compared to cell)

Back 19

Positive

Front 20

How is the cell's polarity maintained?

Back 20

Protein pumps (Na/K pumps)

Front 21

Action potential (action on cell)

Back 21

When a stimulus comes in contact with a neuron's dendrites/cell body, causes protein channels to open, allowing the diffusion of ions from high concentration to low concentration, changing the internal polarity of the cell.

Front 22

Action potential (movement of ions)

Back 22

Start: K high inside / Na high outside
1. Stimulus received
2. Ion channels open
3. Na+ flows inside cell, making it positive
4. Stimulus passes
5. K+ flows outside cell, making it negative
6. Na/K pump activates
7. K is brought inside, Na is pushed outside
8. Starting conditions are restored.

Front 23

Ion movement - starting concentrations (inside)

Back 23

K high / Na low

Front 24

Ion movement - starting concentrations (outside)

Back 24

Na high / K low

Front 25

Ion movement - under stimulus (inside)

Back 25

Na+ moves in

K high and Na high

Front 26

Ion movement - after stimulus (inside)

Back 26

K+ pumped out

Na high / K low

Front 27

Ion movement - return to start (inside)

Back 27

Na/K pump kicks in

K high / Na low

Front 28

Change in charge (polarity)

Back 28

Electrochemical activity

Front 29

Na+/K+ pump

Back 29

moves the K+ ions back inside the neuron and the Na+ ions out of the neuron

Uses active transport (requires ATP)!

Front 30

Where do action potentials occur?

Back 30

Only in the axons of neurons

Front 31

Axon

Back 31

Extension of neuron cell body
Only 1 per neuron
Surrounded by multiple layers of a phospholipid membrane (myelin sheath)

Front 32

Myelin sheath

Back 32

Multiple layers of a phospholipid membrane that surround the axon of a neuron

Produced by specialized non-neuron cells

Front 33

Node of Ranvier

Back 33

Area of axon where there is no myelin sheath (un-myelinated)

Front 34

Movement of action potentials through an axon

Back 34

From one unmyelinated area to the next unmyelinated area (From Node of Ranvier to Node of Ranvier)

Action potentials only move in 1 direction (away from cell body)

Front 35

Refractory period

Back 35

Time after an action potential has passed through an area of the axon where the axon is restoring its charge.

Another action potential cannot propogate through this area of the axon at this time.

Helps to ensure the 1-way flow of action potentials

Front 36

Pre-synaptic neuron

Back 36

1st neuron before the synapse

Front 37

Post-synaptic neuron

Back 37

1st neuron after the synapse

Front 38

Neuron-neuron connections

Back 38

Generally, each time there is a neuronal connection, there is a synapse.

Which means that a neurotransmitter is used

Front 39

Post-synaptic neuron connections

Back 39

May have multiple pre-synaptic neurons connected

Each may cause a different response (some inhibitory, some excitatory)

Front 40

Inhibitory response

Back 40

a kind of synaptic potential that makes a postsynaptic neuron less likely to generate an action potential.

Front 41

Excitatory response

Back 41

temporary depolarization of postsynaptic membrane potential caused by the flow of positively charged ions into the postsynaptic cell as a result of opening of ligand-gated ion channels.

Front 42

What determines the amount of neurotransmitter released from an axon?

Back 42

The rate of the impulse. Faster impulses causes more neurotransmitter to be released.

Front 43

What determines the response of the post-synaptic neuron?

Back 43

Concentration of neurotransmitter. Higher concentration of neurotransmitter causes a greater response of the post-synaptic neuron (faster, stronger muscle contractions, etc.)

Front 44

Higher concentration of neurotransmitter causes what to occur?

Back 44

greater response of the post-synaptic neuron, which could include faster, stronger muscle contractions, more secretions from a gland, increased intestinal movement, etc.

Front 45

Categories of neurotransmitters

Back 45

Products of metabolism
Modified amino acids
Unmodified amino acids
Peptides

Front 46

Neurotransmitters (Products of metabolism)

Back 46

Acetylcholine

(from metabolism of glucose in glycolysis + Vitamin B)

Front 47

Neurotransmitters (Modified amino acides) - Monamines

Back 47

Modification to single amino acids

Serotonin (L-Tryptophan)
Catecholamines (Tyrosine)

Front 48

Catecholamines

Back 48

Monamines made from tyrosine

Epinepherine
Norepinepherine
Dopamine

Front 49

Serotonin

Back 49

Monamine made from L-Tryptophan

CNS

Regulates anxiety, emotions, appetite

Front 50

Epinepherine/Norepinepherine

Back 50

Catecholamines

CNS - conscience arousal
PNS - muscle activity

Front 51

Dopamine

Back 51

Catecholamine

CNS – behavior and reward systems
PNS – skeletal muscle coordination

Front 52

Neurotransmitters (unmodified amino acids)

Back 52

Glycine
GABA (gamma amino butyric acid)

Front 53

Glycine

Back 53

Inhibitory neurotransmitter

CNS (spinal cord)
» Aids in skeletal muscle control, sequencing

Front 54

GABA

Back 54

Inhibitory neurotransmitter

CNS (brain)
» Coordination of muscle sequence/order

Front 55

Neurotransmitters (peptides)

Back 55

Short chains of amino acids

Usually involved in sensory perception

Front 56

Central Nervous System (CNS organization)

Back 56

1. Brain
A. Cerebrum
B. Cerebellum
2. Diencephalon
A. Thalamus
B. Hypothalamus
3. Brainstem
A. Medulla Oblongata
B. Pons
C. Midbrain
4. Spinal cord

Front 57

Grey matter

Back 57

Brain matter that is composed of neuron cell bodies and their dendrites

Front 58

Grey matter - where found

Back 58

Cortex (outer layer) of cerebrum
Nuclei (collection of neuron cell bodies deep in brain)
Central area of spinal cord

Front 59

White matter

Back 59

Brain matter that is composed of neuronal axons and their myelin sheaths

Found in every region of the CNS

Front 60

Cerebrum

Back 60

Largest part of the brain. Composed of several lobes

Front 61

Cortex of cerebrum

Back 61

Outer layer made of grey matter

Has convolutions (folds)

Divided into left and right hemispheres

Front 62

Convolutions

Back 62

folds in cerebral cortex.

Greatly increase the surface area.

Front 63

Gyrus (gyri)

Back 63

Elevated folds

Front 64

Sulcus (sulci)

Back 64

Depressed grooves

Front 65

Cerebral cortex (Lobes)

Back 65

L & R hemispheres, divided into 5 lobes by deep sulci

1. Frontal
2. Parietal
3. Temporal
4. Occipital
5. Insula

Front 66

Corpus callosum

Back 66

Structure that is a pathway of axons that connects the hemispheres of the cerebral cortex. Axons go in both directions.

Front 67

Lateralization of fuction

Back 67

Specialization of function in one hemisphere or the other.

Front 68

Left hemisphere function

Back 68

Language & analytical ability

Front 69

Right hemisphere function

Back 69

Visual-spacial ability

Front 70

Cerebral cortex function

Back 70

sensory perception
voluntary motor control

Front 71

Frontal lobe functions

Back 71

voluntary motor control
Personality
Higher intellectual processes
Verbal communication

Front 72

Parietal lobe functions

Back 72

Sensory perception
Understanding speech and formulating words
interpretation of textures and shapes

Front 73

Temporal lobe functions

Back 73

Interpretation of auditory sensations
Memory of auditory and visual experiences

Front 74

Occipital lobe functions

Back 74

Vision
Visual memory

Front 75

Insula function

Back 75

Memory
Sensory (pain)
Visceral integration

Front 76

Central sulcus

Back 76

Fissure that divides the frontal and parietal lobes of the cerebrum

Front 77

Post-central sulcus

Back 77

Anterior portion of the parietal lobes (posterior to central sulcus)

Responsible for processing sensory impulses.

Amount of postcentral sulcus area varies based number of sensory receptors in a specific area of the body

Front 78

Pre-central sulcus

Back 78

Posterior portion of the frontal lobes (anterior to central sulcus)

Responsible for voluntary motor control

Front 79

Cerebellum

Back 79

Small portion of the brain inferior to the cerebrum and posterior to the brain stem

Front 80

Cerebellum - function

Back 80

Coordinates and smooths out muscle movements (movements initiated by motor cortex)

Regulates posture and balance

Front 81

Arbor vitae

Back 81

Another name for cerebellum

Cerebellum contains a Grey matter cortex and White matter axonal tracts
– White matter resembles the “branches of a Tree”

Front 82

Diencephalon

Back 82

Inner/central area of the brain

Contains the thalamus and hypothalamus

Front 83

Thalamus

Back 83

Portion of the diencephalon

Acts as a relay station (gateway)
- directs sensory impulses from the body to the sensory cortex (postcentral sulcus)

All sensory receptors go through the thalamus

Front 84

Hypothalamus

Back 84

Regulates homeostatis

Primary controller of the pituitary gland
Temperature control
Thirst control
Water/electrolyte control

Front 85

Cranial Nerves

Back 85

12 Pairs (L&R)
Numbered I-XII

Originate from
Brain (I&II)
Brainstem (III-XII)

Generally contain both afferent and efferent neurons

Front 86

Brainstem

Back 86

Area between diencephalon and spinal cord

Composed of:
Midbrain
Pons
Medulla oblongata

Front 87

Midbrain - main function

Back 87

vision/response

Front 88

Midbrain - nuclei

Back 88

Contains nuclei involved in:
- movement of eye
- movement of head/neck to visual stimuli (startle)
- substantia nigra (releases dopamine)

Front 89

Midbrain - cranial nerves

Back 89

Nerves for:
- Sensory for body position
- Motor for eyelids, eye movement, pupils, lens

Front 90

Pons - function

Back 90

Relay for voluntary movements

Helps regulate breathing

Front 91

Pons - cranial nerves

Back 91

Sensory:
- Face
- Taste

Motor for:
- Eye movement
- Mastication
- Facial expression
- Tear & salivary glands

Front 92

Medulla oblongata - nuclei

Back 92

- Cardiovascular center
- Respiratory center

Others (reflexes):
- Vomiting
- Coughing
- Swallowing
- Sneezing

Front 93

Medulla oblongata - nerve connections

Back 93

White matter contains all the sensory and motor axons between the spinal cord and other parts of the brain

Front 94

Brainstem function summary

Back 94

Midbrain - visual
Pons - skeletal muscle / breathing
Medulla oblongata - everything else

Front 95

Medulla oblongata - cranial nerves

Back 95

Sensory:
– Hearing & Balance
– Throat, tongue, Carotid arteries
– Organs of the Thoracic & Abdominal cavities

Motor:
– Swallowing, Salivary glands
– Speech, Organs of the Thoracic & Abdominal cavities
– Tongue, Soft palate, Throat, Vocal cords
– Muscles of the Neck & Back

Front 96

Spinal cord - organization

Back 96

Central area
Peripheral areas
Ascending tracts
Descending tracts

Front 97

Spinal cord - central area

Back 97

Grey matter

Front 98

Spinal cord - peripheral areas

Back 98

White matter

Front 99

Spinal cord - ascending tracts

Back 99

Afferent neurons (sensory to the brain)

Front 100

Spinal cord - descending tracts

Back 100

Efferent neurons (motor to muscles)

Front 101

Peripheral nerves - divisions

Back 101

1. Somatic
- Spinal
- Cranial
2. Autonomic

Front 102

Spinal nerves

Back 102

Originate at the levels designated by the bones of the vertebral column

Part of the PNS

Contain both afferent (sensory) and efferent (motor) neurons

Front 103

Spinal nerves - number & designation

Back 103

Cervical – 8 nerves
Thoracic – 12 nerves
Lumbar – 5 nerves
Sacral – 5 nerves

Front 104

Cranial nerve I
(name & function)

Back 104

Olfactory

Sensory/smell

* just sensory

Front 105

Cranial nerve II
(name & function)

Back 105

Optic

Sensory/vision

* just sensory

Front 106

Cranial nerve VII
(name & function)

Back 106

Facial

sensory/taste
motor/facial muscles

Front 107

Cranial nerve VIII
(name & function)

Back 107

Vestibulocochlear

sensory/hearing, balance

* just sensory

Front 108

Cranial nerve X
(name & function)

Back 108

Vagus nerve

sensory/motor
- thoracic-abdominal structures

Front 109

Cranial nerve XII
(name & function)

Back 109

Hypoglossal

Mixed
Primary motor nerve for tongue

Front 110

Autonomic nervous system

Back 110

Functions without conscious effort
Controls visceral activities
Regulates smooth muscle, cardiac muscle, and glands
Regulates blood pressure, respiration, digestion etc.

Front 111

Autonomic nervous system divisions

Back 111

Sympathetic
Parasympathetic

Front 112

Sympathetic nervous system

Back 112

Prepares body for "fight or flight" responses
Uses epinepherine/norepinepherin as neurotransmitter

Front 113

Parasympathetic nervous system

Back 113

Prepares body for resting and digesting activities
Uses Acetylcholine as neurotransmitter

Front 114

Sympathetic Responses (affected systems)

Back 114

Adrenal glands
Eyes
Sweat glands
Saliva glands
GI Tract
Liver
Lungs
Heart

Front 115

Sympathetic Responses (adrenal glands)

Back 115

Release of epinepherine

Front 116

Sympathetic Responses (Eye)

Back 116

Dilate pupil

Front 117

Sympathetic Responses (GI Tract)

Back 117

decrease motility, closes sphincters

Decrease function, blood shunted away to muscles

Front 118

Sympathetic Responses (Lungs)

Back 118

dilates bronchioles

Increase oxygen absorption

Front 119

Sympathetic Responses (Heart)

Back 119

increase rate, increases conduction, increases strength

Increases Cardiac Output

Front 120

Senses

Back 120

Sensory neurons have structures called receptors that respond to a stimulus. Receptors are connected to the neuron by dendrites.

Front 121

General senses

Back 121

Receptors for theses senses are widely distributed throughout the body. (ex: skin, organs, joints)

Front 122

Specialized senses

Back 122

Receptors for these are confined to structures in the head (ex: eyes, ears)

Front 123

Senses - flow

Back 123

1. Stimulation of a receptor results in an action potential
2. Impulses are carried by the PNS to the CNS via afferent neurons
3. CNS (brain) analyzes and interprets the impulses

Front 124

Sensation

Back 124

Occurs when the brain becomes aware of a sensory impulse

Front 125

Perception

Back 125

Occurs when the brain identifies a sensory impulse

Front 126

What determines what the "sensation" is?

Back 126

The part of the cerebral cortex that receives the impulse.

(ex: if the temporal lobe receives an impulse, it is interpreted as sound)

Front 127

How is the intensity of a stimulus perceived?

Back 127

The rate of impulses (action potentials reaching the brain).

The higher the rate, the more intense the sensation

Front 128

Common feature of receptors

Back 128

Each type responds to a specific type of stimulus.

They are less sensitive to other forms of stimulation.

Front 129

Adaptive response

Back 129

If a stimulus is constant for a period of time, the receptor may adapt (i.e., stop producing action potentials)

Front 130

Phasic adaptors

Back 130

Receptors that adapt quickly.

ex: Touch, temp receptors

Front 131

Tonic adaptors

Back 131

Adapts slowly or not at all

ex: pain receptors

Front 132

Types of receptors

Back 132

Chemoreceptors
Nocireceptors
Photoreceptors
Thermoreceptors
Mechanoreceptors

Front 133

Chemoreceptors

Back 133

Respond to changes in chemical substances

Front 134

Chemoreceptors - examples

Back 134

smell, taste, oxygen levels

Front 135

Nocireceptors

Back 135

Pain

Respond to tissue damage

Front 136

Photoreceptors

Back 136

Respond to light

Front 137

Thermoreceptors

Back 137

Respond to changes in temperature

Front 138

Mechanoreceptor types

Back 138

Proprioreceptors
Baroreceptors
Stretch receptors

Front 139

Proprioreceptors

Back 139

Type of mechanoreceptor

Respond to changes in positions

Front 140

Baroreceptors

Back 140

Type of mechanoreceptors

Respond to changes in pressure

Front 141

General senses - types

Back 141

Exteroreceptive senses
Visceroreceptive senses

Front 142

Exteroreceptive senses

Back 142

Changes occuring at the body's surfaces

Front 143

Visceroreceptive senses

Back 143

Changes occuring in the viscera (organs)

Front 144

Exteroreceptive senses

Back 144

Touch & pressure
Temperature
Pain
Proprioception

Front 145

Exteroreceptive - pain

Back 145

Results from tissue damage due to various causes

Receptors respond to more than one cause

Front 146

Exteroreceptive - touch & pressure

Back 146

Sense the displacement of tissues

Superficial receptors sense fine touch

Deep receptors sense pressure/vibration

Front 147

Exteroreceptive - temperature

Back 147

Two types of receptors
1. Warm receptors
2. Cold receptors

Relative amount of each determines temperature felt (usually 2:1 cold)

Front 148

Warm receptors

Back 148

Type of temperature receptors

Detect temp from 25-45C

Front 149

Cold receptors

Back 149

Type of temperature receptors

Detect temp from 10-20C

Front 150

Exteroreceptive - proprioception

Back 150

Stretch receptors provide information about the condition of muscles and tendons

2 types of receptors:
1. Muscle spindle apparatus
2. Golgi tendon organ

Front 151

Muscle spindle apparatus

Back 151

Receptor found in skeletal muscles

Used to determine the # of muscle cells needed to turn on for a specific weight

Front 152

Golgi tendon organ

Back 152

Found in the tendons/ligaments of skeletal muscles
Used as a safety mechanism to prevent over-stretching

Front 153

Visceroreceptive senses

Back 153

Pressure
Stretch
Chemical
Pain

Front 154

Visceroreceptive - pressure

Back 154

Senses changes in blood pressure in vessels

Front 155

Visceroreceptive - stretch

Back 155

Fullness after eating, bladder

Front 156

Visceroreceptive - chemical

Back 156

Food in stomach stimulates acid production

Front 157

Visceroreceptive - Pain

Back 157

Tissue damage

In heart - angina

In bowel - abdominal cramps (stretch)

Front 158

Special senses

Back 158

Smell
Taste
Hearing
Equilibrium
Sight

Front 159

Ear structure

Back 159

Outer section
Middle section
Inner section

Front 160

Ear - outer section

Back 160

Structures external to tympanic membrane

Gathers and transmits sound vibrations to internal structures

Front 161

Ear - middle section

Back 161

Air filled cavity within the temporal bone

Contains 3 bones (auditory ossicles)

Transmits and amplifies sound vibrations to inner ear

Front 162

Auditory ossicles

Back 162

Small bones in middle ear

Malleus
Incus
Stapes

Front 163

Ear - inner section

Back 163

System of inter-communicating chambers

Cochlea
Semicircular canals
Vestibule

Front 164

Cochlea

Back 164

Inner ear structure

Spiral/shell-shaped structure

Functions in hearing

Front 165

Hearing - mechanism

Back 165

1. Sound waves enter External ear (Different sounds produce different pressures)
2. Sound pressures cause tympanic membrane to produce vibrations
3. Auditory ossicles amplify and transmit vibrations to the Cochlea
4. Specialized receptor cells (hair cells) in the Cochlea respond to different frequencies of vibrations
5. Hair cells respond by releasing neurotransmitters
6. Neurotransmitters stimulate sensory neurons in Cranial nerve VIII
7. Impulses travel along Cranial nerve VIII to the Auditory cortex in the Temporal lobe for interpretation

Front 166

Equilibrium

Back 166

Special sense, from organs in inner ear

Static equilibrium
Dynamic equilibrium

Front 167

Static equilibrium

Back 167

Senses the position of the head when the body is not moving.

Sensed in the Vestibule.

Front 168

Inner ear - vestibule

Back 168

Sensor for static equilibrium

Has specialized receptor cells (hair cells)
- bending of hairs results in generation of nerve impulse

Front 169

Dynamic equilibrium

Back 169

Senses rotation and movement of the head and body

Sensed in the semicircular canals

Front 170

Inner ear - semicircular canals

Back 170

Sensor for dynamic equilibrium

Composed of 3, fluid filled canals at right angles

Has specialized receptor cells (hair cells)
- bending of hairs results in generation of nerve impulse

Front 171

Special senses - sight

Back 171

Function of visual receptors located in the eyes (photoreceptors)

Assisted by several accessory organs
- eyelids
- lacrimal apparatus
- extrinsic ocular muscles

Interpretation of visual stimuli performed by the visual cortex in the occipital lobes

Front 172

Eye structure

Back 172

Eye composed of 3 layers
1. Outer layer
2. Middle layer
3. Retina

Front 173

Eye - outer layer

Back 173

Contains:
- Cornea
- Sclera

Front 174

Eye - cornea

Back 174

Anterior 1/6 of outer layer
Transparent (lack of blood vessels, extremely regular pattern of connective tissue fibers)

Helps focus entering light

Front 175

Eye - sclera

Back 175

Posterior 5/6 of outer layer

White portion of the eye

Protects eye, attachment site for muscles

Front 176

Eye - middle layer

Back 176

Contains:
Ciliary body
Iris

Front 177

Eye - Ciliary body

Back 177

Contains the ciliary muscles and ciliary processes

Suspensory ligaments off the ciliary processes hold the lens in place

Contraction and relaxation of the ciliary muscles changes the shape of the lens for focusing

Front 178

Eye - Iris

Back 178

Thin diaphragm of connective tissue and smooth muscle

Colored portion of the eye

Contains the pupil (central opening)
- controls the intensity of light entering

Front 179

Eye - inner layer

Back 179

Contains:
Retina
Macula Lutea
Optic disc

Front 180

Eye - Retina

Back 180

Contains the photoreceptors

Continuous with the optic nerve

Dense capillary network

Front 181

Eye - Macula lutea

Back 181

Central portion of the retina

Produces the sharpest vision

Front 182

Eye - optic disc

Back 182

Medial to Macula Lutea

Nerve fibers leave here and become part of the optic nerve

Does not contain any receptor cells (blind spot)

Front 183

Types of visual receptors

Back 183

Rods
Cones

Front 184

Rods

Back 184

Photoreceptors

Long, thin projects at their terminal ends

Sensitive to light (intensity)

Produce colorless vision

Front 185

Cones

Back 185

Photoreceptors

Have short, blunt projections at their terminal end

Produce sharp images

Responsible for color vision

3 sets of cones
- red
- green
- blue

Front 186

Cones - color perception

Back 186

Depends on which set of cones is stimulated

White - all 3
Black - none