Nervous System Test

The nervous system is divided into (2)

Central Nervous System (CNS) and Peripheral Nervous System (PNS)

Central Nervous System is made up of

brain and spinal column

Peripheral Nervous System is made up of

cranial and spinal nerves

2 major divisions of the peripheral nervous system

Sensory (afferent) division

Motor (efferent) division

Sensory (afferent) division

Nerve fibers that carry information to the central nervous system

- pick up information from sensory receptors

Motor (efferent) division

Transmits impulses from the CNS to effector organs (muscles and glands)

Motor (efferent) division is divided into (2)

somatic nervous system and autonomic nervous system

somatic nervous system

the division of the peripheral nervous system that controls the body's skeletal muscles

- carries information to skeletal muscle

autonomic nervous system

the part of the peripheral nervous system that controls the glands and the muscles of the internal organs (such as the heart).

- carries information to smooth muscle

neuron labeled

white matter

Whitish nervous tissue of the CNS consisting of neurons and their myelin sheaths.

What forms white matter?

scwann cells and oligodendricytes

- inside deep tissue of brain, outside spinal cord, myelinated

gray matter

Brain and spinal cord tissue that appears gray with the naked eye; consists mainly of neuronal cell bodies (nuclei) and lacks myelinated axons.

- unmyelinated

Where on a neuron do you find chemically gated channels?

Dendrites and cell body

What causes the chemically gated channels to open? What comes out?

Opened by the binding of neurotransmitters to the channel

- sodium in, potassium out

Where on a neuron do you find voltage gated channels?

Axon

What causes them to open? What moves through the channels?

Opened by changes in membrane potential --\> depolarization

- sodium comes out

resting membrane potential

the electrical charge of a neuron when it is not active

-70mv

How can a neuron go from resting membrane potential to threshold?

Depolarization occurs (-55 to -50 mV), at threshold, depolarization becomes self-generating

How action potential is generated

If a receptor is a neuron and the change in membrane potential reaches threshold an action potential is generated

- membrane becomes more permeable to sodium ions b/c of the opening of sodium voltage gated channels causing RAPID/SUDDEN influx of sodium and depolarization of membrane

How a cell returns back to resting membrane potential

The activation gate of Na+ voltage gated channels are closed, K+ voltage gated channels close, K+ flows out of cell

What does the sodium-potassium pump do for a neuron?

Restores ionic conditions

- pumps 3 sodiums in per every 2 potassium that enter

What affects the conduction velocities amongst neurons?

Influenced by myelin sheath thickness and internode distance

What are the different types of neurotransmitters?

-acetylcholine

-biogenic amines (catecholamines and indolamines)

-amino acids (GABA, glycine, aspartate, and glutamate)

-neuropeptides

-purines such as ATP

-novel messengers

How are neurotransmitters broken down or removed from the system?

Removed by diffusion in combination with re-uptake into nerve terminals/ surrounding glial cells, degradation by transmitter or a combination

Meninges (3)

dura mater, arachnoid mater, pia mater

Dura mater

thick, outermost layer of the meninges surrounding and protecting the brain and spinal cord

arachnoid mater

weblike middle layer of the three meninges

pia mater

the delicate innermost membrane enveloping the brain and spinal cord.

Ventricles of the brain

2 lateral ventricles, third ventricle, fourth ventricle

How do the ventricles of the brain relate to the CSF

They are interconnected cavities that are continuous with central canal of spinal cord filled with CSF- cerebrospinal fluid.

- It is a clear liquid that completely surrounds the brain and spinal cord

- nutritive and protective

What are the functions of the spinal cord?

sends motor commands from brain to the body, sends sensory information from the body to the brain, coordinates reflexes, spinal reflexes

What are the functions of the brain?

- interprets sensations

- determines perception

- stores memory

- reasoning

- makes decisions

- coordinates muscular movements

- regulates visceral activities

- determines personality

What are the functions of the cerebrum?

-Interprets impulses from sense organs

-Initiates voluntary muscular movement

-Stores information as memory

-Reasoning, intelligence, personality

identify lobes of the brain

insula- between frontal and temporal

cutaneous sensory area

-parietal lobe

-interprets sensations on skin

visual area

occipital lobe, interprets visual information

auditory area

temporal lobe, interprets auditory information

Sensory area for taste

Near base of the central sulcus

Includes part of insula

Sensory area for smell

arises from centers deep within temporal lobes

What do association areas do?

- analyze and interpret sensory experiences

- help provide memory

- reasoning

- verbalizing

- judgement

- emotions

Things controlled by left hemisphere

- writing

- reading

- verbal skills

- analytical

- computational skills

Things controlled by right hemisphere

- nonverbal/ motor tasks

- understanding and interpreting music/visual patterns

- provides emotional and intuitive thought processes

How are short term memories converted into long term memories

memory consolidation: repeated stimulation causes changes in structure/ functions of neurons

short-term memory

- working memory

- closed neuronal circuit

- impulse flow ceases, memory ceases.

long-term memory

- changes structure and function of neurons

- enhances synaptic transmission

What do motor areas do?

generate signals to direct the movement of the body

What are the structures of the diencephalon?

thalamus, hypothalamus, optic tracts, posterior pituitary gland, pineal gland

Thalamus

receives all sensory impulses, channels impulses to appropriate part of cerebral circuit

Hypothalamus

maintains homeostasis by regulating visceral activities links nervous and endocrine

Optic tracts

carry visual information

posterior pituitary gland

store and release hormones

Pineal gland

receive and convey information via production and secretion of melatonin