Unit 2- Nervous System

What is the function of the nervous system?

Input→Intergration→Motor Output

What are the two divisions?

Central Nervous System (cns) and the peripheral nervous system (pns)

What is the the CNS?

The brain and spinal cord

What is the PNS?

Nerves that lead to and from the CNS?

Gyri

Bumps

Sulci

Grooves of the brain

What is white matter in the brain?

Cells that contain a fatty insultiong layer called (myelin)

What is grey matter?

Cells that lack myelin

What is the function of the Cerebral cortex?

It is the outer layer of cerebrum involved with higher level thinking (ex. decision making)

What type of matter is the cerebral cortex made of?

Grey matter

What is the longitudinal fissure?

Deep grove that separates the two halves of the cerebrum

Cerebral hemispheres

two halves of the brain

What are the regions of the cerebrum?

Frontal lobe, parietal lobe, occipital lobe, and temporal lobe

What is the function of the frontal lobe?

Its is an output center that regulates personality, speech, higher orders of thinking, and morals and ethics.

What is the motor area?

It controls voluntary muscle movement

Where is the motor area?

In the frontal lobe

What is the function of the parietal lobe?

It is an input center that integrates sensory information such as touch (includes pain and coldness)

What is the function somatosensory area?

It perceives touch information and control specific movements in body

Where is the somatosensory area located?

In the parietal lobe

What is function of the temporal lobe?

Processes hearing information

What is the function of the occipital lobe?

Processes visual information

What is the function of the corpus callosum?

It connects the right and left cerebral hemispheres which allows them to communicate with each other

What does the limbic system consist of?

The hippocampus and the amygdala

How does the hippocampus work?

it processes long-term memory and emotional responses

How does the amygdala work?

It processes emotional memories; particularly fear

What is the function of the thalamus?

It relays sensory information to the correct part of the cerebrum

What is the function of the hypothalamus?

It works with the pituitary gland to regulate feeding, fleeing, fighting, and mating

What is the purpose of the cerebellum?

Coordinates motar movements; helpng with balence and coordination

What is the function of the brain stem?

Regulation of basic physiological processes such as heart rate and breathing

What is cerebrospinal fluid

It cushions the brain within skull

What is the function of ventricles?

It produces and stores cerebrospinal fluid

What is dura mater?

Outer protective layer of the brain; tough, white, and opaque (connective tissue)

what is pia mater?

Inner protective layer; things and transparent (connective tissue)

What is the function of the dendrites?

it receive the signal from neighboring cells

What is the structure of the axon?

relays signal from dow neuron; conducts nerve impulses

What is the myelin sheath?

Layer of insulation around axons; allows signals to travel faster

What is synaptic terminal?

Where cell connects to dendrites of other cells

What are the nodes of ranvier?

Gaps in the myelin sheath

What is resting/membrane potential?

difference in charge across the membrane

What is an action potential?

Depolarization causes ion channels to open Na opens and rushes into the cell. K opens and rushes out of the cell. The Na/K pump uses energy(atp) to transport Na and K against thier concentration gradient to establish resting potential

Sodium channels

membrane proteins that allow Na to cross the membrane by opening during depolatization

Potassium channels

Membrane proteins that allow K to cross membrane by opening slowly in response to depolarization

Sodium-Postassuim Pump

uses energy(atp) to transport Na and K against thier concentration gradient to establish resting potential

How does the myelin sheath relate to action potentials?

It speeds up transmission of a signal by “hopping” from one node of ranvier to the next

Synapse

Gap between the synaptic terminal of one neuron and the dendrite of another

What is function of neurotransmitters?

Chemical that transports a message from one neuron to the next

What are synaptic vesicles?

store neurotransmitters

What is function of receptors?

Bind neurotransmitters and initate signal in the next cell

What is an excitatory signal?

Depolarizes next cell; increase chance of action potential

What is an Inhibitory signals?

Hyperpolarizes next cell; decrease chance of action potential

Summation

all excitatory and inhibitory signala sum; if the cell is depolarized past threshold, an action potential occurs

What is the process of neurontransmission?

Action potential reaches synaptic terminal—> neurotransmitters travel across the synapse—→ signal is initiated in next cell (excitatory, inhibitory, or summation)—→ the neurotransmitter is removed from the synapse (re-uptake channel or enzymes)

What is purpose of re-uptake channels?

Transport neurotransmitter back to original cell (in and out)

How does cocaine effect the brain?

it blocks re-uptake channels (the “high’) for dopamine and receptors get destroyed

How does alcohol effect the brain?

It mimics neurotransmitters called GABA; it inhibits nerve transmission

How does the brain develop?

1. A vast number of connections randomly during childhood

2. pruning occurs which strengthens used myelinated connections and breaks down the unused

What are nerves?

Bundle of neurons

Divisions

1. sensory

2. motor

What is the function of the sensory system?

It brings info from the sense organs to the CNS

What is purpose of the motor division?

It sends motor movement from the CNS to the muscles

What are the divisions to the motor system?

1. Somatic

2. Autonomic

Somatic divsion (PNS)

Control voluntary movement

Autonomic

Controls involuntary movement

Autonomic divisions

1. Sympathetic

2. Parasympathetic

What is the sympathetic division?

Division of autonomic that prepares the body for action. “flight or fight”

What is the parasympathetic division?

Division of autonomic system that calms the body down and stimulates digestion. “rest and digest”

What is a reflex?

A simple automatic response to a stimulus