Physio -Jenkins- Exam 2

The Cell Body.  Contains nucleus and most organelles

These are the long slender threads that protrude from the soma.  This is the reception area for incoming information from the Axon Terminals of another neuron.

The long fiber that extends from the base of the soma to transmit electrical impulses called action potentials.

These are the alien fingers (with pods) that branch off of the Axon. They release neurotransmitters to the dendrites of the next neuron.

These are these are the pods at the end of the Axon Terminals where the exchange of neurotransmitters happens.  This is the site of communication between the presynaptic neuron to the postsynaptic neuron and an effector organ

• ~Always Open
• ~Potassium only 
• ~Located throughout a neuron

~Open or close in response to ligand binding

•                            -70 mV   
• ~When the neruron is at rest. 
• ~The inside of the neuron is negative inside
•   and the outside is more positive.
• ~K+ can cross through the membrane easily.

Open or close in a response to change in the membrane potential.

• ~Sensory/Visceral receptors
• ~temp and pressure
• ~PNS to CNS

• ~Effector Organs
• ~CNS to PNS

• ~Fat dense cells which form meylination for 
•   multiple axons and provide protection.
• ~form segments of myelin sheaths of numerous
•   neurons at once.
• 

• ~PNS
• One schwann cell forms ONE myelin sheath that myelinates one section of an axon. Seperated by the Node of Ranvier
• 

Determines the equalibrium of potentials for sodium and potass

• 1. Ion concentration gradients
• 2. Membrane permeability
• 3. Ion Channels

• ~As potassium diffuses outof the cell the
•   inside of the cell becomes more negative.
• ~Eletrical driving force "pulls" potassium into
•   the cell until equalibrium equals -94 mV.
• ~These driving forces are opposite in direction
•   and equal in magnitude.

• ~As sodium diffuses into the cell the inside becomes less negative (positive).
• ~eletrical driving force "Push" sodium outside of the cell.
• ~Equalibrium is +60mV

Potassium

potassium and organic anions

Sodium and Chloride

Positive

Negative

the period immediately following the firing of a nuron when it cannot be stimulated no matter how great a stimulus is applied.

• The time when an action potential is below   
• -70mV

a change in a cell's membrane potential that makes it more negative

the amount of time it takes for an excitable membrane to be ready for a second stimulus

The return to resting membrane potential

a change in a cell's membrane potential, making it more positive

the point at which sodium ions start to move into the cell (instead of out of the cell) to bring about the membrane depoloarization

Muscle or gland

two neurons linked together by gap junctions finctions in nervous system

• most of sensations and motor signals are carried via chemical synapse.
• Neuron to Neuron or Neuron to Muscle

where synapse occours.

From axon to presynaptic neuron

synapse to soma

presynaptic synapses to axon of post synaptic neuron

Delivering signal

Receiviving signal

a change in the charge on the membrane of the post synaptic cell

Excitatory and inhibatory

makes the cell more likely to depolarize.  They Hypopolarize to less negative.

less likely to produce a potential.  hypopolarzation (more negative).

one nuron to multiple

multiple nurons signal to one nuron

• addition of all effects of the ISP & ESP
• the sum of all their signals on one cell

Temporal and Spatial

one synapse fires rapidly onto the next nuron

lots of different synapses occouring all at the same time and in close proximity

a potential that does not reach threshold

does not increase

• Rignt Brain controls Left side of body
• Left Brian controls Right side of body

• Creativity
• Spatial Perception

• logic
• analytical
• language

Central (CNS)

afferent neuron

sensory

interneuron

motor

skeletal muscle

SIGNAL-SODIUM RELEASE-AFFERENT NURON-CNS-EFFERENT NEURON-EFFECTOR ORGAN-RESPONSE

• skeletal muscle:
• one motor nuron to a single muscle cell.
• ALWAYS EXCITATORY
• ALWAYS CALLED LOWER MOTOR NEURON

ACTIVATE THE MOTOR NEURON

DO NOT ACTIVATE A MOTOR NEURON

TEMP AND PRESSURE

DETERMINE ONE FINGER TOUGH AND TWO FINGER TOUCH. SENSE RELATION OF BODY WITH OBJECTS. EX. WALKING AT NIGHT DOWN STAIRS.

Huntingtons: blocks ability to coordinate motor movement. lots of involuntary movement.

• lack of dopamine in substantia Nigra
• involuntary movement

both divisions (parasympathetic and sympathetic) innervate most effector organs.

• parasympathetic: rest and digest
• sympathetic: fight or flight

To regulate and maintain homeostasis

the preganglionic neurons are short and called 'cholinergic neurons'.

 postganglionic ones are long ending and embedded in the receptor sites and called 'adrenergic neurons'.

• cardiac
• smooth muscle
• glands
• adapose tissue

short pregang. and long postgang.

long pregang and short postgang

above the kidneys

cranial nerves x Vagus nerves controls what happens in viceral organs.

autonomic

viceral, CNS

ACH

Epinepherine or norepinepherine

Cardiac only

Excitatory

Inhibatory

• smooth muscles
• glands
• adapose tissue (fat)

Beta 2

Beta 2

Alpha 1

Beta 2

cholinergic

motor nuron, skeletal, muscle

• sodium potassium pump that pumps sodium out
• voltage gated channels
• potassium out
• sodium in
• leak chanels sodium in potassium out

reagions where we can not open sodium channels.  once it is open you cant have another action potential again.

no action potential

can have another action potential but it will require more stimulius