Biology - Nervous System, Endrocrines, Reflex Arcs

Myelin Sheath

• helps with regeneration of a neuron

• encloses the axon

• makes an impulse move faster

Dendrites and Cell body

Part(s) of the neuron that processes an impulse coming in

If I am smelling a delicious meal, what type of neuron is being used with my olfactory senses

Sensory Neuron

Role of Sensory Receptor during a reflex arc in the knee

touch receptors in the knee that take in impulse

Role of Sensory neuron during a reflex arc in the knee

sends info to spinal cord

Role of Interneuron during a reflex arc in the knee

interprets impulse wihtin spinal cord

Role of Motor Neuron during a reflex arc in the knee

takes impulse from spinal cord and sends it to leg muscle

Role of Effector during a reflex arc in the knee

leg muscles contract

this part of the PNS deals with conscious activity (ex: wanting to raise youre hand or transmitting nerve impulses)

Somatic system

this part of the PNS deals unconscious activty (ex: breathing, digesting food, heartbeat)

Autonomic system

Neuron function

transmits info through electrical + chemical signals (nerve impulses)

Nodes of Ranvier

spaces between myelin that alows impulses to jump from node to node through salvatroy conduction

Schwann Cells

forms myeling by wrapping around the axon

Acetylcholine (Ach) and its role in the synaptic cleft

diffuses across synaptic cleft to the postsynaptic membrane so it can attach to Na+ channels, allowing them to open and flow down axon (depolirization)

Cholinesterase and its role in the synaptic cleft

removes and releases acetyl from the Na+ channels, allowing them to close

Threshold

helps neurons meet in order to have an impulse

“all-or-none” effect

once threshold is met at around -55mv, it causes an impulse

How depolarization moves down the axon

Sodium channel opens up, allowing Na+ to flood down channel, then recovers then rests

Movement of Na+ and K ions during polarization

Both K+ and Na+ channels sligthly open, allowing +1 Na+ ions and K+ in at a time

Movement of Na+ and K ions during repolarization

Sodium channel closes, Na+ cant come into axon; Potassium channels open wide, allowing K+ ions to flood out of axon

Movement of Na+ and K ions during depolarization

Na+ floods down axon and through sodium channels; potassium channel closes, not allowing any K+ ions out

Role of Sodium Potassium Pump during polarization, depolarization and repolirization

removes 3 Na+ and adds in 2 K+ ions every time it spins

STEP 1 on how neurotransmitters (Ach) make their way to the membrane and are released into synaptic cleft

Nerve impulse goes down Presynaptic knob

STEP 2 on how neurotransmitters (Ach) make their way to the memebrane and are released into synaptic cleft

Calcium ions signal a synaptic vessicle to start moving toward the end of Presynaptic knob

STEP 3 on how neurotransmitters (Ach) make their way to the memebrane and are released into synaptic cleft

through process of exocytosis, synaptic vesicle release neurotransmitters (Ach) into synaptic cleft

Axon

conducts impulses away from cell body

The axon may be surrounded by a fatty material called

Myelin

Axon ending

contains synaptic vessicles

STEP 1 of the recovery period (repolarization)

K+ floods out of the potassium channels (overshoots to -90mv)

STEP 2 of the recovery period (repolarization)

Sodium Potassium Pump slowly kicks out Na+ and gets charge back at -70mv

After firing an impulse, a neurone is incapable of responding to another stimulua for the duration of its…

Recovery period

Fill in the blanks: In a neruon at rest, K+ are located primarily on the __________ of the axon

inside

Fill in the blanks: The ________________ is required to generate a full action potential

stimulus