Unit 3 Phys Review

Open Na & Cl channels

What causes depolarization at a neuron?

Graded potential

The term used for the change in cell membrane potential on the Neuron

-70mv

What is resting potential for neurons?

-55mv

What is minimum threshold for neurons?

Axon Hillock

What is the “trigger zone” or initial segment of the axon where action potentials are initiated for neurons?

Action Potential

All or nothing electrical signal down the Axon.

No they dissipate over time

Do graded potentials remain constant?

Input signal, Depolarizing or Hyperpolarizing

What type of signal is a graded potential?

Dendrites and cell body of neuron

Where does a graded potential occur?

Mechanically, voltage, or chemically gated channels

Types of channels involved with an action potential?

Depends on stimulus’ sum

Strength of signal

Entry of ions through gated channels

What initiates a graded potential?

It will be additive

How will 2 signals coming together close in time react for a graded potential?

Regenerating Conduction Signal, Depolarizing

What type of signal is an action potential

Axon hillock

Where do action potentials occur

Voltage-gated channels

What type of ion channel is involved with Action Potentials?

All or nothing, all the same

Strength of Action Potentials?

Graded potential > -55mv at axon hillock

What initiates an action potential?

Refractory period, can’t be fired too close together

Can two action potentials be fired close in time?

Propagation

Conduction of action potential along non-myelinated axons, slower

Saltatory Conduction

Conduction of action potentials along myelinated axons, faster

Refractory period

What prevents backwards conduction of Action potentials?

Na channels deactivate and K channels open slowly until fully opened.

What causes the neuron to repolarize?

Efflux of K ions because it closes slowly

Why does a neuron hyperpolarize?

Pre-synaptic cell

The neuron that is secreting a neurocrine into the synaptic cleft.

Synaptic cleft

The area in between pre & post synaptic cells

Post-synaptic cell

Target cell for pre-synaptic cell

Voltage gated Ca channels open

What happens at the axon terminal when an action potential arrives?

Exocytosis of neurocrine

What happens when there is an influx of Ca?

Re-uptake, Degradation, Diffusion

How does the body terminate neurocrine action?

Any form of active transport

How does a cell re-uptake?

They are degraded by specific enzymes at the synapse

How do neurocrines degrade?

Acetylcholine & Monoamines

What are the 2 main types of neurocrines we are studying?

Acetyl Coenzyme A & Choline

How is acetylcholine formed?

Cholinergic neurons and receptors

What kind of neurons and receptors does Acetylcholine have?

Nicotinic and Muscarinic

What type of cholinergic receptors are there?

Nicotinic Neural and Muscular

What kinds of Nicotinic receptors are there?

CNS

Where are Nicotinic Neural receptors located?

Neuromuscular junction

Where are Nicotinic Muscular receptors located?

1 to 5

What types of Muscarinic receptors are there?

Acetyltransferase

What enzyme synthesizes Acetylcholine?

Acetylcholinesterase

What enzyme degrades Acetylcholine?

Acetate and Choline seperate

What happens to the degraded acetylcholine

Choline gets recycled via secondary active transport

What happens to Choline and Acetate

Epinephrine, Norepinephrine, and Dopamine

What are monoamine neurocrines

Adrenergic Receptors

What kinds of receptors do monoamines use?

Alpha and Beta

What kinds of adrenergic receptors are there?

Alpha 1-2

What kinds of alpha receptors are there?

Beta 1-3

What kind of beta receptors are there?

Phospholipase C/ Insoitol Triphosphate/ Diacylglycerol pathway

How do alpha receptors alter target cell function

Adenylyl Cyclase pathway

How do beta receptors alter function?

Norepinephrine

What affinity do Alpha 1 & 2 receptors have?

Both

What affinity do Beta 1 receptors have?

Epinephrine

What affinity do Beta 2 receptors have?

Norepinephrine

What affinity do Beta 3 receptors have?

G-coupled receptors

What kind of receptors are adrenergic receptors?

Adrenergic receptors can be both

Are adrenergic receptors excitatory or inhibitory?

Dilation

What are eye pupils sympathetic response?

Alpha receptors

What are pupils adrenergic receptor?

Constriction

What are pupils parasympathetic response?

Mucus, enzyme secretion

What are salivary glands sympathetic response?

Alpha and beta 2 receptors

What are salivary glands adrenergic receptor?

Watery secretion?

What are salivary glands parasympathetic response?

Increased heart rate and blood pressure

What is the heart’s sympathetic response?

Beta 1 receptors

What is the hearts’ adrenergic receptor?

Slowed heart rate and blood pressure

What is the heart’s parasympathetic response?

Constriction and dilation

What are arterioles and veins sympathetic response?

Alpha for constriction, Beta 2 for dilation

What are arterioles and veins adrenergic receptor?

None, tonically controlled

What are arterioles and veins parasympathetic response?

Bronchiole dilation

What are lungs’ sympathetic response?

Beta 2 receptors

What are the lungs’ adrenergic receptors?

Bronchiole constriction

What are the lungs’ parasympathetic response?

Decreases motility and secretion

What is the digestive tracts sympathetic response?

Alpha and beta 2 receptors

What is the digestive tract’s adrenergic receptor?

Increases motility and secretion

What is the digestive tracts’ parasympathetic response?

Decrease enzyme production

What is the exocrine pancreas sympathetic response?

Alpha receptors

What is the exocrine pancreas adrenergic receptors?

Increase enzyme production

What is the exocrine pancreas parasympathetic response?

Inhibits insulin secretion

What is the endocrine pancreas sympathetic response?

Alpha receptors

What is the endocrine pancreas adrenergic receptors?

Stimulates insulin secretion

What is the endocrine pancreas’ parasympathetic response?

Secretes catecholamines

What is the adrenal medulla’s sympathetic response?

None, tonically controlled

What is the adrenal medulla’s parasympathetic response?

Increase renin secretion

What is the kidney’s sympathetic response?

Beta 1 receptors

What is the kidney’s adrenergic receptors?

None, tonically controlled

What is the kidney’s parasympathetic response?

Urinary retention

What is the urinary bladder’s sympathetic response?

Alpha and beta 2 receptors

What is the urinary bladder’s adrenergic receptors?

Release of urine

What is the urinary bladder’s parasympathetic response?

Lipolysis

What is adipose tissue’s sympathetic response?

Beta 3 receptors

What is adipose tissue’s adrenergic receptors?

None, tonically controlled

What is adipose tissue’s parasympathetic response?

Ejaculation (male)

What are sex organs sympathetic response?

Alpha receptors

What are sex organs adrenergic receptors?

Erection

What are sex organs’ parasympathetic response?

Depends on stage of cycle

What is the uterus’ sympathetic function?

Alpha and beta 2

What is the uterus’ adrenergic receptors?

Depends on the stage of cycle

What is the uterus’ parasympathetic response?

Inhibitory

What is lymphoid tissue’s sympathetic response?

Alpha and beta 2 receptors

What is lymphoid tissue’s adrenergic receptors?