PNS EFFERENT

which motor efferent division is voluntary and which is involuntary and what are their effectors?

Somatic NS is voluntary + goes to skeletal muscles

ANS is involuntary + goes everywhere (cardiac + smooth muscle, + glands)

What interesting things does ANS do?

1. Support somatic reactions

2. Mediate emotional states

3. Adjust/Regulate homeostatic body states

How does ANS support somatic reactions? Give example

- supports increased metabolic demand

- you cannot run w/out the support of ANS using/increasing your HR, BP, etc

How does ANS mediate emotional states? Give example

- rage = red face

- blushing cheeks

How does ANS adjust or regulate homeostatic body states? give example

ANS cools us down when warm, if we are cold then peripheral vessels vasoconstrict,

What does dual innervation mean?

it means that a body organ receives neural innervation from both sympathetic and parasympathetic nerves. Has mostly opposite effects

what organs in our body are not dually innervated?

- Skin (sweat, adrenal glands, etc bc PNS does not control sweat)

- Adrenal glands (bc they're an extension of sympathetic NS)

Cranialsacral refers to ___________ where as thoracolumbar refers to _________

cranialsacral = Parasympathetic innervates from cranial + sacral

thoracolumbar = sympathetic innervates from thoracic and lumbar

Parasympathetic division promotes maintenance activities and conserves body energy: GIVE EXAMPLES

- lowers BP, HR, Resp Rate,

- Pupils constrict

- Excites digestive tract

- GI tract activity is high

- dominant for small intestine

sympathetic division mobilizes body during activity: GIVE EXAMPLES

- Increases HR, BP, RR,

- Bronchioles dilate to breathe better

- pupil dilation

- liver releases glucose to blood

- blood flow is shunted to skeletal musc+heart

what things do the somatic and ANS systems differ in?

effectors, efferent pathways and their NTs, and target organ responses to NTs

the SOMATIC EFFERENT pathway goes from CNS --> Skeletal Muscle. Why is that?

We have a singular somatic motor fiber that is thick and heavily myelinated w/ schwann cell going straight to muscle/effector

how does the ANS EFFERENT pathway differ from the somatic one?

ANS pathway is a two neuron chain, takes 2 neurons to get to the effectors.

- 1st neuron is preganglionic neuron

- 2nd neuron is postganglionic neuron

describe the pre-ganglionic neuron

- it is still in the CNS, has a thin and lightly myelinated axon, synapses to 2nd neuron

describe a post-ganglionic neuron?

- in PNS, has an unmyelinated axon that extends to effectors

Somatic neurons in somatic NS only release 1 neurotransmitter, what is that NT and its effects?

Somatic motor neurons release acetylcholine (ACh) and its effects are excitatory/stimulatory

ANS takes two neurons to get to an effector, what NT can each neuron release and what are its effects?

the preganglionic fiber releases ACh, and the postganglionic fiber releases NE (norepinephrine) or also ACh which depends if its for sympathetic or parasympathetic

- effects can be stimulatory or inhibitory

the neurons that release ACH, and the receptors that bind to ACh, are called ____________

Cholinergic

Adrenaline is another word for Norepinephrine, fibers that secrete NE and receptors that NE bind to are called ___________

Adrenergic

There are 2 types of cholinergic receptors that bind ACh, what are they?

1. Nicotinic: ligand gated, nicotine binds as if it were ACh

2. Muscarinic: stimulates metabolism

cholinergic receptors are named after what?

named after drugs that bind to them and mimic ACh effects

effects of ACh at nicotinic receptors is always

stimulatory/excitatory

effects of ACh at muscarinic receptors ..

- can be inhibitory or excitatory

- depends on target organ receptor type

what are the two types of adrenergic receptors?

alpha and beta

effects of NE depend on...

on subclass of receptors on target organ

describe the adrenergic receptor types and its effects:

B1: excitatory associate w/ heart

B2: inhibitory associate w/ lungs

A1: excitatory associate w/ blood vessels