Chapter 11 Autonomic NS

What is the primary function of the autonomic nervous system

regulate organs to maintain homeostasis or involuntary functions

The two branches of the autonomic nervous system are

sympathetic and parasympathetic

the “fight or flight” part of the autonomic nervous system:

sympathetic

the “rest and digest” side of the autonomic nervous system:

parasympathetic

Parasympathetic and sympathetic activities tend to be __________ and _____________

antagonistic; dually innervated

Sympathetic branch neurons originates from the:

spinal cord

Parasympathetic branch neurons originates in the:

brainstem and sacral spinal cord

what does dual innervation of the autonomic NS mean

both branches of the autonomic nervous system communicate with all the organs and have influence over their function

If one branch causes an organ to become more active, the other branch causes it to become ____________. This means they are _________

less active; antagonistic

what does antagonistic relationship mean in terms of the branches of the autonomic NS

the branches compete with each other and are opposites

A typical efferent autonomic signal originates from the

central nervous system

The cell bodies that can be found in the central nervous system are

preganglionic and postganglionic neurons

Preganglionic neurons send signals down the axon into the:

peripheral nervous system

In the PNS after preganglionic neurons are sent they arrive in a grouping of more autonomic neurons called the

postganglionic neurons

The structure where the postganglionic neurons live in is called an:

autonomic ganglion

Postganglionic neurons go to

effector organs

Examples of effector organs are:

cardiac muscle, smooth muscle, glands, adipose tissue, skeletal muscle

there is a __________ between the preganglionic neuron and postganglionic neuron

chemical synapse

there is a ___________ between the postganglionic neuron and the effector organs

chemical synapse

The sympathetic part of the ANS has ___________ that are short and ___________ that are long

preganglionic neurons; postganglionic neurons

preganglionic neurons originate in the:

thoracolumbar spinal cord

aside from preganglionic and postganglionic neurons there are also _______________ in the sympathetic NS, which can be found further away

collateral ganglia

what ganglia is this

preganglionic neurons

what ganglia is this

postganglionic neuron

In the parasympathetic NS there can found long _____________ and sho

preganglionic neurons; postganglionic neurons

The autonomic ganglia are located ____ to their effector organs or ______ the effector organ

near; within

organs are dually innervated which means

each organ receives input from efferent branches of both sympathetic and parasympathetic

when parasympathetic NS is activated it creates a state of

rest and digest

when the sympathetic NS is activated causes an increase in

excitation

both parasympathetic and sympathetic branches are always active but:

as one decreases the other increases

this autonomic branch is associated with:

• quiet, relaxed states

• rest and digest

• heart rate is reduced

• SLUDD

• vasodilation to some organs

parasympathetic

what does SUDD include

salivation, lacrimation or tear production, urination, digestion, defecation

What does vasodilation to organs mean

increased blood flow to digestive urinary organs

this autonomic branch is associated with:

• fight or flight response

• prepares for emergence, stress, exercise

• increases heart rate & blood pressure

• dilates pupils

• energy is mobilized

• decreases digestion and urination

• dilation of blood vessels to skeletal muscles = more blood flow

• tunnel vision, selective hearing

sympathetic

Preganglionic neurons release a neurotransmitter called

acetylcholine

the preganglionic neurons that release acetylcholine are called

cholinergic

the postganglionic neurons that release norepinephrine are called

adrenergic

the receptors on the postganglionic neurons are called

nicotinic cholinergic receptors

the nicotinic cholinergic receptors on the postganglionic neuron are

ionotropic

the postganglionic neuron releases a neurotransmitter called

norepinephrine

the target effectors that receive signals from the postganglionic neurons have receptors called

adrenergic receptors

the postganglionic neurons in the parasympathetic branch also release

acetylcholine

the target effectors of the parasympathetic branch have what type of receptors

muscarinic cholinergic receptors

the receptors for the target effectors of the parasympathetic branch are what type of receptors

metabotropic

metabotropic receptors use

G coupled receptors

types of cholinergic receptors

nicotinic ACh receptors, muscarinic ACh receptors

this type of ACh receptors are

• ionotropic

• cause cation channel to open

• channel opening cause depolarization

nicotinic ACh receptors

this type of ACh receptors are

• G protein coupled

• effect depends on receptor subtype

muscarinic ACh receptors

type of adrenergic receptors

• there are two main classes

• each has subclasses

• all are metabotropic

alpha and beta

Subclasses of alpha receptors

alpha 1 and alpha 2

subclasses of beta receptors are

beta 1, beta 2, beta 3

these type of adrenergic receptors are

• located in effector organs of sympathetic NS

• MOST COMMON ADRENERGIC RECEPTOR

• almost always excitatory

alpha receptors

these type of adrenergic receptors are

• all activate adenylate cyclase

  • amplifying enzyme to make cAMP

• affinities for norepinephrine and epinephrine

beta receptors

this subclass of beta receptors are

• located in cardiac muscle (heart) and kidneys

• usually excitatory

beta 1

this subclass of beta receptors are:

• located in some blood vessels and smooth muscle (digestive tract)

• usually inhibitory

  • causes smooth muscle to relax

beta 2

this subclass of beta receptors are:

• located in adipose tissue

• usually excitatory

beta 3

the parasympathetic branch does not have any

adrenergic receptors

phospholipase C is

an amplifying enzyme

beta receptors _____ production of cAMP

increases

Neuroeffector junction

synapse between postganglionic neuron and effector organ

where neurotransmitter is released

varicosities

Neurotransmitter is released through

exocytosis

events at the neuroeffector junction

sends commands directly or indirectly to the preganglionic neurons, thus controlling signal output

hypothalamus

hypothalamus is

• integration and command center of all auto functions

• communicates with CNS and gets inputs from everywhere

• influenced by emotions

• controls all ANS

Brainstem is

• in charge of breathing and bp, heart rate

spinal cord controls

• reflexes for defecation and urination

definition of a reflex

a patterned response because of a stimulus and doesn’t require higher brain processing

autonomic reflexes are

• aka visceral reflexes

• no cortex involved

• control all involuntary activities

endocrine organs that are apart of endo system

secrete hormones

In the endo system __________ is primary control center

hypothalamus

organ that

• receives commands from hypothalamus and directs other endo glands

pituitary gland

primary or secondary gland of endo system

• main function is hormone secretion

  • like thyroid gland, and pineal gland

primary

primary or secondary gland of endo system

• hormone secretion as secondary function

  • heart

secondary

target cells of endo system have

hormone receptors

main purpose of endo system is

maintain homeostasis

homeostasis is

stable internal environment to changes in external and internal

homeostasis cycle

• stimulus activates a receptor

• receptor sends info the afferent signaling