Chpt 11

BIOL 240 Exam 2

The efferent divisions of the peripheral nervous system are . . .

somatic motor division, autonomic division

___________ division controls skeletal muscles through neuromuscular joints and is mostly voluntary

somatic

___________ division controls cardiac and smooth muscles and glands in homeostasis, and is mostly involuntary

autonomic

the _______ division controls antagonistic controls and agonists and antagonists in research and medicine

autonomic

The two branches of the autonomic system are the ______ and ____________

sympathetic, parasympathetic

the __________ branch of the autonomic system promotes “fight or flight” mode

sympathetic

The ____________ branch promotes homeostasis and maintenance

parasympathetic

The parasympathetic maintains what is commonly known as the “____ and _______” mode

rest, digest

much of homeostatic nervous regulation is __________ and reflects a balance between opposing control systems

autonomic

__________ activity prepares the body for short-term actions and responses

sympathetic

__________ activity adjusts body physiology for long-term well-bring

parasympathetic

this part of the brain integrates much of our sensory information, and is also a major point of efferent control

hypothalamus

Coordination of homeostatic responses can occur in three ways

autonomic, endocrine, behavioral

The hypothalamus regulates . . .

water balance, temperature, hunger

The pons regulate . . .

respiration

The medulla regulates

respiration, cardiac, vomiting, swallowing

Autonomic control centers in the brain include . . .

hypothalamus, pons, medulla

The control of the __________ division is unconscious, although we can become aware of its effects.

autonomic

Most internal organs are under ______ control, and receive two separate nervous inputs with opposite effects

antagonistic

The _____ nerve carries most of the parasympathetic information and contains about 75% if all parasympathetic fibers

vagus

The contains (sensory/efferent/both) nerves

both; sensory and efferent

Autonomic system efferent nerves are typically (mono/bi)-synaptic and make use of ganglia just outside of the CNS

bi

Bi-synaptic connections require _____ synapses, and these differ between the sympathetic and parasympathetic systems

two

Neurons from both divisions use ______________ as the neurotransmitter at their ganglionic synapses

Acetylcholine (ACh)

__________ neurons use Acetylcholine (ACh) at their target tissues, while __________ neurons use Norepinephrine (NE).

parasympathetic, sympathetic

At their target tissues, autonomic neurons have many __________ (swellings) which release neurotransmitter collectively at **neuroeffector junctions**

varicosities

Autonomic neuron NT release, function, and removal at neuroeffector junctions are of classic __________ ____________ form

Chemical synapse

Much of the sympathetic activity is mediated by the release of epinephrine by the _______ portion of the adrenal gland

medulla

The ______ (cortex) region of the adrenal gland is glandular, while the _______ (medulla) portion is a modified sympathetic ganglion

outer, inner

The _______ is activated by spinal sympathetic input and releases **adrenalin** into the bloodstream

adrenal medulla

The adrenaline from the adrenals and norepinephrine from the sympathetic neurons act on (the same/different) target tissue receptors

the same

Pupil dilation, salivation, increased heart rate, and fat breakdown are all results of _____________ nervous activity

sympathetic

inhibited digestion, inhibited pancreas secretion, and inhibited urination are indicative of _____________ nervous activity

sympathetic

constricted pupils and bronchioles, slow heart rate, insulin release, urination, and digestion are indicative of _____________ nervous activity

parasympathetic

At parasympathetic target tissues, ACh acts upon __________ receptors and triggers ___________ effects

muscarinic, metabotropic

The _____ _____ pathway provides voluntary control of skeletal muscles

Somatic

Motor neuron axons are mostly ______________

myelinated

motor connections are __________ , use Ach at nicotinic (ionotropic) receptors, and are __________

monosynaptic, excitatory

Neurons that innervate muscle fibers are termed __________ __________, and the synapses they make are called __________ __________

motor neurons, neuromuscular junctions (NMJs)

________________ junctions are large, branched, and powerful

neuromuscular

neuromuscular junctions deliver a large amount of what neurotransmitter at once

Acetylcholine (ACh)

NMJ operation (in typical manner of chemical synapses- see other side)

Motor neuron action potential → \n Depolarization of the neuron terminal (at the NMJ) → \n Opening of voltage-gated Ca++ channels → \n Ca++ influx into neuron terminal → \n ACh vesicle cycling and ACh release into the synapse → \n ACh binds nicotinic ACh receptors on the muscle fiber → \n Na+ channels open, allowing Na+ influx into the muscle fiber → \n Muscle fiber depolarizes → \n Muscle fiber contracts