ch15 learning activity

Single innervation

Stress response via the adrenal medulla

Vasomotion for most blood vessels

Organ is innervated by only one branch

dual antagonistic

most common: includes heart (heart rate), eyes (pupil diameter), breathing (breathing rate)

Dual antagonist

organ is innervated by both the sympathetic and parasympathetic branches and they oppose each other

dual cooperative

organ is innervated by both the sympathetic and parasympathetic branches and they work together

dual cooperative

saliva production

somatic

crossed extension reflex (contralateral contraction of extensors)

automatic (visceral)

baroreceptor reflex (maintenance of homeostatic blood pressure)

pupillary response (dilation/constriction)

salivation reflex (production of saliva)

the autonomic nervous system

visceral motor branch

regulates its effectors; effectors are active without stimulus

enteric nervous system

regulates motility of the digestive tract

Part of this is missing in Hirschsprung disease; can result in chronic constipation & even perforation of the bowel

Autonomic tone

normal background rate of sympathetic and parasympathetic activity

parasympathetic tone

maintains heartrate at 70 beats per minute

maintains smooth muscle tone in the intestines

sympathetic tone

maintains blood pressure by keeping blood vessels partially constricted

preganglionic efferent neuron

it is myelinated

is short for most sympathetic pathways

for the sympathetic division, most arise in the thoracic or lumbar regions of the spinal cord

for the parasympathetic division, most arise in cranial nerves or in the sacral region of the spinal cord

postganglionic efferent neuron

it is not myelinated

is short for most parasympathetic pathways

terminates in the effector

First route of efferent neuron of the sympathetic division

preganglionic fiber synapses with the postganglionic neuron at the same level of the spinal cord where it exited

Second route of efferent neuron of the sympathetic division

preganglionic fiber moves up or down the chain, before it synapses with the postganglionic neuron

Third route of efferent neuron of the sympathetic division

Preganglionic fiber passes through the chain and into the abdominopelvic region before it synapses with the postganglionic neuron

First route

form paravertebral ganglia

Second

connect the ganglia into a chain

Third route

forms part the sympathetic splanchnic nerve

Third route Innervates the

abdominopelvic organs

Third route connects the

nervous system to the endocrine system by innervating the adrenal gland

Stress response

True for the preganglionic neurons of all three routes

nerve fibers exit the spinal cord via the anterior root

somas are clustered in the lateral horn of the spinal cord

hypothalamus

helps maintain homeostasis via the autonomic nervous system

one of main brain regions that regulates the autonomic nervous system

Hypothalamus

adrenal medulla

a gland that secretes the "stress hormones", epinephrine and norepinephrine

Adrenal medulla

since the sympathetic branch innervates it, this allows the nervous and endocrine systems to work together to mediate the stress response

vasomotion

mechanism the sympathetic division uses to regulate blood pressure

can increases blood flow (by dilation); can decreases blood flow (by constriction)

changing the diameter of blood vessels