Exam 4 (weeks 9-10) Flashcards
(27 cards)
What are the functions of autonomic nervous system?
Controls the functions of the visceral organs (composed of smooth muscle, cardiac muscle and glands).
It connects your brain to your sweat glands, heart, lungs, bladder, digestive system, and other important structures
What types of tissues does the ANS innervate?
Smooth muscle, cardiac muscle, and glands (ex. Salivary, sweat).
Compare and contrast the somatic and autonomic nervous systems
Autonomic nervous system
- The visceral motor/efferent portion of the nervous system
- controls functions of visceral organs
- have no conscious awareness
- has two divisions: parasympathetic and sympathetic
- tissue: cardiac, smooth, glands
- two neurons: preganglionic and postganglionic neurons
Somatic nervous system
- controls the function of skeletal muscles
- we have conscious control
- one neuron
Explain the difference between preganglionic and postganglionic neurons
Preganglionic neurons start in the CNS and extend to the PNS to the ganglion
Postganglionic originate in the ganglion and extend to the target tissue
List the two divisions of the ANS and describe their basic functions
Sympathetic
- Fight or flight/ prepares our body for crisis
- Originates in thoracolumbar region of the spinal cord
- Short preganglionic axon
- Long postganglion axon
Parasympathetic
- rest and digest or return to normal response
- takes over when we are relaxed
- originates in the cranial sacral region of the spinal cord/brain stem
- long preganglionic axon
- short postganglionic axon
Where is the parasympathetic preganglionic and postganglionic cell bodies located?
Preganglionic cell bodies are located in the craniosacral region (brain stem,S-S4 gray matter of the spinal cord)
Postganglionic cell bodies are located in intramural and terminal ganglia located on or near effector tissue (synapse)
Intramural-within the wall of the organ
Terminal-really close to the organ
What are the 4 cranial nerves that carry parasympathetic fibers?
CN III
CN VII
CN IX
CN X
CN III (parasympathetic)
Oculomotor nerve
Parasympathetic innervation to the ciliary muscles and the lens of the eye
Parasympathetic effect: Pupil constriction (limit amount of light into eye Lens accommodation (for near/close vision).
CN VII (parasympathetic)
Facial nerve
Parasympathetic innervation to lacrimal gland and sublingual and submandibular salivary glands
The parasympathetic effect:
Secretion of tears from lacrimal gland
Secretion of saliva for salivary glands
CN IX (parasympathetic)
Glossopharyngeal nerve
Parasympathetic innervation to the parotid salivary gland
Parasympathetic effect:
Secretion of saliva for salivary glands
CN X (Parasympathetic innervation)
Vagus nerve
Parasympathetic innervation to most organs:
- thorax: heart, lungs
- abdomen: foregut, midgut organs
Parasympathetic effect:
- decrease heart rate and force of contraction
- constrict bronchioles of ling and increase mucus production
- increase peristalsis (digestion)
Pelvic splanchnic nerves (parasympathetic)
Parasympathetic innervation to abdominal and pelvic organs
Abdomen: Hindus organs
Pelvic organs
Parasympathetic effects:
- increase peristalsis (digestion):
- urination
- defecation
- erection
What are the locations of sympathetic preganglionic and postganglionic cell bodies?
-preganglionic cell bodies are located in the thoracolumbar region (lateral horn of T1-L2 spinal cord)
Postganglionic cell bodies are located in a prevertebral (preaortic) or sympathetic chain (prevertebral) ganglia (synapse)
Specify the location of the sympathetic chain (paravertebral) ganglia and the prevertebral (preaortic) ganglia
Sympathetic chain (paravertebral) ganglia -located with the right abs left sympathetic chains
Prevertebral (pre-aortic) ganglia
-located on abdominal aorta
Does the white ramus communicans carry preganglionic or postganglionic axons?
Preganglionic axons are used to enter the chain (on ramps)
Does the gray ramus communications carry preganglionic or postganglionic axons?
Postganglionic axons are used to exit the chain (off ramps)
Do the splanchnic nerves carry preganglionic axons or postganglionic axons?
Preganglionic axons that did not synapse in sympathetic chain ganglia
do not use gray ramus communications to exit the chain
instead take a splanchnic nerve to the prevertebral (pre-aortic) plexus and synapse there
Sympathetic: body wall (spinal nerve pathway)
Pathway primarily to blood vessels and sweat glands of the body wall
preganglionic axon enters the sympathetic chain using white ramus
synapse in sympathetic chain (paravertebral)
- can stay at the same level and synapse
- can ascend and synapse
- can descend and synapse
postganglionic axon exits the chain using gray ramus to spinal nerve then continues to effector tissue (blood vessels of skin, sweat glands)
Sympathetic effect:
Vasodilation (dilation of blood vessels)
Secretion of sweat glands
Pathway to organs of head (T1-T4/5)
Pathway to organs of the head (pupil, salivary/ lacrimal glands)
Preganglionic axon enters the sympathetic chain using white ramus
- ascends to the cervical region of the sympathetic chain
- synapse in a cervical sympathetic chain (paravertebral)
Postganglionic axon exits the chain using a sympathetic nerve (not a gray ramus) then continues to effector tissue
Sympathetic effect:
Head:
-dilation of pupil
-inhibited secretion of salivary/lacrimal glands
Pathway to organs of the thorax (T1-T4/5)
Preganglionic axon enters the
sympathetic chain using white ramus
-ascends to the cervical region of the sympathetic chain
-synapse in a cervical sympathetic chain (paravertebral)
Postganglionic axon exits the chain using a sympathetic nerve (not a gray ramus) then continues to effector tissue.
Sympathetic effect:
Thorax: increased heard rate and force of contraction of heart
Dilation of bronchioles and increased respiration
Pathway to organs of abdomen
Pathway to organs of abdomen and pelvis
Preganglionic axon enters the sympathetic chain using white ramus
-uses a splanchnic nerve to exit the sympathetic chain (does not synapse in chain)
-travels to prevertebral (preaortic) ganglion and synapses
Postganglionic axon continues to the effector tissue
Sympathetic effect: decreased digestion (peristalsis)
Sympathetic adrenal medulla pathway
Pathway to adrenal medulla only
Preganglionic axon enters the sympathetic chain using white ramus
- uses a splanchnic nerve to exit the sympathetic chain (does not synapse in chain).
- travels through preaortic plexus (does not synapse)
- travels to adrenal medulla and synapses
Postganglionic axon continues short distance to effector tissue of adrenal medulla
Sympathetic effect:
-release adrenaline and noradrenaline into blood
How are somatic pain and visceral pain different?
Somatic pain:
- Somatic afferents from skeletal muscle, joints, skin
- Easy to locate where the pain is
Visceral pain:
- visceral afferents from smooth muscle, cardiac muscle, glands
- cannot localize pain
- dull or achy pain that is hard to locate or nausea
- often refers pain
Define referred pain
Pain from a structure that is felt in a different location
The body mistakes pain coming from one area for pain coming from another area
