Autonomic Nervous System Flashcards
Parasympathetic nerves perform
- Constrict pupils
- stimulate saliva
- slow heartbeat
- constrict airways
- stimulate stomach activity
- inhibit release of glucose; stimulate gallbladder
- stimulate activity of intestines
- contract bladder
- promote erection of genitals
Sympathetic nerves perform
- dilate pupils
- inhibit salivation
- increase heartbeat
- relax airways
- inhibit activity of stomach
- stimulate release of glucose; inhibit gallbladder
- inhibit activity of intestines
- secrete epinephrine and norepinephrine
- relax bladder
- promote ejaculation and vaginal contraction
Autonomic nervous system control
blood vessels and internal organs
What plays a major role in controlling blood pressure
Autonomic Nervous system
Sympathetic system regulates
blood flow sent to organs and tissues during emergency
sympathetic system regulates bloodflow by
- vasoconstriction to skin, skeletal muscles and GI tract
- Vasodilation to skeletal muscles
Sympathetic neurons
- cell bodies in spinal cord T1-L2
- axon exit spinal column and enter sympathetic trunk (one on each side of column)
- each trunk has 20-25 sympathetic ganglia along posterior body wall
What are specific function of the sympathetic nervous system in the thoracic region?
- Regulates flow of blood to skin and skeletal muscle
- shunts blood to organs in need of blood during an emergency
- innervate smooth muscles of they eye
- Innervate salivary glands
- dilation of trachea and bronchi
- innervate the heart
What are specific functions for the sympathetic nervous system in the abdomen and pelvis?
- innervate walls of digestive tract, pelvic organs and blood vessels that supply these organs
- decrease function of digestive and urinary systems
- cause vasoconstriction to raise BP
- innervates the adrenal gland
- causes an adrenaline rush
What are the two sympathetic neurotransmitters?
- Acetylcholine (ACH): cholinergic synapses are found on sweat gland and arterioles that supply skeletal muscles
- Norepinephrine (NE): multiple locations in the body
What are the function of Acetylcholine (cholinergic receptors)?
- vasodilation and increase blood flow to skeletal muscles
- sweating and cooling of the body
What are the function of the Norepinephrine (adrenergic receptors)?
- general vasoconstriction and increase systemic blood pressure
- increased heart rate and contraction strength
- relaxation of airways
- decreased digestion and urinary function
Parasympathetic neurons facts
- travel with cranial or spinal nerves to innervate cardiac or smooth muscles cells
- cell bodies are in the brainstem or sacral plexus
- do innervate internal organs
- do not innervate skin, muscles or blood vessels
- all neurons release Acetylcholine
What are the specific functions of the parasympathetic nervous system?
- Innervate the pupillary constrictor muscle of the eye and allow the shape of the lens to change
- results in constriction of the pupil
- allows the lens to focus on close object
- innervates the lacrimal glands which produces tears
- innervates the salivary glands which produces salivation
specific functions of the parasympathetic nervous system
Vagus nerve (CNX) contain parasympathetic neurons which:
- -slows heart rate
- -decrease heart contraction strength
- -constrict trachea and bronchi
- -stimulate activity of the liver, gall bladder and pancreas
specific functions of the parasympathetic nervous system
Parasympathetics from sacral region form pelvic splanchnic nerves which:
- stimulate bladder emptying
- stimulate vasodilation of erectile tissue
- increase motility of the lower GI tract and control defecation
Autonomic nervous system is controlled by?
Hypothalamus
What are central autonomic fibers?
neurons from the hypothalamus that run through brainstem to synapse on autonomic neurons
What is the limbic system?
limbic areas regulate emotions, basic drives and memory
it can account for physiological changes as a result of emotions
What is autonomic dysreflexia?
- A risk for patients with a spinal cord injury above T6
- Most of the autonomic nervous system is disconnected from the hypothalamic control center
- Patient cannot feel painful stimulus such as a pressure sore, tight clothing or shoes, blocked/kinked catheter
- Body has a large sympathetic response (Continually increasing blood pressure) even though stimulus isn’t felt
- Due to lesion, parasympathetic signals at level of lesion are blocked and can’t mediate sympathetic response
- Parasympathetic response above level of lesion causes bradycardia and vasodilation
- Patients experience a pounding headache, flushing of the skin and sweating above the level of the lesion
What is Complex Regional Pain syndrome?
- Abnormal response of the sympathetic nervous system to injury
- Used to be called RSD
- Symptoms include intense, burning pain in the affected area, swelling, edema and red, shiny skin
- Patients are typically hesitant to have the area touched or to move it
