(Lesson 19) Chapter 16: Sympathetic & parasympathetic Divisions Flashcards
How does the somatic nervous system operate?
The somatic nervous system operates under conscious control
What type of muscles does the SNS control?
The skeletal muscle
In addition to controlling skeletal muscles, what other function does the SNS serve for the body.
It affects long term survival
How does the autonomic nervous system operate?
It operates automatically
What does the ANS control?
ANS controls visceral effectors
(adipocytes, smooth/cardiac muscles, glands)
Which systems does the ANS coordinate?
The ANS coordinates
1. Cardiovascular
2. Respiratory
3. DIgestive
4. Urinary
5. Reproductive
What makes up the organization of the ANS?
- Integrative centers
- Visceral motor neurons
Integrative centers
autonomic act. = hypothalamus
Integrative centers
autonomic act. = hypothalamus
Where are Visceral motor neurons found?
Found in brain & spinal cord (also known as preganglionic neurons)
Preganglionic fibers
Axons of preganglionic neurons leave CNS and synapses on ganglionic neurons
(Visceral motor neurons)
Autonomic ganglia
- Contains many ganglionic neurons
- Ganglionic neurons innervate viscereal effector
Postganglionic fibers
Axons of ganglionic neurons
What are the 2 divisions of the ANS?
- Sympathetic division
- Parasympathetic
What’s the difference between parasympathetic and sympathetic?
Sympathetic increases alertness, HR, and muscular abilities (flight/fight). On the other hand parasympathetic relaxes the body during restful conditions, such as reduction of HR.
Can the two divisions work together?
Yes the divisions could work independently or they could work together, with each division in charge of a specific process.
Characteristics that make up the sympathetic division?
- Preganglionic fibers (thoracic and superior lumbar spinal segs.) synapse in ganglia near spinal cord.
- Preganglionic fibers are short
- Post ganglionic are long
- Prepares the body for crisis.
What is the exception for having a long postganglionic fiber w/ the sympathetic division?
At adrenal medulla
What are the 7 responses to increased sympathetic activity?
- Heightened mental alertness
- Increase metabolic rate
- Reduced digestive and urinary function
- Energy reserve activated
- Increased respiratory rate and respiratory passageways dilate.
- Increased HR & BP
- Sweat glands activated.
What are the characteristics that make up the parasympathetic division?
- Preganglionic fibers that originate in the brain stem & sacral segments of the spinal cord
- Synapses in ganglia close to or within target organs.
- Preganglionic fibers are long & postganglionic are short.
- Parasympathetic division stimulates visceral activity
- Conserves energy and promotes sedentary activities.
What are the 5 responses to increased parasympathetic activity?
- Decreased metabolic rate
- Decrease HR and BP
- Increase secretion of salivary and digestive glands
- Increase motility (movements of material in digestive tract) and blood flow in digestive tract
- Urination & defecation stimulation.
Parasympathethic =
Craniosacral division
Sympathetic=
Thoracolumbar division
What is the 3rd division of the ANS?
The enteric nervous system
What are the characteristics that make up the ENS?
- Extensive network in digestive tract walls
- Complex visceral reflexes coordinated locally (heavily influenced)
- Roughly 100 million neuron
- All neurotransmitters are found within this system.
How many neurons are found in sensory & motor neurons?
Sensory= 10 million
Motor= 0.5 million
Where is the sympathetic division located?
- The sympathetic division between segments T1 and L2 of the spinal cord
- Ganglionic neurons in ganglia near vertebral column
- Cell bodies of preganglionic neurons in lateral gray horns of spinal cord.
Where do ganglionic neurons occur?
Occur in 3 locations
1. Sympathetic chain ganglia
2. Collateral ganglia
3. Adrenal medullae
The sympathetic chain ganglia is located in?
- Both sides of the vertebral column
The sympathetic chain ganglia controls effectors within the:
- Body wall
- Inside the thoracic cavity
- In heads
- In limbs
Collateral ganglia
- are anterior to vertebral bodies
- Contain ganglionic neurons that innervate tissues and organs in abdominopelvic cavity.
- Adrenal medullae
- Very short axons
- When stimulated releases neurotransmitters into blood stream.
- Function as hormones to affect target cells throughout body
What hormones does adrenal medullae release into the blood stream?
The adrenal medullae releases the hormones epinephrine & norepinephrine into the bloodstream
Organization & anatomy of the sympathetic division?
- Ventral roots of spinal segments T1-L2 contain sympathetic preganglionic fibers
- Give rise to myelinated white ramus
- Carry myelinated preganglionic fibers into sympathetic chain ganglion
- May pass through sympathetic chain ganglion and synapse at collateral ganglia or in adrenal medullae.
What are the physical characteristics that make up neural tissue?
- Extremely delicate
- Extracellular environment must maintain homeostatic limits
- If regulatory mechanisms breakdown, then this results in neurological disorders.
When do neurological disorders appear?
They appear why regulatory mechanisms break down.
What functions does the nervous system serve?
(The orchestra conductor of the body)
- It monitors all other systems
- Issues commands that adjust their activities (like a conductor)
What are the effects of anatomical changes in the NS?
- Linked to functional changes
- Neural processing becomes less efficient w/ age
- Memory consolidation become more difficult
- Secondary memories become harder to access
The effects of anatomical change to the NS w/ sensory systems?
- loss in acuity of hearing, balance, vision, smell, and taste
- Reaction time slows down
- Weakened reflexes or being to disappear.
Impact of motor control on the NS with aging
- Precision decreases
- Takes longer to perform
What is incaptation and which age group does it impact?
Incapacitation means that the individual’s NS can no longer function adequately to fulfill daily activities. It generally impacts the elderly or those have have suffered CNS damage.