Autonomic nervous system

Question 1

What makes up the sympathetic trunk?

Answer 1

(Spinal cord – thoracic and lumbar nerve pathway making contact with ganglia known as sympathetic trunk)

Question 2

What does the parasympathetic nervous system do?

Answer 2

• organ specific control (Eyes, mouth, lungs, heart, bladder, intestines
• Eg. Cranial nerve 10 supplying sympathetic control to most of viscera (organs in chest region)

Question 3

What does the parasympathetic nervous do?

Answer 3

Rest and Digest
- Craniosacral
- Myelinated preganglionic Long fibres and nerve pathways (more quick action potential) and short non-myelinated postganglionic fibres or nerve pathways
-** Releases acetylcholine at synapses **

Question 4

What does the sympathtic nervous system do?

Answer 4

**Flight and fight **
- Two sympathetic trunks on either side of spinal cord associated with sympathetic ganglion
- AP along major spinal nerve (in grey ramus) out then nerve fibre passes through **white ramous **entering sympathetic trunk and sympathetic ganglion
- Gray ramus neurones control blood vessels, sweat glands and hair follicles
- Some branch out from white ramus along prevertebral ganglion to the viscera (organs in abdomen)
- Then others go to organs in chest

• Relatively short lightly myelinated preganglionic axons
• acetylcholine at synapse then short non-myelinated postganglionic axon and release nor epinerorine (nor adrenaline) onto effector organs

Question 5

What is the paravertebral ganglia?

Answer 5

Ganglia of sympathetic trunk
Send branches to pre vertebral ganglia which controls organs of the abdomen

Question 6

WHats the prevertebral ganglia?

Answer 6

preaortic ganglia
Called solar plexus (winding is when this is put under pressure)
- Celiac ganglia - stomach and liver
- Superior mesenteric ganglia – colon and small intestine
- Aortorenal ganglia – renal system of kidneys
- Inferior mesenteric ganglia – colon and rectum

Question 7

What adrenal glands are in the kidneys?

Answer 7

medualla and cortex

Question 8

What does the medulla gland do in kidney?

Answer 8

• contain chromaffin cells which are modified neurone releasing **epinephrine and nor epinephrine (adrenaline) **–
• attached to sympathetic nervous system by celiac ganglion into adrenal medulla

Question 9

What does the cortex gland do in the kidney?

Answer 9

• producing of stress hormone cortisol also promoting glycogenesis in liver, liberation of nutrients, glucose and proteins and promotes gluconate
• rich blood supply

Question 10

What is a neurohemal organ?

Answer 10

Chromatin cells release epinephrine or nor epinephrine directing into the blood

Question 11

Whats the process of the parasympathetic nervous system?

Answer 11

rest and digest
Body recovery and resupply of tissues with nutrients
- **Broncho constriction **of lungs (less blood circulation and ventilation of lungs)
- **pupils constrict **– focusing on short/ close vision
- Increased salvation – watery - getting ready to eat
- Gastrointestinal tract – activated to secrete acid and digestive juices – preparing to eat

Question 12

What happens when the sympathtic nervous system is activated?

Answer 12

• Heart – rate increase, stroke volume increased
• Blood flow redistributed – increased to skeletal muscle and cardiac blood vessels
• Broncho dilation – more oxygen needed with more ventilation
• **Salivary glands – activated – viscous **thick saliva – to protect delicate membranes in mouth
• Pilo erection – hair stand on end – contracting pili cells
• Pupils of eyes dilate – focus further away
• **Liver – glucogenesis in liver releases glucose **form liver – increasing respiration
• **Releasing fatty acids **from white fat of the body

Question 13

Whats the distribution differences of the sympathetic and parasympathtic nervous system?

Answer 13

• Not all tissues have symp and parasym nerve system
• Hair follicles – only sympathetic
• Blood vessels mainly sympathetic
• Sweat and adipose only sympathetic
• Iris only parasympethic

Question 14

How does brain stem change in autonomic control?

Answer 14

Reticular formation:
- Cardiac fazers and respiratory centres
- Those areas responsible for blood pressure, circulation, blood flow and salivation change due to activation of sympathetic nervous system

Question 15

What the 4 nuclei involves in brain stem control of cardiac output?

Answer 15

1. solitary nucleus
2. sepressory area
3. nucleus ambiguous
4. pressor are

Question 16

How does the solitary nucleus control cardiac output?

Answer 16

**- sensory input zones with **baro receptors **and input
- pressure sensers and chemoreceptors
- pH of blood and blood gases – links to 2 and 3

Question 17

What doe depressor areas do to control cardiac output?

Answer 17

• inhibition of sympathetic nervous system
• when activated inhibits sympathetic tone in pressor area

Question 18

How does the nucleus ambiguoud control cardiac output?

Answer 18

• controls vagus nerve
• in response to changed blood pressure
• changing cardiac output and regulation of blood

Question 19

How does the pressor area control cardiac output?

Answer 19

– sympathetic area activated by depressor area

Question 20

What are three main nuclei involbes in brain stem control of respiratory function?

Answer 20

1. ventral respiratory group
2. dorsal respiratory group
3. pontine nuclei

also solidary nucleus

Question 21

How does the ventral respiratory group control repsiratory function?

Answer 21

• central pattern generator
• two sets of brain cells pattern of inspiration and exploration complimentary

Question 22

How does the dorsal respiratory group control repsiratory function?

Answer 22

• info from **solitary nucleus **as well as lots of information from receptors where ventral respiratory group is controlled due to stimuli

Question 23

How does the pontine nuclei control repsiratory function?

Answer 23

higher level of control than dorsal as regulates relationship between nuclei smoothing motor activity

Question 24

What does the vagus nerve do in autonomic control?

Answer 24

• 90% parasympathetic NS go through area
  -** Input of sensory** (stretch and chemoreception) info from lungs, bladder, circulatory system and digestive tract
• Adjustments made via autonomic nervous effectors

Question 25

What does hypothalamic control mean?

Answer 25

• ‘boss’ with overall integration of controlling SNS and PNS in ANS
• Autonomic sensory inputs into hypothalamus by visual stretch receptors of vagus nerves – temp, HR, pH, CO2 levels, osmilary system
• Regulatory zone

Question 26

WHat does the cerebral cortex do?

Answer 26

• Frontal lobe
• Cognitive stressor
• To control hypothalamus and limbic system due to psychosocial output

Question 27

What does the limbic system do?

Answer 27

• Emotional input – eg. Comfort eating, reproduction. – scared
• Emotional input of sensory experiences