DSA: Autonomy Flashcards
Describe a simple reflex arc involving skeletal muscle
- Afferent (sensory) stimulus detects unexpected stretch of a muscle
- Sends signal to muscle spindle located in the dorsal root ganglion of the spinal cord–> ventral root
- Synapse on alpha-motor neuron of stretched muscle
- FIRES
- Release ACh at the NMJ
- Causes contraction (shorterning of the stretched muscle
Did we use our brain for the reflex arch involving the skeletal muscle?
No.
In the autonomic NS, sensory information tells our body what?
When there is a change in our homeostasis.
Are we aware of the of the stimulus that activates our ANS?
No.
But ones that are, we do not control the responses.
What are sensory stimuli that can modify our ANS?
BP, PaO2, pH.
What controls the activation of somatic reflexes?
Any level of the CNS: but many of them are generated in the spinal cord.
What controls the activation of the ANS?
Lower levels of the brain: medulla–> hypothalamus.
Efferent (motor) neuron in the somatic reflex is made up of how many neurons?
1 alpha-motor neuron
Efferent (motor) neuron in the ANS is made up of how many neurons?
2: pre-ganglionic and post-ganglionic
How does your sympathetic NS respond to stimuli?
- Increase O2 to the “right” parts of the body by [increase HR and blood flow]
- Increase glucose;
- [liver]–> glucose to the blood for use by skeletal muscles.
- Other less important tissue will use FFA.
- We need to be able to clearly identify threats and responses
- control focus and pupil (dilate)
How does your parasympthatetic NS respond to stimuli?
- Decrease O2 and decrease HR
- Sends blood to digestive tract
-
Increase digestion
- Glands in GI tract–> secrete enzymes/electrolytes
- Increases instestinal motility
- Relax sphincters so contents can from one part of the digestive tract to the other -
Store NRG
- Liver–> store glucose; decrease ability to release
- Adipose tissue–> store FFA
What are functions of the parasympathetic NS?
- Pupils
- Saliva production
- HR
- Bronchi
- Digestive organs
- Bladder-
Other?
- Constricts pupils
- Increase saliva production
- Decrease HR
- Constricts bronchi
- Stimulates digestive organs, pancreas, bladder
- Causes erection
What are functions of the sympathetic NS?
- Pupils
- Saliva production
- HR
- Bronchi
- Digestive organs
- Bladder-
Other?
- Dilates pupils
- Decreases saliva production
- Increases HR
- Dilates the bronchi
- Inhibits digestive organs, pancreas and gallbladder
- Relaxes bladder
- adrenal medulla release of NE and EPI
- Stimulates orgasm
Describe the pathway of parasympathic NS and sympathetic NS
Post-ganglionic neurons in the sympathetic NS bind to what type of receptors?
Adrenergic
