Central Nervous System Flashcards
What parts of the autonomic nervous system is due to the control of the CNS?
- Cerebral Cortex
- Amygdala
- Hypothalamus
- Brainstem
- Spinal Cord
What does the SPINAL CORD control in the autonomic nervous system?
Visceral Spinal Reflexes:
- Urination reflex
- Defacation reflex
- Erection reflex
- Ejaculation/orgasm reflex
What does the BRAINSTEM control in the autonomic nervous system?
- RETICULAR FORMATION exerts most direct influence over autonomic functions
- MEDULLA OBLONGATA - cardiact center, vasomotor center, digestive activities
- PERIAQUEDUCTAL GRAY MATTER IN MIDBRAIN - exerts sympathetic fear response
What does the HYPOTHALAMUS control in the autonomic nervous system?
- Main integration center of the autonomic nervous system by influencing preganglionic autonomic neurons in brainstem and spinal cord through direct connections and relays in reticular formation and periaqueductal gray matter.
- Medial and anterior parts direct parasympathetic functions
- Lateral and posterior parts direct sympathetic functions
What does the AMYGDALA control in the autonomic nervous system?
- Main limbic region for emotions
- Communicates with the hypothalamus and the periaqueductal gray matter can stimulate sympathetic activity, especially previously learned fear-related behavior
What does the CEREBRAL FRONTAL CORTEX control in the autonomic nervous system?
- People can exert some conscious control over some autonomic functions by developing control over their thoughts and emotions.
- Feelings of calm achieved during meditation are associated with cerebral cortex enhancing the parasympathetic centers in the hypothalamus via limbic structures.
- Voluntary recall of a frightful experience can activate the sympathetic system via the amygdala.
Autonomic Nervous System disorder: Raynaud’s disease
Characterized by constriction of blood vessels
-Provoked by exposure to cold or by emotional stress
Autonomic Nervous System disorder: Hypertension
High blood pressure.
- Can result from overactive sympathetic vasoconstriction
What is the Autonomic Nervous System (ANS)?
It is a visceral motor neuron system that innervates:
- Smooth muscle in organs and blood vessels
- Cardiac muscle
- Glands
The ANS has a chain of two motor neurons, compared to single somatic motor neuron
- Autonomic motor system:
- Preganglionic neuron: thinly myelinated
- Post-ganglionic neuron: unmyelinated
- Preganglionic and postganglionic neurons synapse in a ganglion - Somatic motor system:
- Axons are well myelinated and conduct impulses more rapidly
- Have one axon that extends from CNS to the muscle
There are sympathetic and parasympathetic divisions of the ANC
This innervates mostly the same structures but cause opposite effects.
What does the sympathetic nervous system do?
- Fright, flight, or fright response.
- Increase heart rate and breathing rate.
- Increases blood and oxygen to skeletal muscles
- Dilates pupils and airways
- Inhibits motility of the digestive tract and urinary tracts
- Stimulates sweat glands
- Stimulates arrector pili muscles which causes hairs to stand up vertically
