AUTONOMIC NERVOUS SYSTEM
Sympathetic nervous system generally means:
"fight, flight, or fright" Activated during exercise, excitement, and emergencies
Parasympathetic nervous system generally means:
"rest and digest" Concerned with *conserving energy.*
The Neurotransmitter released by *preganglionic* axons in both sympathetic and parasympathetic nervous system is:
*ACETYLCHOLINE* for both branches (cholinergic)
Describe the *Sympathetic Pathways to Periphery*:
*ENTRY = WHITE RAMUS-> SYNAPTIC CONTACT -> GRAY RAMI -> SPINAL NERVE* Exit is at a *DIFFERENT LEVEL* not exactly on the same level, can go one level up or one level down.
What structure is considered to be the *BOSS OF the ANS*?
*HYPOTHALAMUS*- the boss of overall *INTEGRATION* of ANS *Receives input from emotional system-> limbic in frontal lobe-> then sends input to the brainstem.*
What is the function of the *periaqueductal gray matter of the midbrain*?
*LOCATED AROUND THE CEREBRAL AQUEDUCT* *Controls many AUTONOMIC FUNCTIONS, especially the SYMPATHETIC FEAR response during a threatening encounter* *RICH IN ENDORPHINS THAT BIND TO THE MORPHINE RECEPTOR- NUMB PAIN*
Where are the *PREGANGLIONIC cell bodies of the parasympathetic nervous system* located?
*Located in visceral motor region of spinal gray matter* *-> Form splanchnic nerves*
Describe the *SYMPATHETIC TRUNK GANGLIA*:
*Located on both sides of the vertebral column* *Linked by short nerves into sympathetic trunks* *Joined to ventral rami by white and gray rami communicates* *Fusion of gangliafewer ganglia than spinal nerves*
What is the role of the *Adrenal Medulla* in the Sympathetic Division
*Major organ of the SYMPATHETIC nervous system* *Secretes GREAT QUANTITIES OF EPINEPHRINE (a little norepinephrine)* *Stimulated to secrete by preganglionic sympathetic fibers* *EFFECTS ARE SYSTEMIC!!!!*
The medial and anterior parts of the hypothalamus direct:
*Parasympathetic functions*
The only neurotransmitter that is associated with *NOREPINEPHRINE* (adrenergic) is:
*Postganglionic SYMPATHETIC* *Associated with anxiety, depression.*
The neurons in *laminae VII and VIII*:
*Project bilaterally as SPINORETICULAR fibers*
*Parasympathetic Nervous System: Sacral* emerges from:
*S2-S4* *Innervates organs of the pelvis and lower abdomen*
*Sympathetic innervation for the head & neck* comes from:
*SPINAL CORD*- long axons reaching the head and neck region.
The Autonomic Nervous System INNERVATES:
*Smooth muscle* *Cardiac muscle* *Glands* Regulates *visceral* functions Heart rate Blood pressure Digestion Urination
Sympathetic nervous system is called:
*Thoracolumbar division* *T1-L2*
Describe *PREVERTBRAL GANGLIA* of the SYMPATHETIC NERVOUS SYSTEM:
*UNPAIRED* Not segmentally arranged *Occur only in abdomen and pelvis* Lie *anterior to the vertebral column*
What is activated when people *decide to recall a frightful experience*?
*Voluntary sympathetic activation* *Cerebral cortex acts through the amygdaloid body*
SACRAL outflow supplies:
*remaining ABDOMINAL & PELVIC ORGANS*
The *FOUR main ganglia of the SYMPATHETIC NERVOUS SYTEM* are:
- CELIAC - SUPERIOR MESENTERIC - INFERIOR MESENTERIC - INFERIOR HYPOGASTRIC
Centers in the *medulla oblongata* regulate:
- Heart rate (cardiac centers) - Diameter of blood vessels (vasomotor center) - Many digestive activities.
*VISCERAL REFLEXES* INVOLVE WHAT 3 THINGS?
- STIMULATED RECEPTOR - SENSORY COMPONENT - MOTOR COMPONENT
Describe the *REFLEX ARC ASSOCIATED WITH VISCERAL REFLEXES*:
1- *BARORECEPTORS IN CAROTID SINUS ARE STIMULATED* 2- SENSORY FIBERS CARRIED ON *GLOSSOPHARYNGEAL* NERVE (CN 9) 3- INTEGRATION OCCURS IN THE *MEDULLA OBLONGATA* 4- *EFFERENT FIBERS ARE CARRIED VIA THE VAGUS NERVE (10)* 5- PARASYMPATHETIC STIMULATION OF HEART *DECREASES THE HEART RATE* 6- *BLOOD PRESSURE DECREASES.*
The Neurotransmitter released by *Parasympathetic POSTganglionic axons* is:
ACETYLCHOLINE
The *FOUR MAJOR PARAVERTEBRAL* ganglia are:
Celiac Superior Mesenteric Ganglion Inferior Mesenteric Ganglion Parasympathetic Ganglia
The *ADRENAL MEDULLA* associated with the *transmission of neurotransmitters via the bloodstream* involves:
EPINEPHRINE!!!!!
True or False: The AUTONOMIC nervous system is *completely INVOLUNTARY*.
FALSE!!! *Stress response, blood pressure, heart rate, etc.* These things can be affected/regulated by yoga and other relaxation techniques. *The hypothalamus receives input from emotional system-> limbic in frontal lobe-> then sends input to the brainstem.*
True or False: The *CELL BODIES* of cranial nerves *3, 7, 9 & 10 (parasympathetic)* are located in the lateral horn.
FALSE!!! Cell bodies are located in *cranial nerve nuclei in the BRAINSTEM.*
Describe the *VISCERAL SENSORY COMPONENT of the AUTONOMIC NERVOUS SYSTEM* :
General visceral sensory neurons MONITOR: *Stretch* Temperature *Chemical changes* Irritation The cell bodies are located in the *dorsal root ganglia*
Through the ANS, the *hypothalamus controls*:
Heart activity Blood pressure Body temperature Digestive functions.
Where are cranial nerves *9 & 10* located?
MEDULLA
Where is the *OCULOMOTOR nerve (cranial nerve 3)* located
MIDBRAIN
IN A REFLEX, IF THERE IS A *DIRECT COMPONENT BETWEEN SENSORY AND MOTOR*=
MONOSYNAPTIC
The Neurotransmitter released by *POSTganglionic SYMPATHETIC* axons:
Most release *NOREPINEPHRINE (adrenergic)*
*PREganglionic fibers* run via which *4 cranial nerves*?
Oculomotor nerve (III) Facial nerve (VII) Glossopharyngeal nerve (IX) Vagus nerve (X)
IF A REFLEX INVOLVES: *INTERNEURON OR FIBERS*=
POLYSYNAPTIC
Where is cranial nerve *7 (FACIAL)* located:
PONS
Describe the *pathway of neurotransmitter release associated with the ADRENAL MEDULLA*:
PREGANGLIONIC GETS INTO THE GANGLIA *BUT THERE IS NO SYNAPTIC CONTACT IN THE GANGLIA*... THE AXON WILL REACH THE ADRENAL GLAND AND WILL RELEASE NEUROTRANSMITTER IN RESPONSE, THE ADRENAL GLAND WILL RELEASE EPINEPHRINE & NOREPINEPHRINE INTO THE BLOODSTREAM
What are the *FOUR CONTENTS of a SPINAL NERVE*?
SENSORY SOMATIC MOTOR SOMATIC SENSORY AUTONOMIC MOTOR AUTONOMIC
The *lateral and posterior parts of the hypothalamus* direct:
SYMPATHETIC functions
The Adrenal Medulla CLINICAL:
Stress-Induced Hypertension: Continual stress can promote overactive sympathetic stimulation causing *VASOCONSTRICTION*-> hypertension, or high blood pressure- a circulatory condition that can have a variety of contributing factors. Hypertension is always serious because: It increases the workload on the heart, possibly precipitating heart disease It increases the wear and tear on artery walls. *STRESS-INDUCED HYPERTENSION is treated with drugs that prevent smooth muscle cells in the walls of blood vessels from binding norepinephrine and epinephrine (beta-blockers).*
THE KEY STRUCTURE FOR EMOTION IS:
THE AMYGDALA
The main *limbic region for emotions*, including fear is:
THE AMYGDALA
CRANIAL outflow comes from:
THE BRAIN *Innervates organs of the head, neck, thorax, and abdomen*
WHAT IS THE PATHWAY OF CONTROL OF THE AUTONOMIC NERVOUS SYSTEM?
TO CONTROL AUTONOMIC RESPONSE: *INPUT FROM THE AMYGDALA-> HYPOTHALAMUS-> BRAINSTEM ->SPINAL CORD*
True or False: *ACETYLCHOLINE Is linked to memory and alzheimers*
TRUE
True or False: *Somatic motor system* is a *ONE MOTOR NEURON* system that extends from CNS -> skeletal muscle.
TRUE
True or False: A GANGLION is located *outside of the CNS*
TRUE
True or False: Axons are *well myelinated & conduct impulses rapidly* in the SOMATIC MOTOR SYSTEM
TRUE
True or False: Conduction is *slower in the ANS due to thinly or unmyelinated axons*
TRUE
True or False: Sympathetic and parasympathetic divisions *innervate mostly the SAME structures but cause OPPOSITE effects.*
TRUE
True or False: The *pre-vertebral ganglia* of the sympathetic nervous system only occurs at the level of the *abdomen and pelvis*.
TRUE
True or False: The *prevertebral ganglia of the sympathetic nervous system lies ANTERIOR to the vertebral column* and are unpaired.
TRUE
True or False: The SYMPATHETIC nervous system contains *MORE GANGLIA* than the parasympathetic division.
TRUE
True or False: People *can exert some conscious control over some autonomic functions* by developing control over their thoughts and emotions.
TRUE Example: feelings of *extreme calm achieved during meditation* Associated with *cerebral cortex influence on the parasympathetic centers in the hypothalamus via various limbic structures.*
True or False: The *POSTGANGLIONIC neurons of the SYMPATHETIC NERVOUS SYSTEM* can be very long- potentially extending from the THORAX->CRANIUM
TRUE ex: *Salivatory gland* function
True or False: *NOREPINEPHRINE & EPINEPHRINE RELEASED BY THE ADRENAL GLAND INTO THE BLOODSTREAM ARE VASOCONSTRICTORS*
TRUE! CONTRIBUTING TO STRES-INDUCED HYPERTENSION, ATHEROSCLEROSIS & MYOCARDIAL INFARCTION.
True or False: EPINEPRHINE & NOREPINEPHRINE ARE *STRESS-RELATED NEUROTRANSMITTERS*.
TRUE- *SECRETED BY THE ADRENAL MEDULLA*
True or False: Visceral PAIN is perceived to be *SOMATIC* in origin.
TRUE- known as *referred pain*
TRUE OR FALSE: The ADRENAL GLAND *functions as a ganglia*
TRUE. It receives PREganglionic input and releases neurotransmitters into the bloodstream.
*How many neurons* are in the AUTONOMIC NERVOUS SYSTEM?
TWO!!!! Preganglionic neuron & Postganglionic neuron
Cells in *laminae I and V* project mainly to:
The *CONTRALATERAL* side as part of the *ANTEROLATERAL SYSTEM (ALS)*
Parasympathetic nervous system is called:
The *CRANIOSACRAL DIVISION* *S2-S4*
Which structure in the *brainstem* appears to exert the *most direct influence over autonomic functions*?
The *reticular formation* of the brainstem.
Where are the cell bodies of the *VISCERAL SENSORY COMPONENT OF THE AUTONOMIC NERVOUS SYSTEM*?
The cell bodies are located in the *DORSAL ROOT GANGLIA*
Describe the MASS REFLEX REACTION*
The cord injury is follow wed by a *temporary loss of all reflexes inferior to the level of the injury*. When reflex activity returns, it is *exaggerated because of the lack of inhibitory input from higher (brain) centers.* The ensuing episodes of mass reflex reaction involve surges of both visceral and somatic motor output from large regions of the spinal cord. The usual trigger for such an episode is a strong stimulus to the skin or the overfilling of a visceral organ, such as the bladder. *During the MASS REFLEX episode, the body goes into flexor spasms, the limbs move wildly, the colon and BLADDER empty, and profuse sweating occurs. Most seriously, sympathetic activity raises BLOOD PRESSURE to life- threatening levels.*
Where is the injury typically localized when associated with the *Mass Reflex Reaction*?
The mass reflex reaction affects *quadriplegics and paraplegics with spinal cord injuries ABOVE THE LEVEL OF T6*
The Hypothalamic center's influence:
The preganglionic autonomic neurons in the spinal cord and brain both through direct connections and through relays in the reticular formation and periaqueductal gray matter.
How does the amygdaloid body stimulate sympathetic activity, *especially previously learned fear- related behavior*?
Through *communications with the hypothalamus and periaqueductal gray matter*
DESCRIBE *REFERRED PAIN*:
VISCERAL PAIN ENTERS SPINAL CORD AT DIFFERENT AREA NOT CLOSE TO THE TARGET AREA THIS IS CONSIDERED *REFERRED PAIN* EXAMPLE: PAIN IS IN THE *LEFT ARM FOR MYOCARDIAL INFARCTION* *FIBERS ENTER AT CERVICAL LEVEL*!!!! FOR INTERNAL ORGANS-IT DEPENDS ON ENTRY LEVEL OF SENSORY INPUT
*Sympathetic Trunk* Ganglia location?
Vertical row *beside the vertebral column.* Postganglionic sympathetics innervate organs ABOVE the diaphragm.
Where do the *PREganglionic neurons of the SYMPATHETIC nervous system* synapse?
With POSTganglionic neurons in the terminal ganglia that are *located close or within the wall of the visceral organ* e.g. *ciliary ganglia* *submandibular ganglia* *otic ganglia*
Where are the Cell bodies of *3, 7, 9 & 10* located?
located in *cranial nerve nuclei in the BRAINSTEM*
*Visceral sensory and autonomic neurons* are involved in which two reflexes?
• *DEFECATION* reflex • *MICTURITION* reflex
What is the Basic organization of the *SYMPATHETIC nervous system*?
• Issues from *T1-L2* • Preganglionic fibers form the *LATERAL GRAY HORN* • Supplies visceral organs and structures of superficial body regions • Contains more ganglia than the parasympathetic division