ANS Flashcards
What are the 3 differences between Somatic & Autonomic Nervous System?
-SNS
1) consciously perceived sensations
2) excitation of skeletal muscle
3) Only 1 neuron connects CNS to effector
-ANS
1) unconsciously perceived visceral sensations
-involuntary inhibition or excitation of smooth or cardiac muscle or glands
3) 2 neurons needed to connect CNS to effector (pre & post ganglionic neurons)
SYSTEMS DO NOT HAVE SEPARATE SENSORY NEURONS BUT DIFFERENT MOTOR NEURONS
What does the ANS regulate? (3)
1) Smooth muscle (hollow organs)
2) Cardiac Muscle (diaphragm)
3) Certain Glands (Adrenal, Salivary, & Sweat glands)
Where does the ANS receive input from?
Limbic system (Hypothalamus) & other regions of Cerebrum
- Responds to emotions & visceral sensation info
EX: smell, taste, temp, osmolarity of blood, etc.
What are the 2 characteristic differences between preganglionic & postganglionic neurons?
-Preganglionic
1) Start in brain stem or spinal cord
2) myelinated axons to autonomic ganglion
-Postganglionic
1) cell body in PNS in an autonomic ganglion
2) unmyelinated axons that terminate in smooth/cardiac muscle & glands
Sympathetic vs. Parasympathetic Nervous System
SNS= “Fight or Flight”
PNS= “Rest & Digest”
SNS Effects
1) Pupil Dilation (increase size)
2) Increased HR, BP, contraction force
3) Increased blood flow to skeletal/cardiac muscle
4) Increased respiratory rate
5) Increased blood glucose levels
6) Decrease blood flow to non essential organs (stomach/kidneys)
PNS Effects
1) SLUDD (salivation, lacrimation, urination, digestion, & defication)
2) Decreases HR, Pupil Size, &
Dual Innervation
- One system stimulates & the other inhibits.
- Operates most organs
What structures only experience Sympathetic System innervation?
Adrenal Medulla (gland that makes adrenaline, either on or off)
Kidney
Skin/Arrector Piili (goosebumps)
Sweat Glands
What only experiences Parasympathetic System innervation?
Lacrimal Gland (tears)
Describe length of ganglionic neurons is each division & location of ganglia
What makes up ganglia?
Sympathetic
-Short pre& long post
- Ganglia just outside spinal Cord (paravertebral)
Parasympathetic
- Long pre & short post
-Ganglia at effector (at organ/gland)
Ganglia is made up of postganglionic neuron cell bodies
List the main SYMPATHETIC Plexuses and the organs they serve (6)
1) Cardiac (Heart)
2) Celiac (Stomach)
3) Hypogastric (reproductive organs)
4) Inferior Mesenteric (Small Intestine)
5) Superior Mesenteric (Large Intestine)
6) Pulmonary (Lungs)
What nerves supply the Sympathetic vs. Parasympathetic?
Sympathetic- Cervical, Thoracic, & Lumbar
Parasympathetic- Cranial Nerves (Occulomotor (III), Facial (VII), Glossopharangeal (IX), Vagus (X)) & Sacral Nerves (S2-S4)
Adrenergic vs. Cholenergic
Where are they found?
Adrenergic neurons release NE (only found in SYMP POSTGANG neurons)
Cholenergic neurons release Ach ONLY (BOTH PREGANG but only PARA POSTGANG neurons)
What only experiences Parasympathetic System innervation?
Lacrimal Gland (tears)
