Chapter 16: Neural Integration II The Autonomic Nervous System and Higher-Order Functions

What are the two divisions of the ANS?

Sympathetic Division

Parasympathetic Division

This ANS division “kicks in” only during exertion, stress, or emergency and includes “fight, flight, or fright”

Sympathetic Division

This ANS division controls during resting conditions and during “rest and digest”

Parasympathetic Division

What are the seven responses to increased sympathetic activity?

1. Heightened mental alertness (Hungry)

2. Increased metabolic rate (Iguanas)

3. Reduced digestive and urinary functions (Run)

4. Energy reserves activated (Eagerly)

5. Increased respiratory rate and respiratory passageways dilate (In)

6. Increased heart rate and blood pressure (Intense)

7. Sweat glands activated (Sunlight)

What are the five responses to increased parasympathetic activity?

1. Decreased metabolic rate (Mellow)

2. Decreased heart rate and blood pressure (Hippos)

3. Increased secretion by salivary and digestive glands (Slowly)

4. Increased motility and blood flow in digestive tract (Move)

5. Urination and defecation stimulation (Up)

This nervous system includes fast fibers (Type A) ending in skeletal muscles

Somatic

In this division, the presympathetic ganglion is longer and includes Type B fibers ending with smooth muscle glands

Parasympathetic

In this division the postsynaptic ganglion is longer and includes Type C fibers ending with smooth muscle glands

Sympathetic

In the sympathetic division preganglionic fibers synapse in the ganglia near where?

Spinal cord

Cell bodies of preganglionic neurons in the sympathetic division are found where?

Lateral gray horns

Axons of the sympathetic division enter what roots of segments?

Ventral

What ganglionic neurons are paired and aim for target neurons of visceral effectors in the thoracic cavity, head, body wall, and limbs?

Sympathetic chain ganglia

What ganglionic neurons are unpaired and aim for visceral effectors in the abdominopelvic cavity?

Collateral ganglia

What ganglionic neurons are paired but do not synapse and aim for organs and systems throughout the body?

Adrenal medullae

What are the two types of adrenergic membrane receptors?

Alpha receptors (NE more potent)

Beta receptors

Alpha and beta receptors activate enzymes on the inside of the cell membrane via what proteins?

G proteins

This Alpha receptor is excitatory releasing intracellular calcium ions from reserves in the ER

Alpha-1

This Alpha receptor is inhibitory and lowers cAMP levels in the cytoplasm

Alpha-2

This beta receptor increases metabolic activity in the heart, kidney, and liver (producing more glucose) and it is excitatory

Beta-1

This beta receptor triggers relaxation of smooth muscles along the respiratory tract (smooth muscles of bronchi and B.V. of heart and sk. muscles and it is inhibitory

Beta-2

*Agonist given to people with asthma

This beta receptor is mostly in brown fat and leads to lipolysis, the breakdown of triglycerides in adipocytes

Beta-3

These terminals innervate sweat glands of the skin and blood vessels of skeletal muscles and brain

They stimulate sweat gland secretion and dilate blood vessels

Cholinergic (ACh) sympathetic terminals

These synapses release nitric oxide (NO) as neurotransmitters, neurons innervate smooth muscles in walls of blood vessels in skeletal muscles and the brain, and they produce vasodilation (opening up of blood vessels) and increased blood flow

Nitroxidergic synapses

What cranial nerves are parasympathetic nuclei associated with?

III, VII, IX, X (to help remember: 3+7=10 NOT 9)

Parasympathetic nuclei are found where?

In lateral gray horns of spinal segments S2-S4 (Craniosacral division)

These fibers of the parasympathetic division are long (Type B)

Preganglionic

These fibers of the parasympathetic division are short (Type C)

Postganglionic

These ganglion are near the target organ and are usually paired

Terminal ganglion (4 pairs)

These ganglion are embedded in tissues of target organs (on wall or organ), are interconnected masses, and clusters of ganglion cells

Intramural ganglion (majority)

Cranial nerve 3 (oculomotor) leads to what ganglionic neurons and what target organs?

Ciliary ganglion

Intrinsic eye muscles (pupils and lens shape) as the target organs

Cranial nerve 7 (facial) leads to what ganglionic neurons and target organs?

Pterygopalatine and automandibular ganglia

Nasal glands, tear glands, and salivary glands as the target organs

Cranial nerve 9 (glossopharyngeal) leads to what ganglionic neuron and target organs?

Otic ganglion

Parotid salivary gland as the target organ

Cranial nerve 10 (vagus) leads to what ganglionic neurons and what target organs?

Intramural ganglia

Visceral organs of the neck, thoracic cavity, and most of the abdominal cavity as the target organs

What ganglia takes orders to the spleen?

Intramural

Pelvic nerves lead to what ganglionic neurons and target organs

Intramural ganglia

Visceral organs in inferior portion of abdominopelvic cavity as the target organs

Parasympathetic neurons release what as neuromuscular and neuroglandular junctions?

ACh

What are the two types of Cholinergic receptors (for ACh)

Nicotinic and Muscarinic (only on targets)

These receptors are always excitatory when exposed to ACh and are on surfaces of ganglion cells

Nicotinic receptors

These receptors are at cholinergic neuromuscular or neuroglandular junctions (parasympathetic), at few cholinergic junctions (sympathetic), G proteins, and can be excitatory or inhibitory

Muscarinic receptors

If a toxin inhibited nicotinic receptors, what would be affected?

Parasympathetic + skeletal muscles