physiology notes: homeostasis

1. Brain: autonomic nervous system
2. Hypothalamus: tests blood; releases hormones
3. Hypothalamus functions:
   1. Cardiovascular: anterior↑ posterior↓
   2. Body temperature: ↑ normal: sweating vasodilation or surface vessels

↓ normal: shivering and vasoconstriction

3. 3. Water and electrolytes: ADH retains water; thirst center
   4. Hunger: blood nutrients↓ feeding center stimulated

Blood nutrients ↑ satiety center stimulated

3. 5. sleeping: sleep center; wakefulness center for levels of consciousness
   6. sexual: stimuli from tactile sensors in genitals
   7. emotions: anger, fear, pain, pleasure
   8. endocrine : hormones through pituitary gland
4. Pituitary gland: endocrine function
5. Pons: apneustic and pneumotaxis nuclei; work with medulla to regulate rate/depth of breathing
6. Medulla:
   1. Cardiac center: impulses ↑ and ↓ impulses
   2. Vasomotor center: constrict smooth muscle of arteriole; blood pressure↑
   3. Respiratory center: rate and depth of breathing with pons→ rhythmic breathing
7. Spinal cord
   1. Reflex integration: stimuli→receptor→sensory neuron→spinal cord→motor neuron→effector
   2. Impulse conduction: brain→PNS and PNS back to brain
   3. Ascending tracts: spinal cord→brain (sensory)
   4. Descending tracts: brain→to PNS (glands and muscles)

8. Autonomic Nervous System: innervate organs not under voluntary control
9. Preganglionic: CNS to ganglion

Postganglionic: ganglion to organ

10. Sympathetic: speeds up

Parasympathetic: slows down

11. Sympathetic:
    1. Cardiac Muscle:↑
    2. Digestive: ↓
    3. Pupils: dilate
    4. Sweat glands↑
    5. Blood vessels to skin and viscera: contraction
    6. Bronchial tubes: dilation
    7. Blood glucose↑ from liver

12. Acetylcholine: from preganglionic neurons; activates postganlionic neurons; Nicotinic receptors

Norepinephrine: most postganglionic cells; adrenergic; stimulation and Inhibitory

13. Alpha adrenergic: contraction of smooth muscle

Beta 1adrenergic: stimulates heart rate and contraction force

Beta 2 adrenergic relaxes smooth muscle

14. Adrenal medulla: innervated by preganglionic neurons of sympathetic;

Releases epinephrine (same effect as norepinephrine)

15. Mass activation: divergence and convergence of presynaptic neurons on to

Postsynaptic cell bodies→activation of nearly all of sympathetic system as a unit

16. Parasympathetic:
    1. Eye pupils: constriction
    2. Cardiac muscle: ↓
    3. Digestive : ↑
    4. Bronchi: contraction of smooth muscle

17. Cholinergic receptors: respond to acetylcholine
18. Nicotinic receptors: autonomic ganglia
19. Dual Innervation: from both sympathetic and parasympathetic
20. Antagonisitc:

Cardiac: sympathetic↑; parasympathetic ↓

GI tract: sympathetic↓; parasympathetic↑

21. Sympathetic only: adrenal medulla, sweat glands, blood vessels of skin and Skeletal muscle