Ch. 4 (other sense organs) Flashcards
Taste
salty: (NaCl)
sour: H+ shut down, K+ (depolarize) eg. citrus
sweet: calorie/ nutritious (glucose)= G-protein + cAMP
- second messenger pathway
bitter: eg. morphine
- trigger 2nd messenger- G-protein= gustducin
umani: flavor or meaty
- MSG, glutamate, high lipid foods- trigger G-protein and 2nd messenger
Trigeminal
move muscle; not tastebuds
- face/ speech
Transduction in Cranial Nerves
- reaches to parietal lobe (gustaltory region)
7: anterior tongue
9: glassopharyngeal- posterior tongue
10: taste buds
11: provides 4 regions
12: tongue muscles
Olfaction Pathway
nerve cells- G olfaction or Golf- cAMP pathway- olfactory bulb (produce smell files)- glomeruli and mitral cells
- higer cortex
- limbic/ emotion
Vomeronasal Organ
- detects pheromones
- passed subconsciously
Autonomic Nerve Pathway
- 2 neurons
- preganglionic fiber- autonomoic ganglion- postganglionic- target organ or effector (gland, organ, fat)
Sympathetic VS Parasympathetic
- stressful “fight or flight”, heart rate increases, blood vessels dilate, breakdown glycogen in liver to glucose (ATP), hypothalamus releases catecholamins, digestions is low priority
- daily activities, “rest and digest”, heart rate decrease
Antagonistic VS Complementary Action VS Co-operative Action
- sympathetic: increase heart rate, para: reduce heart rate
- salivary glands: sympathetic- thick, viscous, para: watery (end)
- para: erection, sym: ejaculation
Sympathetic and Parasympathetic Nerve Pathways
- Thoracolumbar as trunk, preganglion is short, ganglion is close, postganglion is long, preganglion secretes ACh, ganglion receives nicotonic, postganglion secretes E and NE, target receptors are adrenergic receptors (ADERNERGIC)
- Craniosacral as trunk, preganglion is long, ganglion is far from origin, postganglion is short, preganglion secretes ACh, ganglion receives nicotinic, postganglion secretes ACh, target is muscarnic receptors (CHOLINERGIC)
Cholinergic Receptors
- nicotinic receptors: activated by tobacco plant
- muscarinic receptors: activated by the mushroom poison muscarine
- nicotonic found on postganglionic cell in all autonomic ganglia; respond to ACh released from preganglion fibers
- muscarinic receptors are found on effector cell membranes, bind with ACh released from parasympathetic postganglionic fibers which activate secondary messenger
Adrenergic Receptors
- 2 primary types of catecholamine receptors: Alpha and Beta
- act through secondary messengers to transfer from cell surface into cytoplasm
Alpha Receptors
A1: excitatory response in effector organ, present in most sympathetic target tissues, favors NE, Ca+ 2nd messenger
A2: inhibitory (decrease cAMP), favors NE, smooth muscle contraction decreased (end of digestion)
Beta Receptors
- B1: excitatory, equal favour of NE and E, found primarly in heart, increased heart rate and kidney function, cAMP 2nd messenger
- B2: inhibitory, favours E, cAMP 2nd messenger, blood vessels decrease, smooth muscle of resp. tract relax
- B3: excitatory, favours NE, cAMP 2nd messenger, adipose tissue breakdown
Somatic Nervous System
- one neuron “motor” neuron, affects skeletal muscle
- neuromuscular junction
action potential (terminal)- calcium ions- ACh vesicles- ACh released- motor end plate (muscle)- Na+ channels- end plate potential- action potential (contraction)
motor end plate- removal of ACh- relaxation- enzyme AChE - acetic acid (waste) and choline (recycled)
Vulnerability of Neuromuscular Junction
black spider venom: causes explosive release of ACh, rapid depolarization; failure in respiratory system or cardiac
botulism toxin: blocks release of ACh, no depolarization; no muscle tone which leads to flaccid paralysis
curare: blocks action of ACh at receptor sites, leads to death because no EPP occurs
organophosphates: prevent inactivation of ACh, nerve gases and insecticides, no reuptake of ACh (destroys AChE)
myasthenia: inactivates ACh receptor sites, autoimmune disease, muscle degeneration, eyes droop, muscles no tone, wheelchair bound
