Cell Physiology Flashcards
3 ways activity of ACh are terminated at synapse naturally
- diffuse away from receptors 2. chemical degradation by ACh esterase 3. reabsorption back into presynaptic membrane
What is responsible for the release of ACh into the synapse in a neuromuscular junction upon depolariziation of an action potential
Calclium channels open and allow the ion to flow into cytoplasm
What is responsible for making ACh within a cell?
the ER-Golgi complex
List several mechanisms how we interfere with synaptic transmission
- block receptors 2. block reabsorption 3. esterase inhibitors 4. competition for receptor sites 5. deplete/exhaust stores
what is one example of a drug interrupting the reuptake of a neurotransmitter
An SSRI (selective serotonin reuptake inhibitor) such as Prozac act on interrupting synaptic transmission
What is an example of a ACh esterase inhibitor?
Malathion (pesticide), physostigmine, neostigmine also Pyridostigmine (useful in myasthenia gravis as it leaves ACh in cleft for longer compensating for the autoimmune disease that destroys own receptiors
How would a ACh esterase inhibitor (such as pyrdostigmine) actually help pts with myasthenia gravis?
It leaves ACh in cleft longer, allowing for compensation for the autoimmune disease that destroys receptor cells
What is an example of blocking the release of ACh
botulism toxin
What are two examples of how a receptor site can be competed for
Succinylcholine-causes depolarization
Curare, vecuronion, atracurium-block depolarization
What is an example of a chemical that mimics the action of ACh which are not degraded by their esterase
Nicotine
What are two examples of IPSP (inhibitory post-synaptic potential
GABA and Glycine
What is the mechanism of the IPSP’s
hyperpolarize the cell by opening Cl- channels
What are some causes of atrophy
decreased work load, use, nurtrition, blood supply, and nervous stimulation. Altered hormonal stimulation,
Can u give a few examples of physiologic atrophy
skin as we age, loss of estrogen due to menopause causes atrophy of endometrium, vaginal epithelium, and breast
can u give an example of pathologic atrophy
carpal tunnel syndrome, damage to median nerve at wrist causes shrink in muscles of the hand
2 physiological examples of hypertrophy(increase in cell size)
pregnancy & uterine muscle
skeletal muscle from weight lifting
an example of pathologic hypertrophy
cardiac
define dysplasia & list example
abnormal change in size, shape, organization of mature cells. Rate as mild, moderate, or severe (often near cancer cells & often reversible) ex-barretts esophagitis (due to GERD)
What is the mechanism of carpel tunnel syndrome on the nervous tissue
Demyelinates
what would you use for numbing an area before suturing?
Lidocaine (diffuses through tissues and occupies Na+ channels so nerve CANT depolarize
An example of metaplasia and define
cells are replaced, smokers columnar in trachea with squamous cells
Define cell hypoxia and some results
inadequate O2 delivery. Cells swell, pH decreases, lysosomes burst, mitochondria swell
Impairment of plasma and organelles (ATP using pumps ,Na K, Ca, Cl, glucose transport
