BIOL 1344 Study Guide - Spring 2018, Comprehensive Midterm Notes - Water, Sodium, Aldosterone
12 Oct 2018
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Department
Course
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BIOL 1344
MIDTERM EXAM
STUDY GUIDE
Fall 2018
Chapter 17: Endocrine System (PART 1)
Cell-cell communication
- There can be electrical signals; very fast-acting (few milliseconds); their effects last
for a short amount of time (few seconds or minutes)
- Within electrical signals, there is action potential: complete reversal of polarity
(AKA depolarization)
ACTION POTENTIAL CAN:
- Can travel long distances along and strength (voltage) does not fade with
time and space.
- Self-generating and self-propating
- All-or-none; THEY DON'T OVERLAP
- Action potential is generated by voltage-gated Na+ channels
Graded Potentials:
- fade over time and space; they can be depolarizing or hyperpolarizing type
- If there was a cell, the inside would be negative and outside would be positive at -
70Mv resting membrane potential (cell is polarized)
- Cell can go from -70Mv ---> -50Mv ----> -30Mv ----> 0Mv ----> +20mV (+20mV is
called ACTION POTENTIAL, -50mV - -20mV is called GRADED POTENTIALS
(depolarizing type))
find more resources at oneclass.com
find more resources at oneclass.com
2
- At this point, the cell inside is positive and outside is negative (cell gets
depolarized)
- AT DEPOLARIZED: Na+ influx
- AT REPOLARIZATION: K+ efflux
- When the cell becomes more negative (from -70mV---> -90Mv) it is called
hyperpolarization
- at -90mV, it is called GRADED POTENTIAL (hyperpolarizing type)
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Chemical signals: Slow to act; effects last for a long time; can be characterized by:
- Neurotransmitters: transmitted from neurons
ex) acetylcholine, epinephrine, norepinephine, dopamine, glycine, aspartic acid,
glutamic acid, tryptamine, atp, CO, NO, gamma amino butyric acid (GABA) are
examples of neurotransmitters
- Neurohormones: Released by neurons in the brain (specifically hypothalamus)
- they target the tissue and elicits response
- Anti-diuretic hormone (ADH, or vasopressin): this hormone gets out of the
hypothalamus and elicits effect
- ADH prevents diuresis (diuresis is uniary loss of water)
- If ADH is present, less urine is passed out. no dehydration; person isn't
thirsty
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
There can be electrical signals; very fast-acting (few milliseconds); their effects last for a short amount of time (few seconds or minutes) Within electrical signals, there is action potential: complete reversal of polarity (aka depolarization) Can travel long distances along and strength (voltage) does not fade with time and space. Action potential is generated by voltage-gated na+ channels. Fade over time and space; they can be depolarizing or hyperpolarizing type. If there was a cell, the inside would be negative and outside would be positive at - Cell can go from -70mv ---> -50mv ----> -30mv ----> 0mv ----> +20mv (+20mv is called action potential, -50mv - -20mv is called graded potentials (depolarizing type)) At this point, the cell inside is positive and outside is negative (cell gets depolarized) When the cell becomes more negative (from -70mv---> -90mv) it is called hyperpolarization. At -90mv, it is called graded potential (hyperpolarizing type)
