UNIT TEST BIGGG IDEAS Flashcards
Steroid hormones
Lipid-based (non-polar)
Ex: estrogen and testosterone
It can get through the lipid bilayer of the cell membrane
Attaches to its target cell on its specific receptor inside the cell
Water-soluble hormones
Polar and cannot get through the lipid bilayer of the cell membrane
Ex: epinephrine and insulin
They bind to a receptor and initiate a response on the cell membrane
The impact of this hormone is amplified
Menstrual cycle: follicular stage
In the follicular stage, the anterior pituitary increases FSH secretion, stimulating follicular development. The maturing follicle releases estrogen (will act on the anterior pituitary to inhibit the secretion of FSH and maintain sex organs and secondary sexual characteristics) and progesterone
The anterior pituitary then secretes LH which triggers ovulation. Ovulation ends the follicular stage and starts the luteal stage.
Luteal stage
Once the egg is released, LH causes the follicle to develop into a corpus luteum
The corpus luteum secretes progesterone and some estrogen (inhibits LH and FSH in the anterior pituitary)
As the corpus luteum degenerates, progesterone and estrogen levels drop, causing increased FSH secretion from the anterior pituitary
uterine stage
From day 1 to 5 the corpus luteum is degenerating and progesterone and estrogen levels are low (menstruation)
At the end of menstruation, the endometrium is very thin but then starts thickening on day 6 (a new follicle is maturing during this time and releasing estrogen)
Day 14= ovulation occurs and the release of progesterone from the corpus luteum causes the rapid thickening of the endometrium.
If fertilization does not occur: the corpus luteum degenerates, the levels of sex hormones drop, the endometrium breaks down, and menstruation begins.
If fertilization does occur: the fertilized egg releases hCG which stops the breakdown of the corpus luteum. the progesterone maintains the uterine lining and the estrogen prevents a new follicle from maturing.
The fertilized egg travels to the uterus over 7 days and plants itself in the uterine lining where new life will develop
Urine formation Glomerular filtration
water and solute from blood plasma > nephron
Factors that affect glomerular filtration:
permeability of the capillaries of the glomerulus
- blood pressure
Tubular reabsorption
Moves useful substances from the filtrate and returns them to the blood for reuse by the body
**The loop of henle causes the kidney to produce urine that is hypertonic to the blood plasma
Tubular secretion
Moves additional wastes and excess substances from the blood into the filtrate
water reabsorption
Removes water from the filtrate and returns it to the blood for reuse by the body
Diabetes insipidus
ADH secretion is insufficient which causes a person to urinate more frequently
Water is excreted faster than it is consumed
This causes severe dehydration and ion imbalance
Synthetic ADH can be taken to restore the balance of water reabsorption
Urinalysis
Found in urine
Glucose
Diet is high in sugar
Diabetes mellitus
Protein
Intense exercise
Renal insufficiency/kidney failure
Ketones
Low carb diet
Fasting
Diabetes mellitus
Low concentration of solutes
Super hydrated
Diabetes insipidus
Diabetes mellitus
the pancreas does not make enough insulin or the body does not respond properly to insulin
Type one: the immune system produces antibodies that attack and destroy the beta cells of the pancreas
Type two: Tends to develop gradually, often because the insulin receptors on the body’s cells stop responding to insulin.
Maintaining resting membrane potential
The resting membrane potential is the potential difference across a membrane in a resting neuron (-70mV)
3 factors contribute to maintaining resting membrane potential:
The sodium-potassium pump (3 sodium out and 2 potassium in)
Large negatively charged protein molecules are present inside the cell and not outside
The cell membrane contains sodium and potassium ion leak channels that allow for the passive movement of these ions across the membrane
Action Potential
Step 1: an action potential is triggered when the threshold potential is reached (goes from -70mV to -50mV)
Step 2: sodium channels open at -50mv. Sodium rushes into the cell and depolarizes the membrane (goes from -50mV to +40mV)
Step 3: sodium channels are inactivated at +40mV. Potassium channels open at +40mV. Potassium ions exit the cell and hyperpolarize the membrane to slightly below the resting potential
Step 4: potassium channels close. Sodium channels change from inactivated to closed state. Resting membrane potential is restored.
Neurotransmitters
Neurotransmitters have either excitatory or inhibitory effects on the postsynaptic membrane
Excitatory molecules, like acetylcholine, cause action potentials by opening sodium channels
Inhibitory molecules, like painkillers, cause potassium channels to open, causing hyperpolarization
