exam 3 lecture Flashcards
Total fluid in plasma + interstitial fluid + intracellular fluid equals how many liters?
~42 liters
Explanation: The total body fluid is ~60% of body weight in males (~42 L for a 70 kg person), with ~28 L intracellular fluid (ICF) and ~14 L extracellular fluid (ECF). ECF consists of plasma (~3 L) and interstitial fluid (~11 L).
Low circulating calcium ions lead to the release of parathyroid hormones from the parathyroid glands. Which of the following mechanisms of hormone release is this?
Humoral mechanism
Explanation: Hormones released in response to changes in blood ion/nutrient levels follow a humoral stimulus, as seen with calcium and parathyroid hormone.
Insulin is released due to high circulating glucose levels. Based on the structure and classification of insulin, which of the following cell signaling mechanisms does insulin follow?
Tyrosine kinase receptor mechanism
Explanation: Insulin is a peptide hormone that binds to tyrosine kinase receptors, initiating a signaling cascade for glucose uptake.
How does the endocrine system compensate to increase blood pressure during hypotension?
Releases aldosterone and ADH, and activates the renin-angiotensin-aldosterone system (RAAS)
Explanation: Aldosterone increases sodium and water reabsorption, ADH retains water, and angiotensin II causes vasoconstriction, all raising blood pressure.
Which hormones are elevated during a sympathetic response?
Epinephrine, norepinephrine, and cortisol
Explanation: The adrenal medulla releases epinephrine and norepinephrine, while cortisol supports the prolonged stress response.
How would you classify thyroid-releasing hormone, thyroid-stimulating hormone, and thyroid hormones?
Tropic hormones
Explanation: These hormones regulate the activity of other endocrine glands or stimulate hormone secretion (e.g., thyroid hormones).
Correct pathway that sperm follows in the male reproductive system?
Testis → Epididymis → Vas deferens → Ejaculatory duct ( seminal vesicles, prostate gland, and bulbourethal glands) → Urethra
Explanation: Sperm is produced in the testis, matures in the epididymis, and travels through the vas deferens, ejaculatory duct, and urethra during ejaculation.
Function of rising progesterone levels after the corpus luteum rupture?
Maintains the uterine lining for implantation
Explanation: Progesterone stabilizes the endometrium, preparing it for a potential pregnancy.
Cause of a significant drop in progesterone and estrogen during pregnancy?
Loss of the placenta
Explanation: The placenta produces progesterone and estrogen, so its loss (e.g., after delivery) causes hormone levels to drop.
True regarding sex differentiation?
The SRY gene on the Y chromosome drives male differentiation.
Explanation: The SRY gene initiates testes development, which produces hormones driving male sexual development.
What changes lower testosterone levels?
Decreased LH secretion or GnRH suppression.
Explanation: LH stimulates testosterone production in the testes; reduced LH or GnRH impacts this process.
Normal physiologic osmolarity of ECF and ICF?
~300 mOsm/L.
Explanation: Osmolarity is similar between ECF and ICF to prevent osmotic imbalance across cell membranes.
What happens if plasma fluid volume is too high?
Fluid shifts into interstitial compartments, causing edema.
Explanation: Excess plasma fluid increases hydrostatic pressure, pushing fluid into interstitial spaces.
True statements about nephron anatomy/organization?
a. Most of the nephrons are cortical.
b. Nephrons are the functional unit of the kidney.
c. Each nephron’s capillary beds are arranged in parallel.
d. Nephron epithelial cells have tight junctions to limit intercellular fluid/solute movement.
e. Nephron epithelial cells have microvilli to maximize surface area for exchange.
ALL
Filtration fraction with RPF of 200 mL/min and GFR of 100 mL/min?
50%
.
Explanation: Filtration fraction = GFR / RPF = 100/200 = 0.5 or 50%.
