Other questions from other SG Flashcards
How is urine formed
- Filtration of blood to remove waste and small molecules.
- Reabsorption of essential substances to the bloodstream.
- Secretion of additional waste and toxins into the filtrate.
- Concentration of urine to balance the body’s hydration and excrete waste efficiently.
What pressure influence urination?
- Hydrostatic pressure for filtration in the kidneys.
- Intravesical pressure as the bladder fills.
- Urethral sphincter pressure for storage and controlled release.
- Abdominal pressure to aid voiding.
- Neural signals to balance bladder contraction and sphincter relaxation.
PCT type of cells are found in the tubules of the nephron?
Cell type- simple cuboidal with microvilli
special feature- microvilli with mitochondria
main function- reabsorption of nutrients, ions, and water
Thin loop type of cells are found in the tubules of the nephron?
Cell type- simple squamous
main function- reabsorption of nutrients, ion, and water
thick ascending limb type of cells are found in the tubules of the nephron?
cell type- simple cuboidal
special feature- man mitochondria
main function- active ion transport
DCT type of cells are found in the tubules of the nephron?
cell type- simple cuboidal with few microvilli.
special features- fewer microbial and many mitochondria
main function- reabsorption and secretion
collection duct type of cells are found in the tubules of the nephron?
cell type- principla and intercalated cells
special features- hormone responivness
main function- water, sodium, and acid base regulation
Countercurrent multiplier function and effect
Function- creates the medullary concentration gradient
effect- concentrates filtrate in descending limb , dilutes it in ascending the limb
countercurrent exchanger function and effect
function- maintain the mudllary gradient
effect- preserves medulla osmolarity while removing reabsorbed water
ADH regulation function and effect
function- adjust collecting duct premeability
effect- concentrates or dilutes urine based on hydration on hydration needs
What triggers micturition?
- Bladder filling and activation of stretch receptors.
- The micturition reflex, which coordinates bladder contraction and sphincter relaxation.
- Voluntary control by the brain to initiate or delay urination.
What is osmoalrity? What role does it play in water loss or retention?
- Osmolarity determines water movement and is crucial for maintaining fluid balance across body compartments.
- High osmolarity triggers water retention (via ADH) and thirst to restore balance.
- Low osmolarity promotes water loss in urine to prevent overhydration.
What occurs during oogenesis? In relation to meiosis.
Oogenesis- Arrests at Prophase I before birth and Metaphase II until fertilization.
What occurs during meiosis that creates genetic variability in gametes? At what stage does that occur?
Crossing Over at Prophase 1
How does GnRH stimulate oogenesis and spermatogenesis?
O/S- stimulates FSH and LH release
How does FSH stimulate oogenesis and spermatogenesis?
O- matures ovarian follicles
s- stimulates sperm development
How does LH stimulate oogenesis and spermatogenesis?
O- trigger ovulation and corupus luteum formation
S- produce testosterone
What hormones are responsible for the ovarian and uterine cycle?
GnRH, LH, FSH, Estrogen, and Progesterone
what roles does GnRH take in ovarian Cycle role and Uterine cycle role
OV- stimulates FSH and LH
UT- nothing?
what roles does FSH take in ovarian Cycle role and Uterine cycle role
OV- stimulates folliculare growth
UT- Nothing
what roles does LH take in ovarian Cycle role and Uterine cycle role
OV-triggers ovulation, corpus lute formation
UT- nothing
what roles does estrogen take in ovarian Cycle role and Uterine cycle role
OV- stimultes follicle growth early
UT- thickrn the endometrium (proliferative phase)
what roles does progesterone take in ovarian Cycle role and Uterine cycle role
OV- maintain the corpus lute (luteal phase)
UT-prepares the endometrium for implntation (secretory phase)
what are the stages of endometrial cycle
- menstrual
- proliferative
- secretory
Menstrual phase
Days 1-5
key events- sheddinf of the functional layer of the endometrium
Proliferative phase
Days- 6-14
Regrowth and thickening of the endometrium
secretory phase
days 15-28
glands secrete nutrients, and endometrium prepares for implantaion
What is the major hormone that stimulates ovulation?
LH
What hormone develops the breast: at puberty
estrogen and GH
- What hormone develops the breast for ductal system
estrogen and progesterone
What hormone develops the breast alveoli
progesterone and prolactin
What hormone develops the breast for milk production
prolactin
- What hormone develops the breast for milk ejection
oxytocin
When does fertilization occur? Where?
- When? Fertilization typically occurs within 12–24 hours after ovulation.
- Where? In the ampulla of the fallopian tube.
- What is the role of the acrosome?
- Function: Helps the sperm penetrate the egg’s protective layers for fertilization.
- Mechanism: Stores and releases digestive enzymes during the acrosome reaction.
- Importance: Without the acrosome and its reaction, sperm would be unable to reach or fertilize the egg.
What is the pronucleus?
the haploid nucleus of a gamete (sperm or egg) during the process of fertilization, before the fusion of the two nuclei to form the zygote. It represents one of the final stages in gamete development and the beginning of the new organism’s genetic formation.
What is syngamy?
the process of fusion of the male and female pronuclei within a fertilized egg (zygote), resulting in the formation of a diploid nucleus.
What occurs during the first week after fertilization?
day 0- fertilization
day 1-3~ cleavage
day 3-4~ morula formation
day 4-5~ blastocyst formation
day 5-6~ hatching of the blastocyst
day 6-7~ begining of implantation
What is a blastocyst?
a hollow, multicellular structure formed during the early stages of embryonic development, typically around days 4–5 after fertilization.
What is the function of uterine milk?
provide nourishment, support, and protection to the developing embryo before the placenta forms.
What are the three germ layers?
Ectoderm, mesoderm, and endoderm
What is the hormone of labor
oxytocin, prostaglandins, and rexlaxin
What is the hormone of pregnancy
hCG, progesterone, estrogen, hPL, relaxin
What is the hormone of lactation
prolactin, oxytocin, and hPl
What are the stages of labor?
- First Stage: Dilation of the Cervix
- Second Stage: Delivery of the Baby
- Third Stage: Delivery of the Placenta
What is the role of oxytocin? How does it accelerate labor?
Function:
* Stimulates uterine contractions.
* Enhances cervical ripening (indirectly via prostaglandins).
* Facilitates delivery of the baby and placenta.
* Prevents postpartum bleeding by contracting the uterus.
* Mechanism:
* Works via a positive feedback loop to ensure contractions are efficient and labor progresses.
What stimulates lactation?
- What stimulates lactation?
* Prolactin stimulates milk production in the mammary glands.
* Oxytocin triggers the let-down reflex, ejecting milk from the glands.
* Suckling by the infant is the primary stimulus for both hormones, creating a positive feedback loop that sustains lactation.
