AP 4.30

kylerigonan's version from 2015-05-15 09:12


Question Answer
What does the countercurrent mechanism consist of?Countercurrent multiplier and countercurrent exchanger
What is the countercurrent exchanger? The Vasa Recta allows for 2 exchanges with the medulla. The descending Vasa Recta will allow for Na to enter blood from medulla and water to leave blood into medulla. The Na will leave the ascending vasa recta into medulla and the water will enter ascending vasa recta.
Dilute urine Dilute=well hydrated and appropriate nutrients in the body=Na actively pumped out to medulla and as long as body hydrated then no ADH will be made and aquaporins will remain closed
what are the chain of events if dehydrated?ADH produced by supraoptic nerve @ hypothalamus. ADH will target DCT and collecting ducts. DCT will increase permeability. ADH will target principle cells in the collecting duct and open aquaporins and the water from the collecting duct will osmotically flow into the salty medulla
why is the Na gradient important in the medulla?The Na gradient is important in the medulla because the water are attracted to the Na in the medulla and because aquaporins are channels not pumps
Urination Process1) storage reflex stimulated by stretch of bladder and causes contraction of internal and external urethral sphincter and relaxation of detruser muscle
2) voiding reflex stimulated by the increase stretch in bladder (about 200 mL urine). When bladder full, it'll cause a stimulation of detruser muscle to contract
Why is the testes housed outside of the body?in order for testes to properly make effective sperm it'll need to be about 2-3 degrees lower than core body temperature
what are the temperature control of the testes?Dartos muscle (smooth m.) if testes are cold then it'll wrinkle and cover testes and if testes are warm then skin will drop further away from the body
Cremaster muscles If cold then contract and pulls testes closer to abdomen and further from core body
what is the function of the epididymis?storage of sperm and allow for sperm to mature
what does the spermatic cord contain? 5ANS nerve fibers, testicular vessels, vas deferens and cremaster muscle
diploid2n/46 chromosomes
sex cell contains how many chromosomes23
what is interphase?interphase is the time between divisions, making proteins/enzymes, cell is growing, cell is replicating DNA,
what is meiosis2 divisions PMAT1 PMAT2
what occurs in prophase 1: chromatin coil into chromosomes, nuclear envelope and nucleoi dissolve, synapsis and crossing over
Question Answer
what is synapsispairing up of homologous chromosomes
what is crossing overwhen pairs of chromosomes get close togeth and info get mixed. homologous pairs exchange some genetic material
what occurs in metaphase 1line up the 23 homologous pairs at the center of cell
what occurs in anaphase 1break pairs at crossover points
what occurs in telophase 1split daughter cells apart, reverse prophase (nuclear envelope appear, uncoil chromosomes become chromatin, and mitotic spindle breaks down) then meiosis 2 begins
what is the end result of meiosis 14 haploid daughter cells (unreplicated DNA)
What is the role of meiosis1) reduce 46 chromosomes to 23. 2) introduces genetic variability (mixes genetic info)