Hormones and Reporduction Flashcards
Define hormone
Molecule released in small amounts into blood to bring messages to different parts of the body (need target cells and receptors)
What does homeostasis involve?
Maintaining internal environment between limits, including blood pH, CO2 concentration, blood glucose concentration, body temp, and water balance
Where is insulin made and what is its function?
- Made in beta cells in the pancreas (“binsulin”)
- When blood glucose is too high, insulin stimulates other cells to absorb glucose for cell respiration
Where is glucagon made and what is its function?
- Made in alpha cells in the pancreas
- When blood glucose is too low, it stimulates breakdown of glycogen into glucose (in muscle and liver)
What is the function of thyroxin?
Regulate metabolic rate + control body temperature
What is the function of leptin?
Acts on hypothalamus of the brain to inhibit appetite
What is the function of melatonin?
- Encourages drowsiness in evening, and low levels in morning to wake
- Drops core temperature
- Released by hypothalamus to maintain daily rhythems
What is diabetes?
Malfunction in blood glucose control system
Describe cause, age onset, and treatment of type 1 diabetes
- Pancreatic cells are attacked by own immune system so beta cells don’t produce enough insulin (auto immune disorder)
- onset usually childhood
- treated by insulin shots (diet not enough)
Describe cause, age onset, and treatment of type 2 diabetes
- When target cells become insensitive to insulin (deficient in insulin receptors)
- onset generally after childhood (gradually)
- Low car diet + exercise can usually treat/control
What are dangers of not treating diabetes?
- high glucose levels can damage blood cells, nerves, and organs
- impairs water reabsorption in kidneys
List the parts of the male reproductive system and give 4 functions
- Testis: produce sperm and testosterone
- epididymis: store sperm until ejaculation
- sperm duct: transfer sperm during ejaculation
- seminal vesicle: secrete fluid containing alkali, proteins, and fructose, which is added to sperm to make semen alkaline
- other parts: penis, urethra, bladder, prostate gland, scrotum
List the parts of the female reproductive system and give 4 functions
- ovary: produces eggs, estrogen + progesterone
- uterus: provides for needs of embryo and fetus during pregnancy
- oviduct: collects eggs @ ovulation, provides for fertilization, the moves embryo to uterus
- cervix: protects fetus, dilates for birth canal
- others parts: opening duct, vagina
Outline the patterns of the 4 hormones involved in the menstrual cycle
- FSH: rises @ start of cycle, stimulating follicle development + estrogen secretion
- Estrogen: rises to peak by end of follicular phase, stimulates endometrium thickening and repair (high estrogen inhibits FSH and stimulates LH secretion)
- LH: sharp peak @ end of follicular, stimulates meiosis in oocyte and partial digestion of follicular wall (causes wall to become corpus luteum, stimulating estrogen + progesterone)
- Progesterone: rises @ start of luteal phase (after ovulation), promotes endometrium thickening and inhibits FSH and LH
What happens to hormones when implantation does not occur?
Progesterone + estrogen levels crash –> allows FSH to rise, and signal start of bleeding
Name the parts of a male gamete (sperm)
Arcosome (exterior), haploid nucleus, plasma membrane, helical mitochondria (for energy), microtubules and protein fibers (in tail)
Name the parts of a female gamete (egg)
Layer of follicle cells, cortical granules, first polar cell, plasma membrane, cytoplasm, two centrioles, haploid nuclei
List 3 roles of testosterone in males
- Cause male genetelia to develop in fetus
- Sperm production and development of secondary characteristics during puberty (beard, lower voice)
- Maintains sex drive, leading to intercourse and passing of genes in adulthood
Outline the processes involved with spermatogenesis in order
- germinal epithelial cells divide by mitosis producing diploid cells
- undergo growth to form primary spermatocytes
- these undergo meiosis I to form 2 primary spermatocytes
- Spermatocytes undergo meiosis II to make 2 spermatids (4 total)
- Spermatids associate with nurse cells (sertoli) and differentiate into spermatozoa
- they detach (all occurs in seminiferous tubules in testis)
Outline the processes involved in oogenesis
- germinal cells in female fetus undergo mitosis and grow to primary oocyte
- 1st stage of meiosis starts but stops during prophase I
- primary oocyte and surrounding epithelial form primary follicle
- meiosis I of primary cycles completed during menstruation: forms 2 haploid nuclei with unequal distribution of cytoplasm for form large secondary oocyte and polar body
- secondary oocyte starts meiosis II, stops during prophase II, follicle cell divides increasing fluid
- ovulation: follicle bursts releasing secondary oocyte (meiosis II completes after fertilization + another polar body made)
Compare and contrast spermatogenesis and oogenesis
Spermatogenesis: Starts in puberty and goes to old age, 4 sperms per meiosis, continuous (produces a lot), small cells
Oogenesis: Starts in fetal development and goes until menopause, 1 egg per meiosis, produces once a month (pausing a lot), pretty large cells
Both: begin with germinal epithelial cells, undergo mitosis, growth
Describe the process of fertilization
- Sperm attracted by chemical signal, then bind to zona pellucida.
- Triggers arcosome reaction: protease from arcosome digests holes in zona pellucida
- Fusion of plasma membrane of egg and sperm triggers cortical reaction
- Cortical reaction: cortical granules fuse w/membrane, releasing enzymes than cause glycoproteins to cross link in zona pellucida (making it impenetrable).
Outline early embryo development. to implantation of blastocyst
- In fallopian tube, 2-cell embryo divides until becoming blastocysts (hollow ball)
- Travels thru oviduct to uterus, and implants in uterine lining
- hCG secreted after implantation to keep corpus luteum secreting hormones.
What is the role of placenta?
- Produce estrogen + progesterone (n place of corpus luteum)
- Region of exchange between mother + fetus (O2, nutrients, water, hormones)
