Bio 101, Unit 4 body sytems

Homeostasis

The process by which living organisms regulate internal conditions, such as temperature and pH, to maintain a stable, constant state despite external changes.

homeostatic mechanisms

mechanisms that keep internal conditions “steady” even with large changes in the environment. One example of this is the sleep cycle.

Germ cell

cells that go on to become gonads aka testes and ovaries

Oogenesis

The process by which eggs are developed, at the end of both rounds of meiosis, one egg is developed, and 3 polar bodies are left. This process occurs during development. Haploid gametes are formed.

spermatogenesis

,Creation of sperm via both rounds of meiosis, at the end 4 sperm cells are created. This process begins during puberty. Haploid gametes are formed

Steps in the menstrual cycle

Ovary → growing follicle → mature follicle → egg is released → hormones are released → secondary oocyte

primary oocyte

gamete cell, what’s hanging out in the ovaries

preovulation

Hypothalamus secretes releasing hormones to cause the release of pituitary hormones. The pituitary releases low levels of Lutenizing hormone (LH) and follicle-stimulating hormone (FSH)

ovulation

In response to LH and FSH. The follicle (ovary) cells make more and more estrogen. A peak of estrogen causes a burst of LH (and an increase in FSH) → release of secondary oocyte.

Post ovulation

ruptured follicle (corpus luteum) produces estrogen and progesterone which leads to the thickening of the uterus wall in preparation for fertilization.

semen

-200-500 million sperm per ejaculation, takes about 2-7 weeks to make a sperm

3 glands that produce secretions in semen

prostate gland, seminal vesicle, bulbourethral gland,

produces fructose(help produce ATP for movement), alkaline substances(neutralization in the vagina) and mucus (lubrication)

symptoms of an enlarged prostate

frequent urination,

path for sperm to exit the body

testis→ epididymis(matured sperm storage)→ vas deferens (where vasectamys are preformed) → ejaculatory duct → urethra → out

path of the sperm after it enters the vagina

cervix → uterus → oviduct (fallopian tube, this is where it meets the egg)