Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
72 Cards in this Set
- Front
- Back
|
Define sexual reproduction |
Production of offspring the meiosis, gametes, and fertilization |
|
|
Define gametes |
Reproductive cells, a.k.a. germ cells, ova or sperm |
|
|
Define fertilization |
Union of sperm and ovum |
|
|
What are the three purposes of the reproductive system? |
1. Produce gametes 2. Enable the union of gametes 3. House/nourish developing offspring, female |
|
|
What are primary sex organs? |
Organs that produce gametes, testes or ovaries |
|
|
What are secondary sex organs? |
- is sensual for reproduction, but do not make gametes - Male: ducts, glands, and penis (to deliver the sperm cells) - female: uterine tubes, uterus, and vagina (transport the egg, receive the sperm, and nourish the developing fetus) |
|
|
What are secondary sex characteristics? |
- external features that distinguish men and women - not directly involved in reproduction - features that develop at puberty: pubic, axillary, and facial hair, scent glands, body morphology and low pitched voice and males |
|
|
What is the default human body plan? |
Female development occurs in the absence of male or female hormones |
|
|
What two sets of ducts exist before before the sex of the fetus is determined? |
- Mesonephric ducts, wolffian ducts: develop into male reproductive system - Paramesonephric duct, Müllerian ducts: develop into female reproductive tract |
|
|
When do gonads begin to develop? |
- they begin to develop at six weeks as gonadal bridges, near the primitive kidneys |
|
|
What does the SRY gene do? |
- sex determining region of y gene - in males, codes for a protein (testis determining factor) that causes development of testes - testes secrete testosterone that directs development of male characteristics, secretes Müllerian-inhibiting factor that degenerates the paramesonephric ducts |
|
|
What are androgens? |
Male hormones that cause masculinization |
|
|
What is androgen insensitivity syndrome? |
- XY chromosomes - testes are present and secrete testosterone - Target cells lack receptors for the hormone - no masculinizing effects occur - no ovaries, uterus, or vagina |
|
|
Describe the descent of the testes? |
- begin development near the kidney - The gubernaculum (cord like structure containing muscle) extends from the gonad to the abdominopelvic floor - it shortens and guides the testes to the scrotum, passes through the abdominal wall via the inguinal canal, accompanied by testicular nerve, artery, and they name |
|
|
When does that descent of the testes take place? |
Descent begins in 6 to 10 weeks and is finished by about 28 weeks |
|
|
What is cryptochidism? |
3% of boys are born with undescended testes |
|
|
Why is it essential that the testes drop? |
Location outside the pelvic cavity is essential for low temperatures needed for sperm production |
|
|
Describe the testes |
- oval organs, 4 cm long by 2.5 cm in diameter - located in scrotum: muscular pouch outside body, spermatogenesis cannot occur at normal body temperatures, needs about 2°C cooler - muscles in scrotum contract relax to maintain temperature, closer or further from body core, also countercurrent exchange - surrounded by tunica albuginea |
|
|
What are the two primary functions of the testes? |
Produce sperm in secrete testosterone (plus estrogen and inhibin) |
|
|
What do seminiferous tubules do? |
Drain into network called rete testis, lead to epididymis |
|
|
Describe the spermatic cord |
The spermatic cord travels up from the scrotum to pass through the abdominal wall, inguinal canal - contains testicular artery, then, nerves, lymphatics, ducts (vas deferens) - Pampiniform Plexus = veins ascending near testicular artery, countercurrent heat exchange cools arterial blood entering testis |
|
|
Describe testosterone |
- steroid hormone: male sex hormone (androgen) - produced in testes by Leydig cells: A.k.a. interstitial cells - Basic functions: masculinizes fetus before birth, promotes sexual maturation at puberty, induces secondary sex characteristics, and is essential for spermatogenesis - stimulates erythropoiesis and libido, during adulthood sustains libido, spermatogenesis, and reproductive tract |
|
|
What are the three parts of the spermatozoa? |
1. Head: contains DNA and acrosome (enzyme cap) 2. midpiece: lots of mitochondria, produces ATP 3. Tail: whip like flagellum, provides motility |
|
|
What are five functions of Sertoli cells? |
1. Blood-testes barriers: tight junctions = selective transport, provide nourishment in protection to developing sperm 2. Phagocytose spermatic cytoplasm during remodeling: also phagocytose damaged cells 3. Secretes fluid that contains androgen-binding proteins: fluid washes sperm into tract system, and binds testosterone and keeps testosterone levels high in lumen of seminiferous vesicles 4. Have receptors for FSH (follicle stimulating hormone): site of FSH control of spermatogenesis 5. secretes inhibin: hormone that provides negative feedback for FSH levels |
|
|
Why is androgen binding protein necessary to keep testosterone levels high? |
Testosterone is hydrophobic and would just die fuse away |
|
|
How is LH (Leutenizing hormone) controlled and what does it do? |
- acts on Leydig cells - increased LH equals increased testosterone - controlled by the anterior pituitary where LH secreting cells reside |
|
|
How is FSH controlled and what does it do? |
- acts on Sertoli cells - increased FSH = increased spermatogenesis, increased FSH = increased spermiogenesis - FSH secreting cells are located in the anterior pituitary |
|
|
What does gonadotropin releasing hormone do? |
- acts on the anterior pituitary to secrete FSH and LH - it is released by the hypothalamus |
|
|
What do you male accessory sex glands do? |
Provide the majority of seminal fluid, semen is a mix of fluids, sperm, clotting factors, and mucus |
|
|
What do you male accessory sex glands do? |
Provide the majority of seminal fluid, semen is a mix of fluids, sperm, clotting factors, and mucus |
|
|
What do the seminal vesicles do? |
- supply fructose (energy for motility) - secrete prostaglandins: stimulate smooth muscle contraction of male and female reproductive tract (paracrine secretion that helps move sperm toward over them) - secrete fluid, constitutes about half of semen |
|
|
What does the prostate gland do? |
- secretes alkaline fluid: neutralizes acidic vaginal secretions, keep sperm alive longer - secretes clotting enzymes: Keeps sperm in the female reproductive tract |
|
|
What do bulbourethral glands do? |
Neutralize acidic urine residue |
|
|
What are the three columns of erectile tissue in the penis? |
- two columns of corpora cavernosa - one column of corpus spongiosum |
|
|
How does an erection occur? |
- arterioles relaxed - blood fills erectile tissue - vasocongestion, expansion constricts veins |
|
|
Discuss aging and sexual function in males. |
- testosterone secretions slowly declined after age 20 - rise in FSH and LH secretion after age 50 produces mail climacteric which can have a variety of symptoms: mood changes, hot flashes, illusions of suffocation - impotence, erectile dysfunction increases with age |
|
|
What are the five purposes of the female reproductive system? |
1. Receive sperm-vagina 2. Produce mature ovum (egg) - ovaries 3. Transfer egg from ovary to uterus-fallopian tubes 4. Prepare uterus for pregnancy 5. Maintain and accommodate fetus until birth-uterus |
|
|
What are the major regions of the fallopian tubes? |
- near uterus forms a narrow isthmus - middle portion = ampulla - flared distally into infundibibulum with fimbriae (funnel) |
|
|
Describe what happens in the fallopian tubes |
- one ovum released each menstrual cycle from ovary, alternate sides - ovum is swept into fallopian tube, infundibibulum with fimbriae - ampulla is the common site for fertilization - move ovum toward uterus, ciliated epithelium in tube |
|
|
What are the three layers of the uterus? |
1. Perimetrium - external serosa layer 2. Myometrium - thick wall of smooth muscle 3. Endometrium - lining of uterus, sickness determined by progesterone/estrogen |
|
|
Define puberty in females |
- begins at age 9 or 10 for most girls in the United States - triggered by rising levels of Gonadotropin releasing hormone which stimulate anterior lobe of the two Terry to produce FSH and LH - SSH stimulates follicles to secrete estrogen and progesterone, second sex organs maturation, increase in height and width of pelvis, prepares uterus for pregnancy |
|
|
Define menarche |
First menstrual period that occurs at around age 12, it requires at least 17% body fat in teenager and 22% in adult |
|
|
What is the sexual cycle? |
- events recurring every month when pregnancy does not occur - describe based on ovarian changes and/or uterine changes, averages 28 days but can range from 20 to 45 days |
|
|
What are the two ways to describe the sexual cycle? |
- ovarian cycle: focused on events in the ovaries - menstrual cycle: focused on changes in the uterus |
|
|
What for hormones cause changes in the sexual cycle? |
Gonadotropic hormones: 1. LH 2. FSH Gonadal hormones: 3. Estrogen 4. Progesterone |
|
|
What are the two phases of the ovarian cycle? |
1. Follicular phase 2. Luteal phase |
|
|
What are the two phases of the ovarian cycle? |
1. Follicular phase 2. Luteal phase |
|
|
Describe what occurs during the follicular phase. |
- an increase in FSH from the anterior pituitary - proliferation of granulosa cells = follicular cells, secrete estrogen - creates zona pellucida: gel-like material that separates ovum from granulosa cell |
|
|
Describe what occurs during ovulation |
- mature follicle takes about 14 days to mature and consists mostly of the antrum (a fluid filled space) - A mature follicle produces large amounts of estrogen which causes LH to search from the anterior pituitary - The large amounts of estrogen produce inhibin which depresses FSH levels - The follicle ruptures in response to a surgeon and LH, a follicular enzymes digest the follicular wall - The oval is taken up into the Fallopian tube where it is surrounded by corona radiation - LH causes ovulation and transition to the corpus luteum |
|
|
What occurs during the luteal phase? |
- corpus luteum is present - leutenization: Old follicular cells hyper trophy (involution), follicular cells converted into steroidogenic cells, secrete progesterone and estrogen - prepares uterus for implantation: if no implementation of fertilized ovum, corpus luteum degenerates in about 14 days |
|
|
What hormones control the ovarian cycle in early/middle for follicular stage? |
- follicle secretes though (but increasing) levels of estrogen - increasing levels of estrogen inhibits FSH release, this prevents too many follicles from maturing and has no effect on LH - LH levels increase very slightly |
|
|
What hormones control the ovarian cycle in the late follicular stage. |
- follicle is secreting estrogen and inhibin - very high levels of estrogen induces gonadotropin releasing hormone and LH surge - The LH surge causes a positive feedback loop and induces ovulation and leutenization - inhibin secretion keeps FSH levels from rising too much and prevents maturation of new follicles |
|
|
What hormones control the ovarian cycle in the luteal stage? |
- corpus luteum secretes estrogen and progesterone and secretes more and more as it develops - hi levels of estrogen tries to induce gonadotropin releasing hormone and LH release - high levels of progesterone inhibit LH release, prevents another LH surge - loss of LH causes corpus luteum to shrink and die and estrogen and progesterone levels fall |
|
|
Describe the uterine cycle |
Fluctuations in estrogen and progesterone affect the endometrium, the in her urine layer that contains blood vessels and glands |
|
|
Describe the uterine cycle |
Fluctuations in estrogen and progesterone affect the endometrium, the in her urine layer that contains blood vessels and glands |
|
|
What are the three phases of the uterine cycle? |
1. Proliferation phase 2. Secretory phase 3. Menstrual phase |
|
|
Describe what occurs during the proliferation phase of the uterine cycle |
- endometrium grows (proliferates the mitosis), under influence of estrogen begins preparations for implantation - grows 3 to 5 mm thick - ends at ovulation |
|
|
Describe what occurs during the secretory phase of the uterine cycle |
- induced by progesterone from corpus luteum - endometrium swells, inserts glandular tissue (secretes glycogen), continued estrogen keeps endometrium think - now I'm capable of supporting an embryo |
|
|
Describe what occurs during the menstrual phase of the uterine cycle |
- if no embryo and plants, endometrium sloughs off, this marks the beginning of the monthly cycle - menstruation induced by loss of estrogen and progesterone, caused by degeneration of corpus luteum - A decrease of estrogen/progesterone causes an increase of prostaglandin that causes vasoconstriction, the endometrium loses blood supply and the same prostaglandin causes uterine contractions to help expel the endometrial debris |
|
|
What occurs during menopause? |
- cessation of menstrual cycle, a decrease in estrogen levels - cause by lack of receptors, consequence equals little estrogen |
|
|
Describe gestation (pregnancy) |
- When is an average of 266 days from conception to childbirth or 38 weeks - just stational calendar can be measured from first day of the woman's last menstrual period or from ovulation/conception |
|
|
Describe sperm transportation |
- more than 100 million sperm in ejaculate, most die in acidic environment of vagina, sperm swim 1 to 4 mm/h and can live for 2 to 4 days in the female reproductive system - must travel through cervical canal, uterus, most of oviduct to reach ovum - cervical canal blocked by mucous plug, impenetrable to sperm except for 2 to 3 days around ovulation, an increase in estrogen changes mucus to allow sperm to pass |
|
|
Describe sperm transportation in the uterus |
Muscular contractions disperse sperm this is induced by an increase of estrogen and seminal prostaglandins |
|
|
Describe sperm transportation in the uterus |
Muscular contractions disperse sperm this is induced by an increase of estrogen and seminal prostaglandins |
|
|
Describe sperm transportation in the oviduct |
- cilia in oviduct beat toward uterus in order to move ovum toward uterus - anti-peristaltic movements, smooth muscle contractions push sperm upstream this is induced by an increase of estrogen and seminal prostaglandin |
|
|
Describe egg and sperm interaction |
- egg releases allurin: A chemical signal from the egg that attracts sperm - many sperm required to break down and eggs defenses (acrosome reaction) - only a few thousand sperm reach ovum, although only .001% of ejaculated sperm reach egg (10,000 left) |
|
|
Describe fertilization |
- Union of male and female gametes, often occurs in the ampulla, sperm binds to specific receptors on zona pellucida (fertilin/sperm and integrin/egg) ensures only same species produce offspring - Acrosomal reaction: enzymes on sperm tunnel through corona radiata/zona pellucida, - - when the sperm penetrates the ovum the ovum changes to prevent another sperm from also penetrating and prevents polyspermy |
|
|
What are the five stages of embryonic development? |
1. Zygote-fertilized egg 2. Morula 3. Blastocyst-less than two weeks old, hollow ball, becomes fetus, and implants in uterus 4. Embryo-composed of three germ layers from 3 to 8 weeks old 5. Fetus-nine weeks to birth |
|
|
What are the five stages of embryonic development? |
1. Zygote-fertilized egg 2. Morula 3. Blastocyst-less than two weeks old, hollow ball, becomes fetus, and implants in uterus 4. Embryo-composed of three germ layers from 3 to 8 weeks old 5. Fetus-nine weeks to birth |
|
|
What is polyspermy? |
- Several sperm fertilize an egg, which cannot survive - fertilized egg prevents polyspermy by quickly blocking additional sperm from penetrating |
|
|
What are the three germ layers of the embryo? |
1. Endoderm: inner layer, GI tract lining 2. Mesoderm: middle layer, becomes muscle, bone, and circulatory tissue 3. Ectoderm: outer layer, forms first, and becomes the nervous system and the skin |
|
|
What is the amniotic sac? |
- fluid filled protective sack - surrounds fetus - filled with amniotic fluid, feel urine and excretions, practice for in preparation for eating digesting and defecating |
