CHAPTER 14: REPRODUCTION MALES 3 5 2 1 4 Structure Function 1. Testes Seminiferous Tubules Interstitial Cells Site of Spermatogenesis inside the seminiferous tubules & Testosterone production in the
interstitial cells 2. Epididymis Sperm finish maturing and become motile here. 3. Vas Deferens Sperm travel here from epididymis and during ejaculation 4. Ejaculatory Duct During ejaculation, the ejaculatory duct contracts and propels sperm along with secretions from the 3 accessory organs into the Urethra. This is now called semen. Seminal Vesicle Adds fructose secretions so mitochondria can produce ATP for flagellum to move sperm
Prostate Gland Secreted an alkaline fluid to protect sperm from acidity in urethra and vagina. Also provided prostaglandins to help uterus contract so sperm and travel up the female tract Bulborethral Gland Adds mucus for lubrication during intercourse 5. Urethra When penis is erect and during orgasm, the penis contracts to propel semen out of the penis and into the female . It is also a passage for urine Sperm Head = contains the 23 chromosomes which will provide the genetic
information to create a new human Acrosome = covers the head and contains powerful enzymes that can dissolve through the egg shell to penetrate Middle Piece = contains mitochondria that breaks down fructose in semen to produce ATP for flagellum movement Tail = a flagellum that helps the sperm to move towards the egg Hormones 1. Hypothalamus secretes GnRH which stimulates the anterior
pituitary 2a. LH is secreted from the anterior pituitary and stimulates the interstitial glands to produce testosterone 3a. Interstitial cells produce testosterone which helps with sperm production. It also exerts negative feedback on the hypothalamus to 2b. FSH is secreted from the anterior pituitary and stimulates the seminiferous tubules for Sertolli spermatogenesis 3b. cells in the
tubules takes up testosterone which helps nourish the sperm during spermatogenesis. At the same time, inhibin is secreted which exerts negative Effects of Testosterone During Puberty Causes initiation of sperm production = spermatogenesis Increased growth of the gonads (testes and penis) Increases hair grow (chest, axillary,
pubic) Larger larynx for deeper voice Broader shoulders Testosterone also contributes to aggressive behaviour FEMALES 21 3 4 5 Structure Function 1. Ovaries Follicles are stimulated by FSH to help the egg mature. Only ONE follicle and egg will mature; while at the same time secreted estrogen. After ovulation, the follicle becomes the corpus luteum which produces progesterone.
2. Oviducts (Fallopian Tubes) At ovulation when the egg is released, the Fimbriae sweep the egg into the oviducts. Cilia and smooth muscle contractions help move egg to the uterus. Fertilization would occur in the oviducts. 3. Uterus The lining of the uterus is called the endometrium ; which is made of vascular tissue. If egg is fertilized, then the embryo would attach to the endometrium lining. If no embryo, then the endometrium sheds at the end of the menstrual cycle. 4. Cervix Opening to the uterus. Usually plugged with mucus to protect uterus from bacteria. Becomes watery at ovulation to allow sperm to enter.
5. Vagina Organ of sexual intercourse. Penis enters and ejaculate can introduce sperm into female tract so fertilization can occur. Clitoris Contains erectile tissue and can facilitate an orgasm. Hormones Day 1-5: FSH stimulates follicle development and oogenesis. Estrogen production increases
Day 613: FSH decrease s due to negative feedback of estrogen Day 14: estrogen exerts positive feedback causing the LH surge which triggers ovulation Day 15-28: LH is higher and
helps to maintain the corpus luteum in the ovary; this increases production of progestero ne Day 28: Due to negative feedback of progestero ne, the LH levels decrease and the corpus luteum
degenerate s causing lower levels of progestero ne and estrogen Day 1-5: menstruati on due to the low hormone levels from end of previous cycle Day 6-14: as follicle grows there is an increase production of
estrogen which causes the endometrium to become Day 14-28: the corpus luteum secretes progesterone causing the endometrium to double/triple in thickness Effects of Estrogen During Puberty Menstrual cycle beings promoting
production of eggs (oocytes) = initiates oogenesis Promotes breast develop Increased hair axillary and pubic hair growth Promotes wider hips Increases fat deposition on body IMPLANTATION After ovulation, the egg only survives for 12-24 hours or it will disintegrate and be removed along the endometrium during menstruation. If it is fertilized inside the oviduct, then cell divisions begin as it continues to travel towards the uterus. When the embryo reaches the uterus
it can implant in the endometrium = this is called IMPLANTATION It releases the hormone HCG which signals to the ovary to maintain the corpus luteum The corpus luteum continues secreting progesterone and estrogen which helps to keep the endometrium intact and prevents menstruation along with exerting negative feedback on the hypothalamus and anterior pituitary to keep FSH low so no new follicles will develop. When the placenta develops, it Cilia in oviduct helps conduct egg or embryo to uterus Embr yo Implantation
of the embryo in the endometrium Fertilizati on of the egg occurs here Birthing = positive feedback of At the end of 9 months when the fetus has grown very large, it exerts a greater pressure on the cervix oxytocin This sends a signal in the form of action potentials to the hypothalamus
The hypothalamus produces oxytocin which is secreted out of the posterior pituitary Oxytocin causes uterine contractions which squeeze the fetus and causes it to push more on the cervix as it dilates. This continues to cause oxytocin to increases which causes increased uterine contractions until the baby and placenta is birthed. Oxytocin and milk letdown During breast feeding, the suckling of the nipple sends a signal to the hypothalamus to produce and secrete oxytocin which is secreted out of the posterior pituitary. Oxytocin causes the milk to letdown from the mammary
Function Organ of sexual intercourse Stores urine Secretes Fructose into semen Provides and alkaline fluid and prostaglandins to semen Site of sperm maturation and gain ability to swim Site of spermatogenesis and testosterone production Secretes mucus for lubrication during intercourse and into semen Common passage for semen and urine Stores sperm and transports it during ejaculation Contractions help add secretions to make semen enter urethra A B
C D Function Produces estrogen and progesterone along with oocyte Opening to uterus and normally plugged with mucus J Stores urine Contains erectile tissue and plays and important role in female orgasm Organ of sexual intercourse Houses fetus
Transports urine out of body Function B Follicle C A F E Oocyte D Estrogen Ovulation Corpus Luteum
Progesterone G B F C A D E Ovulation occurs at Day ______. ___________________ must occur within 12-24 hours after ovulation or the egg will disintegrate Fertilization occurs in the __________________ The embryo travel to the _____________ by movement of _________ and muscle contractions The embryo implants in the ________________________ and secretes the hormone __________ This hormone prevents the ____________ _____________ from degenerating so the hormone
levels remain high. Levels of __________________ and ___________________ remain high to keep endometrium intact and prevent _______________________ Process of Birthing 1 Fetus head exerts pressure on the _____________ 2 Impulse (______________) is sent to the _________________ 3 Oxytocin is produced and secreted out the ___________ __________
4 _______________ causes uterine contractions 5 Increases pressure of fetus on the ___________ 6 ________________ produces increased ______________ causing increased uterine contractions until fetus birthed
