Reproductive System PDF

What are ovaries Ovarian follicles contain oocyte What is an oocyte immature gamete, surrounded by supporting and hormone producing cells What are the uterine tubes and their 3 functions Receives oocyte after ovulation 1. Capture: Ampulla- distal portion provides site for fertilisation. Infund...

What are ovaries Ovarian follicles contain oocyte What is an oocyte immature gamete, surrounded by supporting and hormone producing cells What are the uterine tubes and their 3 functions Receives oocyte after ovulation 1. Capture: Ampulla- distal portion provides site for fertilisation. Infundibulum: Funnel shaped opening. Fimbriae: Fringe draped over the ovary have cilia that aid in capture of oocyte. 2. Transport via: Peristalsis of smooth muscle. Cilia. 3. Nourish: Non ciliated cells produce fructose rich secretions.. What is the uterus Receives, retains, nourished fertilised ovum Describe the uterine wall Perimetrium: Serous peritoneum. Myometrium: Smooth muscle. Endometrium: Mucosal lining. Functional layer: Cyclic changes in response to hormones causes the functional layer to shed monthly. Basal layer: Forms new functional layer after menstruation. Describe the blood supply to the uterus Spiral arteries feed the functional layer. Spasm in response to cyclic hormones leads to shedding. What is the vagina External passage, highly distensible. Adventitia – fibroelastic. Muscularis – smooth muscle. Mucosa – stratified epithelium contains APC, & acid secretions. Where in the urinary tract is skeletal muscle found? External sphincter What are mammary glands, what do they do, what is the structure and what hormones are related to them? Both male and females have mammary glands although they normally function in females to produce milk. Hormones: Oestrogen cause the mammary glands to enlarge during puberty. Progesterone stimulates milk production. Structure: Modified sweat/sebaceous glands consisting of 15-25 lobes that radiate around and open at the nipple. Lobes contain glandular alveoli that produce milk in lactating women Suspensory ligaments attach the breast to underlying muscle fascia.. Compound alveolar glands pass milk to lactiferous ducts, which open to the outside. Describe the phases of the ovarian cycle Follicular Phase (day 1-14) Gonadotropin releasing hormone (GnRH) causes the release of follicle stimulating hormone (FSH) and luteinizing hormone (LH). During this phase, the ovarian follicles mature and get ready to release an egg. The follicle that reaches maturity is called a tertiary, or Graafian, follicle, and it contains the ovum. Ovulation (day 14) Increase in (LH) causes the rupture of the Graafian follicle through the ovarian wall. The oocyte leaves the ruptured follicle and moves out into the peritoneal cavity through the stigma, where it is caught by the fimbriae at the end of the fallopian tube. After entering the fallopian tube, the oocyte is pushed along by cilia, beginning its journey toward the uterus Luteal Phase (day 14-28) If no pregnancy occurs the graafian follicle collapses becomes the corpus luteum. If a pregnancy does occur thecal and granulosa cells increase in size and secrete progesterone and some oestrogen to support the pregnancy. If the oocyte is not fertilised the corpus luteum deteriorates to the corpus albicans and hormones decrease. If the oocyte is fertilised the corpus luteum continues to produce progesterone for about three months. Describe the steps of the menstrual / uterine cycle Series of monthly cyclic changes to the lining (functional layer) of the uterine wall. Coordinated with the ovarian cycle gonadotropin release. Menstrual phase day 1-5: The discharge of the functional layer. This will only occur if no viable pregnancy occurs. Uterus sheds most of the endometrium. Proliferative stage day 6-14 (oestrogen): Rebuilding of the endometrium and new functional layer. Secretory stage day 15-28 (progesterone): The functional layer secretes nutrients to support the developing embryo. Cervical plug formed to prevent the entry of sperm. Premenstrual stage: No set time frame but all hormone levels fall. Not a stage but a familiar time in the cycle for many. Describe the hormones produced and used during the female menstrual cycle 1. Hypothalamus releases GnRH. 2. Anterior Pituitary releases FSH, LH. 3. FSH causes follicle growth causing oestrogen production to begin. 4. Initially, this results in inhibition of the hypothalamus. 5. Follicles continue to mature causing ongoing oestrogen production. 6. High oestrogen stimulates release of large amount of stored LH. 7. High LH stimulates oocyte to undergo first meiotic division and ovulation. 8. LH converts follicle to corpus luteum. 9. Corpus luteum produces and secretes progesterone and oestrogen. 10. Progesterone and oestrogen inhibit hypothalamus. 11. The corpus luteum (yellow body) continues to produce progesterone & oestrogen. If no pregnancy arises the corpus luteum becomes the corpus albicans (white body) progesterone and oestrogen are no longer produced and the cycle begins again. What is the ruptured follicle following the ejection of an oocyte from the ovary called? The corpus luteum Describe Oogenesis. An oocyte (egg) is produced in the ovary during female gametogenesis. The female germ cells produce a primordial germ cell, which then undergoes mitosis, forming oogonia. During oogenesis, the oogonia become primary oocytes. Each month a primary oocyte becomes part of the graafian follicle. Unlike the male sperm only one oocyte of the possible four is matured to an ovum (the rest are destroyed). This process consists of two meiotic divisions. What are the gonads Testes; produce sperm, secrete hormones and produce gametes What is the scrotum Skin covering. Houses the testes. Maintains sperm temp 3°C less than body temperature What is the Dartos muscle: Smooth muscle in the superficial fascia. Contracts causes wrinkles skin; decreases surface area causes the testes to be drawn toward the body for warming. Relaxation causes skin to be flaccid, increases surface area, causes the testes to move away from the body to lower temperature. What is the Cremaster muscle: Skeletal muscle. Contraction elevates scrotum to increases temperature. Relaxation causes the scrotum to descend decreases temperature (for optimum sperm health men should not wear tight underwear). What is the male delivery system / ducts describe it Epididymis; 6m long tube, Stores sperm for several months. Cells secrete nourishment (fructose). Smooth muscle contracts to expel sperm (ejaculation). Ductus (vas) deferens; 45cm long. From epididymis thru inguinal canal. Smooth muscle contracts to expel sperm. the Seminiferous tubules; Tubules produce sperm from spermatogenic cells. Interstitial cell surrounding the tubules produce testosterone Urethra; joint function in the male as an ejaculatory duct for sperm, and to transport urine What are the male Accessory Glands: 3 glands produce seminal fluid containing several components besides sperm. Proteolytic and other enzymes as well as fructose are elements of seminal fluid which promote the survival of spermatozoa and provide a medium through which they can move or "swim". The sperm and the seminal fluid are called semen. Seminal Vesicles; Joins the vas deferens to form ejaculatory ducts. Produces 60% semen. Alkaline fluid neutralises vaginal acid (sperm cannot "swim" in acidic fluid). Fructose nutrient is produced. Co-aglint enzymes - coagulates semen so it stays at cervix long enough for the sperm to swim thorough and into uterus. Prostaglandins - decreases the viscosity of cervical mucous. Stimulates reverse peristalsis of uterus to help the sperm into the uterus. Prostate; Encircles the base of the urethra. Produces 30% semen. Enzymes activate sperm. Citrate nutrient is produced to nourish the sperm. Fibrinolysin dissolves clotted semen (so sperm can swim out). Hyaluronidase is an aid in penetration of membrane of oocyte. Closes the urethra during ejaculation Bulbourethral gland; Alkaline mucous neutralises urine acidity prior to ejaculation. Describe the process of erection and ejaculation The corpus cavernosa found on either side of urethra fills with blood causing an erection it also contains smooth muscle which is contracted to cause ejaculation. Parasympathetic stimulation causes: o Releases nitrous oxide causing vasodilation filling the corpus cavernosa with blood and causing an erection. o The bulbourethral gland secretes lubricating mucus. Sympathetic stimulation causes spinal reflex: o Ducts contract causing ejaculation. o Bladder sphincters contract (preventing any leakage of urine). o Penile muscles contract aiding ejaculation. What is testosterone and what actions does it have primary male sex hormone and an anabolic steroid. In men, testosterone plays a key role in the development of male reproductive tissues such as the testis and prostate. Steroid hormone, made from cholesterol. Acts by - protein synthesis in target cells. 1. Spermatogenesis (the production of sperm). 2. Formation and maintenance of male genitalia/reproductive tissues such as the testis and prostate 3. At puberty bone, muscle, and larynx growth. 4. Androgenic actions include haemopoiesis and setting the basal metabolic rate. 5.- Promoting secondary sex characteristics such as increased muscle and bone mass, and the growth of body hair. What is Spermatogenesis the process in which spermatozoa are produced from spermatogonia stem cells by way of mitosis and meiosis. the development of the spermatids into a functioning sperm. What Factors Inhibiting chance of fertilisation: Life span: 24–72hrs. Destruction by the vaginal acid mantle. Passage blocked by cervical mucus. Uterine phagocytes. What Factors enhancing fertilisation: The physical design of sperm (tail enhances motility). A high number of mitochondria in the midsection (high energy users). High glucose content in seminal fluid (energy boost). Prostatic fluid high pH protects sperm from the acid environment of the vagina. What are the Requirements for successful fertilisation Capitation: the membrane of the head becomes fragile as cholesterol-depleted Acrosomal Reaction: release hyaluronidase and proteases to break down oocyte membrane Fusion: protein binders aid in binding with oocyte membrane, enhancing fusion, aiding insertion. Why are human eggs and sperm similar? They have the same number of chromosomes.