Notes for 22, 24, 29 March
Notes for 22, 24, 29 March BIO 151
Popular in Human Biology
verified elite notetaker
Popular in Biology
This 11 page Class Notes was uploaded by Chelsea Notetaker on Saturday April 2, 2016. The Class Notes belongs to BIO 151 at Central Michigan University taught by Professor Learman in Winter 2016. Since its upload, it has received 16 views. For similar materials see Human Biology in Biology at Central Michigan University.
Reviews for Notes for 22, 24, 29 March
Report this Material
What is Karma?
Karma is the currency of StudySoup.
You can buy or earn more Karma at anytime and redeem it for class notes, study guides, flashcards, and more!
Date Created: 04/02/16
22 March >Stem cells have a significant potential for use in medicine -some are more versatile than others -there are four different levels of stem cells based on their ability to specialize >Zygote – the first cell that forms in human development: totipotent >Pluripotent: embryonic stem cell -can become all embryonic cell types (not the placenta, outside-the-body cells, etc) >Multipotent – restricted to one type of tissue, an adult cell, tissue-specific >Unipotent/Differentiated/Specialized – usually not a stem cell, doesn’t divide into different cell types >Totipotent – can develop into any type of cell (blastocyst, includes placenta, amniotic sac) >Pluripotent – contributes to physical body cells >Multipotent – found in grown organisms – differentiate into many different cells within a type of tissue >Unipotent – terminally differentiated – no longer a stem cell >Adult stem cells – exist in many tissues: brain, bone marrow, skin, liver, other organs; are both uni- and multipotent >Umbilical cord stem cells – collected from umbilical cord blood at birth; multipotent >Embryonic stem cells – can be harvested from the inner cell mass of a blastocyst; pluripotent >The therapeutic use of stem cells has the potential to improve the quality of human life: replace damaged cells, grow new organs/limbs >Somatic Cell Nuclear Transplant – procedure by which the nucleus from a somatic body cell is transferred to an egg from which the nucleus has been removed. -new cell is then stimulated to begin embryonic development. New cells of all different types could develop. This is a form of cloning. Both therapeutic and reproductive cloning potential. >Reproductive cloning – created embryo is implanted in a surrogate mother for the clone to develop (grows beings) >Therapeutic cloning – inner cell mass cells from embryo blastocyst are harvested and grown in a culture (for part-growing) -poses no risk of immune system rejection -can also be used to introduce healthy genes (gene therapy) Activity Who would a cloned sheep look like? The surrogate mother sheek, the donor of a mammary cell whose nucleus was used, or the donor of an egg cell without a nucleus? A) The donor of the mammary cell with the nucleus An embryonic stem cell is: A– totipotent B – pluripotent C – multipotent D – unipotent (B) An adult stem cell is: A– totipotent B – pluripotent C – multipotent D – differentiated (Either C or D depending on the cell.) Multipotent means: A– can become all cell types B – can become all embryonic cell types C – can become many, but not all, cell types D – can become one cell type only (C) Cells that are terminally differentiated: A– will undergo apoptosis within a few days B – will no longer differentiate C – are unable to move D – no longer produce protein (B) >Mouse embryonic stem cells: A– can only be produced through therapeutic cloning B – can become all tissues and cell types in the body except gamete cells C – can be implanted in foster mothers to produce cloned cows and other animals D – are normally found only in early embryos (blastocysts) (D) 24 March >The testes are the male reproductive organ -held outside the body in the scrotum for temperature regulation -produce testosterone as well as sperm (called spermogenesis) >Sperm is produced in the tubes within the testes (seminiferous tubules) -immature sperm travel through the tubes to the epididymis where they mature and are stored for use. >Head of the sperm contains chromosomes from the father—it’s covered by an enzyme-filled sack, helps it penetrate the egg >Midpiece contains mitochondria that will provide ATP for swimming >Tail is for propulsion; flagella and cytoskeleton >Ejaculation – sperm leave the testes through the vas deferens, through several accessory glands, and leaves through the urethra >Semen-fluid is composed of 5% sperm and 95% secretions from accessory glands – helps kickstart the swimming and keeps sperm alive in female reproductive environment -also picks up fructose; semen is basic and female reproductive system is acidic; prostaglandins which stimulate uterine contractions to aid in sperm movement >Penis – delivers sperm; filled mostly with spongy tissue that fills with blood during an erection -the enlarged tip contains many sensory nerves important for arousal Disorders/Diseases/Problems >Testicular cancer – 96% survival rate; average diagnosis age 33; affects < .5% of men >Prostate cancer – 86% survival rate; average age of diagnosis 66; second most common cancer in men; affects ~15% of men; metastasizes to bone >Erectile dysfunction – can be caused by stress, depression, nerve damage, alcohol, smoking, etc; affects ~ 25% of men Lady Parts >Ovaries – oogenesis (production of eggs), as well as estrogen and progesterone -one germ cell creates four follicles: one egg and three ‘support cells’ >Meiosis began during female embryonic development -at about eight weeks she has ~2 million potential eggs (follicles) – paused eggs -she’ll have 1 million at birth -she’ll have 4000,000 by puberty >At puberty meiosis restarts, one egg finishing per cycle (takes 10-14 days) -mature eggs (secondary oocytes) pause at meiosis two and are released into the fallopian tube – meiosis two only finishes after fertilization -can only be fertilized 12-24 hours after ovulation -only about 400 eggs are released over a lifetime >Endometrium – lining of the uterus – prepared monthly for potential implantation (lining gets softer and thicker); blood vessels fill with nutrients -if no fertilization occurs, egg degrades, endometrium dies, and is diffused during menstruation >200-600 million sperm per ejaculate -~1% reach the uterus; ~200 reach fallopian tubes -can survive 208 days in female environment Fertilization 1: Sperm touches egg, enzymes to dissolve exterior of egg are released 2: enzymes digest a pathway through the layers; requires many sperm 3: one sperm touches the inner plasma membrane and fuses with it 4: sperm nucleus enters egg 5: instantly the exterior of the egg hardens and becomes impassable to other sperm 6: sperm and egg nuclei fuse to form a zygote >Uterus receives and nourishes the developing baby during pregnancy >Cervix forms the end of the uterus that extends into the vagina >Vagina receives penis for fertilization then serves as the birth canal >Birth dates place ~ 38 weeks after fertilization -baby’s face needs to be toward the spine, head down, pushing on the cervix >Asignal stimulates mother’s body to begin positive feedback loops (oxytocin hormone) that result in uterus contractions 1: Dilation phase: cervix opens, starts with contractions and ends at dilation (10cm/~4 inches) 2: Expulsion: full dilation to delivery through cervix and vagina (push, honey, push) 3: Placental: after delivery to expulsion of placenta (the body can’t break it down) >Menopause – ovulation and menstruation stops (~51 years) -Age 20 is peak for fertilization, followed by a gradual decrease – body is less responsive to hormones and ovaries stop producing eggs Disorders/Diseases/Problems >Ovarian cancer – 36% survival rate -causes more deaths than any other female reproductive system-related cancer >Cervical cancer – 68% survival rate -rate has been declining in recent years >Premenstrual Syndrome (PMS) >Menstrual cramps -caused by high levels of prostaglandins produced by endometrial cells (to expel them) >Endometriosis -tissue from lining of the uterus is found outside uterine cavity (fallopian tubes – ectopic pregnancy) >Contraception -failure/success rates depend on perfect use -average pregnancy rate without contraception is 85% >Sterilization – seals the tubes that transport gamete cells -vasectomy – Failure Rate < 1% -tubal ligation – fallopian tubes severed; FR < 1% Hormonals – synthetic hormones to prevent implantation or maturation/release of the egg >Injection – FR <1-6% >Oral – hormone component varies; FR <1-9% >Patch/Ring – FR 4-9% -all have risk of blood clots with nicotine users >Intrauterine device – disrupts the normal uterine environment to prevent motility of sperm or implantation of egg; FR <1% -can have severe side effects if the wires move: ectopic pregnancy, embedded wires – recommended only for women who have already had a child (uterus is bigger than that of someone who hasn’t yet had a child) Barriers – prevent the travel of sperm >Diaphragm – FR 6-12% >Cervical cap – FR 9-14% >Sponge – FR 9-12% >Male condom – FR 2-18% >Female condom – FR 5-21% > Spermicides – FR 18-28% >Fertility Awareness – avoidance of intercourse when fertilization is likely to occur – FR 3-24% Emergency contraception – high doses of hormones taken after unprotected intercourse >Morning After Pill – FR 15% (when taken within 72 hours) – won’t impact an implanted egg >15% of US couples have infertility (the inability to conceive for 6-12 months after trying to) -causes in women: hormone abnormality, endometriosis, ovulation, blocked fallopian tubes, blocked/damaged/absent ovaries, stress/weight/nutrition/environmental factors -causes in men: low sperm count, no sperm, low sperm motility, erectile dysfunction, unknown -other factors: smoking, personal habits, chemicals, radiation, age, health Assisted Reproductive Technology >Hormone therapy – correct imbalanced hormones in affected individual; can stimulate/facilitate gamete production; alter female reproductive environment >Donation of gametes: eggs and sperm – egg donation is much harder (involves lots of hormone treatment, surgery and immediate use of the eggs) >Artificial insemination – sperm is placed directly into the uterus at ovulation – sperm don’t need to swim as far and aren’t exposed to female environment as long >In vitro fertilization – a sperm and egg are incubated outside the body, then zygotes/blastocysts are transferred to the uterus (still requires successful implantation to bring pregnancy) >Surrogacy – a third party carries the pregnancy throughout term (can also be the egg donor, or donated egg and sperm can be implanted [gestational]) Problems with these^ >Hormones can cause hyperovulation, which can lead to lots of extra babies in there at once >Increased risk of multiple, premature, underweight births >Raises the question of what to do with unused embryos? >Is expensive and there’s no guarantee of success STDs/STIs >Sexually transmitted infections/diseases/venereal diseases -requires direct mucosal (mucus membranes) contact with infected individual -promiscuity-linked, the having of multiple partners -are largely asymptomatic (especially with women) -BUT affect women more severely than men -after having an infection once you CAN be reinfected -having one can predispose you to be more vulnerable to others -they’re extremely common -can have long-term effects -the longer it’s left untreated, the more damage it’ll cause (infertility, etc) >Bacterial ones can be treated with antibacterials, but virals cannot be >1/2 of sexually active adults acquire one before age 25 >22 million new infections a year >No cures for the viral infections >20% of US population is infected with incurable STIs >50-75% are asymptomatic Prevention >Abstinence, monogamy, latex condoms >Regular screening – women suggested to check every 6 months >Common long-term effects are more severe in women: sterility, pain, disease, ectopic pregnancy, etc st -1 infection – 25% chance of infertility -2 infection – 50% chance of infertility rd -3 infection – ~100% chance of infertility >Human Papilloma Viruses (HPVs) -transmitted through sexual contact, and through fomites (non-body parts/things, and not just toys [doorknobs, for example; think of how the flu can be shared]), birth -virus replicates epithelial cells of mucus membrane and can integrate into host cell chromosomes >>incubation before symptoms show can be 1 month to years >>can lead to cancer -can cause genital warts, which can be small/large and flat/raised -long-term – types 16 and 18 are associated with cervical cancer -most common STI in the US -no cure – cells with the virus have to be killed (lasers, surgery, chemicals) -vaccines are >90% effective in men and women
Are you sure you want to buy this material for
You're already Subscribed!
Looks like you've already subscribed to StudySoup, you won't need to purchase another subscription to get this material. To access this material simply click 'View Full Document'