Download Internal fertilization

Internal fertilization
 Increased chance of fertilization
 Increased chance of survival of gametes
Male Reproductive System
Scrotum
 Contains testis
 Regulates temperature of testis for optimal sperm
development (95oF)
Testis
 Produce sperm which mature in the… Epididymis
 Produce testosterone
Semen
Composed of sperm cells and nutrient rich fluid from
 Seminal vesicles
 Prostate gland
 Bulbourethral gland
Penis
 Transfers sperm through the urethra to the vagina
Female Reproductive System
Ovaries
 Produce eggs (ovum)
 Produce hormones that regulate uterine lining
 Estrogen and Progesterone
Fallopian tubes
 Transport egg to uterus
Vagina
 Receptacle for sperm
Uterus
 Holds developing embryo
Cervix
 Ring of muscles at the entrance of the uterus
Menstral cycle (right)
1. Bring and egg to maturity
2. Prepare uterus for implantation
3. Controlled by hormones
- Hormones secreted by the pituitary gland control
ovarian activity
FSH (follicle stimulating hormone)
 Starts an egg maturing in follicle
LH (luteinizing hormone)
 Causes ovulation
- Hormones secreted by ovaries control uterine lining
Estrogen – initiates build up of uterine wall
Progesterone – maintains lining until implantation
Menstration – sloughing of the uterine lining when
pregnancy does not occur
Fertilization
 Combining of egg and sperm in the fallopian tube
 Sperm swims to the egg and then digests its way
through the egg’s cell membrane

Best chance of this happening is within 12 hours of
ovulation
Embryonic Development
1st trimester = cell organization into vital organs
egg + sperm = fertilization -> zygote
3 days = in uterus
5-8 days = implantation
50 – 60 cells -> blastocyst
8 weeks -> fetus
2nd trimester = organs and body features become more
refined
3rd trimester = growth in body size
Mother / child bond
Placenta
 structure made of uterine and extraembryonic tissues
 carries nutrients to and waste from embryo
 afterbirth
Major STD’s
Bacterial (treatable)
 Syphilis
Chancre – site of infection and indication of
infection
Untreated can cause serious damage to central
nervous system and circulatory organs
 Gonorrhea
Painful urination, puss discharge from penis or
vagina
Infertility, infections of eyes, and digestive tract
 Chlamydia
Most common in U.S.
Symptoms similar to gonorrhea
Lead to infertility
Viral
 Hepatitis B
Liver damage including cancer
Vaccination available
 Genital Herpes
Recurring blisters and sores on genitals
Never completely destroyed
 HPV (papilloma)
Causes genital warts, possibly cancers of cervix,
vagina, vulva, penis
No cure
HIV - Human immunodeficiency virus
retrovirus - codes for an enzyme that transcribes viral
RNA into the host's DNA.
Targets the macrophages, T - cells, and to a lesser
extent the B - cells and some brain cells.
T-cells:
- not as responsive to recognized antigens
- decrease production of chemical messengers
that direct other lymphocytes
- causes cells to clump together and die
B-cells:
- produce fewer specific antibodies
- lose responsiveness to ordinary signals
macrophages:
- will engulf the virus, but will not break it down for
identification for antibody production
- transports it secretly around the body, secreting
HIV chemicals that are harmful to other cells.
Incubation Period
Latency period may last for years and perhaps for life.
- The virus may be passed on while it is latent.
- Person may be most infectious several months
just prior to symptom development.
Once activated:
Transactivation gene adjusts production of new
viruses (20 times faster than flu virus)
Rapid reproduction overpowers the body's
defense system.
HIV mutates quickly. (100 - 1000 times faster than the flu
virus)
** to have a vaccine there must be one specific
target **
HIV-specific antibodies apparently have no impact on HIV
HIV Disease, Stage Four: AIDS
A – Acquired I – Immune D – Deficiency S - Syndrome
Categories of illnesses that characterize AIDS
1. Wasting Syndrome
A. rapid, unexplained weight loss of ten percent or
more of body weight
B. Persistent fever of 100 degrees or more for at least
30 days
C. Chronic unexplained diarrhea
* May be directly related to the HIV in that recent
research suggests that HIV attacks lower intestinal
cells.
2. AIDS Dementia
- Caused by HIV secretions from the macrophages or
direct attack of brain cells
A. Memory loss, forgetfulness, and confusion
B. Changes in gait or coordination, blurring of
vision/hearing, slurring speech
C. Mood swings and depressive states
D. Delusions, numbness in limbs, paralysis, and
degeneration of the spinal cord in late stages.
* At least two-thirds of AIDS patients have some signs
of this disorder before they die.
3. Secondary (opportunistic) Infections
A. Not common or significant in persons with healthy
immune systems
B. Most common: Pneumocystic carinii pneumonia
(PCP)
4. Rare cancers
A. Not found in persons with healthy immune systems
B. Kaposi's sarcoma : most common, but rarely the
cause of death.
Treatment
A. Anti-infectives - attempt to combat the secondary
infections
B. Anti-virals – “cocktail”
- highly active antiretroviral therapy, or HAART.
C. Immune modulators
- Replenishing T-cells via bone marrow transplants,
and white cell injections have had no success to
date.
Transmission methods (HIGH RISK BEHAVIORS)
A. Sexual intercourse with an infected individual
B. Sharing needles and syringes for intravenous drug
use
C. Receiving contaminated blood products
D. HIV positive pregnant women to fetus or newborn
Engaging in, or abstaining from these activities is a
personal decision that determines if you are a
person at risk.