TOPIC 6.6- HORMONES, HOMEOSTASIS, AND REPRODUCTIONShefali Waghray, Josh Russell, Reina Budesa

Period 1

VOCABULARY• Homeostasis• Hormone• Insulin• Thyroxin• Leptin• Melatonin• Glucagon• Blood Glucose• Diabetes• Testis• Scrotum• Epididymis

• Vas deferens• Prostate gland• Penis• Urethra• Ovaries• Fallopian tubes• Uterus• Endometrium• Cervix• Vagina• In vitro fertilization (IVF)• Hormone Therapy

HOMEOSTASIS

• Homeostasis- the control process that maintains the conditions within the body● Initiated by the nervous system and endocrine

system• The body stays within certain variables:

● Blood pH● CO2 concentration● Blood glucose concentration● Body Temperature- 37˚ C or 98.7˚F● Water Balance● Virtual Lab:

http://www.pbslearningmedia.org/asset/tdc02_int_bodycontrol/

HORMONES AND THEIR FUNCTIONS

• Thyroxin-● Secreted in the thyroid gland● Regulates temperature and increases

the metabolic rate• Leptin-

● Produced in the fat tissue of the body● Increases appetite when fat reserves

are low• Melatonin-

● Secreted by the pineal gland ● Regulates 24-hour cycle of activity

(circadian rhythm)● Virtual Lab:

http://www.biomanbio.com/GamesandLabs/Physiogames/endocrineed.html

INSULIN • Both hormones are produced by

pancreas• Insulin-

● Produced by beta cells● Secreted into the bloodstream ● Insulin opens protein channels

in the cell’s plasma membrane● Channels allows glucose to

diffuse into cell● If blood is high in glucose, it

enters the liver by the hepatic vein

● The excess glucose converts into glycogen

● Lowers glucose concentration

Glucagon

• Produced and secreted by alpha cells in pancreas

• Produced when glucose concentration is below optimum level

• Glucagon hydrolyzes glycogen stored in liver to produce glucose

• Increase glucose concentration in the bloodstream

Type I Diabetes• Type I Diabetes

● Autoimmune disease - Body attacks own beta cells

● Beta Cells do not produce sufficient insulin

● Controlled by the injection of insulin at appropriate times

● Develops mostly in children and young adults

HUMAN REPRODUCTION

• Male gamete (sperm) + female gamete (egg) = zygote

• Ensures genetic variation in species

• Female reproductive system ensures a location for fertilization● Provides an

environment for the growth of embryo

● Virtual Lab: http://www.glencoe.com/sites/common_assets/science/virtual_labs/grade8/LS26/LS26.html

Type II Diabetes

• Type II Diabetes● Body cell receptors do

not respond properly to insulin

• Effects of uncontrolled diabetes● Kidney Failure● Nerve Damage● Increased risk of

cardiovascular disease● Poor wound healing● Possibly gangrene

leading to amputation● Associated with:

• Genetic History• Obesity• Lack of Exercise• Advanced age

Male Reproductive System• Testis- produces semen • Epididymis- where sperm

is received• Scrotum- sacs that hold

the tests so sperm occurs at a cooler temperature

• Vas deferens-carries sperm

• Seminal vesicles- produce and add seminal fluid to semen

• Prostate gland- produces seminal fluid

• Penis- becomes erect to facilitate ejaculation

• Urethra- tube that leads semen out of the penis

Female Reproductive System

• Ovaries- Produce and secrete estrogen

• Fallopian Tubes- carry the early embryo to the uterus

• Uterus- early embryo implants here

• Endometrium- inner lining of the uterus

• Cervix- lower portion of the uterus

• Vagina- tube that leads from external genitals to the cervix

Puberty

• Growth of facial, underarm, chest and pubic hair

• Enlargement of larynx

• Increased muscle mass

• Enlargement of the penis

• Enlargement of breasts

• Growth of pubic and underarm hair

• Widening of hips• Start the menstrual

cycle

Male Female

In Vitro Fertilization (IVF) and Hormone Therapy

• IVF- reproductive technology where an egg is removed from a woman and is then fertilised by a sperm in a tube. This process produces an embryo which then divides.

• Some couples are unable to bear children for seasons like:● Males with low sperm counts● Males with impotence (failure to achieve

erection)● Females who cannot ovulate normally● Females with blocked Fallopian Tubes

• Hormone therapy helps to maximize the number of ova that a woman has