Flashcards in Topic 6.6: Hormones, Homeostasis, and Reproduction Deck (27)
What happens when blood glucose levels are high?
Insulin is released from beta (β) cells of the pancreas and cause a decrease in blood glucose concentration
What happens when blood glucose levels are low?
Glucagon is released from alpha (α) cells of the pancreas and cause an increase in blood glucose concentration
What is the difference between Type I and Type II diabetes in terms of onset?
Type I: usually occurs during childhood (early onset)
Type II: usually occurs during adulthood (late onset)
What is the difference between Type I and Type II diabetes in terms of insulin production?
Type I: body does not produce sufficient insulin
Type II: body does not respond to insulin production
What is the difference between Type I and Type II diabetes in terms of cause?
Type I: caused by the destruction of B-cells (autoimmune)
Type II: caused by the down-regulation of insulin receptors
What is the difference between Type I and Type II diabetes in terms of treatment?
Type I: requires insulin injections to regulate blood glucose
Type II: controlled by managing diet and lifestyle
What is thyroxin and what is its function?
Thyroxin is a hormone secreted by the thyroid gland in response to signals initially derived from the hypothalamus. Thyroxin is secreted by the thyroid gland to regulate the metabolic rate and help control body temperature
What is leptin and its function?
Leptin is a hormone produced by adipose cells that regulates fat stores within the body by suppressing appetite. Leptin is secreted by cells in adipose tissue and act on the hypothalamus of the brain to inhibit appetite
What is melatonin and its function?
Melatonin is a hormone produced by the pineal gland within the brain in response to changes in light. Melatonin is secreted by the pineal gland to control circadian rhythms.
What does testosterone cause?
Testosterone causes pre-natal development of male genitalia and both sperm production and development of male secondary sexual characteristics during puberty
What do estrogen and progesterone cause?
Estrogen and progesterone cause pre-natal development of female reproductive organs and female secondary sexual characteristics during puberty
What is the function of the testis?
The testis (plural: testes) is responsible for the production of sperm and testosterone (male sex hormone)
What is the function of the epididymis?
Site where sperm matures and develops the ability to be motile (i.e. ‘swim’) – mature sperm is stored here until ejaculation
What is the function of the vas deferens?
Long tube which conducts sperm from the testes to the prostate gland (which connects to the urethra) during ejaculation
What is the function of the seminal vesical?
Secretes fluid containing fructose (to nourish sperm), mucus (to protect sperm) and prostaglandin (triggers uterine contractions)
What is the function of the prostate gland?
Secretes an alkaline fluid to neutralise vaginal acids (necessary to maintain sperm viability)
What is the function of the urethra?
Conducts sperm / semen from the prostate gland to the outside of the body via the penis (also used to convey urine)
What is the function of the ovary?
The ovary is where oocytes mature prior to release (ovulation) – it also responsible for estrogen and progesterone secretion
What is the function of the fimbria?
Fimbria (plural: fimbriae) are a fringe of tissue adjacent to an ovary that sweep an oocyte into the oviduct
What is the function of the oviduct?
The oviduct (or fallopian tube) transports the oocyte to the uterus – it is also typically where fertilisation occurs
What is the function of the uterus?
The uterus is the organ where a fertilised egg will implant and develop (becoming an embryo)
What is the function of the endometrium?
The mucous membrane lining of the uterus, it thickens in preparation for implantation or is otherwise lost (via menstruation)
What is the function of the vagina?
Passage leading to the uterus by which the penis can enter (uterus protected by a muscular opening called the cervix)
What is the function of the follicle-stimulating hormone?
Stimulates follicular growth in ovaries
Stimulates estrogen secretion (from developing follicles)
What is the function of the leutinizing hormone?
Surges causes ovulation
Results in the formation of a corpus luteum
What is the function of estrogen?
Thickens uterine lining (endometrium)
Inhibits FSH and LH for most of cycle
Stimulates FSH and LH release pre-ovulation