science quiz Flashcards
are chemical substances secreted by the endocrine glands that have specific regulatory effects on cells in the different parts of the body.
Hormones
is a protein molecule to which the hormone attaches.
receptor molecule
hormone action may directly or indirectly inhibit further glandular secretory action.
negative feedback control system
increases hormone concentration to stimulate the endocrine gland and produce more hormones.
positive feedback system
found in the frontal region of the brain is a regulatory center for maintaining homeostasis.
hypothalamus
a small, pea-shaped gland, is connected to the hypothalamus by the pituitary stalk.
pituitary gland
stimulates the gonads to produce sex hormones and the release of the egg cell from the female ovary.
luteinizing hormone
stimulates the sex organs to produce gametes or sex cells
follicle stimulating hormone
is the primary male sex hormone, which stimulates the development of male secondary characteristics such as growth of body hair and deeper voice.
testosterone
the formation of sperm cells, occurs in the testes in coiled tubes called seminiferous tubules.
spermatogenesis
which refers to the development of an ovum, occurs in the ovary.
oogenesis
is the monthly discharge of blood and the uterine lining or endometrium
menstruation
A sharp increase in the concentration of LH occurs about a day before ovulation. This hormone causes?
ovulation
The zygote divides rapidly into two cells, then four cells, then eight cells, and so on forming a ball of cells called?
morula
The growing mass of hundreds of cells then forms a hollow ball called?
blastocyst
