final exam review Flashcards
what are hormones
chemical messengers that are released in one part of the body, travel through the blood, then affect other parts of the body
what is the endocrine system made up of ?
glands that release hormones into the blood.
what do hormones do in the endocrine system?
deliver messages throughout the body
what are target cells
cells that have a receptor for particular hormone
where do the exocrine glands release their secretions
through tub like structures called ducts either out the body or into digestive system
where do the endocrine glands release their secretions
directly into the blood
what does the hypothalamus gland do
make hormones that control the pituitary gland and hormones stored in it
pituitary gland
produces hormones that regulate other endocrine glands
parathyroid glands
release parathyroid hormones that regulate the level of calcium
thymus
releases thymosin to develop the immune system
adrenal glands
release hormones that help body respond to stress
pineal gland
releases melatonin
thyroid
produces thyroxine which regulates metabolism
pancreas
produces insulin and glucagon to regulate level of glucose
ovaries
produces estrogens and progesterone.
what is estrogen needed for
required for development of female secondary sex characteristics and development of eggs
what is progesterone needed for
prepared uterus for a fertilized egg
testes
produce testosterone which is responsible for sperm and production of male secondary sex characteristics
what are prostalglandins
modified fatty acids produced by a wide range of cells
what cells ad tissues do prostalglandins affect
only nearby cells and tissues
describe the process of a steroid hormone
- enters cell by passing directly across cell membrane
- hormone binds to a receptor and forms a hormone-receptor complex
- hormone-receptor complex enters nucleus of cell and binds to region of DNA
- binding activates transcription of gene to mRNA
- mRNA moves into cytoplasm and directs protein synthesis
describe the process of a nonsteroid hormone
- binds to a receptor ON the cell membrane
- binding activates enzymes on inner surface of cell membrane
- enzymes release secondary messengers to relay the hormones message
- secondary messengers activates a wide range of cell activities
what is puberty
period of rapid growth sexual maturation during which reproductive system becomes fully functional
what are the changes in females during puberty
develop breast, hip widening
what are the changes in males during puberty
facial hair, muscular development, deep voice
what happens in males when the reproductive system is fully functional
male can produce and release active sperm
what is the primary male reproductive organ
testes
what is the external sac that holds the testes
scrotum
what temperature must the testes in the scrotum
37 degrees Celsius
why must the temperature be lower than the body temp.
so that sperm can properly develop
where does sperm develop
seminiferous tubules
where does the sperm move after it is developed to be matured and stored
epididymus
where does the sperm move after leaving the epididymus
vas deferens
what is semen
combination of sperm and seminal fluid
what is seminal fluid and what does it do
nutrient rich fluid that nourishes the sperm and protects it from the acidity of the female reproductive tract
what is primary reproductive organ for female
ovaries
what is the main function of the female reproductive system
produce eggs
how many mature mature eggs does a female ovaries release in her lifetime
400
what is the menstrual cycle
process of egg formation and release
what occurs during the menstrual cycle
egg develops in a follicle and released from an ovary. the uterus is also prepared to receive a fertilized egg
what is ovulation
release of an egg from ovary into a fallopian tube
what phase begins after ovulation
corpus luteum
what is menstruation
tissue, blood, and unfertilized egg is released through the vagina
when will the menstrual cycle stop
if the female is pregnant
give one type of bacterial STD
Chlamydia
give examples of a viral STD
hepatitis B, genital warts, genital herpes, AIDS
what is a zygote
fertilized egg
what happens when a single zygote splits apart and produces two genetically identical embryos
identical twins are formed
what is a blastocyst
when the embryo grows and a cavity forms at the center
what is implantation
when the blastocyst attaches to the wall if the uterus and begins to grow into the tissues of the mother
gastrulation
formation of three layers called the ectoderm, mesoderm, and endoderm
neurulation
first step in development of nervous system
what is the placenta
connection between the mother and the embryo
what is the fetus
the embryo after 8 weeks of development
what happens during months 4-6 after fertilization
heartbeat can be heard
the early skeleton is formed
layer of soft hair grows over skin
feel the baby moving
what happens during month 7-9 of development
lungs and organs start preparation for outside life
fetus can regulate body temperature
