Endocrine Flashcards
What do the endocrine and nervous systems do?
Coordinate and direct the activity of the body’s cells.
What differentiates the nervous system from the endocrine system?
The speed of control
Is nervous system or endocrine system slower?
Endocrine
What does the endocrine system use to send messages?
Chemical messengers called hormones
What do the hormones do?
They are released into the blood to be transported leisurely throughout the body
What do the hormones contain?
Calcium, hydrogen, oxygen, nitrogen
How do hormones work?
Chemical substances secreted by cells into the extracellular fluids regulate the the metabolic activity of cells in the body
What two things are hormones classified by?
Amino acid-based molecules (including proteins, peptides and amines) and steroids
What is the third chemical class of hormones?
Prostaglandins
What are prostaglandins made from?
Highly active lipids found in the cell’s plasma membrane
What are target cells or target organs?
Although the blood-borne hormones circulate to all the organs of the body, a given hormone affects only certain tissue cells or organs
What word does the term hormone come from? And why?
The greek word meaning “to arouse”, hormones do just that
Why do hormones mean “to arouse”?
They arouse or bring about their effects on the body’s cells primarily by altering cellular activity
How many mechanisms by which hormones trigger changes in cells are there?
2
What kind of mechanism do steroidal hormones use?
Direct gene activation
What kind of glands are endocrine glands?
Ductless glands
What do endocrine glands release hormones into?
Blood and Lymph
How big is the pituitary gland?
The size of a grape
What is the pituitary gland hung by?
It hangs by a stalk from the inferior surface of the hypothalamus of the brain
What is the pituitary gland surrounded by?
It is snugly surrounded by the “Turk’s Saddle” of the sphenoid bone
What are the two functional lobes of the pituitary gland?
The anterior pituitary and the posterior pituitary
What kind of tissue does the anterior pituitary have?
Glandular tissue
What kind of tissue does the posterior pituitary have?
Nervous tissue
What are tropic hormones?
Hormones that stimulate their target organs
What are the 6 hormones from the pituitary gland?
Growth hormone, prolactin, thyrotropic, adrenocorticotropic, and two gonadotropic hormones
What target organs are also endocrine glands? (9)
Adrenal cortex, bone, muscle, skin, thyroid, testes, ovaries, breast, kidney
How do target endocrine hormones work?
They will secrete their hormones which exert their effects on other body organs and tissue
What kind of hormone is GH?
General metabolic
What does GH do and what are its major effects?
Its major effects are directed to the growth of skeletal muscles and long bones of the body
What does GH play an important role in?
Determining final body size
What does GH do to fats?
Causes them to be broken down and uses it for energy
What does GH do with glucose?
Spares glucose, helping to maintain blood sugar homeostasis
What does pro mean?
For
What does lact mean?
Milk
What is PLR?
Prolactin
What kind of hormone is Prolactin?
Protein hormone
What is prolactin structured similar to?
Growth hormone
Where is prolactin’s target
Its only known target in humans is the breasts
What happens to Prolactin after childbirth?
After childbirth, it stimulates and maintains milk production by the mother’s breasts.
What is the function of prolactin in males?
It is not known
What is TSH also called?
Thyrotropic hormone (TH)
What does TSH do?
Influences the growth and activity of the thyroid gland
What happens as egg follicles mature and why?
They produce estrogen, it is stimulated by FSH
What does FSH do in men?
Stimulates sperm development by the testes
What does luteinizing hormone do in females? (3 things)
Triggers ovulation of an egg from the ovary, causes the ruptured follicle to become the corpus luteum, stimulates the corpus luteum to produce progesterone and some estrogen
What is luteinizing hormone also referred to as?
Interstital Cell-Stimulating Hormone (CSH)
In men, what does luteinizing hormone do?
It stimulates testosterone production by the interstital cells of the testes
What is the pituitary–hypothalamus relationship called?
Master endocrine gland
Why is the pituitary–hypothalamus relationship called the master endocrine gland?
Its removal or destruction has a dramatic effect on the body
What is the hypothalamus?
The structure that controls the anterior pituitary
What does the hypothalamus do and how?
Controls the hormone of the anterior pituitary gland by releasing and inhibiting hormones that it produces
How many hormones does the thyroid produce?
2
What does the thyroid do?
Controls the rate at which glucose is burned or oxidized and converted into body heat and chemical energy
What is calcitonin and where does it come from?
A hormone that aids in the lowering of blood calcium, released by the thyroid
What are the parathyroid glands?
Tiny masses of tissue found on the posterior surface of the thyroid gland
What is the function of the parathyroid glands?
To secrete parathormone (PTH)
What does Parathormone (PTH) do?
The most important regulator of Ca2+ calcium ions
What are the adrenal glands?
The two bean shaped adrenal glands curve over the top of the kidneys
What do the adrenal glands produce?
Three major groups of steroid hormones collectively called corticosteroids
WHat are the three major groups of corticosteroids created by the adrenal glands?
Mineralcorticoids, glucocorticoids, sex hormones
What do the mineralcorticoids mainly consist of?
Aldosterone
What are the mineralcorticoids produced by?
The outermost adrenal cortex cell layer
What do the mineralcorticoids do?
Regulate the sodium and potassium (salt) content in the body
Where are the glucocorticoids made?
In the middle cortical layer along with cortisone and cortisol
What do the glucocorticoids do?
Promote normal cell metabolism to help the body to resist long term stressors by increasing blood glucose levels
What is epinephrine also called?
Adrenaline
What is norepinephrine also called?
Noradrenaline
How does adrenaline work?
When you are threatened physically or emotionally, your sympathetic nervous system brings about the fight or flight response to help you cope with the stressful situation
What does insulin do?
Acts on almost all body cells to increase the ability of the cell to transport glucose across the cell membrane
What does glucose do once inside a cell?
Is used for energy or converted to glycogen or fat for storage
What kind of hormone is insulin?
Hypoglycemic hormone
What kind of hormone is glucagon?
Hyperglycemic
What does being hyperglycemic mean for glucagon?
Its target organ is the liver which it stimulates to break down stored glycogen ti glucose and ti release the glucose into the blood
What does the pineal gland look like?
A small gland found on the third ventricle of the brain
What does the pineal gland do?
Its function is to secrete melatonin
WHat is melatonin?
The body’s sleep trigger that establishes the day/night cycle
Where and what do the ovaries look like?
Paired, almond sized, located in the pelvic cavity
What does the ovaries produce/
Besides producing female sex cells, ova or eggs, the ovaries produce two groups of steroid hormones, estrogen and progesterone
Where is estrogen produced?
The Graafian follicles of the ovaries
What does estrogen do?
Stimulates the development of the secondary sex characteristics in females
What does estrogen work with?
Progesterone
What do estrogen and progesterone do?
Work together yo prepare the uterus to receive a fertilized egg
What does the release of estrogen and progesterone do?
Results in cyclic changes in the uterine lining, which is called the menstural cycle
WHat does progesterone do during pregnancy?
Helps to quiet the muscle of the uterus so that an implanted embryo will not be aborted
What other thing does progesterone do?
Helps prepare breast tissue ofr lactation
Where is progesterone created?
Produced in large amounts by another glandular structure of the ovaries, the corpus luteum
What does testosterone do?
Causes the development of the male’s secondary sex characteristics
WHat are some of the male’s secondary sex characteristics?
Growth of the beard, development of heavy bones and muscles, lowering of the voice, stimulates the male sex drive
What is adulthood testosterone necessary for?
The continuous production of sperm
