Endochrine System Flashcards
What are the major functions controlled by hormones?
Reproduction. Growth and development. Body defense. Metabolism and energy. Maintaining homeostasis.
Major function of the endocrine system?
To coordinate and direct cell activities through the action of horomones
What are the three chemical classes of hormones?
Amino acid based. Steroid based. Prostaglandins.
What are amino acid based hormones?
Proteins. Peptides. Amines.
What are steroid hormones?
Made from cholesterol. Includes sex hormones and hormones of from the adrenal gland
What are prostaglandins?
Localized hormones. Made from lipids in the cell’s plasma membrane.
What is it called when hormones only affect certain cells or organs?
Hormone action
What must a hormone do in order to work?
Attach to the protein receptors of the target cell or target organ
3 categories of stimuli that activate hormone glands
Humoral stimuli. Hormonal stimuli. Neural stimuli.
Hormonal stimuli
When an endocrine gland is stimulated by a hormone released from another endocrine gland (ex. Thyroid stimulating hormone)
Humoral stimuli
When an endocrine gland is stimulated by changing levels of ions and nutrients in the blood (ex. When blood calcium levels change)
Neural stimuli
When the endocrine gland is stimulated by nerve fibers. (Ex. Sympathetic system.)
Exochrine?
Release secretions into ducts
Endochrine
Ductless glands-release secretions directly into the blood
Pituitary gland
A small gland located in the brain very near the hypothalamus. It is divided into two lobes: anterior and posterior. It is called the master gland because it controls the activities of other glands
Hormones of the anterior pituitary?
Growth hormone. Prolactin. Adrenocorticotropic hormone. Thyroid stimulating hormone. Follicle stimulating hormone. Leutenizing hormone.
Growth hormone
Anterior pituitary. Controls growth of long bones and muscle
Prolactin.
Anterior pituitary. Stimulates and maintains milk production in a mothers breasts after childbirth.
Adrenocorticotropoc hormone
Anterior pituitary. Stimulates the activity of the adrenal gland.
Thyroid stimulating hormone
Anterior pituitary. Stimulates the activity of the thyroid gland
Follicle stimulating hormone
Anterior pituitary. Controls production of eggs in females and sperm in males
Leutenizing hormone.
Anterior pituitary. Stimulates ovulation in females and production of estrogen and progesterone. In males it is called the “interstitial sell stimulating hormone” which controls the secretion of testosterone
Hormones of the anterior pituitary
Oxytocin. Antidiuretic hormone
Oxytocin
Posterior pituitary. Stimulates uterin contractions during childbirth and initiates the milk letdown reflex. (Ptosin- synthetic oxytocin)
Anti diuretic hormone.
Posterior pituitary. Promotes wayer retention by the kidneys. Also called VASOPRESSIN
Thyroid gland
Located at the base of the throat. Divided into two lobes joined by a central mass called and isthmus.
Hormones of the thyroid
Thyroxine (t4) + triiodothryronine (t3). Calcitonin.
Thyroxine (t4) + triiodothyronine
Thyroid gland. Iodine containing hormones which stimulate metabolism by controlling the rate at which glucose is oxidized and converted into energy
Calcitonin
Thyroid gland. Decreases blood calcium levels by depositing excess into the bones
Parathyroid gland
Tiny glands located posterior to the thyroid gland
Hormones of the parathyroid gland
Parathyroid or parahormone.
Parathyroid hormone or parahormone
Parathyroid. Increases calcium levels. Works in conjunction with calcitonin to maintain blood calcium homeostasis
Adrenal gland
Located on top of each kidney
Hormones of the adrenal gland
Mineralcorticoids (aldosterone). Glucocorticoids. Sex hormones. Adrenaline + noradrenaline (epinephrine and norepinephrine) (chatecholomines)
Mineralcorticoids (aldosterone)
Adrenal gland. Regulate the mineral content of the blood by controlling sodium and potassium
Glucocorticoids
Adrenal gland. Helps to control normal metabolism and responds to long term stressors by increasing blood glucose levels. Also has an anti inflammatory property
Sex hormones
Adrenal gland. Very small amounts of both male and female sex hormones are released from the adrenal gland
What are the corticosteroids?
Released by the adrenal gland. Includes Mineralcorticoids and Glucocorticoids and Sex hormones.
Adrenaline and noradrenaline (epinephrine and norepinephrine) (chatecholomates)
Adrenal gland. Fight or flight hormone. Assists the body in times of stress. Heart rate increases, blood pressure elevates, blood glucose increases.
Pancreas (islets of langerhans)
Located in the abdominal cavity very near the stomach. The pancreas is called a mixed gland- it has and endocrine and exocrine function
Hormone of the pancreas
Insulin. Glycogen.
Insulin.
Pancreas. Lowers blood sugar levels. Moves excessive glucose in the blood into cells to be oxidized
Glucagen.
Pancreas. Raised blood sugar levels. Converts glycogen stored in the liver to glucose and then releases it into the blood
Pineal gland
A small cone shaped gland located in the brain
Hormones of the pineal gland
Melatonin.
Melatonin.
Pineal gland. Controlls biological cycles such as the wake sleep cycle. Peaks at night. Lowest at noon.
Thymus gland
Located in chest cavity directly posterior o the sternum
Hormones of the thymus gland
Thymosin.
Thymosin
Thymus gland. Functions in immunity. Aids in the maturation of certain white blood cells (lymphocytes)
Gonads consist of two glands. What are they
Testes and ovaries.
Ovaries
Two almond shaped glands in a females pelvic cavity
Hormones of the ovaries
Estrogen and progesterone
Estrogen
Ovaries. Controls the development of secondary sex characertistics. Prepares the uterus to receive the fertilized egg. Controls the menstrual cycle.
Progesterone
Ovaries. Works with estrogen to control the menstrual cycle. During pregnancy it quiets the uterine muscles
Testes
Small oval shaped glands located in a sac called the scrotum outside a males pelvic cavity.
Hormones of the testes
Testosterone
Testosterone
Testes. Controls the development of secondary sex characteristics. Controls the male sex drive. Controls the production of sperm.
Placenta
A temporary gland formed i. The uterus of pregnant women
Hormones of the placenta
Chorionic gonadotropin. Estrogen and progesterone.
Chorionic gonadotropin.
Placenta. Produced to stop the menstrual cycle. Detected in urine on pregnancy tests.
Estrogen and progesterone during pregnancy
Placenta. By the third month of prenatal development the placenta takes over these hormones from the ovaries
Menopause
“Change of life” during late-middle life, the females reproductive system begins to atrophy and the ability to bear children ceases
