Endocrine System Flashcards
Endocrine system
-Responsible for secreting the hormones and other molecules that help regulate the entire body
-there’s a close working relationship between the endocrine system and the nervous system
-the hypothalamus and the pituitary gland coordinate to serve as a neuroendocrine control center
-hormone secretion is triggered by a variety of signals including hormone signs, chemical reactions, and environmental cues
-only cells with particular receptors can benefit from hormonal influence
-this is like the key and lock model for hormonal action
-steroid hormones trigger a gene activation and protein synthesis in some target cells
-protein hormones change the activity of existing enzymes in target cells
-hormones such as insulin work quickly when the body signals an urgent need
-slower acting hormones afford longer, gradual, and sometimes permanent changes in the body
[eight major endocrine glands and functions]
Adrenal cortex
Monitors blood sugar level, helps in lipid and protein metabolism
[eight major endocrine glands and functions]
Adrenal medulla
Controls cardiac function: raises blood sugar and controls the size of blood vessels
[eight major endocrine glands and functions]
Thyroid gland
Helps regulate metabolism and functions in growth and development
[eight major endocrine glands and functions]
Parathyroid
Regulates calcium levels in the blood
[eight major endocrine glands and functions]
Pancreas islets aka isles of langerhans
Raises and lowers blood sugar: active in carbohydrate metabolism
cluster of cells within the pancreas that are responsible for the production and release of hormones that regulate glucose levels
[eight major endocrine glands and functions]
Thymus gland
Plays a role in immune responses
[eight major endocrine glands and functions]
Pineal gland
Has an influence on daily bio rhythms and sexual activity
[eight major endocrine glands and functions]
Pituitary glands
Plays an important role in growth and development
Hypothalamus
-Link between the nervous system and the endocrine system
-located in the brain, superior to the pituitary and inferior to the thalamus
-communicates with the pituitary by secreting releasing hormones (RH) and inhibiting hormones (IH)
[hormones of the hypothalamus and their action]
GnRH- gonadotropin RH
Stimulates anterior pituitary to release LH and FSH
[hormones of the hypothalamus and their action]
GHRH- growth hormone RH
Stimulates anterior pituitary to release GH
[hormones of the hypothalamus and their action]
GHIH- growth hormone IH (somatostatin)
Inhibits the release of GH from the anterior pituitary
[hormones of the hypothalamus and their action]
TRH- thyrotropin RH
Simulates anterior pituitary to release thyrotropin (TSH)
[hormones of the hypothalamus and their action]
PRH- prolactin RH
Simulates anterior pituitary to release prolactin
[hormones of the hypothalamus and their action]
PIH- prolactin IH (dopamine)
Inhibits the release of prolactin from the anterior pituitary
[hormones of the hypothalamus and their action]
CRH- corticotropin RH
Stimulates the anterior pituitary to release ACTH (adrenocorticotropic)
[hormones of the hypothalamus and their action]
Oxytocin
-Targets the uterus: stimulates contractions
-targets the mammary glands: milk secretion
[hormones of the hypothalamus and their action]
ADH- antidiuretic hormone (vasopressin)
Targets the kidneys and blood vessels: increases water retention
Pituitary
-Master gland
-many of the hormones it secretes act on other endocrine glands
-located within the sella turcica of the sphenoid bone, beneath the hypothalamus
-pea-sized gland, hangs from a thin stalk called the infundibulum, and it consists of an anterior and posterior lobe—each with a different function
[pituitary gland ANTERIOR, hormone and action]
TSH- thyroid stimulating hormone (thyrotropin)
Targets the thyroid: stimulates the secretion of thyroid hormones
[pituitary gland ANTERIOR, hormone and action]
ACTH- adrenocorticotropic hormone
targets the adrenal cortex: stimulates the release of glucocorticoids and mineralocorticoids
[pituitary gland ANTERIOR, hormone and action]
GH- growth hormone
Targets muscle and bone: stimulates growth
[pituitary gland ANTERIOR, hormone and action]
FSH- follicle stimulating hormone
Targets the gonads: stimulates the maturation of sperm cells and ovarian follicles
[pituitary gland ANTERIOR, hormone and action]
LH- luteinizing hormone
-Target the gonads: stimulates the production of sex hormones
-surge stimulates ovulation and female
[pituitary gland ANTERIOR, hormone and action]
PRL- prolactin
Targets the mammary glands: stimulates production of milk
[pituitary gland POSTERIOR, hormone and action]
Oxytocin (produced in hypothalamus; stored and released by posterior pituitary)
-Targets the uterus: simulates contractions
-targets the mammary glands: stimulates milk secretion
[pituitary gland POSTERIOR, hormone and action]
ADH- antidiuretic hormone (vasopressin)(produced in hypothalamus: stored and released by posterior pituitary)
Targets the kidneys and blood vessels: increases water retention
[hormone sources of the head and neck: description, hormone, action]
Pineal gland
Description: Situated between the two hemispheres of the brain where the two halves of the thalamus join
Hormone: melatonin
Action: Targets the brain—regulates daily rhythm (wake and sleep)
[hormone sources of the head and neck: description, hormone, action]
Thyroid gland
Description: butterfly-shaped gland: the point of attachment between the two lobes is called the isthmus
the isthmus is on the anterior portion of the trachea, with the lobes wrapping partially around
the trachea
Hormone: T3- triiodothyronine // Action: Targets most cells—stimulates cellular metabolism
T4- thyroxine // Action: Targets most cells—stimulates cellular metabolism
Calcitonin // Action: Targets bone and kidneys—lowers blood calcium

[hormone sources of the head and neck: description, hormone, action]
Parathyroid gland
Description: Four small glands that are embedded in the posterior aspect of the thyroid
Hormone: PTH- parathyroid hormone
Action: Targets bone and kidneys—raises blood calcium
[hormone sources of the abdomen: description, hormone, action]
Thymus gland
Description: located between the sternum and the heart, embedded in the mediastinum. it slowly decreases in size after puberty
Hormone: thymosin
Action: targets lymphatic tissues—stimulates the production of T-cells
[hormone sources of the abdomen: description, hormone, action]
Pancreas
Description: The head of the pancreas is situated in the curve of the duodenum and the tail points towards
the left side of the body
the pancreas is mostly posterior to the stomach
Hormone: Insulin // Action: targets the liver, muscle, and adipose tissue—decreases blood glucose
Glucagon // Action: targets the liver—increases blood glucose
GHIH- growth hormone IH (somatostatin) // Action: inhibits the secretion of insulin and glucagon
[hormone sources of the abdomen: description, hormone, action]
Adrenal medulla
Description: Located on top of the kidneys
the adrenal medulla is the inner part of the gland
Hormone: epinephrine and norepinephrine
Action: Targets heart, blood vessels, liver, and lungs—increase heart rate, increase blood sugar (fight or flight response)
[hormone sources of the abdomen: description, hormone, action]
Adrenal cortex
Description: The adrenal cortex is the outer portion of the adrenal gland
Hormone: mineralocorticoids (aldosterone) // Action: targets the kidneys—helps control the balance of water and salts in the kidney by keeping sodium in and releasing potassium from the body
Glucocorticoids // Action: targets most tissues—released in response to long-term stressors, increase blood glucose (but not as quickly as glucagon)
Androgens // Action: Target most tissues—stimulate development of secondary sex characteristics
[hormone sources of the abdomen: description, hormone, action]
GI tract
Hormone: Gastrin // Action: targets the stomach—stimulates the release of HCl
Secretin // Action: targets the pancreas and liver—stimulates the release of digestive enzymes and bile
CCK-cholecystokinin // Action: targets the pancreas and liver stimulates the release of digestive enzymes and bile
[hormone sources of the abdomen: description, hormone, action]
Kidneys
Hormone: Erythropoietin // Action: targets the bone marrow—stimulates the production of red blood cells
Calcitriol // Action: Targets the intestine—increases the reabsorption of Ca2+
[hormone sources of the abdomen: description, hormone, action]
Heart
Hormone: ANP—atrial natriuretic peptide
Action: Targets the kidneys and adrenal cortex—reduces reabsorption of Na+, lowers blood pressure
[hormone sources of the abdomen: description, hormone, action]
Adipose tissue
Hormone: Leptin
Action: targets the brain—suppresses appetite
[hormone sources of the reproductive system: description, hormone, action]
Ovaries
Description: The ovaries rest depressions in the pelvic cavity on each side of the uterus (note that ovaries produce testosterone in small amounts)
Hormone: estrogen— targets the uterus, ovaries, mammary glands, brain, and other tissues—stimulate uterine lining growth, regulate menstrual cycle, facilitate the development of secondary sex characteristics
Progesterone— targets mainly the uterus and mammary glands—stimulates uterine lining growth, regulates menstrual cycle, required for maintenance of pregnancy
Inhibin— Targets the anterior pituitary—inhibits release of FSH
[hormone sources of the reproductive system: description, hormone, action]
Placenta
Description: Attached to the wall of the uterus during
Hormone: -estrogen— targets the uterus, ovaries, mammary glands, brain, and other tissues—stimulate uterine lining growth, regulate menstrual cycle, facilitate the development of secondary sex characteristics
-Progesterone— targets mainly the uterus and mammary glands—stimulates uterine lining growth, regulates menstrual cycle, required for maintenance of pregnancy
-Inhibin— Targets the anterior pituitary—inhibits release of FSH
-Human chorionic gonadotropin (hCG)— Target‘s the ovaries—stimulates the production of estrogen and progesterone
[hormone sources of the reproductive system: description, hormone, action]
Testes
Description: Located within the scrotum, behind the penis
Hormone: -testosterone— targets the testes and many other tissues promotes spermatogenesis, secondary sex characteristics
-inhibin— targets the anterior pituitary—inhibits release of FSH