Endocrine System Flashcards
The second controlling system of the body
Endocrine System
The Endocrine System uses _____ that
are released into the blood.
chemical messengers (hormones)
With respect to their chemical structure, hormones may be classified into three
groups:
Amines
Proteins
Steroids
these simple hormones are structural variations of the amino acid tyrosine.
This group includes thyroxine from the thyroid gland, epinephrine and
norepinephrine from the adrenal medulla.
Amines
These hormones are chains of amino acids. Insulin from the pancreas,
growth hormone from the anterior pituitary gland, and calcitonin from the thyroid gland are all proteins. Short chains of amino acids may be called peptides. Antidiuretic hormone and oxytocin, synthesized by the hypothalamus, are peptide hormones.
Proteins
Protein
_____ Made by the pancreas, it helps regulate blood sugar levels.
Insulin
Protein
_____ produced by the pituitary gland, it promotes growth development.
Growth hormone
Protein
_____ also from the thyroid gland, it helps regulate calcium levels in the blood.
Calcitonin
Peptide hormones that are synthesized by the Hypothalamus
- Antidiuretic hormone (released by the posterior pituitary gland. It plays a vital role in regulating the body’s water balance and blood pressure).
- Oxytocin (released by the posterior pituitary gland. Often referred to as the “love hormone”)
_____the precursor for the steroid hormones,
cholesterol
cholesterol is the precursor for the steroid hormones, which include _____
and _____ from the adrenal cortex, _____ and ______ from the ovaries, and _____ from the testes.
Cortisol and aldosterone - Adrenal cortex
Estrogen and Progesterone - Ovaries
Testosterone - Testes
A condition characterized by elevated levels of glucose in the bloodstream.
Hyperglycemia
The effects of the hormone reverse the stimulus and decrease the secretion of the hormone.
mechanism called “negative”:
two mechanisms in which hormones act
direct gene activation and second-messenger system
Arrangement of the process of direct gene activation
A. Hormones diffuse through the plasma membrane of target cells.
B. Hormones enter the nucleus.
C. Hormones bind to a specific protein within the nucleus.
D. Hormone-receptor complex bind to specific sites on the cell’s DNA.
E. Activate genes that result in the synthesis of new proteins
Arrangement the process of second
messenger system
A. Hormone binds to a membrane receptor.
B. Hormone does not enter the cell
C. Hormone sets off a series of reactions that activates an enzyme.
D. Enzyme catalyzes reactions that produces a second messenger molecule
E. Second-messenger molecule oversees additional intracellular changes to
promote a specific response
often times called the “master endocrine gland” since it regulates many bodily functions
Pituitary Gland
It is about the size of a pea, which hangs by a stalk from the hypothalamus in the brain.
Pituitary Gland
These releasing hormones
are secreted into capillaries in the hypothalamus and pass through the hypophyseal portal veins to another capillary network in the anterior pituitary gland.
Anterior Pituitary Gland
also called somatotropin, and it does indeed promote growth.
Growth Hormone
The secretion of GH is regulated by two releasing hormones from the
hypothalamus.
- Growth hormone “Somatotropin” releasing hormone (GHRH) - increases the secretion of GH, is produced during hypoglycemia and during exercise.
- Growth hormone inhibiting hormone (GHIH) “Somastatin”- it decreases the secretion of GH. Somatostatin is produced during hyperglycemia.
also called thyrotropin, and its target
organ is the thyroid gland.
Thyroid-stimulating hormone (TSH)
stimulates the normal growth of the thyroid and the secretion of thyroxine (T4) and triiodothyronine (T3).
Thyroid-stimulating hormone (TSH)
stimulates the secretion of cortisol and
other hormones by the adrenal cortex
Adrenocorticotropic hormone (ACTH)
responsible for lactation. More precisely,
initiates and maintains milk production by the mammary glands.
prolactin
one of the gonadotropic hormones. IT stimulates the growth of ovarian follicles; that is, it initiates egg
development in cycles of approximately 28 days. In men, initiates sperm production within the testes.
Follicle-stimulating hormone (FSH)
another gonadotropic hormone. In women, it is responsible for ovulation, the release of a mature ovum from an ovarian follicle. In men, it stimulates the interstitial cells of the testes to secrete testosterone.
Luteinizing hormone (LH)
The two hormones of the posterior pituitary gland
oxytocin and antidiuretic hormone
(also called vasopressin) increases the
reabsorption of water by kidney tubules, which decreases the amount of urine
formed. It also decreases sweating, but the amount of water conserved is much less than that conserved by the kidneys.
Antidiuretic hormone (ADH)
stimulates contraction of the uterus at the end of pregnancy and stimulates release of milk from the mammary glands.
Oxytosin
Anterior Pituitary Gland hormones
- Growth hormone
- Prolactin
- Adrenocorticotropic hormone
- Thyroid-stimulating hormone
- Luteinizing hormone
- Follicle-stimulating hormone
Posterior Pituitary Gland hormones
- Oxytocin
- Antidiuretic hormone
Hypersecretion of growth hormone after long bone growth has ended
(as an adult) is called
acromegaly
Releasing and inhibiting hormones produced by the hypothalamus
influence the activities of the
anterior pituitary gland
Located on the front and sides of the trachea just below the larynx
thyroid gland
The structural units of the
thyroid gland are _____, which produce thyroxine (T4) and triiodothyronine (T3).
thyroid follicles
The third hormone produced by the thyroid gland is_____, which is secreted by parafollicular cells and its function is very different from those of thyroxine and T3.
calcitonin
regulation of energy production and
protein synthesis, which contribute to the growth of the body and to normal body functioning throughout life.
Thyroxine (T4) and T3
These hormones are the most important day-to-day regulators of metabolic rate; their activity is reflected in the functioning of the brain, muscles, heart, and virtually all other organs
Thyroxine (T4) and T3
Secretion of thyroxine and T3 is stimulated by thyroid-stimulating hormone (TSH) from the anterior pituitary gland.
decreases the reabsorption of calcium and phosphate from the bones to the blood, thereby lowering blood levels of these minerals.
Calcitonin
are tiny masses on the posterior of the thyroid.
Parathyroid Glands