Flashcards in Anatomy- The Endocrine System Deck (49):
Chemical messengers released to the blood by the cells of endocrine glands that regulate metabolic activities
Hormones signal target cells to perform specific chemical reactions.
Endocrine glands include:
Which organs help with this?
Tissues that produce hormones from within:
Pituitary,thyroid, parathyroid, adrenal, pineal, and thymus.
Organs that help with this are: pancreas, gonads, hypothalamus.
- Tissues that produce hormones from within: adipose cells, small intestine, stomach, kidneys, heart.
Contain a couple to many amino acids
Example: amines, thyroid hormone, peptides
Synthesized from cholesterol
Biologically active lipids released from nearly all cell membranes.
Mechanisms of Hormone action:
2.stimulate mitosis/cell division
3.stimulates synthesis of protein within the cells.
A system of glands scattered throughout the body that influences the metabolic activities of cells through hormones.
Binds to a DNA-associated receptor protein which turns on transcription & translation of the associated gene.
Hormone release controlled by blood levels of specific ions and nutrients
Nerve fibers simulate hormone release catecholamines.
Catecholamines are epinephrine and norepinephrine.
Other hormones release of a hormone(released by the hypothalamus)
Nervous System Modulation:
The nervous system can override normal homeostatic mechanisms for hormonal control
For example: allow more glucose for fuel to be released during excitement
"Fight or flight" response
Pituitary Gland(anterior pituitary):
Stimulates cell division in most cells.(major targets are bone & skeletal)
IGFs - insulin-like growth factors. Mediates most of the effects of GH
Hypersecretion: can lead to gigantism- long bones develop ACROMEGALY
Hyposecretion: can lead to pituitary dwarfism
Anterior Pituitary: 5 hormones
Name and describe
1. Prolactin(PRL) - stimulates milk production by mammary glands
2. Follicle-stimulating hormone (FSH)- stimulates gamete production in the gonads.
3.Leutinizint hormone(LH) - testosterone, estrogen, progesterone
4. Thyroid-stimulating (TSH)
5. Adrenocorticotropic hormones (ACTH)- release hormones from Adriano cortex.
Receives and stores hormones from hypothalamus for later
Posterior Pituitary(Neurohypophysis): Oxytocin
Produced by the hypothalamus. Stimulates uterine contraction during childhood birth & milk ejection during nursing.
Posterior Pituitary(Neurohypophysis): Antidiuretic Hormone(ADH)
Produced by the hypothalamus.
Stimulates kidney tubules to retain water.
Deficiency of ADH secretion leads to diabetes
List some hormones
Thyroid Gland: Thyroid Hormone
Amino acid hormones containing 2 tyrosine molecules each bound to iodine molecules. Regulates metabolic activities, especially glucose oxidation.
Thyroid Gland: Thyroxine (T4)-
major hormone released from thyroid molecules. ContIns 4 iodine molecules .
Contains 3 iodine molecules.generally formed from T4.
Enlargement of the thyroid gland due to lack of iodine.
Underdeveloped thyroid gland. May lead to mental retardation
Hypothyroidism in adults(weigh gain, hair loss, slow pulse
Hyperthyroidism due to enlarged and overactive thyroid gland
-swelling of the eyes.
Produces by para-follicular cells(C cells) of thyroid gland.
-lowers blood calcium levels
Parathyroid hormone(PTH) :
Praises blood calcium levels and calcium by kidneys
Adrenal glands(Suprarenal glands)
Pyramids shaped glands. Look like hats above the kidneys.
Adrenal glands: Adrenal Cortex
Releases corticosteroid hormones.
Regulate salt in extracellular fluids.
Primary mineralocorticoid. Enhances sodium from kidney tubules.
Influence metabolism of body cells and help resist stressors.
During times of stress(injury,blood loss), glucocorticoids stimulate gluconeogenesis and mobilize fat and proteins used for energy
Glucocorticoids also prevent water loss from cells into tissue fluids
Source of sex hormones. Primarily androgens(testosterone) and estrogen.
May cause puberty
Low level of adrenal context hormones resulting in bronzing of skin, low blood sugar.
High level of adrenal cortex hormones resulting in high blood sugar, high blood sodium, swelling and obesity & and possible masculinization in women.
Adrenal medulla:what does it release?
Describe functions of epinephrine and norepinephrine
Releases catecholamines(norepinephrine and epinephrine)
Epinephrine: stimulates heart rate and metabolism
Norepinephrine: treats low blood pressure and heart failure.
Releases insulin and glucagon from islets of Langerhans.
Released by beta cells of islets; lowers blood glucose levels by stimulating glucose storage
Insulin deficiency may lead to ________.
Insulin-dependent diabetes mellitus(IDDM).?
Non-insulin dependent diabetes mellitus(NIDDM)?
Insulin-dependent diabetes mellitus(IDDM)- autoimmune disease where immune cells attack and destroy beta cells.
Non-insulin dependent diabetes mellitus(NIDDM)- insulin receptors do not properly resolution insulin.
Raises blood glucose levels.
Increases production of glucose in the liver.
Estrogens & progesterone(responsible for female reproductive organs)
Insulin inhibits _______.
Inhibits FSH during ovarian cycle
Released during pregnancy. Increases flexibility of pubic symphysis.
Androgen(male sex hormone)
Testosterone:produced by cells if testes. Is responsible for maturation of male reproductive organs.
produced by cells if testes. Is responsible for maturation of male reproductive organs.
Inhibits FSH to regulate spermatogenesis.