Endocrine System Flashcards
Endocrine Gland
Organ that secretes hormones, ductless glands
Hormones
Chemical messages that travel through the blood to regulate target cells
What does the hypothalamus do in the endocrine system?
It secretes releasing hormones that control the activity of the anterior pituitary gland
Pituitary Gland
Hangs by a stalk from the inferior surface of the hypothalamus. It contains two functional lobes:
>Anterior Pituitary made of glandular tissue
>Posterior Pituitary made of nervous tissue
Posterior Pituitary Gland
Nervous tissue
Oxytocin
Causes uterine contractions during child birth and milk ejection reflex during nursing
Antidiuretic Hormone (ADH)
Stimulates reabsorption of water in the kidneys leading to reduced urine volume
Anterior Pituitary Gland
Glandular Tissue
Thyroid Stimulating Hormone (TSH)
Targets thyroid gland to produce hormones
Adrenocorticotropic Hormone (ACTH)
Stimulates the adrenal cortex to release glucocorticoids
Leutinizing Hormone (H)
Females- stimulates ovulation and progesterone production
Males- Stimulates testes to produce testosterone
Growth Hormone (GH)
Stimulates cell growth and division in skeletal msucle and bone, stimulates the liver to produce insulin-like growth factor (IGF)
Prolactin (PRL)
Stimulates gorwth of the mammary gland and milk production
Thyroid Gland
Butterfly Shaped Gland located in the anterior cervical region
Thyroid Hormones (T3 & T4)
Increase cell metabolism
Calcitonin
Decreases blood calcium levels
Parathyroid Gland
Tiny masses found on the posterior side of the thyroid
What secretes the Parathyroid Hormone (PTH)?
Secreted by chief cells in response to low blood calcium levels
What does (PTH) stimulate?
Stimulates osteoclasts to release calcium from bone, stimulates activation of Vitamin D leading to increased absorption of Ca2+ in digestive tract
Adrenal Glands
Paired, pyramid shaped organs atop the kidneys
Adrenal Medulla
Located in the center of the adrenal gland
What produces Epinephrine?
The adrenal gland
What stimulates the production of epinephrine?
Stimulated by preganglionic sympathetic fibers
Adrenal Cortex
Glandular tissue, outer layer, synthesizes and releases steroid hormones
What are the three layers of the adrenal cortex?
Zona Glomerulosa- Superficial layer
Zona Fasciculata- Middle Layer
Zone Reticularis- Deepest Layer
Pancreas
Organ located posterior to the stomach that functions as both an endocrine and exocrine gland
Acinar Cells
Exocrine cells that produce digestive enzymes that are secreted into the duodenum
Glucagon
Triggers the breakdown of glycogen in the liver, thus increases blood glucose levels
Insulin
Increases the uptake of glucose into the cells, thus decreases blood glucose levels
Pineal Gland
Found in the diencephalon of the brain produces the hormone melatonin
Melatonin
Regulates sleep/wake cycles
Thymus
Located in the upper thoracic cavity over the heart; produces the hormone thymosin
Thymosin
Regulates maturation of T-lymphocytes
Ovaries
Located in the pelvic cavity; produces the steroid sex hormones:
>Estrogen
>Progesterone
Estrogen
Stimulates secondary sex characteristics at puberty, plays role in regulating ovarian and uterine cycles
Progesterone
Works with estrogen to maintain uterine cycle
Testes
Located in the scrotum; produces the steroid sex hormone Testosterone
Testosterone
Stimulates spermatogenesis and secondary sex characteristics at puberty
