Lecture 18 - Endocrine System Flashcards
the collection of glands and tissues of the body that secrete chemical messengers (hormones) into the blood
endocrine system
what is a hormone?
a chemical messenger that is produced and secreted by an endocrine cell or tissue, travels through the circulatory system to reach other tissues, and acts upon specific target cells within the tissues
the prescence or abscence of a receptor determines the cell’s:
response to a hormone
changing the number of receptors at a certain tissue changes the cell’s:
sensitivity to the hormone
the nervous system has ______ activity, while the endocrine system has ______ activity
highly specific, widespread
how long is the duration of nervous system action versus endocrine system action?
nervous system = short term (milliseconds to minutes)
endocrine system = long duration (minutes to days)
while the nervous system is better for creating rapid responses to environmental stimuli, the endocrine system is better for:
regulation of ongoing processes such as growth
endocrine gland located anterior to the trachea and just inferior to the larynx; it is anchored to the first 2-3 tracheal rings and has a butterfly shape
thyroid gland
the right and left lobes of the thyroid gland are joined by an:
isthmus
thyroid follicles are filled with a viscous protein-rich fluid called _____, and are surrounded by follicular cells called _____
colloid, T-thyrocytes
T-thyrocytes produce a large protein called _____, and store it in the _____ of the follicle
thyroglobulin (Tg), lumen
the T-thyrocytes pump _____ into the lumen, and enzymes on their luminal surface will add _____ to the _____
iodine, iodine, thyroglobulin (Tg)
hormone which induces thyrocytes to remove thyroglobulin from the lumen, cleave off T3, T4, and release them into the blood
thyroid stimulating hormone (TSH)
thyroid hormones are derivatives of:
tyrosine
the thyroid releases mainly _____, but _____ is the more active form. peripheral tissues can convert ______ to ______. both regulate ______
thyroxine (T4), triiodothyronine (T3), T4, T3, metabolism
too little thyroid hormone regulation leads to:
weight gain, fatigue, depression
too much thyroid hormone regulation leads to:
weight loss (muscles), anxiety, difficulty sleeping, irregular heartbeat
the hypothalamus and pituitary act as master regulators of:
the endocrine system
the anterior lobe of the pituitary gland is known as the:
adenohypophosis
the posterior lobe of the pituitary gland is known as the:
neurohypophosis
part of the pituitary which contains cuboidal epithelial cells typical of an endocrine gland (produces lots of different hormones)
the adenohypophosis
part of the pituitary which contains nerve terminals and no glandular cells
the neurohypophosis
the adenohypophosis is part of what system?
the hypothalamic-hypophyseal portal system
list the steps that a signal follows through the hypothalamic-hypophyseal portal system
1) neurosecretory cells in the hypothalamus releases hormones into the primary capillary plexus (blood comes in from superior hypophyseal artery)
2) signal travels down the portal veins
3) signals arrive at the secondary capillary plexus
4) endocrine cells in the adenohypophysis receive the signal
5) hormones secreted and sent down efferent veins
list the hormones produced by the adenohypophysis (time to remember your goatflap hormones)
- human growth hormone (hGH)
- thyroid stimulating hormone (TSH)
- follicle stimulating hormone (FSH)
- luteinizing hormone (LH)
- prolactin (Prl)
- adrenocorticotropic hormone (ACTH)
hormone which stimulates body growth and metabolism
human growth hormone (hGH)
hormone that controls thyroid gland function
thyroid stimulating hormone (TSH)
hormones which control secretion of sex hormones and production of gametes
follicle stimulating hormone (FSH) and luteinizing hormone (LH)
hormone which stimulates milk production
prolactin (Prl)