Biology Flashcards - Endocrine System
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Biology Flashcards - Endocrine System
Biology Flashcards Endocrine System
Biology Flashcards - Endocrine System Kaplan MCAT B86-B95
What is the difference between an endocrine gland and an exocrine gland?
Endocrine glands secrete their hormones directly into the blood stream.
Exocrine glands secrete substances that are transported by ducts.
What is the difference between a tropic hormone and a direct hormone?
Tropic hormones stimulate other endocrine glands, while direct hormones act directly on the target organ.
The anterior pituitary is regulated in part by what other endocrine gland?
The hypothalamus regulates the anterior pituitary.
Name all of the hormones secreted by the anterior pituitary gland.
The anterior pituitary secretes:
Growth Hormone (GH)
Adrenocorticotropic hormone (ACTH)
Thyroid stimulating hormone (TSH)
Luteinizing hormone (LH)
Follicle-stimulating hormone (FSH)
(T/F) Growth hormone promotes bone and muscle growth.
What is the function of prolactin?
Prolactin stimulates the production of breast milk.
What is the target gland of ACTH?
ACTH acts on the adrenal cortex.
What is the function of TSH?
TSH causes the thyroid to uptake iodine and produce thyroid hormone.
(T/F) LH and FSH are secreted only in females.
False, LH and FSH are produced and secreted in males as well as females.
Name the hormones synthesized by the posterior pituitary.
None. The posterior pituitary stores hormones (oxytocin and ADH) that are synthesized in the hypothalamus.
What two hormones are released by the posterior pituitary and what are their functions?
Oxytocin increases the strength of contractions during childbirth.
Antidiuretic hormone (ADH, vasopressin) promotes the absorption of water in the nephron.
(T/F) The hypothalamus regulates both the anterior and the posterior pituitary through the hormone secretion and neurosecretory cells.
Name the hormones secreted by the thyroid gland.
The thyroid gland secreted thyroxine and triiodothyronine (collectively known as thyroid hormones), as well as calcitonin.
How do thyroid hormones affect metabolism?
Thyroid hormones increase metabolism.
How does calcitonin affect the level of Ca
in blood plasma?
Calcitonin decreases blood plasma Ca
What hormone does the parathyroid gland produce and what is its function?
The parathyroid secretes parathyroid hormone, which serves to increase blood plasma Ca
Name the three types of hormones secreted by the adrenal cortex.
The three types of hormones are glucocorticoids, mineralocorticoids, and cortical sex hormones.
What is the function of cortisol?
Cortisol is a glucocorticoid that increases the blood's glucose level.
What important mineralocoricoid is released by the adrenal cortex?
Aldosterone is an important mineralocorticoid released by the adrenal cortex.
Which endocrine gland secretes epinephrine and norepinephrine?
The adrenal medulla secretes epinephrine and norephinephrine.
(T/F) Epinephrine and norepinephrine return the body to its resting state and increase nutrient absorption.
False, they slow down digestion and increase the basal metabolic rate.
What are some of the effects of epinephrine?
Epinephrine effects include:
increased heart rate
increased blood glucose level
increased blood supply to the brain, muscle, and heart
decreased digestion and excretion
Which endocrine organ secretes insulin and glucagon?
The pancreas secretes insulin and glucagon.
How does glucagon affect the blood glucose levels?
Glucagon increases blood glucose levels.
How does insulin affect the blood glucose levels?
Insulin decreases blood glucose levels.
(T/F) Too much insulin causes hypoglycemia.
What is the function of somatostatin?
Somatostatin inhibits both glucagon and insul secretion.
(T/F) The testes secret testosterone.
Which two hormones are secreted by the ovaries?
The ovaries secrete estrogen and progesterone.
What are the four phases of the menstrual cycle?
The four phases of the menstrual cycle are follicular phase, ovulation, luteal phase, and menstruation.
What is the corpus luteum?
The corpus luteum develops from a ruptured follicle in the ovary and secretes estrongen and progesterone.
(T/F) The pineal gland secretes melatonin.
How do peptide hormones act on their target cells?
Peptide hormones bind to receptors on the cell membrane, thereby initiating a chain of reactions inside the cell (secondary messengers).
How do steroid hormones act on their target cells?
Steroid hormones pass through the cell membrane and act directly inside the cell.
(T/F) Amino-acid-derived hormones act on their target cells directly.
False, some amino-acid-derived hormones act on their cells directly, while others behave as peptide hormones and use messengers.