Endocrine Glands & Hormones
This master gland, located at the base of the brain, secretes growth hormone and TSH.
What is the pituitary gland (anterior pituitary)?
Steroid hormones exert their effects by binding to receptors located here, rather than on the cell surface.
What are intracellular (cytoplasmic or nuclear) receptors?
Sperm cells are produced through this process, which occurs in the seminiferous tubules.
What is spermatogenesis?
This structure, formed after ovulation, secretes progesterone and estrogen to maintain the uterine lining.
What is the corpus luteum?
A patient presents with excessive thirst, frequent urination, and high blood glucose. A lack of insulin production points to this type of diabetes.
What is Type 1 Diabetes Mellitus (T1DM)?
This adrenal hormone is released in response to stress and raises blood glucose by stimulating glycogenolysis.
What is cortisol (a glucocorticoid)?
This second messenger is generated when a G-protein-coupled receptor activates adenylyl cyclase.
What is cAMP (cyclic adenosine monophosphate)?
These cells in the testes are stimulated by LH to produce testosterone.
What are Leydig cells (interstitial cells)?
Name the three phases of the uterine (endometrial) cycle in order.
What are the menstrual phase, proliferative phase, and secretory phase?
Graves' disease is an autoimmune hyperthyroid condition in which antibodies mimic this pituitary hormone, causing continuous thyroid stimulation.
What is TSH (thyroid-stimulating hormone)?
This hormone, secreted by the thyroid, lowers blood calcium by inhibiting osteoclast activity.
What is calcitonin?
This type of feedback loop is responsible for the LH surge that triggers ovulation.
What is positive feedback?
Sperm mature and are stored in this comma-shaped structure on the posterior side of each testis.
What is the epididymis?
Rising estrogen levels from the dominant follicle exert this effect on the anterior pituitary just before ovulation, triggering the LH surge.
What is positive feedback?
A newborn with a congenital absence of the thyroid gland will develop this condition, characterized by severe intellectual disability and growth failure, if untreated.
What is cretinism (congenital hypothyroidism)?
The zona glomerulosa of the adrenal cortex secretes this mineralocorticoid that regulates sodium reabsorption in the kidneys.
What is aldosterone?
In the hypothalamic-pituitary-thyroid axis, rising T3/T4 levels inhibit TRH and TSH release. Name the principle this demonstrates.
What is negative feedback (inhibition)?
These blood-testis barrier-forming cells also secrete inhibin and androgen-binding protein under FSH stimulation.
What are Sertoli cells (sustentacular cells)?
This layer of the uterus, shed during menstruation, is known as the functionalis and is rebuilt under estrogen during the proliferative phase.
What is the endometrium (stratum functionalis)?
Cushing's syndrome results from chronically elevated cortisol. Identify two classic physical signs of this condition.
What are (any two of): moon face, buffalo hump, central obesity, purple abdominal striae, muscle wasting, hypertension?
This hypothalamic hormone directly inhibits growth hormone release from the anterior pituitary and is also produced in the pancreas to inhibit both insulin and glucagon.
What is somatostatin?
A hormone that requires a second hormone to exert its full effect relies on this phenomenon, such as cortisol's role with epinephrine.
What is permissiveness (or a permissive effect)?
During embryonic development, testosterone is converted to this more potent androgen by 5-alpha reductase to drive development of the prostate and external genitalia.
What is dihydrotestosterone (DHT)?
After fertilization, the developing embryo secretes this hormone to prevent corpus luteum degeneration, which is also the basis of pregnancy tests.
What is hCG (human chorionic gonadotropin)?
A woman has elevated LH:FSH ratio, hyperandrogenism, and anovulatory cycles. She is most likely diagnosed with this endocrine disorder, which is also the most common cause of female infertility.
What is Polycystic Ovary Syndrome (PCOS)?