Endocrine System (Short Answer)

Melatonin contributes to the setting of the body's biological clock and promotes sleepiness, particularly by increasing levels during darkness.

The thymus produces hormones that promote the maturation of T cells, which are crucial for destroying microbes and foreign substances.

The pineal gland is located attached to the roof of the third ventricle of the brain and primarily secretes melatonin to help regulate sleep-wake cycles.

<p>Hormones promote the enlargement of breasts and widening of hips, which are secondary sex characteristics in females.</p> Signup and view all the answers

<p>The pineal gland is covered by a capsule formed by the pia mater.</p> Signup and view all the answers

<p>Thymus hormones may also retard or slow down the aging process.</p> Signup and view all the answers

<p>The pituitary gland, known as the master endocrine gland, secretes several hormones that control other endocrine glands.</p> Signup and view all the answers

<p>The nervous and endocrine systems function together as an interlocking 'supersystem' to regulate bodily activities.</p> Signup and view all the answers

<p>The two portions of the infundibular stalk are the anterior pituitary and the posterior pituitary.</p> Signup and view all the answers

<p>The hypothalamus synthesizes at least nine different hormones that regulate various bodily functions.</p> Signup and view all the answers

<p>The anterior pituitary, composed of epithelial tissue, accounts for about 75% of the gland's weight and secretes hormones that regulate growth and reproduction.</p> Signup and view all the answers

<p>The pars intermedia atrophies during human fetal development and ceases to exist as a separate lobe in adults.</p> Signup and view all the answers

<p>Somatotrophic cells in the anterior pituitary secrete growth hormone (GH), which stimulates body growth and regulates metabolism.</p> Signup and view all the answers

<p>The pituitary gland is located in the hypophysial fossa of the sella turcica of the sphenoid bone.</p> Signup and view all the answers

<p>The posterior pituitary, or neurohypophysis, is involved in the release of hormones synthesized by the hypothalamus.</p> Signup and view all the answers

<p>The stretching of the cervix of the uterus triggers the release of oxytocin.</p> Signup and view all the answers

<p>Oxytocin stimulates milk ejection from the mammary glands.</p> Signup and view all the answers

<p>ADH causes the kidneys to return more water to the blood, decreasing urine volume.</p> Signup and view all the answers

<p>Urine output can increase from a normal 1 to 2 liters to about 20 liters a day.</p> Signup and view all the answers

<p>The thyroid gland is butterfly-shaped, with two lobes connected by an isthmus.</p> Signup and view all the answers

<p>The normal mass of the thyroid gland is about 30 grams (1 oz).</p> Signup and view all the answers

<p>Alcohol inhibits the secretion of ADH, leading to increased urine production.</p> Signup and view all the answers

<p>Oxytocin may be partly responsible for feelings of sexual pleasure during and after intercourse.</p> Signup and view all the answers

<p>The thyroid gland typically consists of right and left lobes, connected by an isthmus.</p> Signup and view all the answers

<p>Thyroid follicles are microscopic spherical sacs that make up most of the thyroid gland.</p> Signup and view all the answers

<p>The suprarenal medulla primarily intensifies sympathetic responses in the body by releasing hormones.</p> Signup and view all the answers

<p>Chromaffin cells primarily release norepinephrine (80%) and epinephrine (20%).</p> Signup and view all the answers

<p>The pancreas is a flattened organ measuring about 12.5–15 cm in length, located in the curve of the duodenum, comprising a head, body, and tail.</p> Signup and view all the answers

<p>Pancreatic acini are clusters of exocrine cells that produce digestive enzymes.</p> Signup and view all the answers

<p>There are four types of hormone-secreting cells in the pancreatic islets.</p> Signup and view all the answers

<p>Alpha cells secrete glucagon.</p> Signup and view all the answers

<p>Beta cells secrete insulin, which helps regulate blood sugar levels.</p> Signup and view all the answers

<p>Somatostatin regulates the secretion of other hormones and inhibits insulin and glucagon release.</p> Signup and view all the answers

<p>Beta cells constitute about 70% of the pancreatic islet cells.</p> Signup and view all the answers

<p>The pancreas is uniquely located in the curve of the duodenum, the first part of the small intestine.</p> Signup and view all the answers

<p>Thyrocytes (follicular cells) are the primary cells that form the wall of each thyroid follicle.</p> Signup and view all the answers

<p>Under the influence of TSH, T thyrocytes change from a low cuboidal to a low columnar shape and become active in secretion.</p> Signup and view all the answers

<p>T thyrocytes produce Thyroxine (T4) and Triiodothyronine (T3).</p> Signup and view all the answers

<p>The basement membrane serves to provide structural support and separation for each follicle.</p> Signup and view all the answers

<p>Thyroid hormones promote synapse formation, myelin production, and growth of dendrites in the nervous system.</p> Signup and view all the answers

<p>Thyroid hormones promote the formation of ossification centers and the synthesis of bone proteins.</p> Signup and view all the answers

<p>Alcohol causes dehydration, leading to thirst and headaches typical of a hangover.</p> Signup and view all the answers

<p>T3 and T4 regulate metabolic rate, heart rate, and blood pressure.</p> Signup and view all the answers

<p>Thyroglobulin is a precursor for the synthesis of thyroid hormones T3 and T4.</p> Signup and view all the answers

<p>Parafollicular cells primarily contribute to the regulation of calcium levels in the body.</p> Signup and view all the answers