Endocrine System

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What is the approximate length of the adrenal glands in adults?

2-3 cm

9-10 cm

7-8 cm

4-6 cm (correct)

What is the function of the unmyelinated axons in the posterior pituitary?

To support the glia cells

To release hormones into the bloodstream (correct)

To transmit neural signals

To stimulate the hypothalamic nuclei

What is the term for the swellings on the axons in the posterior pituitary?

Herring bodies

Pituicytes

Neurosecretory bodies (correct)

Axonal swellings

What is the approximate percentage of the adrenal cortex comprised by the zona reticularis?

10% Signup and view all the answers

What is the main cell type present in the pars nervosa of the posterior pituitary?

Pituicytes Signup and view all the answers

What is the main difference in staining between cells of the zona reticularis and those of other zones?

Cells of the zona reticularis contain fewer lipid droplets and more lipofuscin pigment. Signup and view all the answers

What is the primary function of thyroid-stimulating hormone (TSH) from the anterior pituitary?

Stimulation of thyroid hormone production and secretion Signup and view all the answers

What is the approximate duration of thyroid hormone supply from follicles in the absence of additional synthesis?

Up to 3 months Signup and view all the answers

What is the term for the dense connective tissue covering the adrenal glands?

Capsule Signup and view all the answers

Which embryonic cells give rise to the adrenal cortex?

Mesodermal cells Signup and view all the answers

What is the primary component of thyroid colloid?

Thyroglobulin Signup and view all the answers

What is the approximate weight of the adrenal glands in adults?

8 g Signup and view all the answers

What is the primary hormone produced by the zona reticularis?

Dehydroepiandrosterone (DHEA) Signup and view all the answers

What stimulates the secretion of hormones by the zona reticularis?

Adrenocorticotropic hormone (ACTH) Signup and view all the answers

What is the source of the oxytocin or vasopressin released in the posterior pituitary?

Supraoptic and paraventricular nuclei Signup and view all the answers

What is the consequence of chronic dietary iodine deficiencies on thyroid hormone production?

Decreased thyroid hormone production Signup and view all the answers

What is the result of adrenal cortical insufficiency?

Underproduction of glucocorticoids and mineralocorticoids Signup and view all the answers

What is the function of the capillaries in the posterior pituitary?

To pick up released hormones for distribution Signup and view all the answers

What is the characteristic of the connective tissue separating follicles?

Sparse and reticular Signup and view all the answers

What is the condition resulting from excessive growth of thyroid follicles and enlargement of the thyroid gland?

Goiter Signup and view all the answers

What is the origin of the adrenal medulla?

Neural crest cells Signup and view all the answers

What is the shape of follicular cells in active thyroid glands?

Low columnar Signup and view all the answers

What is the term for the disorder that causes degeneration of any layer of the adrenal cortex?

Addison disease Signup and view all the answers

What is the function of fenestrated capillaries in the thyroid gland?

Transfer of released hormone to the blood Signup and view all the answers

What is the function of the hormones produced by cells of zona glomerulosa in the adrenal glands?

Stimulate renal reabsorption of water and Na+ and secretion of K+ Signup and view all the answers

What is the primary function of thyroglobulin in the thyroid hormone synthesis process?

To contain tyrosyl residues critical for thyroid hormone synthesis Signup and view all the answers

What is the role of Na/I symporters in thyrocytes?

To concentrate dietary iodide in thyroid tissue Signup and view all the answers

Which type of cells in the adrenal glands produce weak androgens?

Cells of zona reticularis Signup and view all the answers

What is the result of decreased levels of circulating iodide?

Increased synthesis of NIS, increasing iodide uptake Signup and view all the answers

What is the function of calcitonin produced by parafollicular or C cells in the thyroid gland?

Lowers blood Ca2+ levels Signup and view all the answers

What is the purpose of the iodide/chloride transporter in thyrocytes?

To pump I– from the thyrocytes into the colloid Signup and view all the answers

Which hormone produced by the pineal gland regulates circadian rhythms?

Melatonin Signup and view all the answers

What is the function of glucagon produced by α cells in the pancreatic islets?

Raises blood glucose levels Signup and view all the answers

What is the characteristic of the thyroid hormone production process in thyrocytes?

Involves both an exocrine phase and an endocrine phase Signup and view all the answers

Where is thyroglobulin synthesized in the thyrocytes?

In the rough ER Signup and view all the answers

What is the function of parathyroid hormone (PTH) produced by chief cells in the parathyroid glands?

Raises blood Ca2+ levels Signup and view all the answers

What is the function of insulin produced by β cells in the pancreatic islets?

Lowers blood glucose levels Signup and view all the answers

What is the consequence of increased iodide uptake in thyroid tissue?

Increased production of thyroid hormones Signup and view all the answers

What is the primary function of the follicular lumen?

To store thyroglobulin released from apical vesicles Signup and view all the answers

What can densely calcified corpora arenacea be used for in radiological examinations of the brain?

To locate the midline of the pineal gland Signup and view all the answers

What is the approximate proportion of somatotrophs in the pars distalis in humans?

One half Signup and view all the answers

Which type of cells in the pars distalis secrete two different glycoproteins?

Gonadotrophs Signup and view all the answers

What is the main protein synthesized in corticotrophs?

Pro-opiomelanocortin (POMC) Signup and view all the answers

What is the function of the capillaries in the pars distalis?

To carry off secreted hormones into the general circulation Signup and view all the answers

Which type of cells in the pars distalis are the least abundant?

Thyrotrophs Signup and view all the answers

What is the characteristic of the staining of chromophobes in the pars distalis?

Poorly stained Signup and view all the answers

What is the purpose of the cords of acidophils and basophils in the pars distalis?

To carry off secreted hormones into the general circulation Signup and view all the answers

What is the characteristic of the hormones produced by the pars distalis?

They have widespread functional activities Signup and view all the answers

What is the primary source of the neural connection of the pituitary gland to the brain?

Hypothalamic-hypophyseal tract Signup and view all the answers

What is the histological characteristic of the pars nervosa and pars intermedia?

Resemble CNS tissue Signup and view all the answers

What is the function of the vascular portal system in the pituitary gland?

Carries small regulatory peptides from the hypothalamus to the adenohypophysis Signup and view all the answers

What is the embryological origin of the pars nervosa and infundibular stalk?

Ectoderm Signup and view all the answers

What is the anatomical relationship between the pituitary gland and the hypothalamus?

The pituitary gland is connected to the hypothalamus at the base of the brain Signup and view all the answers

What is the histological difference between the pars distalis and pars nervosa?

The pars distalis has a different level of staining than the pars nervosa Signup and view all the answers

What is the component of the pituitary gland that wraps around the infundibulum?

Pars tuberalis Signup and view all the answers

What is the significance of the pituitary gland's neural connection to the brain?

It is necessary for the regulation of hormone secretion Signup and view all the answers

What is the primary function of aldosterone in the distal convoluted tubules?

To stimulate Na+ reabsorption Signup and view all the answers

What is the primary stimulus for aldosterone secretion?

Angiotensin II Signup and view all the answers

What is the characteristic of the cells in the zona fasciculata?

They are filled with lipid droplets and appear vacuolated Signup and view all the answers

What is the primary function of hormones produced by endocrine glands?

To act on target cells with specific receptors Signup and view all the answers

What is the primary function of cortisol in the liver?

To stimulate glycogen synthesis Signup and view all the answers

What is the characteristic of endocrine cells in terms of their origin?

They are typically epithelial in origin Signup and view all the answers

What is the primary regulator of glucocorticoid secretion?

ACTH Signup and view all the answers

What is the difference between endocrine and exocrine glands?

Endocrine glands produce hormones, while exocrine glands produce digestive juices Signup and view all the answers

What is the shape of the cords of cells in the zona glomerulosa?

Columnar or pyramidal Signup and view all the answers

What is the type of capillaries present in the zona fasciculata?

Sinusoidal Signup and view all the answers

What is the purpose of the vascularized compartment surrounding endocrine glands?

To provide a route for the uptake of hormones by capillaries Signup and view all the answers

Which organs, besides specialized endocrine glands, contain endocrine cells?

The gut, kidneys, testis, and ovaries Signup and view all the answers

What type of hormones are produced by the cells in the zona fasciculata?

Glucocorticoids Signup and view all the answers

What is the mechanism by which hormones produced by endocrine cells act on target cells?

Through the release of hormones into the bloodstream Signup and view all the answers

What is the significance of the distribution of hormones through the circulation?

It allows hormones to act on target cells at a distance from the site of secretion Signup and view all the answers

What is the characteristic of endocrine cells in terms of their aggregation?

They are typically aggregated as cords or clusters Signup and view all the answers

What is the primary function of the hormones produced by cells of the zona glomerulosa?

Regulation of blood mineral levels Signup and view all the answers

Which type of cells in the adrenal glands are involved in the fight-or-flight response?

Chromaffin cells Signup and view all the answers

What is the characteristic feature of the cells of the zona reticularis?

Small size with few lipid droplets Signup and view all the answers

What is the primary hormone produced by the zona fasciculata?

Cortisol Signup and view all the answers

Which layer of the adrenal gland is located next to the medulla?

Zona reticularis Signup and view all the answers

What is the shape of the cells of the zona glomerulosa?

Columnar or pyramidal Signup and view all the answers

What is the function of the capillaries in the adrenal gland?

Supplying oxygen and nutrients to the cells Signup and view all the answers

What is the characteristic feature of the chromaffin cells of the adrenal medulla?

Large pale-staining cells Signup and view all the answers

What is the primary function of pancreatic polypeptide produced by PP cells in the pancreatic islets?

Inhibits secretion of pancreatic enzymes and HCO3– Signup and view all the answers

Which hormone produced by the parathyroid glands raises blood Ca2+ levels by stimulating osteoclast activity?

Parathyroid hormone (PTH) Signup and view all the answers

What is the primary function of melatonin produced by pinealocytes in the pineal gland?

Regulates circadian rhythms Signup and view all the answers

Which cells in the thyroid gland produce calcitonin, a hormone that lowers blood Ca2+ levels?

Parafollicular or C cells Signup and view all the answers

What is the primary function of thyroid hormones produced by follicular cells in the thyroid gland?

Increases metabolic rate Signup and view all the answers

What is the percentage of the pancreas's total volume that is composed of pancreatic islets?

1-2% Signup and view all the answers

What is the main difference between the granules of norepinephrine-secreting cells and those of cells secreting epinephrine?

Electron density Signup and view all the answers

What is the embryonic origin of the pancreatic islets and pancreatic acinar tissue?

Endoderm Signup and view all the answers

What is the characteristic of the cells of the pancreatic islets in terms of their staining?

Basophilic or acidophilic with fine cytoplasmic granules Signup and view all the answers

What is the approximate diameter of most pancreatic islets?

100-200 μm Signup and view all the answers

Which type of cells in the digestive system are responsible for regulating motility and secretions of all types?

APUD cells Signup and view all the answers

What is the characteristic feature of the cells composing the thyroid gland?

They have apical junctional complexes and rest on a basal lamina Signup and view all the answers

What is the name of the cells in the digestive system that demonstrate amine precursor uptake and decarboxylation?

APUD cells Signup and view all the answers

Where is the thyroid gland located?

Anterior and inferior to the larynx Signup and view all the answers

What is the shape of the thyroid gland?

Butterfly-shaped Signup and view all the answers

What is the embryonic origin of the parathyroid glands?

The third and fourth pharyngeal pouches Signup and view all the answers

What type of cells in the parathyroid glands produce parathyroid hormone?

Chief cells Signup and view all the answers

What is the function of the Na+/I– symporter in thyrocytes?

To transport iodide into the thyrocyte Signup and view all the answers

What is the multistep process shown in the diagram?

The synthesis of triiodothyronine (T3) and thyroxine (T4) Signup and view all the answers

What is the characteristic of the cytoplasm of principal cells in the parathyroid glands?

It is pale-staining, slightly acidophilic Signup and view all the answers

In hypoparathyroidism, what would be the effect on striated muscle contractions?

Abnormal contractions due to inadequate calcium ion concentrations Signup and view all the answers

What is the effect of daylight on melatonin release from pinealocytes?

Inhibits melatonin release Signup and view all the answers

In hyperparathyroidism, what would be the effect on blood calcium levels?

Increased blood calcium levels Signup and view all the answers

What is the primary function of the pineal gland?

Regulating daily rhythms of bodily activities Signup and view all the answers

What is the effect of excessive PTH production on cartilage, arteries, and kidneys?

Pathological deposition of calcium Signup and view all the answers

What is the molecular weight of the hormone produced by β cells in the pancreatic islets?

5700-6000 Da Signup and view all the answers

What is the function of the hormone produced by PP cells in the pancreatic islets?

Stimulates activity of gastric chief cells Signup and view all the answers

Which cells in the pancreatic islets produce a hormone that inhibits the release of other islet cell hormones?

δ cells Signup and view all the answers

What is the approximate proportion of β cells in the pancreatic islets?

70% Signup and view all the answers

What is the function of the hormone produced by α cells in the pancreatic islets?

Acts on several tissues to make energy stored in glycogen and fat available Signup and view all the answers

What is the effect of parathyroid hormone on vitamin D activation?

It stimulates vitamin D activation Signup and view all the answers

What is the characteristic of oxyphil cells in the parathyroid gland?

They are much larger than principal cells and have very acidophilic cytoplasm Signup and view all the answers

What is the significance of the parathyroid gland's location on the posterior surface of the thyroid gland?

It is a random anatomical variation with no functional significance Signup and view all the answers

What is the age-related change in the parathyroid gland?

There is an increase in the number of adipocytes Signup and view all the answers

What is the function of the principal cells in the parathyroid gland?

To regulate calcium levels Signup and view all the answers

What is the characteristic of the parathyroid gland's histology?

It is composed of cords of cells with pale-staining cytoplasm Signup and view all the answers

What is the effect of PTH on calcium absorption in the small intestine?

It increases calcium absorption Signup and view all the answers

What is the relationship between the parathyroid gland and the thyroid gland?

The parathyroid gland is embedded in the thyroid gland's capsule Signup and view all the answers

What is the characteristic of the oxyphil cells in terms of PTH synthesis?

They have low levels of PTH synthesis Signup and view all the answers

What is the significance of the presence of adipocytes in the parathyroid gland?

It is an age-related change with no functional significance Signup and view all the answers

What is the approximate weight of the pituitary gland in adults?

0.5 g Signup and view all the answers

What is the origin of the oral component of the pituitary gland?

Developing oral cavity Signup and view all the answers

What is the name of the cavity in the sphenoid bone where the pituitary gland lies?

Sella turcica Signup and view all the answers

What are the two glands that make up the pituitary gland?

Adenohypophysis and neurohypophysis Signup and view all the answers

What is the term for the stalk that connects the pituitary gland to the brain?

Infundibulum Signup and view all the answers

What is the primary function of luteinizing hormone (LH) produced by gonadotrophs in the anterior pituitary?

Promotes ovarian follicle maturation and progesterone secretion in women Signup and view all the answers

Which cells in the anterior pituitary produce a hormone that stimulates secretion of adrenal cortex hormones?

Corticotrophs Signup and view all the answers

What is the origin of the adrenal medulla?

From neural crest cells Signup and view all the answers

What is the primary function of prolactin (PRL) produced by lactotrophs in the anterior pituitary?

Promotes milk secretion Signup and view all the answers

Which cell type in the anterior pituitary produces a hormone that stimulates thyroid hormone synthesis, storage, and liberation?

Thyrotrophs Signup and view all the answers

During the fetal period, which parts of the pituitary gland complete development?

Posterior and anterior parts Signup and view all the answers

What is the characteristic of the pars nervosa and infundibular stalk?

Resemble CNS tissue Signup and view all the answers

Which part of the pituitary gland receives blood from the vascular portal system carrying small regulatory peptides?

Adenohypophysis Signup and view all the answers

What is the function of the hypothalamic-hypophyseal tract in the pituitary gland?

Carries small regulatory peptides from the hypothalamus to the adenohypophysis Signup and view all the answers

What is the embryological origin of the pars nervosa and infundibular stalk?

Ectoderm Signup and view all the answers

What is the primary function of the hormones produced by the cells of the anterior pituitary that affect the thyroid gland?

Stimulation of thyroid hormone synthesis, storage, and liberation Signup and view all the answers

Which hormone released in the posterior pituitary during breast-feeding increases the secretion of prolactin?

Oxytocin Signup and view all the answers

What is the function of the pars intermedia in the pituitary gland?

Function not clearly established in humans Signup and view all the answers

Which polypeptide produced mainly in the stomach mucosa acts as a releasing hormone for somatotropin secretion?

Ghrelin Signup and view all the answers

What is the characteristic of the cells of the pars nervosa?

They do not contain the cells that synthesize their hormones Signup and view all the answers

What is the primary function of adrenocorticotropic hormone (ACTH) released from the anterior pituitary?

Causing the release of corticosteroids from the adrenal cortex Signup and view all the answers

Which of the following hormones is produced by the adrenal medulla?

Epinephrine Signup and view all the answers

What is the function of the anterior pituitary hormone that stimulates the thyroid gland to release thyroid hormone?

Stimulating the release of thyroid hormone from the thyroid gland Signup and view all the answers

Which of the following hormones is involved in the regulation of androgen production?

Luteinizing hormone (LH) Signup and view all the answers

What is the function of the releasing hormone that stimulates the release of adrenocorticotropic hormone (ACTH) from the anterior pituitary?

Corticotropin-releasing hormone (CRH) Signup and view all the answers

Which part of the pituitary gland produces melanocyte-stimulating hormone (MSH)?

Pars intermedia Signup and view all the answers

What is the primary function of the hormone produced by cells of the zona glomerulosa in the adrenal cortex?

Regulating electrolyte balance and blood pressure Signup and view all the answers

Which of the following hormones is released from the anterior pituitary and stimulates the growth of bone and cartilage?

Growth hormone (GH) Signup and view all the answers

What is the function of the pituitary hormone that stimulates the mammary gland to produce milk?

Stimulating milk production in the mammary gland Signup and view all the answers

Which of the following pituitary hormones stimulates the release of corticosteroids from the adrenal cortex?

Adrenocorticotropic hormone (ACTH) Signup and view all the answers

What is the primary function of ADH in the kidneys?

To increase the permeability of renal collecting ducts to water Signup and view all the answers

What is the result of benign pituitary adenomas involving somatotropic cells in adults?

Acromegaly Signup and view all the answers

What is the location of the cells that produce oxytocin and ADH?

Posterior pituitary gland Signup and view all the answers

What is the effect of osmoreceptor cells in the hypothalamus on ADH synthesis?

Stimulation of ADH synthesis Signup and view all the answers

What is the result of pituitary adenomas involving somatotropic cells in children before closure of the long bones’ epiphyseal plates?

Gigantism Signup and view all the answers

What is the primary consequence of decreased PTH secretion on striated muscle?

Abnormal contractions due to inadequate calcium ion concentrations Signup and view all the answers

What is the primary function of the pineal gland?

Regulation of daily rhythms of bodily activities Signup and view all the answers

What is the consequence of excessive PTH production on blood calcium levels?

An increase in blood calcium levels that can be deposited pathologically in cartilage, arteries, or the kidneys Signup and view all the answers

What is the factor that promotes melatonin release from pinealocytes?

Darkness Signup and view all the answers

What is the site of development of the pineal gland?

Neuroectoderm in the posterior wall of the third ventricle Signup and view all the answers

Endocrine System

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Questions and Answers

What is the approximate length of the adrenal glands in adults?

What is the function of the unmyelinated axons in the posterior pituitary?

What is the term for the swellings on the axons in the posterior pituitary?

What is the approximate percentage of the adrenal cortex comprised by the zona reticularis?

What is the main cell type present in the pars nervosa of the posterior pituitary?

What is the main difference in staining between cells of the zona reticularis and those of other zones?

What is the primary function of thyroid-stimulating hormone (TSH) from the anterior pituitary?

What is the approximate duration of thyroid hormone supply from follicles in the absence of additional synthesis?

What is the term for the dense connective tissue covering the adrenal glands?

Which embryonic cells give rise to the adrenal cortex?

What is the primary component of thyroid colloid?

What is the approximate weight of the adrenal glands in adults?

What is the primary hormone produced by the zona reticularis?

What stimulates the secretion of hormones by the zona reticularis?

What is the source of the oxytocin or vasopressin released in the posterior pituitary?

What is the consequence of chronic dietary iodine deficiencies on thyroid hormone production?

What is the result of adrenal cortical insufficiency?

What is the function of the capillaries in the posterior pituitary?

What is the characteristic of the connective tissue separating follicles?

What is the condition resulting from excessive growth of thyroid follicles and enlargement of the thyroid gland?

What is the origin of the adrenal medulla?

What is the shape of follicular cells in active thyroid glands?

What is the term for the disorder that causes degeneration of any layer of the adrenal cortex?

What is the function of fenestrated capillaries in the thyroid gland?

What is the function of the hormones produced by cells of zona glomerulosa in the adrenal glands?

What is the primary function of thyroglobulin in the thyroid hormone synthesis process?

What is the role of Na/I symporters in thyrocytes?

Which type of cells in the adrenal glands produce weak androgens?

What is the result of decreased levels of circulating iodide?

What is the function of calcitonin produced by parafollicular or C cells in the thyroid gland?

What is the purpose of the iodide/chloride transporter in thyrocytes?

Which hormone produced by the pineal gland regulates circadian rhythms?

What is the function of glucagon produced by α cells in the pancreatic islets?

What is the characteristic of the thyroid hormone production process in thyrocytes?

Where is thyroglobulin synthesized in the thyrocytes?

What is the function of parathyroid hormone (PTH) produced by chief cells in the parathyroid glands?

What is the function of insulin produced by β cells in the pancreatic islets?

What is the consequence of increased iodide uptake in thyroid tissue?

What is the primary function of the follicular lumen?

What can densely calcified corpora arenacea be used for in radiological examinations of the brain?

What is the approximate proportion of somatotrophs in the pars distalis in humans?

Which type of cells in the pars distalis secrete two different glycoproteins?

What is the main protein synthesized in corticotrophs?

What is the function of the capillaries in the pars distalis?

Which type of cells in the pars distalis are the least abundant?

What is the characteristic of the staining of chromophobes in the pars distalis?

What is the purpose of the cords of acidophils and basophils in the pars distalis?

What is the characteristic of the hormones produced by the pars distalis?

What is the primary source of the neural connection of the pituitary gland to the brain?

What is the histological characteristic of the pars nervosa and pars intermedia?

What is the function of the vascular portal system in the pituitary gland?

What is the embryological origin of the pars nervosa and infundibular stalk?

What is the anatomical relationship between the pituitary gland and the hypothalamus?

What is the histological difference between the pars distalis and pars nervosa?

What is the component of the pituitary gland that wraps around the infundibulum?

What is the significance of the pituitary gland's neural connection to the brain?

What is the primary function of aldosterone in the distal convoluted tubules?

What is the primary stimulus for aldosterone secretion?

What is the characteristic of the cells in the zona fasciculata?

What is the primary function of hormones produced by endocrine glands?

What is the primary function of cortisol in the liver?

What is the characteristic of endocrine cells in terms of their origin?

What is the primary regulator of glucocorticoid secretion?

What is the difference between endocrine and exocrine glands?

What is the shape of the cords of cells in the zona glomerulosa?

What is the type of capillaries present in the zona fasciculata?

What is the purpose of the vascularized compartment surrounding endocrine glands?

Which organs, besides specialized endocrine glands, contain endocrine cells?

What type of hormones are produced by the cells in the zona fasciculata?

What is the mechanism by which hormones produced by endocrine cells act on target cells?

What is the significance of the distribution of hormones through the circulation?

What is the characteristic of endocrine cells in terms of their aggregation?

What is the primary function of the hormones produced by cells of the zona glomerulosa?

Which type of cells in the adrenal glands are involved in the fight-or-flight response?

What is the characteristic feature of the cells of the zona reticularis?

What is the primary hormone produced by the zona fasciculata?

Which layer of the adrenal gland is located next to the medulla?