Endocrine System Flashcards
The PRODUCT OF THE ENDOCRINE GLAND is called?
Hormone
What are the THREE KINDS OF SECRETION?
- Autocrine
- Paracrine
- Juxtracrine
In this secretion, LOCALIZED DISPERSAL IN INTERSTITIAL FLUID or THROUGH SHORT OF LOOPS OF BLOOD VESSELS as when gastrin made by pyloric G cells reach target cells in the fundic glands.
Paracrine Secretion
In this secretion, the SIGNALING MOLECULES REMAIN ON THE SECRETING CELL’S SURFACE, or adjacent extracellular matrix and affect target cells when the cells make contact.
Juxtacrine Secretion
In this secretion, CELLS MAY PRODUCE MOLECULES that act on themselves or on cells of the same type.
Autocrine Secretion
Pituitary gland also known as?
Hypophysis
It lies below the brain in a small cavity on the SPHENOID BONE.
Sella Turcica
The ORAL COMPONENT ARISES AS AN OUTPOCKETING of ectoderm from the roof of the primitive mouth and grows cranially, forming a structure called?
Hypophyseal (Rathke) Pouch
What are the parts of the POSTERIOR PITUITARY GLAND (neurohypophysis)?
- Infundibulum Stalk
- Pars nervosa
What are the parts of the ANTERIOR PITUITARY GLAND (adenohypophysis)?
- Pars distalis (Anterior lobe)
- Pars tuberalis
- Pars intermedia (Posterior lobe)
List of anterior pituitary secretes:
- Adrenocorticotropic hormone (ACTH)
- Follicle-stimulating hormone (FSH)
- Growth hormone (GH)
- Luteinizing hormone (LH)
- Melanocyte-stimulating hormone (MSH)
- Prolactin (PRL)
- Thyroid-stimulating hormone (TSH)
List of posterior pituitary releases:
- Antidiuretic hormone (ADH)
- Oxytocin (OT)
Bundles of axons called?
Hypothalamic-Hypophyseal Tract
The peptide hormones ADH (antidiuretic hormone) and oxytocin are synthesized by large neurons in what?
- Supraoptic Nuclei
- Paraventricular Nuclei
This SUPPLY THE MEDIAN EMINENCE and INFUNDIBULAR STALK.
Superior Hypophyseal Arteries
Superior Hypophyseal Arteries divides into?
- Primary plexus of fenestrated capillaries
- Secondary capillary plexus
What are the THREE PARTS of the ANTERIOR PITUITARY?
- Pars Distalis
- Pars Tuberalis
- Pars Intermedia
The COMMON STAINS suggest two broad groups of cells in the PARS DISTALIS with different staining
affinities:
Chromophils and Chromophobes
What are the TWO PARTS of CHROMOPHILS?
Basophils and Acidophils
Acidophils secretes?
Somatotrophs and Lactotrophs
Basophils secretes?
Cortitrophs, Gonadotrophs, and Thyrotrophs
STAIN WEAKLY, WITH FEW OR NO SECRETORY GRANULES, and also represent a heterogeneous group.
Chromophobes
Gonadotrophs secrete two different glycoproteins:
- Follicle-stimulating hormone
- Luteinizing hormone
What do you call the Gonadotrophs secretes?
Interstitial cell-stimulating hormone (ICSH)
A SMALLER FUNNEL-SHAPED REGION surrounding the infundibulum of the neurohypophysis.
MOST CELLS ARE GONADOTROPHS.
Pars Tuberalis
A NARROW ZONE LYING BETWEEN the pars distalis and the pars nervosa, it contains BASOPHILS (corticotrophs), chromophobes, and small, colloid-filled cysts derived from the lumen of the embryonic hypophyseal pouch
Pars Intermedia
Pars intermedia produce?
Melanocyte-stimulating hormone (MSH)
It CONTROLS THE ACTIVITIES of the cells of the anterior pituitary gland.
Hypothalamic hormones
Fill in the blank:
Most of these hormones are __ that stimulate secretion by specific anterior pituitary cells.
Releasing hormone
It BLOCKS HORMONE SECRETION in specific cells of the adenohypophysis.
Inhibiting hormone
Another mechanism CONTROLLING THE ACTIVITY of the anterior pituitary cells.
Negative Feedback
Hormone secretion in the anterior pituitary is AFFECTED BY?
Other hormones from outside the feedback loop or even outside the
major target tissues.
The Posterior pituitary (neurohypophysis) consists of?
- Pars Nervosa
- Infundibulum Stalk
A HIGHLY BRANCHED GLIAL CELLS that resemble astrocytes.
Pituicytes
Axonal dilation where ADH and OXYTOCIN HORMONES are being stored before release to capillaries in the posterior pituitary.
Herring bodies
The NEUROSECRETORY BODIES contain membrane-enclosed granules with either oxytocin or ADH bound to 10-kDa carrier proteins called?
Neurophysin I and II
The adrenal gland also known as?
Suprarenal gland
This PAIRED FLATTENED STRUCTURES with a half-moon shape organs lying near the superior poles of the kidneys, embedded in the pararenal adipose tissue and fascia.
Adrenal gland
Each gland has two concentric regions:
- Yellowish: Adrenal Cortex
- Reddish-brown central: Adrenal Medulla
Contains exceptionally profuse SER and MITOCHONDRIA.
STEROIDS HORMONE diffuses freely from cells through the plasma membrane.
Adrenal Cortex
What are the THREE CONCENTRIC REGION of ADRENAL CORTEX?
- Zona glomerulosa
- Zona fasciculata
- Zona reticularis
It consists of CLOSELY PACKED, ROUNDED, or ARCHED CORDS of columnar or pyramidal cells WITH MANY CAPILLARIES.
The principal product is ALDOSTERONE the MAJOR REGULATOR OF SALT BALANCE.
The OUTERMOST, 15% of the cortex.
Zona glomerulosa
It consists of LONG CORDS OF LARGE POLYHEDRAL CELLS, one or two cells thick, separated by fenestrated sinusoidal capillaries.
These cells secrete GLUCOCORTICOIDS, especially cortisol, MAJOR REGULATOR OF SUGAR.
The MIDDLE, 65-80% of the cortex.
Zona fasciculata
It consists of SMALLER CELLS in a network of irregular cords.
Also, produces cortisol but primarily secretes WEAK ANDROGENS, including DEHYDROEPIANDROSTERONE (DHEA) or TESTOSTERONE, a MAJOR REGULATOR OF SEX.
The INNERMOST, 10% of the cortex.
Zona Reticularis
In Zona Reticularis, secretion in these cells is also stimulated by?
ACTH with regulatory feedback
It is composed of LARGE, PALE STAINING POLYHEDRAL CELLS arranged in cords or clumps and supported by a reticular fiber network.
Adrenal Medulla
Medullary parenchymal cells, known as?
Chromaffin Cells
POSTGANGLIONIC NEURONS, LACKING AXONS, and DENDRITES
and specialized as secretory cells; for the storage and secretion of catecholamines.
(epinephrine & norepinephrine)
Chromaffin Cells
This INCREASES HEART RATE, DILATES BRONCHIOLES, and DILATES ARTERIES of CARDIAC and SKELETAL MUSCLE.
Epinephrine
Constricts vessels of the DIGESTIVE SYSTEM and SKIN, INCREASING BLOOD FLOW TO THE HEART, MUSCLES, and BRAIN.
Norepinephrine
BOTH CATECHOLAMINES, together with Ca2+ and ATP, are bound in granular storage complexes with 49-kDa proteins called?
Chromogranins
Pancreatic islets also known as?
Islet of Langerhans
A COMPACT SPHERICAL or OVOID MASSES of ENDOCRINE CELLS embedded within the acinar exocrine tissue of the pancreas.
Pancreatic Islets
Most islet cells are?
Acidophilic or Basophilic with fine cytoplasmic granules.
It SECRETE PRIMARILY GLUCAGON and is abundant and scattered through most islets.
α or A cells
It PRODUCES INSULIN that is about TWICE AS ABUNDANT as α cells and also usually scattered.
β or B cells
It SECRETING SOMATOSTATIN is much LESS ABUNDANT than the other major cell types.
δ or D cells
It SECRETES PANCREATIC POLYPEPTIDE, A minor fourth cell type, MORE COMMON in islets LOCATED WITHIN THE HEAD OF PANCREAS.
PP cells
Collectively these DISPERSED CELLS, as well as similar cells in the respiratory mucosa, make up the?
Diffuse Neuroendocrine System (DNES)
Many cells of the DNES ARE STAINED BY SOLUTIONS OF CHROMIUM SALTS and have therefore been called?
Enterochromaffin Cells
This STAINING WITH SILVER NITRATE is sometimes called?
Argentaffin Cells
It is LOCATED ANTERIOR and INFERIOR TO THE LARYNX and consists of TWO LOBES united by an isthmus.
Thyroid Gland
Follicular Cells or Thyrocytes secrete?
- Thyroxine (tetra-iodothyronine or T4)
- Tri-iodothyronine (T3)
Parafollicular Cells or C Cells secrete?
Calcitonin
Thyroid colloid contains the LARGE GLYCOPROTEINS.
Thyroglobulin
The production of thyroid hormone and its control.
- Production of thyroglobulin
- Uptake of iodide
- Iodination of tyrosyl residues
- Formation of T3 and T4 (thyroxine)
- Endocytosis of iodinated thyroglobulin
- Secretion of T3 and T4
FOUR SMALL OVOID MASSES that is located on the back of the thyroid gland.
Parathyroid Gland
ENDOCRINE CELLS of the PARATHYROID GLANDS that contain irregularly shaped cytoplasmic granules with PTH.
Principal (Chief) Cells
It REGULATE CALCIUM LEVELS by
ACTING ON BONE, KIDNEY, and INTESTINE.
Parathyroid hormone
Fill in the blanks:
Much SMALLER populations of ___, often clustered, are sometimes also present in parathyroid glands, MORE COMMONLY IN OLDER INDIVIDUALS.
Oxyphil Cells
Pineal Gland is also known as?
Epiphysis Cerebri
Prominent and abundant secretory
cells that PRODUCE MELATONIN.
Pinealocytes
Pineal landmarks are the concretions called?
Corpora Aranacea (Brain Sand)
Which of the following accurately describes glucocorticoids?
A. Include the steroid hormone aldosterone
B. Are produced in response to stimulation by ACTH
C. Are produced primarily by the zona glomerulosa
D. Typically enhances the immune response
E. Include the steroid hormone DHEA
B. Are produced in response to stimulation by ACTH
Pregnant women who have begun labor but in whom this process is no longer progressing are often given an IV injection of Pitocin to stimulate uterine contractions and facilitate parturition. Pitocin is a trade name of a hormone produced in what endocrine tissue?
A. Pars distalis
B. Ovarian follicles
C. Pars nervosa
D. Placenta
E. Pars tuberalis
C. Pars nervosa
What hormone is produced in response to decreased blood calcium levels?
A. Pancreatic polypeptide
B. β-Endorphin
C. Somatostatin
D. Calcitonin
E. PTH
E. PTH
Addison disease (or adrenal cortex insufficiency) is a disorder, usually autoimmune in origin, which can cause degeneration and cell loss in the adrenal glands. Fludrocortisone is a mineralocorticoid used to treat Addison patients. Response to this drug indicates which region of the adrenal glands was involved in the disease?
A. Medulla
B. Zona glomerulosa
C. Zona reticularis
D. Macula densa
E. Zona fasciculate
B. Zona glomerulosa
A glucagonoma is a malignant tumor consisting of what cells?
A. A or α cells
B. B or β cells
C. Chromophils
D. D or δ cells
E. Mucous cells
A. A or α cells
Secretion, chemical modification and storage, reuptake, and digestion of a protein occur in epithelial cells of what endocrine tissue?
A. Neurohypophysis
B. Adrenal medulla
C. Adenohypophysis
D. Thyroid gland
E. Neuroendocrine cells in the duodenum
D. Thyroid gland
Secretion in what neuroendocrine cell is controlled directly by neural activity and involves a hormone that generally slows metabolic
activity at night?
A. Pituicyte
B. Melanocyte
C. Herring body of the neurohypophysis
D. Chromaffin cell
E. Pinealocyte
E. Pinealocyte
Some mammalian endocrine tissues or cells can be experimentally transplanted to other well-vascularized sites (such as the oral mucosa) in genetically similar hosts and the tissue’s function continues normally and with proper regulation. The pars distalis is not a good candidate for such transplantation studies for one of the following reasons?
A. More severe rejection of neurally related tissue occurs compared
with other endocrine organs.
B. Its hormonal source is unavailable after its axonal connections to
the hypothalamus are disrupted.
C. Its cells stop functioning when separated from the hypothalamo-hypophyseal portal system.
D. Neogenesis of blood vessels into this tissue will not occur at the
transplant site.
E. The vascular wall of the superior hypophyseal arteries is
unique.
C. Its cells stop functioning when separated from the hypothalamo-hypophyseal portal system.
A 45-year-old corporate executive presents with the primary complaint of “always being tired.” She comments that she has been tired for 4 months even though she is sleeping more. She complains of
being unable to finish chores at home and “dragging at work.” She
indicates that she is often constipated and is intolerant of cold. She is continuously turning the thermostats in the house and office to higher temperatures, to the dismay of family and coworkers. She also complains that her skin is very dry; the use of lotions and creams has not helped the dryness. A biopsy of her thyroid gland shows dense lymphocytic infiltration with germinal centers throughout the parenchyma and a battery of further tests is carried out, which also suggest thyroiditis. Which of the following results of blood tests
would be most likely in this patient?
A. Elevated TSH levels
B. Elevated T3 and T4 levels
C. Autoantibodies to the thyroid hormone receptor
D. Elevated calcitonin levels
E. Elevated glucocorticoid levels
A. Elevated TSH levels
A 9-year-old girl, the youngest of four daughters, is taken to the pediatrician by her mother, who indicates that for at least 4 months the child has seemed “hyperactive,” unable to sleep soundly because “she says her room is too hot,” and no longer able to concentrate in school. Upon questioning, the mother also remembers that her daughter’s periods also began within the past few months. Blood tests indicate high levels of estrogen-related hormones and cortisol. Which of the following tentative diagnoses is consistent with all of these symptoms?
A. Graves disease, caused by antibodies stimulating the TSH receptor
B. A defect in the PVN
C. Excessively active cells of the adrenal cortex zona glomerulosa
D. A benign tumor involving cells in the adenohypophysis
E. A disabling mutation in the gene for thyroglobulin
D. A benign tumor involving cells in the adenohypophysis
Medical Application:
Benign PITUITARY ADENOMAS often produce excessive numbers of functional acidophils or basophils.
ADENOMAS involving somatotropic cells can cause?
Gigantism
Medical Application:
Posterior pituitary function can be adversely affected by heritable mutations in the gene for vasopressin (ADH) neurophysin, by compression from a tumor in adjacent tissues, and by HEAD TRAUMA.
A disorder characterized by the inability to concentrate urine, which LEADS TO FREQUENT URINATION.
Polyuria and Polydipsia
Medical Application:
It is a disorder, usually AUTOIMMUNE IN ORIGIN, which causes degeneration in any layer of the ADRENAL CORTEX, with concomitant LOSS OF GLUCOCORTICOIDS, MINERALOCORTICOIDS, or ANDROGEN PRODUCTION.
Addison disease or adrenal cortical insufficiency
Medical Application:
In the ADRENAL MEDULLA, BENIGN PHEOCHROMOCYTOMAS periodically secrete high levels of catecholamines that cause swings in blood pressure.
Hypertension and Hypotension
Medical Application:
Diabetes mellitus is characterized by loss of the insulin effect and a subsequent failure of cells to take up glucose, leading to elevated blood sugar.
Caused by the LOSS OF THE β cells from autoimmune destruction and is treated by regular injections of insulin.
Hyperglycemia. Type 1 diabetes or insulin-dependent diabetes mellitus (IDDM)
Medical Application:
β cells are PRESENT BUT FAILED TO PRODUCE adequate levels of insulin in response to hyperglycemia, and the peripheral target cells “resist” or no longer respond to the hormone.
Type 2 diabetes or non–non-insulin-dependent diabetes mellitus (NIDDM)
Medical Application:
It is an AUTOIMMUNE DISORDER in which antibodies produce chronic stimulation of the follicular cells and release of thyroid hormones (hyperthyroidism).
Graves Disease
Medical Application:
DIMINISHED SECRETION OF PTH can cause bones to become more mineralized and denser and striated muscle to exhibit abnormal contractions due to inadequate calcium ion concentrations.
Hypoparathyroidism
