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Cell Endocrine System
Dr. Chase 2/18-2/22/11
30
Medical
Professional
02/21/2011

Additional Medical Flashcards

 


 

Cards

Term

 

- secretory product that is carried by the bloodstream to target cells

- includes paracrine and autocrine

- relatively long-lasting effects

- 3 categories: steroids, small peptides/proteins, amino acid derivatives

Definition

 

Hormones

Term

 

- cholesterol-derived compounds

- secreted by the adrenal cortex and gonads

- require carrier/binding proteins for transport in plasma

- producing cells contain large quantities of smooth ER and mitochondria often have a tubular-shaped cristae

(not the plate-like shape)

Definition

 

Steroids

Term

 

- secreted by hypothalamus, pituitary, (para)thyroid, & neuroendocrine system

- water-soluble but require carriers

- producing cells look like protein producing cells, but with basal granules (vs apical), lots of rough ER

Definition

 

Small peptide, polypeptide, protein hormones

Term

 

- includes catecholamines, thyroid, prostaglandins, prostacyclins and leukotrienes

Definition

 

Amino acid- and arachidonic acid- derivate hormones

Term

 

- activate second messenger cascades following hormone stimulus

- most have stimulatory effects on cell metabolism

Definition

 

Cell surface receptors

Term

 

- generally influence gene expression following hormone stimulus without the help of a second messenger

- most are in nucleus

Definition

 

Intracellular receptors

Term

 

- type of feedback more common regarding hormone control and production

Definition

 

Negative feedback

Term

 

- type of feedback that occurs during childbirth

Definition

 

Positive feedback

Term

 

- Classic endocrine architecture includes groups of glandular epithelial cells and cords & clumps with fenestrated capillaries

- but NONE of these

Definition

 

Ducts

Term

 

- consists of two lobes, anterior & posterior

- derived from ectoderm of oropharynx (Rathke's pouch) and neuroectoderm of the floor of the 3rd ventricle respectively

- produces tropic and non-tropic hormones and ADH/oxytocin

Definition

 

Pituitary Gland

Term

 

- made up of Pars distalis, intermedia and tuberalis

- also called the adenohypophysis

- produce ACTH, TSH, FSH, LH, GH, PRL

- contain Somatotropes, Lactotropes, Corticotropes, Gonadotropes, and Thyrotropes

Definition

 

Anterior Lobe of Pituitary Gland

Term

 

- bulk of the anterior lobe's structure

- most inferior/anterior portion of pituitary gland

Definition

 

Pars distalis

Term

 

- located between the anterior and posterior lobes of the pituitary gland

- has small follicles of unknown significance

Definition

 

Pars intermedia

Term

 

- surrounds the infundibulum (connecting stalk) of the pituitary gland

Definition

 

Pars tuberalis

Term

 

- derived from the neuroectoderm of the floor of the 3rd ventricle

- consists of the pars nervosa and infundibulum & median eminence

- also called the neurohypophysis

- primarily secrete ADH and oxytocin

- contains pituicytes that interact with its blood supply

Definition

 

Posterior lobe of the Pituitary gland

Term

 

- surrounded by pars tuberalis

- connects hypothalamus to posterior lobe of the pituitary

- where hypothalamic inhibitory & releasing factors are discharged into the primary capillary plexus to perfuse the anterior pituitary

Definition

 

Infundibulum & median eminence

Term

 

superior hypophysial arteries --> primary capillary plexus (pars tuberalis, median eminence & infundibulum)

--> hypophysial portal veins

--> secondary capillary plexus perfuses pars distalis of anterior lobe

--> dural sinuses

Definition

 

Hypophyseal Portal System

(Blood supply to adenohypophysis/infundibulum)

Term

 

- Pars nervosa (neurohypophysis) supplied directly by a capillary plexus from thiese arteries

Definition

 

Inferior hypophysial arteries

Term

 

target cells = other endocrine glands

Examples:

Adrenocorticotrophic hormone (ACTH)

Thyroid stimulating hormone (TSH, thyrotropin)

Follicle-stimulating hormone (FSH)

Luteinizing hormone (LH)

Definition

 

Tropic hormones

Term

 

Target cells = NOT endocrine cells

Examples:

Growth hormone (GH)

Prolactin (PRL)

Definition

 

Non-tropic hormones

Term

 

- acidophils (stain redish)

- produce growth hormone

- synthesis increased by hypothalamic growth hormone-releasing hormone (GHRH), thyroid hormone and cortisol

- release inhibited by hypothalamic somatostatin

Definition

 

Somatotropes (GH cells)

Term

 

- acidophil (stains red)

- secrete prolactin

- production stimulated by hypothalamic TRH and other factors associated with pregnancy/nursing

- production inhibited by hypothalamic dopamine

Definition

 

Lactotropes (PRL cells, Mammotrophs)

Term

 

- Basophilic (stain purple)

- produce proopiomelancortin (POMC), which is then cleaved to ACTH, beta-lipotrophic hormone, melanocyte-stimulating hormone, and beta-endorphin

- Stimulated by corticotropin-releasing hormone (CRH)

Definition

 

Corticotropes (ACTH cells)

Term

 

- basophilic (stain purple)

- produce FSH and/or LH

- FSH/LH act on gonads, both ovaries & testes

- stimulated by gonadotropin-releasing hormone (GnRH)

Definition

 

Gonadotropes (FSH & LH cells)

Term

 

- basophilic (stain purple)

- stimulated by hypothalamic thyrotropin-releasing hormone (TRH)

Definition

 

Thyrotropes (TSH cells)

Term

 

- posterior pituitary contains non-myelinated axons and nerve endings from hypothalamus that release hormones near capillary network (from inferior hypophysial arteries)

- the secretory nerve endings have swellings called

Definition

 

Herring bodies

Term

 

- ADH and oxytocin are produced here

Definition

 

Hypothalamus NOT posterior pituitary

Term

 

- acts on distal convoluted tubule & collecting ducts to reabsorb water

- release is controlled through hypothalamic osmoreceptors and feedback from sensory bodies

(carotid body, juxtaglomerular apparatus)

Definition

 

ADH (arginine vasopressin)

Term

 

- promotes smooth muscle contraction

(uterine & myoepithelial cells of mammary gland)

- feedback from cervix, vagina and nipple promote its release

Definition

 

Oxytocin

Term

 

- specialized glial cells associated with posterior lobe capillaries

Definition

 

Pituicytes

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