Endocrine System - Anatomy Flashcards
Ductless glands
Endocrine glands
Major Endocrine organs
Pituitary, Adrenals, Thyroid, Pineal
Endocrine components within solid organs
Testis, Ovaries, Pancreas, Kidneys
TOP K
Diffuse neuroendrocrine system
GI, Respiratory system
Location of the pituitary gland
Sella turcica
Sella turcica is a part of which bone in the skull?
Sphenoid bone
Also known as Neurohypophysis
Posterior Pituitary
Also known as Adenohypophysis
Anterior Pituitary
Weight and Dimensions of Pituitary gland
0.5g (adults)
1.0 - 1.5g (children)
10 x 13 x 16 cm
Embyonically, the pituitary gland is from?
- Developing brain
- Developing oral cavity
Largest area of anterior pituitary gland
75% of the adenohypophysis
Pars distalis
Cells found in anterior pituitary gland
- Chromophils
- Chromophobes
Most abundant cells in Pars distalis?
Least?
Most abundant - Somatotrophs
Least - Thyrotrophs
What are the acidophils and basophils? Color?
Acidophils (red/orange) - Somatotrophs, Lactotrophs
Basophils (blue/purple) - Corticotrophs, Gonadotrophs, Thyrotrophs
Somatotrophs secrete?
Gonadotrophs secrete?
Corticotrophs secrete?
- Somatotropin (GH)
- Gonadotropin (FSH and LH)
- POMC (ACTH and B-LPH)
Funnel-shaped region surrounding the infundibulum of the neurohypophysis
Pars tuberalis
Most abundant cells in Pars tuberalis?
Gonadotrophs
FSH and LH
Zone of basophilic cells between pars distalis and pars nervosa
Pars intermedia
Colloid-filled cyst
Pars intermedia is best developed during?
Fetal life
Pars intermedia is best developed during?
Fetal life
Stimulates growth in epiphyseal plates via IGF produced in the liver
Somatotropin
Promotes milk production
Prolactin
Promotes ovarian follicle development and estrogen secretion
FSH
Mnemonic: FESH - estrogen
Promotes ovatian follicle maturation and progesterone secretion
Luteinizing Hormone
Mnemonic: L-HP
Promotes spermatogenesis
FSH
Note: fSh = Sertoli cells - spermatogenesis
Promotes androgen secretion
Luteinizing hormone
LH - Leydig cells - secretes testosterone and androgen
Stimulates secretion of adrenal cortex hormones
ACTH
Adenocorticotropin (ACTH)
Helps regulate lipid metabolism
LPH
Lipotropin
Adrenal cortex hormones
- Zona glomerulosa - Mineralo corticoids - Aldosterone
- Zona fasciculata - Glucocorticoids - Cortisol
- Zona reticularis - Androgens - Sex hormones
Adrenal medulla hormones
Epinephrine, Norepinephrine
Consists of pars nervosa and infundibular stalk, does not contain the cells that synthesizes the hormones
Neurohypophysis/Posterior Pituitary Gland
Supraoptic cell bodies produce?
ADH
Paraventricular cell bodies produce?
Oxytocin
Types of cells in the Posterior Pituitary gland
- Pituicytes - glial cells, resemble astrocytes, most abundant
- Herring bodies - axonal dilations where ADH and Oxytocin accumulate
Hypothalamic - Hypophyseal tract
Hypothalamus
Supraoptic (ADH), Paraventricular (Oxytocin) -> Infundibulum -> Pars nervosa -> Stored
Peptide hormones
ADH and Oxytocin
Blood supply of the Hypothalamic-Hypophyseal Portal system
Internal carotid artery
1. Superior hypophyseal a. - anterior pituitary
- Primary plexus -> infundibulum and median eminence
- Secondart plexus - pars distalis
2. Inferior hypophyseal a. - posterior pituitary
Hypophyseal vein (drainage)
Damaged anterior pituitary gland = Inc. ACTH -> Inc. cortisol
Cushing’s disease
Benign tumor = excessive functional acidophils and basophils = Inc. activity of secretory cells
Pituitary Adenoma
Adenoma - gland - benign
Excessive growth before closure of epiphyseal bone plates
Gigantism
occurs in children
Excessive growth after closure of epiphyseal bone plates
Acromegaly
occurs in adults
Epiphysis cerebrii
Pineal gland
Size of pineal gland
smallest gland
5-8mm x 3-5mm, pinecone shaped connected to the diencephalon by pineal stalk
Origin of Pineal gland
Neuroectoderm in the posterior wall of 3rd ventricle
Major secretory cells of the pineal gland
Pinealocytes
Round shape, basophilic cytoplasm, euchromatic nuclei
Production of Melatonin
Light -> Retina -> Suprachiasmatic nucleus (hypothalamus) -> Pineal gland
Formed by mineralization of Ca2+, Mg salts and extracellular protein; excellent marker of pineal gland
Corpus arenacea (Brain sand)