Flashcards in Histology of Endocrine Organs Deck (86)
3 basic classes of hormones; which one is the largest?
Peptide/protein hormones - largest class, chains of amino acids
Biogenic amines - produced by altering the structure of a specific amino acid
Steroid hormones - derived from cholesterol
_______ stimuli control hormonal release by monitoring levels of ions and nutrients in the blood; ex: release of PTH stimulated by low [Ca]
______ stimuli control hormonal release using nerve signals; ex: release of epinephrine from adrenal gland in response to a signal from sympathetic nerve fibers
_______ stimuli control hormone release by another hormone secreted into bloodstream by another endocrine cell or organ; ex: release of thyroid hormone stimulated by release of TSH from pituitary
Endocrine gland organization consists of ____________ cells that lack a free surface, arranged as cords/follicles and some as isolated individual cells
Endocrine glands are derived from epithelia and are well vascularized, often with ________ endothelium
Primary site where CNS controls endocrine function via pituitary gland
The hypothalamus is located below the _______, behind the _______ and surrounding the _____ ventricle
Thalamus; optic chiasma; 3rd
The pituitary gland, aka the _______, is located inferior to the hypothalamus
It is a small, slightly oval gland housed within the hypophyseal fossa (sella turcica) of the ______ Bone
It is connected to the hypothalamus by a thin stalk of tissue known as the ________
The pituitary gland is partitioned structurally and functionally into what 2 portions?
Anterior = adenohypophysis
Posterior = neurohypophysis
What are the 3 direct targets of hypothalamic hormones?
Anterior pituitary gland (releasing and inhibiting factors)
Kidney and uterus (releasing ADH, oxytocin, in posterior pituitary)
Adrenal medulla (sympathetic innervation)
The hypothalamus releases hormones, collectively referred to as _____ hormones that stimulate or inhibit release of other hormones from the _____pituitary, thus they cause an effect with indirect targets of the hypothalamus
Tropic hormones from the hypothalamus have an indirect influence by stimulating secretion of the anterior pituitary gland; what are some of the indirect targets of this master control?
Thyroid gland —> TSH
Adrenal cortex —> ACTH
Mammary gland —> Prolactin
Gonads (testes or ovaries) —> FSH, LH
Bone and other organs —> growth hormone, melanocyte stimulating hormone
The anterior pituitary is initially derived from an _________ placode leading to ______ pouch by 3 weeks gestation
The pouch loses its connection with the outside and is near final by 8 weeks. It joins the diverticulum from the developing diencephalon of the _____ _____
The _________ forms the posterior pituitary and infundibular stalk; and ______ pouch form the rest of the pituitary
What hormones are released from the pituitary beginning at 7 weeks thru 13 weeks gestation?
ACTH (7 weeks)
GH (8-9 weeks)
TSH and LH (12 weeks)
FSH (13 weeks)
______ = space left between the migrated diencephalon and rathke’s pouch forming anterior and posterior pituitary
Which part of the pituitary constitutes 80% of the gland, comprised of glandular epithelium cells controlled by neurohormones released from the hypothalamus?
The posterior pituitary is comprised of axons from the _______ and glial/support cells.
These axons carry _____ and _____ for storage and release in the posterior pituitary
_______ = part of rathke’s pouch that wraps around the stalk/infundibulum of the pituitary gland
3 components of anterior pituitary
Pars distalis (aka pars anterior)
2 components of posterior pituitary
What is the remnant of rathke’s pouch that may be seen on a microscopic slide of pituitary?
Major cell types of anterior pituitary and what they secrete
Somatotropic cells - GH
Thyrotropic cells - TSH
Corticotropic cells - ACTH and MSH
Gonadotropic cells - FSH and LH
Mammotropic cells - Prolactin
Acidophils are lighter staining cells of the pars anterior. What 2 cell types in this region are acidophils?
Basophils are darker staining cells of the pars anterior. What 3 cell types in this region are basophils?
Acidophils and basophils are the primary cells of interest on a histological slide of the pars anterior. What other landmarks might be seen on these slides?
Chromophobes - don’t stain as well, unknown function
Sinusoidal (fenestrated) capillaries
On viewing a histological slide, you note small basophils and colloid-filled follicles lined by cuboidal epithelium as well as the appearance of a cleft. What part of the pituitary is this?
[note this is rudimentary in adults; found b etween pars distalis and pars nervosa]
T/F: the pars nervosa is continuous with the median eminence of the hypothalamus via the infundibular stalk
What are the components of the pars nervosa (specifically those that can be seen on histological slide)
Hypothalamic unmyelinated axons - herring bodies = expanded axonal nerve terminals storing ADH/oxytocin
Pituicytes (glia-like) supporting the nerve fibers
The infundibulum suspends the pituitary gland from the hypothalamus.
The neural portion (infundibular stalk) is part of the _________ connecting the pars nervosa and median eminence of hypothalamus
The ________ portion surrounds the pars tuberalis and envelopes the infundibular stalk, possibly forming a partial or total collar, consisting of numerous cuboidal cells arranged in cords