Flashcards in Exam 2 - Endocrine System/ Bone & Cartilage Histology Deck (97):
what type of feedback system is more stable?
complex feedback systems
endocrine glands are more parenchyma or stroma?
protein and Polypeptides -
Hydrophilic/ Lipophilic? Synthesized where? Stored? Bind to what and do what?
hydrophilic, synthesized in the RER, stored in granules (ex insulin), bind to receptors on cell membrane and activate 2nd messengers
what are two types? Hydrophilic/ Lipophilic? Bind to what and do what?
Thyroxine - lipophilic, binds to cytoplasmic receptors, acts as a transcription factor
Epinephrine- hydrophillic, binds to gprotein on cell membrane, activates 2nd messenger
- Hydrophilic/ Lipophilic? Synthesized where? Stored? Bind to what and do what?
lipophilic - carried in blood by albumin, synthesized in SER, NOT stored, binds to cytoplasmic receptors, acts as a transcription factor
posterior pituitary from from the
other names for the anterior pituitary
pars distalis, adenohypophysis, pars anterior
what forms the infundibulum
the neurohypophyseal bud
neurohypophyseal bud is what?
invagination of neuroectoderm that forms the future posterior pituitary
what forms the anterior pituitary?
hypophyseal pouch (rathke's pouch)
how is the anterior pituitary formed?
the hypophyseal pouch(aka rathke's pouch) is an invagination of oral ectoderm
other names for the posterior pitutiary
pars nervosa, neurohypophysis
the Pars nervosa releases what?
ADH and oxytocin
are there cell bodies present in the pars nervosa?
the only cell bodies present are glial cell bodies
are there secretory cells in the Pars Nervosa?
no secretory cells in the pars nervosa/anterior pituitary
what is the pars distalis?
what does the pars distalis release?
this cell releases growth hormone and prolactin
acidophils of the pars distalis
this cell releases TSH, FSH, LH
basophils of the pars distalis
not sure; maybee stem cell, exhausted secretoy cell- pale and not stained
an invagination of neuroectoderm form what?
the neurohypophyseal bud- posterior pituitary and infundibulum
disorder of the anterior pituitary that a benign tumor forms. it is grows too large it can casue a hyper secretion of prolactin or mass effects by compressing the brain stem
posterior pituitary hypersecretion
too much ADH- retention of solue free h20 = hyponatrmia
symptom of hyper and hyposecretion of the posterior pituitary
hyposecretion of the posterior pituitary
reduced ADH - loose capacity to concentrate urine = cental diabetes insipidus - extreme dehydration
what part of the adrenal gland essential for life? and what product and what area of the organ is soo essential.
The adrenal cortex is essential for life - mineralocorticoids, specifically aldosterone produced by the zona glomerulosum is essential for life
the adrenal medulla is derrived from
neural crest cells
the adrenal cortex is derrived from
coelomic epithelium = mesoderm
the parenchymal cells of the adrenal medulla are derrived from ____ which are what type of cells?
adrenal medulla derrived from neural crest cells = chromaffin cells
what is the largest zone of the adrenal cortex
what type of hormones are secreted from the adrenal cortex?
steroid hormones are derrived from?
are steroid hormones stored?
what does the zona reticularis secrete
smallest zone of the adrenal cortex
what do glucocorticoids do?
gluconeogenesis, break down fat and proteins, and suppress the mmune system (anti -inflammatory)
what does aldosterone do?
aldosterone stimulates the resorption of sodium by collection tubules and ducts of te kidneys, water then follows passively.
secrete excess catecholamines
the thyroid produces what from what?
makes t3 and t4 from thyroglobulin
the parenchyma of the thyroid gland
rounded epithelial follicles
what is the colloid
the colloid contains glycoprotein and thyroglobulin
does te thyroid store its secretory product?
the thyroid is the only endocrine gland to store its secretory product (3 months)
how are t3, and t4 produced?
when needed the folicular cells phagocytose the colloid and cleave it into t3 and t4 for release into the blood stream
(throid cells) secrete calcitonin- inhibit osteoclasts
cleaves thyroglobulin into t3 and t4.
where is thyroglobulin made?
the colloid of the thyroid gland
hypothyroidism (Hashimoto's thyroiditis)
autoimmune disorder that destroys the follicular cells- thus low t3 and t4 levels. High TSH levels b/c not under negative feedback loop
symptoms= wight gain, fatigue
hyperthyroidism (graves disease)
antibodies to TSH chronically stimulate follicular cells to synthesis and release hormone= wight loss, heat intolerance
what affect does PHT have on the body
increases octeoclasts, increase ca absorption in the kidneys and inceased activated vitamin d = increase ca absorption in stomach
the parathyroid gland is derrived from what pharyngeal arches?
superior - 4th arch
inferior - 3rd arch
what cells produce PTH
principal (chief cells)
hypercalcemia = decalcification of bones- leads to kidney stones
increase bone density, mental confusion, life threating, from the removal/ destruction of glands
what gland produces melatonin?
The pineal gland develops from what?
pineal gland develops from neuroectoderm- remains attached to brain
(brain sand) - concentration of mg and ca salts in the pineal gland
what affect does melatonin have on the body?
diurna fucntion- converts sensory input to changes in hormone function (light vs dark)
cartilage is composed of what type of collagen
what causes scurvy?
a vtamin C defficiency b/c vitamin C is needed to help hydroxylate proline and lysine in type 1 collagen
what types of collagen aggregate in fibrils and or fibers
collagen 1-3 fibrils
collagen 1&3 into fibers
collagen 2 remains a fibril
what cell attaches cells the the ECM in hyaline cartilage?
sources of chrondrogenic cells and chrondroblasts for growth and repair of cartilage. surrounds permanent hyaline cartilage except articular cartilage. Also present in elastic cartilage but NOT fibrocartilage
groups of 4-8 cells that originated for mitotis divisons of a single chrondrocyte
rich in gags, stains darker, surrounds lacuna
what secretes ECM in cartilage
chrondroblasts and young chrondrocytes secrete ECM
chrondroblasts in perichondrium differentiate into chrondrocytes - produce matrix adding to existing cartilage
proliferation and hypertrophy of chondrocytes
no perichondrium in articular cartilage thus resident chondrocytes serves as the progenitor cells
more cell and matric than hyaline, has a periochondrium
no perichondrium, little gound substancem mostly fibers (type 1 & 2) , ex pubic symphysis and intervertebral disks
periosteum attached to compact bone via
osteocytes derrived from
osteoclasts derrived from
osteoclasts activated by
PTH - increases bone resorption
osteoclasts inhibited by
calcitonin ( produced from parafollicular cells) which decrease bone resorption
type of collage in bone
bone has more organic or inorganic material
inorganic - hydroyapatite = 65%
desmosomes join osteons together at
remnants of remodeled osteons
intramembranous ossification occurs from what? and where?
bone depositived from connective tissue, growth of diameter of bones and the initiation of growth in the diaphysis,
ex. flat bones of the mandible and skull
ossification from existing cartilage
growth of long bones @ epiphysial plate
what percent of total bone replaced yearly by bone remodeling?
space formed under osteoclasts?
a bone fracture is invaded by what types of cells?
myofibroblasts, chondroblasts, osteoblasts
how do bones heal?
by intramembranous and endochondral ossification
what does estrogen do
antiresorptive- prevent the apoptosis of osteoblasts
vitamin d shortage effect on bone
inability to absorb calcium
deffective osteoclasts thus osteoblasts unopposed
what is the protein RANk-L?
expressed on the surface of osteoblasts that can bind to a receptor on monocytes to transform into osteoclasts
what nucleus in the hypothalamus produces oxytocin vs. ADH
Oxytocin - paraventricular nucleus
ADH - Supraoptic nucleus