Endocrine and Exocrine glands Flashcards
how do endocrine secretions enter through the bloodstream
via capillaries
what can happen to endocrine secretions once they have been synthesised
they can be stored or released
what are fenestrated capillaries
capillaries with more pores on them to make them leakier
what are the patterns of endocrine secretion
chronic
acute
periodic
what are chronic patterns of secretion
same time, same amounts, over the same period of time
what are acute patterns of secretion
depend on stimulus
what are episodic patterns of secretion
these follow certain episodes like at meal times
what are the different regulations of hormone secretion
humoral, neuronal and hormonal
what are humoral regulations of hormone secretion
blood borne molecules
what are neural regulations of hormone secretion
neurons stimulate hormone production
what are hormonal regulations of hormone secretion
when hormone secretion stimulates another hormone to be secreted
what are the different classes of hormones
proteins and polypeptides
steroids
derivates of the amino acid tyrosine
what are examples of hormones that are proteins or polypeptides
pancreatic hormones and parathyroid hormones
which class of hormones are secreted by adrenal cortex, ovaries and placenta
steroid
which class of hormones are secreted by the adrenal medulla and thyroid gland
derivatives of the amino acid tyrosine
what is thyroxin
the hormone that regulates metabolism
what type of epithelium lines the thyroid gland
cuboidal epithelium
what are c cells
these are clear cells that take up about 10% of the thyroid gland that produce calcitonin
what is calcitonin
the hormone that regulates calcium levels
what is colloid
a fluid that fills the central cavity of the thyroid gland follicles that are involved in thyroid hormone production.
what are parafollicular cells
the c cells
what are the cells of the thyroid gland
thyrocytes and parafollicular cells
what do thyrocytes do
they synthesis thyroglobulin from which the t3 and t4 hormones are released
what is the functional unit of the thyroid gland
the thyroid follicle
what are thyroid follicles
these are follicles with a central lumen filled with colloid surrounded by c cells and thyrocytes
what is the endocrine control of the thyroid gland
hypothalamus produces thyrotropin releasing hormone
leading to increased thyroid stimulating hormone being released from the pituitary gland
leading to increased synthesis of the thyroid hormones
what are the arteries that supply the thyroid gland
superior and inferior thyroid arteries
what are the veins of the thyroid gland
the superior, middle and inferior thyroid veins
what innervates the thyroid gland
cervical ganglion for sympathetic and recurrent laryngeal nerve for parasympathetic
what are the parathyroid glands
four lentil shaped glands which are located on the back of each lobe of the thyroid gland
what is the function of the parathyroid glands
participate in the regulation of blood calcium levels
what does the parathyroid gland produce
parathyroid hormone, which affects osteoclast cells
how does the parathyroid gland increase the calcium levels of the blood
secretion of PTH, osteoclast breaks down bone, minerals released, calcium levels increase
what is hyperparathyroidism
this is when too much parathyroid is released
why is osteoporosis more common in post menopausal people
the estrogen levels decrease so there is less inhibition of the osteoclasts meaning there is more break down of bone
what are the cells of the parathyroid gland
chief cells and oxyphil cells
what do chief cells do
synthesise and secrete parathyroid hormones
where are chief cells found in the body
the parathyroid gland
what are oxyphil cells
transitional forms of the chief cells that contain numerous mitochondria
function of oxyphil cells
unknown
what are exocrine glands
glands that secrete through ducts that are open directly on the epithelial surface
what are the two types of exocrine gland
unicellular and multicellular
what are an example of unicellular glands
mucous glands
what is an example of a multicellular gland
salivary
sweat
sebaceous
pancreas
what are branched exocrine glands surrounded by
fibrous tissue capsules
what lines interlobar ducts
stratified columnar epithelium
what produces the secretions in exocrine glands
acini
what are the two types of sweat gland
apocrine and eccrine
what are eccrine sweat glands
secrete a watery product that cools the skin
what are apocrine sweat glands
these are found in armpits and secrete a more viscous odorous product
what are merocrine glands
these are exocrine glands that secrete their products to the surroundings without sacrificing their membrane
what are examples of merocrine glands
salivary
pancreatic
most of the sweat glands
what are holocrine glands
these are exocrine glands that release their secretions by bursting the entire cell
what is an example of a holocrine gland
sebaceous glands
which type of exocrine gland dies during secretion
holocrine
describe the nuclei of mucous acini
flat
describe the nuclei of serous acini
round
describe the exocrine pancreas
branched tubuloacinar gland with acinus as the functional unit.
secretes pancreatic juice containing protease and amylase alongside bicarbonate
describe pancreatic cancer
this can affect the endocrine and exocrine portion of the pancreas
which organ is affected by cystic fibrosis
pancreas
describe cystic fibrosis
exocrine portion of the pancreas leads to secretions becoming thick and clogging the ducts of the pancreas. this can cause a decrease in secretion of enzymes.
what are the oral effects of diabetes mellitus
periodontitis, dry mouth, susceptibility to infection
what is hypofunction
reduced hormone release
what is hyperfunction
excessive hormone release
what is hormone resistance
diabetes mellitus
what does the thyroid gland require in order to produce thyroxin
iodine
what are the iodine containing hormones found within the thyroid gland
T3 and T4
what are the secretions of endocrine glands called
hormones
main two functions of endocrine glands
regulation of bodily functions
maintain homeostasis
example of hormonal regulated secretion
hormones from the pituitary gland stimulating the testes
example of neural secretion
sympathetic nervous system stimulating adrenaline release
example of humoural secretion
glucose levels stimulating insulin secretion
what are the different structures of multicellular exocrine glands
simple tubular
simple branched tubular
coiled tubular
simple acinar
simple branched acinar
compound tubular
compound acinar
comound tubuloacinar
which type of multicellular exocrine glands are found in the stomach and colon
simple tubular
which type of multicellular exocrine glands are found in the lower portion of the stomach
simple branched tubular
which type of multicellular exocrine glands are found in sebaceous glands
simple and branched acinar
which type of multicellular exocrine glands are found in mucous glands of the duodenum
compound tubular
which type of multicellular exocrine glands are found in mammary glands
compound acinar
which type of multicellular exocrine glands are found in the pancreas
compount tubuloacinar
describe serous unit structure
acinar, with a narrow lumen
describe the mucous unit structure
tubular with wide lumen
what is parenchyma
glandular tissue
what are interlobar septa
the lobes produced from the division of parenchyma by the septa
what are interlobar septa divided into
lobules
what divides interlobar septa into lobules
introlobular septa
what contract and squeeze secretions from the acini along the duct
myoepithelial cells
which epithelium lines interlobar ducts
stratified columnar
which epithelium lined interlobular ducts
pseudostratified columnar epithelium
which epithelium lines striated ducts
simple cuboidal and columnar
describe the process of merocrine glands
they have vesicles that contain secretory products that release the contents into the duct
describe the process of apocrine glands
the secretory products are stored in the cells and there are pinched off portions of the cell in the secretions
describe holocrine gland secretion
the cell is shed into the duct and releases secretory products
describe serous secretions
watery with enzymes
describe mucous secretions
mucins with hydrate to form mucous
what do the f cells of the islets of langerhans produce
pancreatic polypeptide
what is the most common endocrine disorder
diabetes mellitus
when can endocrine changes be seen
pregnancy
menopause
stress
obesity
where are islets of langerhans most numerous in the pancreas
the tail
which gland produces melanin
pineal gland
