Histo Lecture 1 Flashcards
Thyroid gland
right lobe, isthmus, left lobe
Thyroid follicle
Thyroid
- Cell type
varies from cuboidal (inactive) to columbar (active) with increasing activity
Follicle is bracket, colloid is circle.
inactive at this stage, pretty cuboidal, storing our secretion which is the colloid
follicular epithelium in bracket, colloid
inactive at this stage
what are these cells, where are they found, what do they produce
parafollicular or C cells, found in isolated clusters between follicles or within the follicular epithelium
produce calcitonin
L to R
follicular epithelium, colloid, C cell
Parathyroid glands
what do they make, what are the cell populations
pth hormone
chief (principle) cells,
oxyphil (acidophilic) cells
top to bottom
parathyroid gland, capsule, thyroid gland
Chief cells on left closer together, oxyphil cells on right
A chief, B oxyphil
Hypothalamus Location
floor of?
forms what?
floor of diencephalon, forms part of wall of 3rd ventricle
Parts of the Anterior pituitary
Parts of the Posterior pituitary
pars tuberalis, pars intermedia, pars distalis
infundibular stalk, pars nervosa
Adenohypophysis
what? where does it come from, what % of pituitary, type of tissues, controlled by?
anterior pituitary arises from oral ectoderm, constitutes 80% of pituitary, glandular epithelial cells, controlled by neurohormones
Neurohypophysis
what? where does it come from? controlled by? what does it store?
posterior pituitary, develops from neural ectoderm, controlled by neurons, axons from hypothalamus carry ADH and oxytocin there for storage
what is this?
components?
-tissue type, tissue arrangement, capillary type (makes up what),
pars distalis, aka pars anterior
glandular epithelial cells arranged in thick cords, has a connective tissue stroma, fenestrated capillaries make up part of the secondary capillary plexus
what is secreted by the pars distalis?
Cells of pars distalis are classified into two groups,
what are they? what are their staining characteristics?
top to bottom pars distalis, chromophobes, chromophils
Chromophils: granules readily take up H/E stain-blue pink
chromophobes: less affinity for stains
two kinds of chromophils
which ones are pink, which ones are purple
pink are acidophils, purple are basophils, bottom right are chromophobes
top acidophil bottom basophil
Function?
chromophobe funtion is unknown, they dont produce hormones
What are the three arrows pointing to?
function?
consists of?
unique feature?
it is the pars intermedia
funciton unknown
consists of small basophils, colloid-filled follicles lined by pale cuboidal cells
often has a cleft (remnant of rathke’s pounch)
What is this structure? function?
composed of?
infundibulum, suspends pituitary gland from the hypothalamus
comsposed of neural portion, and surrounding pars tuberalis
Neurohypophysis:
storage for?
what produces these two hormones?
storage site for ADH, and Oxytocin
supraoptic nuclei makes adh, pvn makes oxytocin
Pars Nervosa:
appearance?
composed of?
looks like unorganized brain tissue
composed of pituicytes, unmyelinated axons (nerve fibers), and fenestrated capillaries
Pituicytes:
what do they look like? shape of nuclei?
function?
glial like cells with elongated cells with long processes
oval nuclei
appear to support numerous unmyelinated nerve fibers traveling from the hypothalamus
what are herring bodies?
what do they contain
expanded axon terminals
filled with stored neurosecretory materials
-oxytocin and adh
Pituitary blood supply
what supplies median eminence and infundibulum?
what supplies pars nervosa?
what doesnt have direct blood supply?
superior hypophyseal arteries supply median eminence and infundibulum, inferior hypophyseal arteries supply the pars nervosa
no direct blood supply to anterior pituitary
hypothalamohyophyseal portal circulation
what gives rise to the primary capillary plexus?
what do the hypophyseal portal veins drain into
superior hypophyseal arteries give rise to the primary plexus in the median eminence and they collect hypothalamic secretions
hypophyseal portal veins drain the primary capillary plexus and deliver blood into the secondary capillary plexus in the pars distalis
where is the third capillary plexus derived from? what does it do?
derived from the inferior hypophyseal artery, supplies and collects secretions from neruohypophysis
venous drainage of pituitary
pitiuitary glands secrete hormones–>diffuse into capillaries–>hypophyseal veins–> venous sinuses (petrosal and caveronous)
pineal gland is developed from a posterior outpocketing of what?
what is its role?
how is it regulated?
developed from a posterior outpocketing of the roof of the diencephalon in midline of 3rd ventricle, attached to diencephalon via pineal stalk
role in growth, development, and regulation of circadian rhythyms
regulated by sympathetic nerves
Pineal gland capsule is derived from what?
what/how is it subdivided into incomplete lobules?
what does the pineal gland consist of?
capsule is derived form pia mater, capsule sends trabeculae and septa into the gland subdividing it into incomplete lobules
consists of: pinealocytes, neuroglial cells, calcified granular material (brain sand), NO NEURONS
what are these cells and what are their functions?
pinealocytes manufacture melatonin at night and serotonin during daylight–> circadian rhythym
what are these cells and what are their functions
neuroglial cells
they are interstitial cells with smaller denser nuclei (vs pinealocytes), and they function to support pinealocytes
what are these slides featuring?
what are they made by and what are they made of?
when?
brain sand is secreted by pinealocytes, it is a matrix of calcium phosphate, becomes present in early childhood and evident in second decade, no effect on function
pineal gland, calcified so it is a good marker for midline of the brain. (top of triangle)
exocrine pancreas
what are these cells
islets of langerhans in the pancreas
core of islet contains what cells?
mantle contains what cells?
core contains insulin producing B cells
mantle contains A,D,F
Alpha cells do what?
secrete glucagon into the blood in response to low blood glucose levels
picture is stained for glucagon
beta cells
what do they secrete? how many are there?
secrete insulin in response to high levels of glucose in blood, most numerous cell in islet
slide stained for insulin
D cells secrete what? what does it do?
secretes somatostatin and gastrin, inhibits the release of other islet cell hormones (insulin and Glucagon)
slide stained for somatostatin
what do F cells secrete? what does it do?
secrete pancreatic polypeptide, which inhibits the secretion of somatostatin
slide stained for PP
Endocrine pancreas innervation
done by the pancreatic plexus (mixed sympathetic and parasympathetic)
Sympathetic stimulation decreases insulin
parasympathetic increases insulin and glucagon secretion
blood supply to pancreas
what is this a slide of?
what is the organization of the suprarenal gland?
capsule, cortex with three layers (zona glomerulosa, zona fasciculata, zona reticularis), and then it has a medulla
what gland is this, what are the structures
suprarenal gland
what gland, what are the layers
what does the cortex of the suprarenal gland secrete
Zona Glomerulosa: produces mineralcorticoids such as aldosterone
Zona Fasciculata: produces glucocorticoids such as cortisol, corticosterone
Zona Reticularis: produces androgens such as DHEA, and Androstenedione
arrangement of cells in the zona glomerulosa?
what do some of the cells contain?
closely packed, rounded clusters of cells aka glomeruli
some cells contain droplets of lipids
glomerulus of zona glomerulosa of the suprarenal gland
Zona fasciulata:
what volume of suprarenal gland?
arrangement of cells?
Cell type?
Capillaries?
what do they produce?
75% of total volume of suprarenal gland, arranged in vertical columns aka fasicles,
cells are spongiocytes, which have an accumulation of lipid droplets
fenestrated capillaries separate the adjacent columns
produce glucocorticoids
Zona reticularis
what type of cord network?
what type of granules
contains irregular cords form an anastomosing network
large and numerous lipofuscin granules
Types of cells in suprarenal medulla
what are they a modification of?
contain epinephrine chromaffin cells
contain norepinephrine chromaffin cells
they are both modified postsynaptic sympathetic cells
how do you tell the difference between the types of chromaffin cells in the medulla of the Suprarenal gland?
epinephrine secreting cells are smaller, granules are lighter
norepi cells are larger, denser granules (electron dense)
blood supply to the suprarenal gland?
