Endocrine System Part II Flashcards
Follicular cells can be squamous in shape, cuboidal or columnar, depending on activity and what is happening inside the folicle
Normal thyroid gland: ___ ___
If you don’t get enough TSH released, or something happens when thyroid is not stimulated to make this hormone: thyroid becomes ___ inhape and colloid in follicle ___ and pushes and ___ omn follicular cells so they become ___ in shape.
Just storing colloid, not stiulated to release it
Since its not stimulated to release it, It doesn’t make more thyroid gland. Smaller bc its not being used. Use it or lose it.
Overstimulation of thyroid. Constant TSH release. Gland ___ in size and makes more follicles. Cells are releasing hormone just as fast as they can make it. Cells don’t have a chance to get a lot of colloid stored in the follicle so they become ___ in shape
Follicular cells can be squamous in shape, cuboidal or columnar, depending on activity and what is happening inside the folicle
Normal thyroid gland: simple cuboidal
If you don’t get enough TSH released, or something happens when thyroid is not stimulated to make this hormone: thyroid becomes smaller in shape and colloid in follicle expands and pushes and squeezes on follicular cells so they become squamous in shape.
Just storing colloid, not stiulated to release it
Since its not stimulated to release it, It doesn’t make more thyroid gland. Smaller bc its not being used. Use it or lose it.
Overstimulation of thyroid. Constant TSH release. Gland expands in size and makes more follicles. Cells are releasing hormone just as fast as they can make it. Cells don’t have a chance to get a lot of colloid stored in the follicle so they become columnar in shape
Thyroid Gland Function
•Parafollicular cells.
–Hormone: ___
–Target: ___
• ____ serum Ca++ by ____ numbers and activity of osteoclasts.
Follicular Cells: Forming Follicle. Making T3 and T4
Organ of dual origin. Two sets of cells that have nothing to do with each other
Parafollicular Cells: Secrete Calcitonin
Target Bone.
Bone is biggest reservoir of Ca for the body
If you get a lot of Ca floating around in the blood stream you can take that and dump it back into the bone
Decrease osteoclast activity and get Ca to go back into the bone.
Can also work on GI and urinary sys so not losing Ca
Thyroid Gland Function
•Parafollicular cells.
–Hormone: Calcitonin.
–Target: Bone.
•¯ serum Ca++ by ¯ numbers and activity of osteoclasts.
Follicular Cells: Forming Follicle. Making T3 and T4
Organ of dual origin. Two sets of cells that have nothing to do with each other
Parafollicular Cells: Secrete Calcitonin
Target Bone.
Bone is biggest reservoir of Ca for the body
If you get a lot of Ca floating around in the blood stream you can take that and dump it back into the bone
Decrease osteoclast activity and get Ca to go back into the bone.
Can also work on GI and urinary sys so not losing Ca
Parathyroid Glands
Located on ____ aspect of thyroid gland
Two little bean shaped things.
Very difficult to find. Look like a piece of fat or something.
One on each side of the thryroid gland
Parathyroid Glands
Located on posterior aspect of thyroid gland
Two little bean shaped things.
Very difficult to find. Look like a piece of fat or something.
One on each side of the thryroid gland
Parathyroid Glands
•Development.
–Superior – ___ pharyngeal pouch.
–Inferior –___ pharyngeal pouch.
•Cell types.
–___ cells (principal cells).
–___il cells.
–___s – ___% of gland in older individuals.
Not from dual development. So the whole parathyroid will do the same thing
But two pair of parathyroid glands come from different locations
Inside there are a bunch of types of cells
Chief
Oxyphil: they help us identify parathyroid gland
Parathyroid Glands
•Development.
–Superior – 4th pharyngeal pouch.
–Inferior – 3rd pharyngeal pouch.
•Cell types.
–Chief cells (principal cells).
–Oxyphil cells.
–Adipocytes – 50% of gland in older individuals.
Not from dual development. So the whole parathyroid will do the same thing
But two pair of parathyroid glands come from different locations
Inside there are a bunch of types of cells
Chief
Oxyphil: they help us identify parathyroid gland
In development,
Inf: begin in ___ position relative to what will become the superior
Parathyroid gland attached to the thymus
Thymus begins life ___ in the neck and then migrates ___. Pully the ____ gland down so that it gets lower than superior
In development,
Inf: begin in superior position relative to what will become the superior
Parathyroid gland attached to the thymus
Thymus begins life higher in the neck and then migrates inferiorly. Pully the inferior gland down so that it gets lower than superior
Parathyroid glands histology
Stroma – ___ ___ ___with abundant ___, ___ __, ___ and ___ ___
Parenchyma – __ ___r cells that may secrete the ___ hormone
- Chief or Principal cells: form the ___k of the gland.
____ ____ ____. Synthesize and secrete___. PTH ___ serum calcium levels (anti-Calcitonin)
- Oxyphil cells: function ___ __ but may be a
___ of the chief cell. ___ and ____. Stain very ____c due to high ____ content.
Parathyroid glands histology
Stroma – Connective tissue capsule with abundant nerves, blood vessels, lymphatics and unilocular fat
Parenchyma – Two dissimilar cells that may secrete the same hormone
- Chief or Principal cells: form the bulk of the gland. Small, polygonal, basophilic. Synthesize and secrete PTH. PTH raises serum calcium levels (anti-Calcitonin)
- Oxyphil cells: function not know but may be a
variant of the chief cell. Large and round. Stain very eosinophilic due to high mitochondrial content.
Parenchyma: ____l fcnal portion of the gland
Has CT capsule with a lot of cells in it
Chief: Secrete PTH
PTH is the antagonist to calcitonin
Released to raise Ca levels in the serum.
Secreted when Ca levels are too low in the body
Increase osteoclast activity.
Decrease release from the body
People thought parathyroid was essential for life
How will you regulate Ca levels without it?
Surgeons will try to leave the PT gland if they take out the thyroid or put patient on hormone replacement therapy
Oxyphil cells: No one know was they do.
Some think they ___ OR ___ chief cells
Help us ___ PT gland histologically
Parenchyma: epithelial fcnal portion of the gland
Has CT capsule with a lot of cells in it
Chief: Secrete PTH
PTH is the antagonist to calcitonin
Released to raise Ca levels in the serum.
Secreted when Ca levels are too low in the body
Increase osteoclast activity.
Decrease release from the body
People thought parathyroid was essential for life
How will you regulate Ca levels without it?
Surgeons will try to leave the PT gland if they take out the thyroid or put patient on hormone replacement therapy
Oxyphil cells: No one know was they do.
Some think they immature or old chief cells
Help us identify PT gland histologically
Parathyroid Glands
•Function.
–Hormone: _______
–Target: Bone.
• ____ serum Ca++ by number & activity of osteoclasts.
•Function.
–Hormone: Parathyroid hormone, PTH.
–Target: Bone.
• serum Ca++ by number & activity of osteoclasts.
Adrenal Gland
AKA ____ gland: Above the kidney
Adrenal Glands
•Development – dual origin.
–Cortex – ___ ___
–Medulla – ___ ___ (__ ____).
Dual Development
Medulla: Derivative of___ ___ ____
NS type of cell
Vs Cortex: diff types of cell
Two classes of hormones that it secretes
Adrenal Glands
•Development – dual origin.
–Cortex – dorsal mesoderm.
–Medulla – neural crest (ectomesenchyme).
Dual Development
Medulla: Derivative of sympathetic ganglion cells
NS type of cell
Vs Cortex: diff types of cell
Two classes of hormones that it secretes
Some of the nerve cells in the developing sympathetic ganglia migrate to the medullary region of the adrenal gland and become the medulla cells
Corticol cells come from the dorsal mesoderm which is a diff type of cell
Sympathetic ganglion cells that are migrating in become what are called ____ cells
Some of the nerve cells in the developing sympathetic ganglia migrate to the medullary region of the adrenal gland and become the medulla cells
Corticol cells come from the dorsal mesoderm which is a diff type of cell
Sympathetic ganglion cells that are migrating in become what are called chromaffin cells
Adrenal Glands
•Structure.
–Cortex - divided into ___ zones.
•Zona_____ (15%).
–Outermost.
–___/ ____ ____
•Zona ____ (50%).
–__ ___
–“____s”
•Zona ___ (7%).
–___ ___ of cells.
–___ cells.
No numbers on exam! Just to give you a reference
Bulk is zona ____
He wont ask which is the predominate.
Glomerulosa: cells are arranged in rounding cords. (Think like the kidney)
Fasciculata: Straight arrangement of cells
Cells inside fasiculata are often referred to as spongiocytes. This is bc the hormone secreted here have a high___ content. That leads to the spongy/bubbly appearance.
Reticularis: Network of cells
Retinularis: ____
Adrenal Glands
•Structure.
–Cortex - divided into 3 zones.
•Zona glomerulosa (15%).
–Outermost.
–Arched/rounded cords.
•Zona fasciculata (50%).
–Straight rows.
–“Spongiocytes”
•Zona reticularis (7%).
–Anastomosing network of cells.
–Smallest cells.
No numbers on exam! Just to give you a reference
Bulk is zona Fasciculata
He wont ask which is the predominate.
Glomerulosa: cells are arranged in rounding cords. (Think like the kidney)
Fasciculata: Straight arrangement of cells
Cells inside fasiculata are often referred to as spongiocytes. This is bc the hormone secreted here have a high lipid content. That leads to the spongy/bubbly appearance.
Reticularis: Network of cells
Retinularis: innermost
Adrenal Glands
–Medulla.
- ___ of cells.
- ____ cells.
- Modified ___ ___ ____
Adrenal Glands
–Medulla.
- Cords of cells.
- Chromaffin cells.
- Modified sympathetic postganglionic neurons.
Adrenal Gland Function
•Zona glomerulosa.
–Hormones: ____(e.g., ____).
–Targets: ___, ___ ___, ___ –>____balance.
•Zona fasciculata & reticularis.
–Hormones: ____ (e.g., ___ and ___).
–Targets:
•___ (1o) – __, __, __metabolism.
___d organs - ___ i___ response.
In the 3 zones of the cortex, 3 hormones secreted
Aldosterone: water balance
Fasciculata secretes glucocorticoids. (Like Cortisol)
All these hormones coming out of adrenal cortex are steroid hormones.
Not all steroids build you up.
Cortisol___ you ___. Catabolic.
High stress situations: Will have high cortisol levels
Glucocorticoids act as ____ drugs but too much of it can cause __ __ so don’t put patient on it for a long time
Reticularis: Responsible for secreting ___: __ hormones
Adrenal Gland Function
•Zona glomerulosa.
–Hormones: mineralocorticoids (e.g., aldosterone).
–Targets: kidneys, gastric mucosa, glands _ electrolyte balance.
•Zona fasciculata & reticularis.
–Hormones: glucocorticoids (e.g., cortisone & cortisol).
–Targets:
- Liver (1o) – CHO, protein, fat metabolism.
- Lymphoid organs - ¯ immune response.
In the 3 zones of the cortex, 3 hormones secreted
Aldosterone: water balance
Fasciculata secretes glucocorticoids. (Like Cortisol)
All these hormones coming out of adrenal cortex are steroid hormones.
Not all steroids build you up.
Cortisol breaks you down. Catabolic.
High stress situations: Will have high cortisol levels
Glucocorticoids act as antiinflammatory drugs but too much of it can cause break down so don’t put patient on it for a long time
Reticularis: Responsible for secreting androgens: Sex hormones
Adrenal Gland Function
•Medulla.
–Hormones: _____ (epinephrine & norepinephrine).
–Targets:
- Epinephrine –___
- Norepinephrine – ___ (postganglionic sympathetics).
–
•
That’s what sympathetic neurons release
Nervous: quick on and quick off
If you want to prolong that effect, it comes from the adrenal medulla.
Act in concert with each other.
Adrenal Gland Function
•Medulla.
–Hormones: catecholamines (epinephrine & norepinephrine).
–Targets:
- Epinephrine –metabolic
- Norepinephrine – neurotransmitter (postganglionic sympathetics).
–
•
That’s what sympathetic neurons release
Nervous: quick on and quick off
If you want to prolong that effect, it comes from the adrenal medulla.
Act in concert with each other.
