Endocrine System Part II Flashcards Preview

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Flashcards in Endocrine System Part II Deck (30):
1

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

2

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

3

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

4

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

5

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

6

Parathyroid glands histology

Stroma – ___ ___ ___with abundant ___, ___ __, ___ and ___ ___

Parenchyma – __ ___r cells that may secrete the ___ hormone

1. Chief or Principal cells: form the ___k of the gland.

____ ____ ____. Synthesize and secrete___. PTH ___ serum calcium levels (anti-Calcitonin)

2. 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

1. Chief or Principal cells: form the bulk of the gland. Small, polygonal, basophilic. Synthesize and secrete PTH. PTH raises serum calcium levels (anti-Calcitonin)

2. 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.

7

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

8

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. 

9

Adrenal Gland

AKA ____ gland: Above the kidney

10

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

11

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

12

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

13

Adrenal Glands

–Medulla.

•___ of cells.

•____ cells.

•Modified ___ ___ ____

Adrenal Glands

–Medulla.

•Cords of cells.

•Chromaffin cells.

•Modified sympathetic postganglionic neurons.

14

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

15

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. 

16

Adrenal ___ gets stimulations from ____is specifically ACTH

Adrenal cortex gets stimulations from adenohypophysis specifically ACTH

17

Adrenal Glands

•Blood supply.

–___ arterioles.

–Separate blood supply that passes through ___

–Supply ___ ___ 

 

Two sets of arterioles running thru the adrenal gland

One supply to cortex and one supply to medullary

If you need to release corticohormones you don’t want to release a bunch of medullary hormones too. 

Adrenal Glands

•Blood supply.

–Medullary arterioles.

–Separate blood supply that passes through cortex.

–Supply medullary sinusoids.

 

Two sets of arterioles running thru the adrenal gland

One supply to cortex and one supply to medullary

If you need to release corticohormones you don’t want to release a bunch of medullary hormones too. 

18

Two sets of arterioles

Some come in adrenal gland, bypass entire adrenal cortex and go right to medulllary region and that will pick up hormones and then get released

There are other blood vessels that can create networks within any of the zones within the cortex. These are responsible for getting corticohormones

Two sets of arterioles

Some come in adrenal gland, bypass entire adrenal cortex and go right to medulllary region and that will pick up hormones and then get released

There are other blood vessels that can create networks within any of the zones within the cortex. These are responsible for getting corticohormones

19

Multifcnal

Pancreas has exocrine and endocrine fcns

Secretes digestive enzymes

____ clumps of cells: Serous secretions, diggestive enzymes.

Scattered thruout are Islets of Langerhan that are endocrine fcn of pancreas

Multifcnal

Pancreas has exocrine and endocrine fcns

Secretes digestive enzymes

Red clumps of cells: Serous secretions, diggestive enzymes.

Scattered thruout are Islets of Langerhan that are endocrine fcn of pancreas

20

Islets of Langerhans

•____ pancreas.

•Develop from ___ ___

•Four cell types.

–Alpha cells.

–Beta cells.

–D cells.

–F cells.

 

You cant look at H and E slide and tell difference bw 4 cell types

Have to stain for the product made by one of these cells

Alpha and Beta are the most important

Involved with Glucose levels

They are antagonists to each other

Islets of Langerhans

•Endocrine pancreas.

•Develop from duodenal endoderm.

•Four cell types.

–Alpha cells.

–Beta cells.

–D cells.

–F cells.

 

You cant look at H and E slide and tell difference bw 4 cell types

Have to stain for the product made by one of these cells

Alpha and Beta are the most important

Involved with Glucose levels

They are antagonists to each other

21

Islets of Langerhans

•Function.

–Alpha cells ~20%.

•Hormone: ___

•Target:___ - ____serum glucose –____ factor.

•Acts on several tissues to release energy stored in __ and __

•Function.

–Alpha cells ~20%.

•Hormone: glucagon.

•Target: Liver - ­ serum glucose – hyperglycemic factor.

•Acts on several tissues to release energy stored in glycogen and fat.

22

•Function.

–Beta cells ~70%.

•Hormone:___ 

•Target: ___  ¯ ___serum glucose – ___ factor.

•Acts on several tissues causing uptake of glucose into___

•Function.

–Beta cells ~70%.

•Hormone: insulin.

•Target: Liver - ¯ serum glucose – hypoglycemic factor.

•Acts on several tissues causing uptake of glucose into cells.

23

•Function.

–D cells <5%.

•Hormone: ___

•Target: ___

–Inhibits release of g____

– ____  pancreatic ___ secretion.

•Function.

–D cells <5%.

•Hormone: somatostatin.

•Target: pancreas.

–Inhibits release of glucagon.

–¯ pancreatic exocrine secretion.

24

•Function.

–F cells - rare.

•Hormone: ___ ___

•Target:

–____ - inhibits ___ and enzymes secretion.

–__ ___ – relaxes & ¯ ____ bile secretion.

•Function.

–F cells - rare.

•Hormone: Pancreatic polypeptide.

•Target:

–Pancreas - inhibits HCO-3 and enzymes secretion.

–Gall bladder – relaxes & ¯ bile secretion.

25

Pineal Gland

•Located in ___ ventricle.

•Cells – arranged in ___

–___– functional cell.

–____l cells.

–___ cells.

•Located in 3rd ventricle.

•Cells – arranged in cords.

–Pinealocytes – functional cell.

–Astroglial cells.

–Mast cells.

26

•Brain sand (___ ___a).

–___ layers.

–___cells?

–­ ___ w/age.

–Function?

–____ landmark.

 

What is it?

Like small calcifications (like kidney stones, gall stones)

Radiolucent marker

If you take xray of the brain you can see where pineal gland is located esp on older indivs.

Can see if pineal gland is located where its supposed to be.

To see if brain has shifted or moved.

•Brain sand (corpora arenacea).

–Concentric layers.

–Glial cells?

–­ w/age.

–Function?

–Radiological landmark.

 

What is it?

Like small calcifications (like kidney stones, gall stones)

Radiolucent marker

If you take xray of the brain you can see where pineal gland is located esp on older indivs.

Can see if pineal gland is located where its supposed to be.

To see if brain has shifted or moved.

27

•Function.

–Hormone: ____ – amphibians.

–Respond to ___ stimuli via the __e and ___ nerves.

–Influenced by diurnal light variation (___ ___) and ___ changes (day length).

–Regulate __ ___ cycles (jet lag).

–_____eliminating free radicals

 

Secretes melatonin.

Opp of MSH from the other day.

This is Skin lightening

A lot of people take melatonin for sleep or regulating circadian rhythms to get rid of get lag

Antiaging drug possibly

Lots of potential fcns. Hot topic

•Function.

–Hormone: melatonin – amphibians.

–Respond to light stimuli via the eye and sympathetic nerves.

–Influenced by diurnal light variation (circadian rhythm) and seasonal changes (day length).

–Regulate sleep-wake cycles (jet lag).

–Anti-oxidant eliminating free radicals

 

Secretes melatonin.

Opp of MSH from the other day.

This is Skin lightening

A lot of people take melatonin for sleep or regulating circadian rhythms to get rid of get lag

Antiaging drug possibly

Lots of potential fcns. Hot topic

28

•The pineal gland also contains deposits of ___ ___ and ___s, forming structures called corpora arenacea or brain sand.

•The calcium salts are deposited in concentric rings around an ____ matrix.  These appear in early childhood and increase in ___ throughout life.

•It is unclear exactly how they are formed or how they function.

•Word of warning -- Don’t confuse them with Hassall’s corpuscles.

Big large calcified structures inside pineal gland called corpora aranacea.

Can be used to determine if pineal gland is positioned where its supposed to be

Ex) Brain shift from car accident

•The pineal gland also contains deposits of calcium phosphates and carbonates, forming structures called corpora arenacea or brain sand.

•The calcium salts are deposited in concentric rings around an organic matrix.  These appear in early childhood and increase in size throughout life.

•It is unclear exactly how they are formed or how they function.

•Word of warning -- Don’t confuse them with Hassall’s corpuscles.

Big large calcified structures inside pineal gland called corpora aranacea.

Can be used to determine if pineal gland is positioned where its supposed to be

Ex) Brain shift from car accident

29

•Experimental results.

–Rats.

•Pinealectomy ® ___ sexual development.

–Man.

•Pineal tumors ® pinealocyte destruction ®____puberty.

____ effect on gonadotropic hormones, regulating normal sexual development.

•Experimental results.

–Rats.

•Pinealectomy ® precocious sexual development.

–Man.

•Pineal tumors ® pinealocyte destruction ® precocious puberty.

•Inhibitory effect on gonadotropic hormones, regulating normal sexual development.

30

–Amphibians.

•Melatonin ® aggregation of melanin granules in melanophores.

___ of skin (cf. MSH).

–Amphibians.

•Melatonin ® aggregation of melanin granules in melanophores.

•Lightening of skin (cf. MSH).