endocrine system 2

Question 1

where is the thyroid gland and whet is it made out of

Answer 1

he thyroid gland is a
butterfly-shaped gland
located inferior to the
larynx and anterior to the
trachea
It is composed of follicular
cells and parafollicular
cells

Question 2

2 things that the thiroid gland makes and what how are they made at what do they do

Answer 2

Follicular cells are stimulated
by TSH to produce thyroxine
(T4) and triiodothyronine (T3)
collectively known as thyroid
hormones which function to:
* Increase basal metabolic
rate (BMR)
* Help maintain normal body
temperature
* Stimulate protein synthesis
* Increase the use of glucose and
fatty acids for ATP production
* Upregulate beta (β) receptors
that attach to catecholamines
* Work with hGH and insulin to
accelerate body growth
(growth)

Parafollicular cells
produce the hormone
calcitonin
Calcitonin helps regulate
calcium homeostasis by
stimulating osteoblasts
and inhibiting osteoclast
activity, which lowers
the level of calcium in
the blood

Question 3

Parathyroid Gland where is it what does it look like

Answer 3

Located on the posterior
aspect of each lobe of the
thyroid gland are two
parathyroid glands
* one inferior
* one superior
Total of 4 pea-sized lobes

Question 4

what does the paraythiroid hormoine do what the opsite

Answer 4

Increase the number and activity
rate of osteoclasts
* Increases the rate of calcium and
magnesium reabsorption in the
kidneys
* Promotes formation of calcitriol in
the kidneys which acts to increase
the absorption of calcium and
magnesium from the GI tract

more calcium in blood

calcitoni n

Question 5

adrenal glands where are they what is there formation

Answer 5

The adrenal glands are
located on top of each
kidney and consist of an
outer cortex and inner
medulla

Question 6

Adrenal Glands
There are three main types of
hormones secreted by the
adrenal cortex:

Answer 6

Mineralocorticoids which
regulate mineral homeostasis
* Glucocorticoids which affect
glucose homeostasis
* Weak Androgens which are
hormones with masculinizing
effects

Question 7

aldonstrone is where and does what

Answer 7

is the major
mineralocorticoid secreted
which helps regulate sodium
and potassium homeostasis
The renin-angiotensin-
aldosterone (RAA) pathway
controls secretion of
aldosterone

Question 8

cortisol is where and comes from what

Answer 8

glucocorticoids
(cortisol) is regulated by the
release of corticotropin releasing
hormone and functions to help
control:
* Protein breakdown
* Glucose formation
* Lipolysis
* Resistance to stress
* Inflammation
* Immune responses

Question 9

dehydroepiandrosterone (DHEA comes from where and is what

Answer 9

he major androgen secreted by the adrenal
cortex is dehydroepiandrosterone (DHEA)
* In females, DHEA and other adrenal
androgens play a major role in promoting
libido and are converted to estrogens
* In males, especially after puberty, the
hormone testosterone is secreted in much
larger quantities, so DHEA has virtually no
effect

Question 10

the adrenal medulla

Answer 10

The adrenal medulla is
stimulated by sympathetic
nervous system to secrete
catecholamines such as
epinephrine (adrenaline) and
norepinephrine
(noradrenaline) both of
which are involved in the
fight-or-flight respons

Question 11

where is the pancreas and what does it make

Answer 11

The pancreas is a flattened
organ located posterior and
slightly inferior to the
stomach (located in the
curve of the duodenum

The islets of Langerhans include
four types of cells which secrete
different hormones, we are
concerned with just two of them:
* Alpha (A) cells – glucagon
– Increase blood glucose
levels
* Beta (B) cells - insulin
– Decrease blood glucose
levels

Question 12

pinal gland where is it and what does it do

Answer 12

The pineal gland is attached to
the roof of the third ventricle of
the brain and secretes melatonin
* Melatonin is released in a
diurnal rhythm linked to the
dark-light cycle which helps to
regulate the body’s biological
clock

Question 13

thyums where is it licated and what does it do

Answer 13

The thymus is
located behind the
sternum between
the lungs and
produces hormone
which promote
maturation of the
immune system’s
T cells

Question 14

secondary organs

Answer 14

heart and kidneys

Question 15

Endocrine cells in the walls of the atria within
specialized cardiac muscle cells.
* Release …..
response to …

Answer 15

Endocrine cells in the walls of the atria within
specialized cardiac muscle cells.
* Release atrial natriuretic peptide (ANP) in
response to increased blood volume.

Question 16

ANP causes ………………………………..
and reduces the concentration of…. in the blood.
* ANP acts on the kidneys to reduce the ………..
– causing ….. to be excreted in the urine
* ANP reduces the amounts of ………. by the kidneys and
……………….. released by the adrenal cortex
– further preventing the retention of water.

Answer 16

ANP causes a reduction in blood volume and blood pressure,
and reduces the concentration of Na+ in the blood.
* ANP acts on the kidneys to reduce the reabsorption of Na+
– causing Na+ and water to be excreted in the urine
* ANP reduces the amounts of renin released by the kidneys and
aldosterone released by the adrenal cortex
– further preventing the retention of water.

Question 17

Renin is released in response to
……………………….
and is part of the renin-angiotensin-
aldosterone system that leads to the
release of aldosterone

Answer 17

Renin is released in response to
decreased blood volume or pressure
and is part of the renin-angiotensin-
aldosterone system that leads to the
release of aldosterone

Question 18

The kidneys also release calcitriol, which aids in the
absorption of Ca2+ and phosphate ions.
* Erythropoietin (EPO) is a protein hormone that triggers the
formation of red blood cells in the bone marrow.
– EPO is released in response to low oxygen levels.

Question 19

Renin
* Aldosterone

Answer 19

Renin is released in response to decreased blood volume or pressure and
leads to the release of aldosterone
* Aldosterone then causes the retention of Na+ and water, raising blood
volume