Endocrine

Question 1

Importance of glands in the body( ex pituitary gland)

Answer 1

Each gland is
responsible for
secreting specific
hormones which,
in turn, target and
affect the function
of specific
tissues/organs.

Question 2

what are the Hypothalamus and pituitary?

Answer 2

Hypothalamus regulates the
pituitary, which is responsible for
releasing a number of hormones
involved in critical functions.

○ The pituitary is often called the
“master gland”

○ Many hormones released from
hypothalamus & pituitary are tropic
hormones, meaning they stimulate
other glands to release other
hormones.

Question 3

What is the Posterior pituitary?

Answer 3

Posterior pituitary stores
hormones produced by the
hypothalamus (oxytocin and
ADH)

Question 4

What is the Posterior Anterior pituitary

Answer 4

Anterior pituitary
synthesizes hGH, prolactin,
TSH, ACTH, FSH, and LH

Question 5

Thyroid & Parathyroid Glands

Answer 5

Thyroid  produces thyroxine, calcitonin
○Parathyroid  produces parathyroid hormone

Question 6

Adrenal Cortex & Adrenal Medulla

Answer 6

Different layers of the adrenal glands; located on top of the kidneys

Adrenal medulla  produces epinephrine and
norepinephrine, involved in the short-term stress response

o Adrenal cortex  produces cortisol and aldosterone,
involved in the long-term stress response

Question 7

Pancreas

Answer 7

Specialized clusters of cells (known as islets of
Langerhans) secrete hormones into the bloodstream
responsible for glucose regulation
○ Beta cells secrete insulin, alpha cells secrete glucagon

Question 8

HORMONES

Answer 8

interact
with receptor proteins
specific to their target
tissue, inducing a
change which leads to
a cascade of events
within each cell
HORMONES

Question 9

Two types of hormones, classified by
the way they interact with target cells:

Answer 9

Water soluble hormones (proteins, peptides,
and amino acid derivatives) cannot cross the
lipid membrane, and thus interact with cells by
binding to external receptor cites

○ Fat soluble hormones (steroids) are able to
diffuse across the lipid membrane, and thus
interact with cells by binding to receptor sites
within the cytoplasm

Question 10

Hormones that affect growth and metabolism: Human growth
hormone (hGH)

Answer 10

○ secreted by the
anterior pituitary
○ increases protein
synthesis, cell division
and growth (of bone
and muscle tissue in
particular), and
metabolic release of
stored fats
○ Especially important
during puberty

Hypersecretion
(adulthood): Acromegaly

Hyposecretion: Pituitary
Dwarfism

Hypersecretion
(childhood): Gigantism

Question 11

Hormones that affect growth and metabolism: Thyroxine

Answer 11

Thyroxine
○ Secreted by the thyroid
gland after stimulation
by tropic hormone TSH
○ Increases the rate at
which the body
metabolizes fats,
proteins, and
carbohydrates

Hyperthyroidism:
Grave’s Disease

Question 12

metabolism: Thyroxine and iodine connection

Answer 12

The thyroid requires iodine to
produce thyroxine
○ Insufficient iodine in the diet
thus inhibits thyroxine
production, meaning there will
be no signal to stop the
secretion of TSH
○ The constant stimulation of
the thyroid gland by TSH that
results leads to the
development of a goitre

Question 13

metabolism: Calcitonin

Answer 13

Secreted by the thyroid
○ Plays a role in the
regulation of blood calcium
levels
○ High concentrations of
calcium in the blood trigger
the release of calcitonin,
which stimulates the uptake
of calcium into bones (thus
lowering blood calcium
levels)

Question 14

metabolism: Parathyroid Hormone (PTH)

Answer 14

Secreted by the parathyroid
o Plays a role in the regulation of blood
calcium levels
o Low concentrations of calcium in the
blood trigger the release of PTH, which
stimulates bone cells to reabsorb calcium
into the blood (thus raising blood calcium
levels)

Question 15

Hormones that affect the body’s
response to stress: Epinephrine & Norepinephrine

Answer 15

Epinephrine & Norepinephrine
o Regulate the body’s short-term
response to stress
o When presented with a stressful
situation, neurons from the
hypothalamus relay a signal to
adrenal medulla to secrete
epinephrine & norepinephrine
o Response is rapid, because
hormone release is mediated by
the nervous system

Question 16

Hormones that affect the body’s
response to stress 2) Cortisol

Answer 16

Produced by adrenal cortex after
stimulation by ACTH
○Promotes the break down of fats and
proteins (amino acids) to glucose sugar
○Long-term response to stress (increases
the energy available for use by cells)

Question 17

Hormones that affect the body’s
response to stress
3) Aldosterone

Answer 17

Produced by the adrenal
cortex
○ Increases blood pressure by
increasing the absorption of
sodium into the bloodstream
○ Long-term response to
stress (increases delivery of
oxygen and other nutrients
to cells)

Question 18

Addison’s disease

Answer 18

results from damage to the
adrenal cortex, causing the body to produce
inadequate amounts of cortisol and aldosterone

Symptoms:
* Low blood sugar
* Ion imbalances
* Low blood pressure
* Rapid weight loss
* General weakness

Question 19

Hormones that affect blood sugar
1) Insulin

Answer 19

Secreted by beta cells of the islets of
Langerhans (pancreas)
○ Makes cells more permeable to glucose
after a meal, thereby decreasing blood
glucose
○ Promotes the temporary storage of
glucose as glycogen in the liver

Question 20

Hormones that affect blood sugar
2) Glucagon

Answer 20

Secreted by alpha cells of the islets of
Langerhans
○ Promotes the breakdown of glycogen in the
liver to glucose, which is then released into
the bloodstream
○ Promotes the breakdown of fatty tissue
into glucose, thereby increasing blood
glucose

Question 21

Diabetes Mellitus

Answer 21

Causes blood glucose levels to rise
sharply after meals
○ Lack of insulin to lower blood
glucose and transport it to cells
○ Cells can’t obtain glucose required
for metabolism; individuals
become fatigued
○ Body compensates by
metabolising fats and proteins.
This releases ketones, a toxic by-
product which causes bad breath.

Question 22

Diabetes Mellitus: Type 1

Answer 22

Diagnosed in childhood
o Immune system produces
antibodies that attack and
destroy the beta cells of
the pancreas
o Leads to decreased insulin
production
o Treated with daily insulin
injections

Question 23

Diabetes Mellitus: Type 2

Answer 23

Develops over time
o Cell receptors stop
responding to insulin, or
beta cells produce less
insulin
o Often associated with poor
diet and lack of exercise
o Treated with insulin
injections before meals

Question 24

Antidiuretic hormone (ADH)

Answer 24

Secreted by posterior pituitary
o Regulates water reabsorption by kidneys
o body excretes less, more concentrated urine

Question 25

Diabetes Insipidus

Answer 25

Hyposecretion of ADH

○ Affected individuals produce
large volumes of dilute urine,
resulting in the loss of ions
from the blood
○ Continuous risk of
dehydration
○ Can occur during pregnancy,
as components of the
placenta are known to break
down ADH
○ Treated by administering ADH