Anatomy and Physiology - Ex: melatonin from tryptophan,

secreted by the Pineal gland which

Prepared by: Sofhel Andrea L. Ibanez | BSN – 1F
helps regulate circadian rhythm.
Reference: Anatomy and Physiology by Elizabeth
Mack Co - Epinephrine and norepinephrine
derived from tyrosine are secreted by
the adrenal medulla and play a role in
ENDOCRINE SYSTEM the fight-or-flight response.

• Communication is a process in which a

• Peptide and Protein Hormones: derived
sender transmits signals to one or more
from a single amino acid, peptide and
receivers to control and coordinate actions.
protein hormones consist of multiple
amino acids that link to form an amino
• Endocrine system uses secreted chemical
acid chain.
signals, called hormones, as its means of
communication.
- A chain of up to 50 amino acids is a
peptide, while more 50 amino acids is
a protein.
• Hormones are signaling molecules
released into the bloodstream; can reach
- ADH, example of peptide hormone
most cells of the body and have
consisting of 9 amino acids.
widespread effects.
- Insulin, example of a protein hormone
• Responsible for regulating the body’s use consisting of 51 amino acid.
of calories and nutrients, the secretion of
wastes, the maintenance of blood pressure
and osmolarity, growth, fertility, sex drive, ENDOCRINE CONTROL B THE
lactation and sleep. HYPOTHALAMUS and PITUITARY GLAND

• The hormones also impact mood and

emotion. • Often thought of as the “command center”
of the endocrine system because it plays a
central role in the release of many different
TYPES OF HORMONES hormones.
• Steroid Hormones: produced by
modifying cholesterols; insoluble in water • Hypothalamus, a structure of the
diencephalon of the brain located anterior
- Two famous steroid hormones are and inferior to the thalamus; anatomically
testosterone and estrogen. and functionally linked to the…

• Pituitary glands (anterior & posterior),

• Amine Hormones: produced by modifying which can be sen directly inferior to the
a single amino acid. hypothalamus.

- There are amine hormones produced • Posterior Pituitary Gland: does not
from the modification of either produce hormones, only stores and
tryptophan or tyrosine.
Sofhel Andrea L. Ibanez | BSN – 1F
 secretes hormones produced by the
hypothalamus. • Follicle-Stimulating Hormone and
Luteinizing Hormone: stimulated by
- Paraventricular nuclei = oxytocin; gonadotropin-releasing hormone (GnRH).
supraoptic nuclei = ADH
- FSH: stimulates production and
- Oxytocin: known historically for its maturation of sex cells, or gamete,
role in childbirth and lactation. including oocytes in ovaries and sperm
Stimulates uterine contractions and in testes.
necessary for milk ejection/ “let-down”
reflex. - LH: triggers the release of oocytes in a
process called ovulation, as well as the
- Antidiuretic Hormone: decreases the production of estrogen and
amount of body water that becomes progesterone by the ovaries. It also
urine. In other words, conserve water stimulates production of testosterone in
and keep it in the body rather than the testes.
losing it through urination.

• Anterior Pituitary Gland: produces • Prolactin (PRL): promotes the production

hormones regulates via the tropic of milk in individuals who are lactating.
hormones from the hypothalamus. During pregnancy, it contributes to
development of mammary glands, and
- Growth Hormone (GH): a protein after birth, it stimulates mammary glands
hormone produced and secreted by the to produce breast milk. Secretion is
anterior pituitary gland. Primary inhibited by Dopamine, which typically
function is anabolic; it promotes acts as a NT. Levels only rise in response
protein synthesis and tissue building to prolactin-releasing hormone (PRH)
through direct and indirect from hypothalamus during pregnancy and
mechanisms; controlled release by the lactation.
GHRH and GHIH/somatostatin. It
stimulates lipolysis.
THYROID GLAND

• Butterly-shaped organ, lies over the

• Thyroid-Stimulating Hormone (TSH):
anterior surface of the trachea, just inferior
regulates the activity of the thyroid gland.
to the larynx
Released from the APG in response to
thyrotropin-releasing hormone (TRH)
• Composed mostly of follicles, made up of
from the hypothalamus.
a ring of thyroid epithelial cells
surrounding a central cavity filled with
sticky fluid called colloid, a precursor to
• Adrenocorticotropic Hormone (ACTH):
thyroid hormone.
stimulates the adrenal cortex to secrete
corticosteroid hormones such as cortisol.
• Thyroid follicles produce thyroid
Its release is regulated by corticotropin-
hormones, while between these cells are
releasing hormone (CRH) from the
parafollicular cells which produce
hypothalamus in response to normal
calcitonin.
physiologic rhythms.
Sofhel Andrea L. Ibanez | BSN – 1F
 • Calcitonin: contributes to regulation of
• Iodine is a key ingredient in the production blood calcium. Released in response to a
of TH. Triiodothyronine (T3), a TH with rise in blood calcium levels.
three iodines, Tetraiodothyronine a.k.a.
Thyoxine (T4), a TH with four iodines.
PARATHYROID GLAND
• T3 is more potent than T4 and many cells
• Tiny, round structures found embedded in
convert T4 to T3 through removal of an
the posterior surface of the thyroid gland,
iodine atom.
most people have two to six.

• Often referred to as metabolic hormones

• Oxyphil cells: function is not yet known.
because their levels influence the body’s
Basal Metabolic Rate.
• Chief cells: known to produce and secrete
the parathyroid hormone (PTH), a
• Adequate levels of THs are required for
regulator of blood calcium levels and the
protein synthesis, essential for fetal and
antagonist hormone to calcitonin.
childhood development and growth; these
THs have a complex interrelationship with
• PTH, a peptide hormone, is released in
reproductive hormones and deficiencies
response to a low blood calcium level.
can influence libido, fertility, and otherc
aspects of reproductive function.
• Abnormally high activity of parathyroid
gland can cause hyperparathyroidism,
• Potentiates the effect of epinephrine and
which leads to significant decrease in bone
norepinephrine.
density, leading to spontaneous fractures or
deformities.
• Dietary iodine deficiency can result in the
impaired ability to synthesize T3 and T4.
• In contrast, PTH deficiency is called
When TH cannot be produced, TSH is
hypoparathyroidism, which may develop
secreted in increasing amounts leading to
following injury or surgery involving the
accumulation of colloid in the thyroid
thyroid gland. Low blood calcium
follicles; accumulation leads to increase in
increases membrane permeability to
size, a condition called goiter.
sodium leading to muscle twitching,
cramping, spasms, or convulsions. Severe
• Hypothyroidism: weight gain, feeling
deficits can paralyze muscles, including
cold in rooms where others do not,
those involved in breathing, and can be
fatiguability, and lethargy.
fatal.

• Hyperthyroidism: weight loss, increase in

ADRENAL GLANDS (Suprarenal Glands)
body temperature or feeling warm,
excitability or irritability, and effects of • Adrenal Medulla: secretes epinephrine
even low epi and norepi and potentiated and norepinephrine into the bloodstream
(increase HR, strengthen heartbeat, by the medullary tissue composed of
increase BP). chromaffin cells in response to acute,
short-term stress mediated by the
sympathetic nervous system.

Sofhel Andrea L. Ibanez | BSN – 1F

 - Alpha cell: produces glucagon, low
blood glucose stimulates its release.
• Adrenal Cortex: secretes a group of its
steroid hormones collectively called
- Beta cell: produces insulin, elevated
corticoids. Important the regulation of the
blood glucose level stimulates its
long-term stress response, BP and blood
release.
volume, nutrient uptake and storage, fluid
and electrolyte balance, and inflammation.
- Delta cell: secretes peptide hormones
somatostatin, an inhibiting hormone
- Zona Glomerulosa: most superficial,
that can inhibit release of Growth
produces mineralocorticoids; essential
Hormone, glucagon, and insulin.
for fluid and electrolyte balance.
Aldosterone is the major
- PP cell: secretes pancreatic
mineralocorticoid, a key component in
polypeptide hormone. It is thought to
the RAAS
play a role in appetite.

- Zona Fasciculata: the intermediate

region, produces glucocorticoids. The
most important is the hormone
cortisol, which promotes breakdown
of stored triglycerides into fatty acids
and glycerol and muscle proteins into
amino acids. Another role of cortisol is
the down-regulation of the immune
system, which inhibits the
inflammatory response.

- Zosa Reticularis: deepest region,

produces small amounts of a class of
steroid sex hormones called androgens.
During puberty and most of adulthood,
androgens are produced in the gonads,
androgens produced in the ZR
supplement the gonadal androgens.

PANCREAS

• A long, slender organ, locates posterior to

the stomach. Functions entirely in
secretion but uniquely it is both exocrine
and an endocrine organ.

• Completed by a group of cells called

pancreatic islets that secretes the hormones
glucagon, insulin, somatostatin, and
pancreatic polypeptide (PP).

Sofhel Andrea L. Ibanez | BSN – 1F

Anatomy and Physiology a. Steroid hormones are actively
transported through protein
Prepared by: Sofhel Andrea L. Ibanez | BSN – 1F
channels.
Reference: Anatomy and Physiology by Elizabeth b. Steroid hormones are passively
Mack Co transported through protein
channels.
c. Steroid hormones are actively
ENDOCRINE SYSTEM (QUESTIONS) transported through the cell
membrane.
d. Steroid hormones are passively
1. Which of the following is the chemical transported through the cell
signal used in the endocrine system? membrane.
a. Hormones 5. Someone who has Type 1 diabetes will
b. Neurotransmitters have less insulin in their body. People with
c. Sodium Type 1 diabetes often take an oral form of
d. Calcium insulin as medication. This is an agonist
2. The femoral nerve synapses on the and binds to the same receptors as insulin.
quadriceps muscles. In order to make the When it binds to the hormone receptor, it
muscles contract, the neurotransmitter is activates as G protein. What is the next
released from the axon terminal into the step after the G protein is activated?
synapse, which binds to the receptors of a. Activation of adenylyl cyclase
the neighboring muscle cell. What type of b. Conversion of ATP to cAMP
chemical signaling is this an example of? c. Activation of protein kinase
a. Paracrine signaling d. Initiation of phosphorylation
b. Autocrine signaling cascade.
c. Synaptic signaling 6. Which of the following are true about the
d. Endocrine signaling production of protein hormones? Please
3. The adrenal gland releases a group of select all that apply.
hormones called corticosteroids. These a. Cholesterol is modified to produce
hormones act as an anti-inflammatory the hormone.
agents, maintain blood sugar levels, b. DNA and mRNA synthesize the
maintain blood pressure, and regulate hormone.
water balance. Which of the following c. The hormone will be made upon
explains how these hormones can affect demand.
many organs in the body? d. Vesicles store the hormones until
a. These hormones bind to all the needed.
organs in the body. 7. What is the role of a negative feedback
b. These hormones can bind to loop?
several different receptors. a. To promote further secretion or
c. The body has one receptor hormones.
throughout all organs. b. To inhibit further secretion of
d. Hormones travel in the blood and hormones.
do not target specific organs. c. To initiate hormone breakdown.
4. How are steroid hormones transported 8. Which endocrine gland produces
across a cell membrane? oxytocin?
a. Hypothalamus
b. Anterior pituitary
Sofhel Andrea L. Ibanez | BSN – 1F
 c. Posterior pituitary 14. Which of the following produces and
d. Thalamus secretes parathyroid hormone?
9. Which endocrine gland produces a. Oxyphil cells
adrenocorticotropic hormones? b. Chief cells
a. Hypothalamus c. Thyroid cells
b. Anterior pituitary d. Colloid
c. Posterior pituitary 15. Which of the following effects would you
d. Thalamus expect to see in someone who has
10. When someone has low blood pressure, hyperparathyroidism?
there is a decreased volume of blood in the a. Decreased bone density
arteries. Low blood pressure can be treated b. Decreased calcium resorption
with a medication called vasopressin, c. Muscle twitching
which acts in the same manner as d. Muscle cramping
antidiuretic hormone. Which of the 16. How does the negative feedback
following is an effect of vasopressin? mechanism for regulating PTH secretion
a. Increased water reabsorption differ from that of the thyroid hormones,
b. Increased protein synthesis T3 and T4?
c. Increased secretion of cortisol a. PTH secretion is regulated simply
d. Increased sodium reabsorption by the blood level of calcium,
11. Which of the following would result in a while T3 and T4 secretion is
reduction of thyroid hormone released into regulated through a feedback loop
the bloodstream? involving hormones of the
a. A decrease in circulating thyroid hypothalamus and anterior pituitary
hormone levels. gland.
b. A decrease in circulating thyroid- b. PTH secretion is regulated through
stimulating hormone levels. a feedback loop involving
c. An increase in circulating thyroid- hormones of the hypothalamus and
stimulating hormone levels. anterior pituitary gland, while T3
12. Which of the following occurs once and T4 secretion is regulated
thyroid-stimulating hormone binds to its simply by the blood level of
receptors in the follicle cells? Please select sodium.
all that apply. c. PTH secretion is regulated by the
a. Iodine ions are actively transported blood level of calcium, while T3
into the cell. and T4 secretion is regulated by the
b. Iodine ions are passively blood level of sodium.
transported into the cell. d. The secretion of PTH and the
c. Sodium ions area actively thyroid hormones T3 and T4 are
transported into the cell. both regulated by negative
d. Synthesis of triiodothyronine and feedback loops involving hormones
thyroxine. of the hypothalamus and anterior
13. Which of the following are effects of pituitary gland.
thyroid hormone? Please select all that 17. Prednisone is a synthetic form of
apply. glucocorticoid used as a medication.
a. Increased body temperature. Which zone of the adrenal gland produces
b. An increase in metabolic rate. natural glucocorticoids?
c. Production of insulin. a. Zona glomerulosa
d. Regulation of appetite. b. Zone fasciculata
Sofhel Andrea L. Ibanez | BSN – 1F
 c. Zona reticularis b. Chemical signaling
d. Zona medullaris c. Electrical signaling
18. Identify the effects of glucagon. Please d. Neurotransmitters
select all that apply. 24. Which class of hormone best describes
a. Storage of excess glucose as antidiuretic hormone (ADH), a hormone
glycogen that consists of nine amino acids?
b. Breakdown of glycogen into a. Steroid
glucose b. Amine
c. Formation of triglycerides from c. Peptide
fatty acids d. Protein
d. Absorption of amino acids from the
Alka was out for a walk in the woods when a
blood into the liver for
thunderstorm suddenly blew into the area. Alka
gluconeogenesis
ran to the car as quickly as possible, to get out of
19. During surgery, patients sometimes lose a
the wind, rain, and lightning. Alka’s endocrine
lot of blood. Therefore, it is common for a
system helped their body respond to the new level
patient’s red blood cell count to be low
of activity necessary to reach the safety of the car
after surgery. Which organ is responsible
quickly.
for stimulating the production of red blood
cells? 25. One of the hormones that helped Alka
a. Heart increase their metabolic rate in order to run
b. Kidneys quickly to the car is epinephrine. Which of
c. Liver the following are true of the hormone
d. Skin epinephrine? Please select all that apply.
20. What is the function of thrombopoetin? a. Epinephrine is produced by
a. To stimulate production of platelets modifying cholesterol.
b. To stimulates production of red b. Epinephrine is secreted by the
blood cells adrenal medulla.
c. To stimulate production of white c. Epinephrine can pass through the
blood cells plasma membrane of its target
d. To stimulate production of Vitamin cells.
D3. d. Epinephrine can travel through the
21. Identify the functions of the endocrine blood without binding to a
system. Please select all that. Apply. transport protein.
a. Maintenance of blood pressure 26. Another group of two hormones that will
b. Secretion of wastes help Alka run quickly to the car is the
c. Transportation of nutrients thyroid hormones (triiodothyronine and
d. Detection of changes in thyroxine). Thyroid hormones have a
homeostatic levels of substances. particular structure that causes them to be
22. Which of the following secretes hormones lipophilic, even though they are not
into the bloodstream? produced from cholesterol. Where are the
a. Endocrine tissue receptors for thyroid hormones located?
b. Target cells a. In the. Blood
c. Cell receptors b. On the plasma membrane of the
d. Goblet cells target cells
23. What type of communication is used by c. Inside the target cells
both the endocrine and nervous systems? d. Thyroid hormones do not require
a. Hormones receptors to act on their target cells
Sofhel Andrea L. Ibanez | BSN – 1F
27. Epinephrine and thyroid hormones interact water. Which of the following hormones is
with their target cells by different responsible for retaining water in the
mechanisms, due to their different body?
solubilities in the plasma membrane of a. Oxytocin
their target cells. Which of the following is b. Antidiuretic hormone
true of the mechanism of action of these c. Adrenocorticotropic hormone
hormones with their target cells? d. Prolactin
a. Epinephrine binds to hormone 32. Which of the following are a benefits of
receptors on the plasma membrane the hypothalamic—hypophyseal portal
of its target cells. system? Please select all that apply.
b. Thyroid hormones require the use a. The effects are long-lasting.
of a second messenger to exert b. The reaction happens quickly.
their effects on their target cells. c. The effects will reach distant
c. Due to its structure, epinephrine organs.
would be expected to stimulate d. The hormones will not be diluted.
DNA transcription in its target 33. Acromegaly is a condition in which there
cells. is an excessive production of growth
d. Thyroid hormones must initiate a hormone. Which of the following
cascade of signaling molecules and structures may be impaired, causing
reactions before they can exert acromegaly?
their effects on their target cells. a. Thymus
28. Which of the following factors would b. Thalamus
initiate Alka’s epinephrine secretion while c. Anterior pituitary
they are running to the car to escape the d. Posterior pituitary
storm? Please select all that apply. 34. After your blood test, the doctor diagnoses
a. ACTH secretion from the pituitary you with hypothyroidism, a condition
gland where your body produces less than the
b. Stimulation by the sympathetic typical amounts of thyroid hormones.
nervous system Which of the following symptoms would
c. A feeling of stress or fear you expect to see? Please select all that
d. CRH secretion from the apply.
hypothalamus a. Weight loss
29. Which of the following structures is most b. Lethargy
superior? c. Increase in body temperature
a. Hypothalamus d. Fatigue
b. Anterior pituitary 35. Which of the following is an effect of the
c. Posterior pituitary hormone released by the parathyroid
d. Infundibulum gland?
30. Which of the following organs stores a. An increase in blood calcium levels
hormones produced by the hypothalamus? b. A decrease in blood pressure
a. Anterior pituitary c. An increase. In basal metabolic rate
b. Posterior pituitary d. A decrease in blood glucose levels
c. Adrenal gland 36. Which of the following would you expect
d. Thalamus to happen in a negative feedback loop if
31. After a long soccer game outdoors, the hormone levels were decreasing?
Elizabeth was dehydrated. When a. The body will continue to produce
dehydrated, your body works hard to retain that hormone.
Sofhel Andrea L. Ibanez | BSN – 1F
 b. The body will stop producing that. c. Produce parathyroid hormone
Hormone. d. Differentiate into red blood cells
37. Which of the following are true of the 41. Excessive alcohol consumption can lead to
negative feedback mechanisms for insulin liver failure, which occurs when many
and cortisol, two hormones that affect the liver cells start to die. Which of the
concentration of glucose in the blood? following hormones would be affected due
Please select all that apply. to liver failure? Please select all that apply.
a. Insulin and cortisol are both a. Insulin-like growth factor
regulated directly by the blood b. Angiotensin
level of glucose. c. Vitamin D
b. Insulin is regulated by the blood d. Adipokines
level of glucose.
c. Cortisol is. Regulated by a negative
feedback loop involving hormones
of the hypothalamus and anterior
pituitary gland.
d. Insulin and cortisol are each
regulated by a negative feedback
loop involving hormones of the
hypothalamus and anterior
pituitary.
38. Which of the following lists the order of
the three zones of the adrenal cortex in
order from superficial to deep?
a. Zone reticularis > Zona fasciculata
> Zone glomerulosa
b. Zona reticularis > Zona
glomerulosa > Zona fasciculata
c. Zona fasciculata > Zona
glomerulosa > Zona reticularis
d. Zona glomerulosa > Zona
fasciculata > Zona reticularis
39. Georgia was putting up holiday lights
outside their home when they slipped and
fell off the ladder. Georgia fell on their
back and was rushed to the hospital.
Through imaging, the doctors found left
rib fractures and stomach lacerations.
Which of the following glands are you
most concerned about?
a. Thyroid gland
b. Parathyroid gland
c. Adrenal cortex
d. Pancreas
40. What is the function of thymosins?
a. Development of T lymphocytes
b. Regulate blood calcium levels
Sofhel Andrea L. Ibanez | BSN – 1F