THE ENDOCRINE SYSTEM

Is in charge of body processes that happen

slowly, such as cell growth.

It is separated to the nervous system, they often

work together to help the body function

properly.

Is a system of glands involving the release of

extra-cellular signaling molecules known as

hormones.

Is instrumental in regulating metabolism,

growth, development, puberty, tissue function

and also plays a part in determining mood.

FUNCTIONS OF ENDOCRINE

Is to secrete hormones directly into the

bloodstream to target cells designed to

receive its message.

Hormones are chemical substances that

affect the activity of another part of the

body (target site)

It serves as messengers, controlling and

coordinating activities throughout the

body

GLAND

It is a group of cells that produces and

secretes, or gives off chemicals

It selects and removes materials from the

blood, processes them and secretes the

finished chemical product for use

somewhere in the body

ENDOCRINE GLANDS

Are ductless glands that release hormones directly into the blood

Are also parts of other body systems1. The Pineal Gland

2. The Hypothalamus

3. The Pituitary Gland

4. The Thyroid and Parathyroid Gland

5. The Thymus Gland

6. The Adrenal Gland

7. The Pancreas

8. The Gonads (Ovary and Testes)

PROBLEMS WITH THE ENDOCRINE

SYSTEM Too much or too little of any hormone can

be harmful

Controlling the production of or replacingspecific hormones can treat manyendocrine disorders:

1. ADRENAL INSUFFICIENCY: decreasedfunction of the adrenal cortex & theconsequent underproduction of adrenalcorticosteroid hormones. Symptoms-weakness, fatigue, abdominal pain, nausea,dehydration and skin changes.

2. CUSHING SYNDROME: excessive amounts

of glucocorticoid hormones in the body.

Symptoms- may take years to develop and

include obesity, growth failure, muscle

weakness, easy bruising of the skin, acne, high

blood pressure and psychological changes.

3. TYPE 1 DIABETES: when the pancreas fails

to produce enough insulin, it is previously

known as juvenile diabetes. Symptoms-

excessive thirst, hunger, urination, and weight

loss. It can cause long-term complications,

including kidney problems, nerve damage,

blindness and early coronary heart disease and

stroke.

4. TYPE 2 DIABETES: the body is unable torespond to insulin normally. The symptomsand possible complications of type 2diabetes are basically the same as those oftype 1.

5. GROWTH HORMONE PROBLEMS: toomuch growth hormone in children will maketheir bones and other body parts growexcessively, resulting in gigantism. This rarecondition is usually caused by a pituitarytumor and can be treated by removing thetumor. In contrast, when the pituitary glandfails to produce adequate amounts of growthhormone, a child’s growth in height isimpaired.

6. HYPERTHYROIDISM: is a condition in whichthe levels of thyroid hormones in the blood areexcessively high. Symptoms- weight loss,nervousness, tremors, excessive sweating,increased heart rate and blood pressure,protruding eyes, and goiter.

7. HYPOTHYROIDISM: is when the levels ofthyroid hormones in the blood are abnormallylow. Symptoms- slows body processes and maylead to fatigue, a slow heart rate, dry skin,weight gain, constipation.

8. PRECOCIOUS PUBERTY: body changesassociated with puberty may occur at anabnormally young age in some kids if thepituitary hormones rise prematurely.

THYMUS GLAND Is positioned in the upper

part of the chest cavity,

directly behind the sternum

It is pinkish grey in color and

blends with the surrounding

color and age.

It’s role is to process

lymphocytes which are white

blood cells that travel to the

body through the

bloodstream.

They stop at lymph nodes to

ensure everything us working

properly, and if not, it is

believed that they jump into

action o fix any tissues.

THE PANCREAS Has 2 important

hormones, insulin

and glucagon.

It serves as a ducted

gland, secreting

digestive enzymes

into the small

intestine.

It serves as a ductless

gland in the Islets of

Langerhans that

secrete insulin and

glucagon.

PINEAL GLAND Lies on the upper surface

of the midbrain

Secretes the hormone

melatonin, a modified

amino acid that may help

regulate the wake-sleep

cycle.

Contains light-sensitive

cells or has nervous

connections from the eyes

Melatonin production is a

link between a biological

clock (sleeping) and daily

or seasonal activities,

such as reproduction.

HYPOTHALAMUS A collection of

specialized cells that is

located in the lower

central part of the brain

The primary link between

the endocrine and

nervous systems

Relays information

sensed by the brain (such

as environmental,

temperature, light

exposure, patterns and

feelings) to the pituitary

gland

PITUITARY GLAND Produces chemicals that

either stimulate or suppress

hormone secretions

Located at the base of the

brain just beneath the

hypothalamus

Most important part of

endocrine system

Often called the “master

gland”

It is divided into 2 parts:

anterior lobe & posterior

lobe.

ANTERIOR LOBE

Regulates the activity of the thyroid, adrenals and reproductive glands

Is the most active part secreting at least 6 distinct hormones, all are proteins1. Growth Hormone – which stimulates the growth

of bone and other body tissues and plays a role in the body’s handling of nutrients and minerals.

2. Prolactin – which activates milk production in women who are breastfeeding

3. Thyrotropin – which stimulates the thyroid gland to produce thyroid hormones

2. Corticotropin – which stimulates the adrenal

gland to produce certain hormones

3. Endorphins – chemicals that act on nervous

system to reduce sensitivity to pain

4. Gonadotropins – controls the ovulation and

the menstrual cycle in women.

POSTERIOR LOBE

Releases antidiuretic

hormone, which helps

control body water

balance through its effect

on the kidneys and urine

output; and oxytocin

which triggers the

contractions of the uterus

that occur during labor.

Develops as an out-

pocketing of the lower

surface of the brain.

THYROID GLAND It is located in the front part of the

lower neck

Shaped like a bow tie or butterfly

and produces the thyroid hormones

thyroxine and triiodothyronine.

These hormones control the rate at

which cells burn fuels from food to

produce energy

Also play a key role in bone growth

and the development of the brain &

nervous system in children.

The production & release of thyroid

hormones is controlled by

thyrotropin which is secreted by the

pituitary gland..

PARATHYROID GLAND

Attached to the thyroid gland

4 tiny glands that functions together

Releases parathyroid hormone

(parathormone(PTH)), which regulates the

level of calcium in the blood with the help of

calcitonin, which is produced in the thyroid

When it is enlarged or if tumors grow in

them, an excess of PTH is secreted. Defects

in skeletal system may be observed

ADRENAL GLANDS Are pair of glands that sit on top of

kidneys.

It has 2 parts (medulla & cortex); each

of which produces a set of hormones

and has a different function

◦ Medulla produces catecholamines,

such as epinephrine. Also called

adrenaline, epinephrine increases

blood pressure & heart rate when the

body experiences stress.

◦ Cortex produces hormones called

corticosteriods that influence or

regulate salt and water balance in the

body, the body’s response to stress,

metabolism, the immune system and

sexual development and function.

THE GONADS

Are the main source of sex hormones

These hormones regulate body changesassociated with sexual development

In males, they are located in the scrotum.Male gonads or testes, secrete hormonescalled androgens, the most important ofwhich is testosterone. The female gonadsor ovaries, produce eggs and secrete thefemale hormones estrogen andprogesterone.