Endocrine

system

نظمي فلوح:اعداد

الدين شبليحسام.د.أ:اشراف

The endocrine system is a chemical messenger system comprising of the hormones released by internal glands of an organism directly into the circulatory system.

The pituitary gland

The pituitary gland

▪ The pituitary gland, in humans, is a pea-sized gland(weighing 0.5 grams)

▪ that sits in a protective bony enclosure called the sella turcica.

▪ It is composed of three lobes: anterior, intermediate, and posterior.

The pituitary gland

▪ The anterior lobe :

S.No. Type of cell Hormone secretedPercentage of

type of cell

1. Somatotropes human growth hormone (hGH) 30-40%

2. Corticotropes adrenocorticotropin (ACTH) 20%

3. Thyrotropes thyroid stimulating hormone (TSH) 3–5%

4. Gonadotropes

gonadotropic hormone i.e., both luteinizing

hormone (LH) and follicle stimulating hormone

(FSH)

3–5%

5. Lactotropes prolactin (PRL) 3–5%

The pituitary gland

▪ The posterior lobe:

▪ The posterior pituitary stores and secretes (but does not synthesize) the following important endocrine hormones:

▪ Antidiuretic hormone (ADH, also known as vasopressin and arginine vasopressin AVP)

▪ Oxytocin

The Thyroid :

The Thyroid :

▪ The thyroid gland is a butterfly-shaped organ composed of two lobes.

▪ It weighs 25 grams in adults.

▪ with each lobe being about 5 cm long, 3 cm wide, and 2 cm thick.

▪ The thyroid is near the front of the neck, lying against and around the front of the larynx and trachea .

Hypothyroidism :

Symptoms: Fatigue

Increased sensitivity to

cold

Muscle aches and

weakness

Constipation Pain, stiffness or swelling

in your joints

Heavier than normal or

irregular menstrual

periods

Signs : Dry skin

Weight gain Slowed heart rate

carpal tunnel

syndrome

Slowed heart rate

Hoarseness Impaired memory

Elevated blood

cholesterol level

Enlarged thyroid

gland (goiter)

Thinning hair myxedema

Hyperthyroidism :

Symptoms:

Increased sweating and

heat intolerance

palpitations

lethargy Increased bowel

frequency

Breathlessness Muscle weakness

Signs: Tachycardia

Warm extremities Goitre

Arrhythmias Proximal myopathy

Increased irritability Loss of weight

The Adrenal glands:

The Adrenal glands:

▪ The adrenal glands (also known as suprarenal glands) are endocrine glands that produce a variety of hormones.

▪ They are found above the kidneys. Each gland has an outer cortex which produces steroid hormones and an inner medulla.

▪ The adrenal cortex itself is divided into three zones:

1. the zona glomerulosa.

2. the zona fasciculata.

3. the zona reticularis.

The Adrenal cortex:

▪ Zona glomerulosa:( المنطقة الكبية)

▪ Is The outermost zone of the adrenal cortex It lies immediately under the fibrous capsule of the gland

▪ This layer is the main site for production of aldosterone, a mineralocorticoid

▪ Zona fasciculata : (المنطقة الحزمية)

▪ it is situated between the zona glomerulosa and zona reticularis.[

▪ It is the largest of the three layers, accounting for nearly 80% of the volume of the cortex.

▪ This layer is the main site for production of glucocorticosteroids (cortisol)

▪ Zona reticularis ( :المنطقة الشبكية)

▪ The innermost cortical layer

▪ . It produces androgens, mainly dehydroepiandrosterone (DHEA), DHEA sulfate (DHEA-S), and androstenedione (the precursor to testosterone) in humans.

Cushing’s syndrome:

Cushing’s syndrome:

Symptoms:

oligomenorrhea

Decreased sex drive

Hirsutism(females)

fatigue

Muscle weakness

Signs: Central obesity

Moon face Acne

bruising Purple strains

Osteoporosis Secondary diabetes

Poor wound healing Pigmentations(ACTH related)

High levels of free fatty acids Arterial hypertension

Addison’s disease :

Symptoms:

Weakness

Lethargy

Salt craving

anorexia

amenorrhea

Decreased sex drive

signs

Hyperpigmentation of the skin

Hypotension

Weight loss

Vitiligo(البهاق يتظاهر عند مرضى داء اديسون المناعي الذاتي )

The pancreas :

The pancreas :

The pancreas is an organ of the digestive system and endocrine system of vertebrates.

In humans, it is located in the abdomen behind the stomach and functions as a gland.

The pancreas has both an endocrine and a digestive exocrine function.

As an endocrine gland, it functions mostly to regulate blood sugar levels, secreting the hormones insulin,

glucagon, somatostatin

Diabetes Mellitus:

Diabetes Mellitus:

Symptoms:

Frequent urination

Excessive thirst

Extreme hunger

Sudden vision changes

Tingling or numbness in the hands or feet

Feeling very tired much of the time

Signs:

Unexplained weight loss

Very dry skin

Sores that are slow to heal

More infections than usual

The pituitary gland

Sheehan syndrome:

Symptoms:

•irregular menstrual

periods (oligomenorrhea)

or no periods

(amenorrhea)

•fatigue or weakness

•difficulty breastfeeding

or an inability to

breastfeed

•intolerance to cold

•decreased sex drive

• joints pain

Signs: •weight gain

•loss of pubic and

underarm hair

•slowed mental

function

•breast shrinkage •fine wrinkles

around the eyes

and lips

•low blood sugar •low blood

pressure

•irregular

heartbeat

Diabetes

Insipidus( نادربشكل)

تسلسل ظهور األعراض و العالمات في متالزمة شيهان

فشل أو نقص في اض انخف)الدرةالحليبية

(البروالكتين

انقطاع الطمث الثانوي

قصور درق ثانوي قصور كظر ثانوي

Pituitary Gland Tumor:

Symtptoms:

Headaches

Vision problems

Unexplained tiredness

Changes in menstrual cycles in women

Erectile dysfunction

Inappropriate breast growth or production of

breast milk

Signs:

Mood changes

Irritability

Infertility, which is the inability to have

children

Cushing’s syndrome

Acromegaly