Human Anatomy and Physiology (BSCI 4001)
Lesson 9:
Endocrine System
Prepared by Arianne V. Julian
Endocrine System
• Endocrine system- composed of endocrine
glands and specialized endocrine cells located
throughout the body
Gland
↓
Hormones
↓
Target tissues or effectors
Functions
Functions
1. Metabolism
2. Control of food intake and digestion
3. Tissue development
4. Ion regulation
5. Water balance
6. Heart rate and blood pressure regulation
7. Control of blood glucose and other nutrients
8. Control of reproductive functions
9. Uterine contractions and milk release
10.Immune system regulation
Endocrine Glands
Endocrine Glands and
Their Hormones
Pituitary and Hypothalamus
• Pituitary gland (hypophysis)
• divided into two parts:
1. Anterior pituitary- made up of epithelial cells
derived from the embryonic oral cavity
2. Posterior pituitary- an extension of the brain and is
composed of nerve cells
Pituitary Gland
Pituitary gland
Pituitary Gland
Anterior Pituitary Gland
Hormone Target Tissue Function
Growth hormone Most tissues • Stimulates the growth of bones,
muscles, and other organs
• Breakdown of lipids, and release of fatty
acids from cells
• Increases blood glucose levels
Anterior Pituitary Gland
Dwarfism, gigantism, acromegaly
Anterior Pituitary Gland
Hormone Target Tissue Function
Thyroid-stimulating Thyroid gland • Increases thyroid
hormone hormone secretion
(TSH)
Anterior Pituitary Gland
Hormone Target Tissue Function
Adrenocorticotropic Adrenal cortex • Increases secretion of
hormone glucocorticoid
(ACTH) hormones, such as
cortisol
• Increases skin
pigmentation at high
concentrations
Anterior Pituitary Gland
Hormone Target Tissue Function
Melanocyte-stimulating Melanocytes in skin • Increases melanin
hormone (MSH) production in melanocytes
to make skin darker in
color
Anterior Pituitary Gland
Hormone Target Tissue Function
Luteinizing hormone (LH) Ovary in females • Promotes ovulation and
progesterone production in
ovary
Testis in males • Promotes testosterone
synthesis and support for
sperm cell production in testis
Anterior Pituitary Gland
Hormone Target Tissue Function
Follicle-stimulating Follicles in ovary in • Promotes follicle maturation
hormone females and estrogen secretion in
(FSH) ovary
Seminiferous tubules • Promotes sperm cell
in males production in testis
Anterior Pituitary Gland
Hormone Target Tissue Function
Prolactin Ovary and mammary • Stimulates milk production and
gland in females prolongs progesterone secretion
following ovulation and during
pregnancy in women
Testis in males • Increases sensitivity to LH in males
Posterior Pituitary Gland
Hormone Target Tissue Function
Antidiuretic hormone Kidney Conserves water
(ADH) Constricts blood vessels
Posterior Pituitary Gland
Hormone Target Tissue Function
Oxytocin Uterus • Increases uterine contractions
Mammary gland • Increases milk letdown from
mammary glands
Thyroid Gland
Hormone Target Tissue Function
Thyroid hormones Most cells of the body • Increase metabolic rates
(thyroxine, • Essential for normal process
triiodothyronine) of growth and maturation
Thyroid Gland
Goiter Cretinism
Thyroid Gland
Hormone Target Tissue Function
Calcitonin Primarily bone • Decreases rate of bone
breakdown
• Prevents large increase in blood
Ca2+ levels following a meal
Parathyroid Gland
Hormone Target Tissue Function
Parathyroid hormone Bone, kidney • Increases rate of bone breakdown
by osteoclasts
• Increases vitamin D synthesis,
essential for maintenance of normal
blood calcium levels
Adrenal medulla
Hormone Target Tissue Function
Epinephrine mostly, heart, blood • Increases cardiac output
some norepinephrine vessels, liver, fat • Increases blood flow to
cells skeletal muscles and heart
• Increases release of glucose
and fatty acids into blood
• In general, prepares body for
physical activity
Adrenal cortex
Hormone Target Tissue Function
Mineralocorticoids Kidneys; to lesser • Increase rate of sodium
(aldosterone) degree, intestine and transport into body
sweat glands • Increase rate of potassium
excretion
• Secondarily favor water
retention
Adrenal cortex
Regulation of Aldosterone Secretion from the Adrenal Cortex
Adrenal cortex
Hormone Target Tissue Function
Glucocorticoids most tissues (e.g., • Increase fat and protein
(cortisol) liver, fat, skeletal breakdown
muscle, immune • Increase glucose synthesis from
tissues) amino acids
• Increase blood nutrient levels
• Inhibit inflammation and
immune response
Adrenal cortex
Hormone Target Tissue Function
Adrenal androgens Most tissues • Insignificant in males
• Increase female sexual drive, growth of
pubic and axillary hair
Pancreas
Hormone Target Tissue Function
Insulin Especially liver, skeletal • Increases uptake and use of
muscle, adipose tissue glucose and amino acids
Pancreas
Hormone Target Tissue Function
Glucagon Primarily liver • Increases breakdown of
glycogen and release of glucose
into the circulatory system
Testes
Hormone Target Tissue Function
Testosterone Most tissues • Aids in sperm cell production,
maintenance of functional
reproductive organs, secondary
sexual characteristics, sexual
behavior
Ovaries
Hormone Target Tissue Function
Estrogens, Most tissues • Aid in uterine and mammary
progesterone gland development and function,
external genitalia structure,
secondary sexual characteristics,
sexual behavior, menstrual cycle
Uterus, ovaries, inflamed tissues
Hormone Target Tissue Function
Prostaglandins Most tissues • Mediate inflammatory responses
• Increase uterine contractions and
ovulation
Thymus
Hormone Target Tissue Function
Thymosin Immune tissues • Promotes immune system
development and function
Pineal Gland
Hormone Target Tissue Function
Melatonin Among others, • Inhibits secretion of
hypothalamus gonadotropin-releasing
hormone, thereby inhibiting
reproduction
Reference: Seeley’s Essentials of Anatomy and Physiology 9th Edition
