Post on 19-Dec-2015
description
ENDOCRINE
Secretions enter interstitial
fluid and then
bloodstream
Stay in the body: ENDO -
Examples: all hormones such
as growth hormone, insulin,
adrenalin, estrogen
EXOCRINE
Secrete substances that
enter ducts
Ultimately exit the body
(exo-)
Examples: mucus, saliva and
other digestive secretions,
sweat, tears
HORMONES
Intercellular chemical signals
“hormon” – set into motion
Lipid-soluble Steroids, such as testosterone, estrogens
Thyroid hormones: T3 and T4
Water-soluble Amino acid derivatives, such as epinephrine,
norepinephrine
Peptides: antidiuretic hormone (ADH), oxytocin
Proteins: insulin and growth hormone
HYPOTHALAMUS AND PITUITARY
Hypothalamic cells synthesize
Many releasing and inhibiting hormones
Two hormones (oxytocin and ADH) that are then stored
and released from the posterior pituitary
Anterior pituitary synthesizes 7 hormones
Regulate growth, development, metabolism and
homeostasis
GROWTH HORMONE (GH)
CELLS Somatotropes
STRUCTURE Polypeptide
REGULATED BY • GH- releasing hormone (GHRH)
• Somatostatin (inhibiting hormone)
TARGET TISSUE Most tissues
FUNCTION • promotes growth of bone and cartilage
• increases protein synthesis
• promotes lipid breakdown to fatty acids
• increases blood glucose concentration
PROLACTIN
CELLS Lactotropes
STRUCTURE Protein
REGULATED BY • Prolactin – releasing
• Prolactin inhibitory factor (PIF)
TARGET TISSUE Female: ovary and mammary glands
Male: testis
FUNCTION • stimulates milk production and secretion
• prolongs progesterone secretion
• increases sensitivity to LH in males
ADRENOCORTICOTROPHIC
HORMONE (ACTH)
CELLS Corticotropes
STRUCTURE Polypeptide
REGULATED BY • Corticotropin releasing hormone (CRH)
TARGET TISSUE Adrenal cortex
FUNCTION • stimulates secretion of cortisol
• increases skin pigmentations at high conc
MELANOCYTE – STIMULATING
HORMONE
CELLS Corticotropes
STRUCTURE Protein
REGULATED BY • Prolactin – releasing
• Prolactin inhibitory factor (PIF)
TARGET TISSUE Mammary glands
FUNCTION • stimulates milk secretion
LUTEINIZING HORMONE (LH)
FOLLICLE STIMULATION HORMONE (FSH)
CELLS Gonadotropes
STRUCTURE Glycoproteins
REGULATED BY • Gonadotrohic releasing hormone (GnRH)
TARGET TISSUE Ovary and testis
FUNCTION • LH• promotes ovulation and progesterone production
• testosterone synthesis and support for sperm cell
production
• FSH• promotes follicle maturation and estrogen secretion
• sperm cell production
THYROID – STIMULATION HORMONE
CELLS Tyrotropes
STRUCTURE Glycoprotein
REGULATED BY • Thyrotropin – releasing hormone
TARGET TISSUE Thyroid gland
FUNCTION • increases thyroid hormone secretion
• Thyroxine
• Triiodothyronine
ANTIDIURETIC HORMONE (ADH)
ORIGIN Hypothalamus (supraoptic nuclei)
STRUCTURE Peptides
REGULATED BY • Osmotic changes in blood (Na+)
TARGET TISSUE Kidneys
FUNCTION • promote reabsorption of water into the blood
circulation
• potent vasoconstrictor
OXYTOCIN
ORIGIN Hypothalamus (paraventricular nuclei)
STRUCTURE Polypeptides
REGULATED BY • sucking reflex communicated via
hypothalamus
TARGET TISSUE Uterus and mammary gland
FUNCTION • increase uterine contractions
• increases milk “let-down”
THYROID GLAND
Structure and function
Follicular cells produce hormones and
store them in follicles Thyroxine (T4)
Triiodothyronine (T3)
Parafollicular cells produceCalcitonin (CT)
PARATHYROID GLAND
Small round masses in posterior of thyroid gland
Release parathyroid hormone (PTH)
Increases blood Ca2+ in 3 ways
Increases number and activity of osteoclasts that break down bone
Slows loss of Ca2+ and Mg2+ in urine
Promotes production of calcitriol (vitamin D) increases rate of Ca2+, Mg2+ and HPO4
2- absorption in GI tract increase blood Ca2+
Chromaffin cells
produce catecholamines
Epinephrine
Norepinephrine
Dopamine
Reinforce the effect of the sympathetic division
ADRENAL MEDULLA
MINERALOCORTICOIDS
Major hormone: Aldosterone
Function:
regulate blood volume and blood levels of
K+ and Na+
part of renin-angiotensin-aldosterone
pathway
ADRENAL CORTEX
GLUCOCORTICOIDS
Major hormone: cortisol
Function:
Increases rate of protein breakdown
Stimulates liver formation of glucose
Breaks down triglycerides in adipose
Anti-inflammatory effects
Inhibit white blood cells
ADRENAL CORTEX
ANDROGENS
Small amount secreted from adrenal cortex in
both females and males
At puberty, in both genders, androgens
stimulate axillary and pubic hair growth
contribute to adolescent growth spurt
ADRENAL CORTEX
Low blood glucose stimulates glucagon release
Glucagon stimulates liver to release glucose increased blood glucose
High glucose levels stimulate insulin release
Insulin increases glucose transport into skeletal muscle and adipose cells decreased blood glucose
Insulin promotes amino acid uptake, protein synthesis, and lipid storage
INSULIN AND GLUCAGON
GONADS: OVARIES AND TESTES
Produce gametes: sperm and oocytes
Produce hormones
Testosterone in males
Estrogen and progesterone in females
Regulated by
GnRH from hypothalamus
FSH + LH from anterior pituitary
PINEAL GLAND
Small gland attached to roof of third ventricle of
brain
Produces melatonin
Sets body’s biological clock
More released in darkness, less in sunlight