09 Jan. 2013 Endocrine-Glands.ppt 1
Endocrine Glands
09 Jan. 2013 Endocrine-Glands.ppt 2
Endocrine Glands
• Hypothalamus• Pituitary
– Anterior lobe– Posterior lobe
• Thyroid gland• Parathyroid glands• Adrenal Glands
– Cortex– Medulla
• Islets of Langerhans• Gonads
– Ovaries
– Testes
• Pineal gland• Thymus• others
09 Jan. 2013 Endocrine-Glands.ppt 3
Hypothalamus
• Part of brain– Regulates ANS,
emotions, feeding/satiety, thirst, body temperature, etc.
– Hormones related to these functions
• “Releasing hormones”
• Axonal transport to posterior lobe
09 Jan. 2013 Endocrine-Glands.ppt 4
Hypothalamus
• “Releasing” hormones regulate Anterior Pituitary– Growth hormone-releasing H.
– Growth hormone-inhibiting H.
– Thyrotropin-releasing H.
– Corticotropin-releasing H.
– Gonadotropin-releasing H.
– Prolactin-releasing H.
09 Jan. 2013 Endocrine-Glands.ppt 5
Hypothalamus
• Hypothalamic cell bodies synthesize oxytocin and ADH
• Axonal transport to posterior pituitary
• Release from posterior pituitary
09 Jan. 2013 Endocrine-Glands.ppt 6
Pituitary
• Anterior lobe (= adenohypophysis)– Growth H. (hGH)– Prolactin– Melanocyte-stimulating H. (MSH)– Thyroid-stimulating H. (TSH)– Adrenocorticotropic H. (ACTH)– Follicle-stimulating H. (FSH)– Luteinizing H. (LH)
09 Jan. 2013 Endocrine-Glands.ppt 7
Pituitary—Anterior lobe
• Growth hormone (GH or hGH)– Promotes mitosis, cell
division
– Elongation of long bones, etc.
– Healing of wounds
– Lack of hGH retards growth
09 Jan. 2013 Endocrine-Glands.ppt 8
Pituitary—Anterior lobe
• Growth hormoneLack of hGH retards growth
Charles Stratton, 1838-1883, “adopted” & trained by P.T. Barnum.
“General Tom Thumb”
~ 33 in. (84 cm) tall
Married Lavinia Warren, 1863.
Died of CV disease.
09 Jan. 2013 Endocrine-Glands.ppt 9
Pituitary—Anterior lobe
• Growth hormone– Oversecretion in youth
produces giantism
– Oversecretion in adult produces acromegaly
09 Jan. 2013 Endocrine-Glands.ppt 10
Pituitary—Posterior lobe
• Posterior lobe (= neurohypophysis)
• Site of release of hormones synthesized in hypothalamus– Oxytocin
– Antidiuretic H. (ADH)
09 Jan. 2013 Endocrine-Glands.ppt 11
Pituitary—Posterior lobe
• Oxytocin– Stimulates smooth muscle contraction of
uterus & mammary glands.
• Antidiuretic H.– Stimulates water reabsorption in collecting
ducts.– Stimulates vasoconstriction (vasopressin)– Lack diabetes insipidus
09 Jan. 2013 Endocrine-Glands.ppt 12
Thyroid Gland
• Location in neck– Inferior to larynx
– Anterior & lateral to trachea
• Thyroxine (T4)
• Triiodothyronine (T3)
• Calcitonin
09 Jan. 2013 Endocrine-Glands.ppt 13
Thyroid Gland• Composed of follicles
– Follicle cells produce thyroglobulin• Thyroxin (T4)
• Triiodothyronine (T3)
– Parafollicular cells• Calcitonin
09 Jan. 2013 Endocrine-Glands.ppt 14
Parathyroid Glands
• Four small glands embedded in posterior of thyroid– Parathyroid hormone
(PTH)
– Stimulates osteoclasts to free Ca from bone
– Stimulates Ca uptake from intestine
09 Jan. 2013 Endocrine-Glands.ppt 15
Adrenal Glands
• One on top of each kidney– Cortex
• Steroid hormones
– Medulla• Epinephrine
• Norepinephrine
09 Jan. 2013 Endocrine-Glands.ppt 16
Adrenal Glands• Cortex
– Activity stimulated by ACTH
– Mineralcorticoids• Aldosterone
– Glucocorticoids• Cortisol
– Gonadocorticoids• Androgens
• Estrogens
09 Jan. 2013 Endocrine-Glands.ppt 17
Adrenal Glands
• Medulla– Develops as
“misplaced” sympathetic ganglion
– Cells are modified neurons (lack axons)
– Epinephrine
– some Norepinephrine
09 Jan. 2013 Endocrine-Glands.ppt 18
Islets of Langerhans
• “About a million” embedded in pancreas
• Control centers for blood glucose
• Insulin from beta cells• Glucagon from alpha
cells
09 Jan. 2013 Endocrine-Glands.ppt 19
Islets of Langerhans
• Insulin stimulates glucose uptake, glycogenesis
• Glucagon stimulates glycogenolysis, glucose release from liver
09 Jan. 2013 Endocrine-Glands.ppt 20
Gonads
• Ovaries– Estrogens– Progesterone
• Testes– Testosterone, etc.
• Reproductive functions when we study reproductive system.
09 Jan. 2013 Endocrine-Glands.ppt 21
Pineal gland
• Suspended in third ventricle from diencephalon
• Melatonin– ? Inhibits early puberty– ? Day/night cycles
• Timing of sleep, body temperature, appetite
09 Jan. 2013 Endocrine-Glands.ppt 22
Thymus
• = “Thymus gland”
• Thymopoietins, thymic factor, thymosins– Influence development of T lymphocytes
09 Jan. 2013 Endocrine-Glands.ppt 23
others
• Stomach, small intestine• Heart ANP
• Kidneys erythropoietin
• Adipose tissue leptin
• Skin cholecalciferol (vit. D precursor)
• Placenta progesterone