09 jan. 2013endocrine-glands.ppt1 endocrine glands

09 Jan. 2013 Endocrine-Glands.ppt 1

Endocrine Glands


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


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


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.


Hypothalamus

• Hypothalamic cell bodies synthesize oxytocin and ADH

• Axonal transport to posterior pituitary

• Release from posterior pituitary


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)


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



• 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.



• Growth hormone– Oversecretion in youth

produces giantism

– Oversecretion in adult produces acromegaly


Pituitary—Posterior lobe

• Posterior lobe (= neurohypophysis)

• Site of release of hormones synthesized in hypothalamus– Oxytocin

– Antidiuretic H. (ADH)


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


Thyroid Gland

• Location in neck– Inferior to larynx

– Anterior & lateral to trachea

• Thyroxine (T4)

• Triiodothyronine (T3)

• Calcitonin


Thyroid Gland• Composed of follicles

– Follicle cells produce thyroglobulin• Thyroxin (T4)

• Triiodothyronine (T3)

– Parafollicular cells• Calcitonin


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


Adrenal Glands

• One on top of each kidney– Cortex

• Steroid hormones

– Medulla• Epinephrine

• Norepinephrine


Adrenal Glands• Cortex

– Activity stimulated by ACTH

– Mineralcorticoids• Aldosterone

– Glucocorticoids• Cortisol

– Gonadocorticoids• Androgens

• Estrogens


Adrenal Glands

• Medulla– Develops as

“misplaced” sympathetic ganglion

– Cells are modified neurons (lack axons)

– Epinephrine

– some Norepinephrine


Islets of Langerhans

• “About a million” embedded in pancreas

• Control centers for blood glucose

• Insulin from beta cells• Glucagon from alpha

cells


Islets of Langerhans

• Insulin stimulates glucose uptake, glycogenesis

• Glucagon stimulates glycogenolysis, glucose release from liver


Gonads

• Ovaries– Estrogens– Progesterone

• Testes– Testosterone, etc.

• Reproductive functions when we study reproductive system.


Pineal gland

• Suspended in third ventricle from diencephalon

• Melatonin– ? Inhibits early puberty– ? Day/night cycles

• Timing of sleep, body temperature, appetite


Thymus

• = “Thymus gland”

• Thymopoietins, thymic factor, thymosins– Influence development of T lymphocytes


others

• Stomach, small intestine• Heart ANP

• Kidneys erythropoietin

• Adipose tissue leptin

• Skin cholecalciferol (vit. D precursor)

• Placenta progesterone

09 jan. 2013endocrine-glands.ppt1 endocrine glands

Documents

ppt1 endocrine glands

small glands

posterior lobe slide

ppt14 parathyroid glands

ppt15 adrenal glands

adh slide

posterior pituitary

intestine slide