Nur 0003Lab 01 - Endocrine Anatomy and HistologyGoals1.To Identify the location of the major endocrine glands in the body.2.To understand the histology of the major endocrine glands.3.To learn the major hormones secreted by the major endocrine glands. I.The Endocrine System A.Location of major endocrine glands 1.Head Hypothalamus(junction between the endocrine and nervous systems)Pituitary (a.k.a. hypophysis)Pineal body2. Neck ThyroidParathyroid – posterior of thyroid gland3. Thorax Thymus(especially enlarged in fetuses and infants)Heart4 Abdomen PancreasAdrenalsGonads - ovaries and testesStomach and intestinal liningsB.Hormones and their Targets1.Hormone Chemical Signal Released in small amounts by specialized epithelialcellsTravels through blood to target tissues.2.TargetsTarget tissues have receptors that will bind with the appropriate hormone.Receptors can be membrane bound (protein) or intracellular (steroid)Some target tissues will down regulate over time, meaning they become less sensitive to the amounts of hormone present.1
Nur 0003II.Pituitary GlandA. Anatomy of the Pituitary glandLocated in the sella turcica (Turkish saddle) of the sphenoid bone.Connected to the hypothalamus by a stalk called the infundibulum.Adenohypophysis (anterior pituitary) - cuboidal epithelial tissue.The anterior pituitary is connected the hypothalamus via a portal system (a special system of blood vessels in which two capillary beds are connected together directly) known as the hypothalamohypophyseal portal system.Releasing hormones from the hypothalamus trigger the anterior Pituitary to secrete its hormones, or in some special cases inhibit the anterior pituitary from releasing hormones(the inhibiting hormones)Examples of releasing and inhibiting hormones include: GHRH, GnRH, TRH, CRH, and PIH and GHIH.Neurohypophysis (posterior pituitary)- nervous tissue.The posterior pituitary does not secrete*any hormones because it is primarily nervous tissue. Axons from the hypothalamus pass down the hypothalamohypophyseal tractto terminate here and releasetheir chemical products as needed.B.Hormones secreted by the anterior pituitary gland 1. Growth Hormone (GH) a.k.a. somatotropinStructure- proteinTarget – Many tissues, but mainly muscle and connective tissue.Response - a.a uptake for protein & glycogen synthesis, growth in tissues, stimulates muscle and bone growth.Clinical- pituitary dwarfism and pituitary giants (gigantism), and acromegaly 2. Prolactin (PRL)Structure – proteinTarget - mammary glands (primarily)Response - stimulates mammary glands to produce milk soon after birthTropic hormones - hormones whose targets are other endocrine glands.