Anatomy & Physiology 1
Pineal Gland 1. Pineal gland 2. Pons of brainstem 3. Cerebellum 4. Cerebrum
The small pineal gland (body) is located inside the skull cavity, surrounded by the brain. t produces melatonin, whose concentration varies in tune with the 24-hour cycle of the day (cir- cadian rhythm)-melatonin production is highest during a person's normal sleeping hours, and drops off as the body begins to wake The pineal gland probably has an effect on the ovaries and testes, and may influence mood.
Thvroid Gland-anterior vievw 1. Thyroid cartilage (of larynx) 2. Cricoid cartilage (of larynx) 3. Right lobe of thyroid gland 4. Trachea 5. Isthmus of thyroid gland 6. Left lobe of thyroid gland of the endocrine glands, the thyroid gland .
of the endocrine glands, the thyroid gland Description: The largest consists of two lobes, joined together at the midline by a narrow isthmus (bridge). The thyroid gland is located in the neck, immedi ately below and in front of the larynx. follicles, which produce The thyroid gland is made of up many called T4, or tetraiodothyronine) and triiodothyronine (T3) hormone is composed of two different substances: thyroxine (also thyroid hormone and secrete it into the bloodstream. Thyroid thyroid hormone is under the control of thyroid-stimulating control the metabolic rate of body tissues. The production of Thyroid hormone has several functions, the main one being to Thyroid hormone is necessary for the normal growth and hormone (TSH), which is released from the pituitary gland development of children
Adrenal Gland-microstructure 1. Capsular artery 2. Capsule 3. Zona glomerulosa 4. Capillaries 5. Zona fasciculata 6. Spongiocyte 7. Zona reticularis 8. Medulla 9. Venule
Description: The adrenal gland is divided into an outer cortex and an inner medulla. The adrenal cortex is further divided into three zones (zona glomerulosa, zona fasciculata and zona reticularis). The entire gland is richly supplied with a capillary plexus so that hormones can be carried away to the rest of the body. Cells of the zona glomerulosa make the hormone aldosterone under the influence of angiotensin II. Aldosterone regulates water and sodium levels in the body. Cells of the zona fasciculata have abundant lipid globules in their cytoplasm and are called spongiocytes. They make the glucocorticoid hormone called cortisol under the influence of ACTH from the anterior pituitary gland. Cortisol is an anti-inflammatory hormone that is secreted in response to stress. Cells of the zona reticularis mainly make sex steroids and contribute to libido. The adrenal medulla makes epinephrine and norepinephrine under the control of the sympathetic nervous system. The hormones of the medulla are secreted in an emergency situation to increase heart rate and contractility, increase blood flow to muscles and dilate airways to improve ventilation of the lungs. The whole gland is surrounded by a fibrous capsule
Pancreas (endocrine function) 1. Head (of pancreas) 2. Accessory pancreatic duct 3. Uncinate process 4. Main pancreatic duct 5. Tail (of pancreas) 6. Body (of pancreas) 7. Neck (of pancreas)
Description: The pancreas is an elongated gland lying behind the stomach. s large head is framed by the C-shaped loop of the duodenum, while its tail touches the spleen. The pancreas plays a role in both the digestive and endocrine systems The endocrine function of the pancreas is hormonal and is involved in the regulation of glucose mobilization and storage. The two pancreatic hormones responsible for these functions are glucagon and insulin, respectively. These two hormones are pro- duced in special cell types within many tiny spherical clumps of pancreatic panereatic sue, tissue, which are known as the panereatic slets or the islets of Langerhans. Within the islets of Langerhans, the alpha cells secrete glucagon, which elevat bod sugar; beta cells secrete insulin, which affects the metabolism of fats, protein s, and carbohydrates: and delta cells secrete somatostatin, which can inhibit the release of both glucagon and insulin.
Pancreas-microstructure (Islets of Langerhans) 1. Alpha cell in the mantle zone of an islet of Langerhans 2. F cell in the mantle zone of an islet of Langerhans 3. Beta cell in the core of an islet of Langerhans 4. Delta cell in the mantle zone of an islet of Langerhans 5. Acinus of exocrine pancreas 6. Duct of exocrine pancreas
Description: The pancreatic component of the pancreas consists of clumps of endocrine cells called the islets of Langerhans. Each islet has a core and mantle zone. The core contains beta cells that produce insulin to lower blood glucose. The mantle zone contains several types of cells. The most numerous cell type in the mantle zone is the alpha cel that makes glucagon, a hormone that raises blood glucose levels. Delta cells of the mantle produce the hormones gastrin and somatostatin. Gastrin acts on the stomach to increase acid secretion and somatostatin inhibits the production of both insulin and glucagon. F cells secrete the hormone pancreatic polypeptide that inhibits the secretion of somatostatin and the secretion of pancreatic enzymes from the exocrine pancreas.
Pituitary Gland-microstructure 1. Optic chiasm 2. Hypophyseal artery 3. Capillary plexus of anterior pituitary 4. Anterior pituitary (adenohypophysis) 5. Vein draining anterior pituitary 6. Hypophyseal artery 7. Axon terminals of hypothalamoneurohypo- physeal tract 8. Vein draining posterion pituitary 9. Capillary plexus of posterior pituitary 10. Posterior pituitary (neurohypophysis) 11. Hypothalamohypophyseal portal venous system 12. Pituitary stalk 13. Neurosecretory cells in hypothalamus 14 Mammillary body
Description: The putary is known as the master gland of the endocrine system, becs t directs the functions of several other endocrine glands (thy roid, adrenal corte, testes, ovaries). The pituitary is divided into an anterior pituitary (adenohypophysis) and posterir pituitarv ( neurohypoph 、 sis ) . Ihe functions ol the adenohypophysis are directed by reguatory hormones or factors secreted by cells in the hypothalams of te brain and passed down to the adenohypophysis along the hypothalamohypophyseal venous portal system. The regulatory factors stimulate the anterior pituitary to secrete its hormones-thyroid stimulating hormone TSH), adrenocorticotrophic horne (ACTH). prolacin PRI follicle stimulating hormone (FSIH), luteinizing hormone (LH) growth hormone (GH)-into the veins draining the anterior pituitary capillary plexus. The posterior pituitary (neurohypophysis) receives axons of neurosecretory cells in e hypot. These axons directly release hormones (oxytocin, and vasopressin or antidiuretic hormone) into the capillary plexus of the posterior pituitar 、 and out into the 、 eins draining the Pituitary .
Thyroid Gland-microstructure 1. Parafollicular cell 2. Thyroid epithelium (follicle cell) 3. Capillary 4. Chief cells of parathyroid gland 5. Cavity of thyroid follicle for colloid 6. Capsule of parathyroid 7. Oxyphil cells of parathyroid gland
Description: The thyroid and parathyroid glands are found in the lower neck. The thyroid gland contains two endoerine components. The first are the thyroid follicles, which consist of thyroid epithelial cells (follicle cells) surrounding cavities filled with a proteinaceous fluid called colloid. The colloid is a storage /one or thvroid hormones. The thvroid follicle cells make triiodothvronine and thyrovine (called T3 and T4, respectively) under the influence of thyroid stimulating hormone (TSH) from the anterior pituitary. T3 and T4 affect the metabolic rate of all cells in the bodv. Parafollicular cells in the thyroid make calcitonin, a hormone that decreases the concentration of calcium in the blood. Four parathyroid glands located behind the thyroid gland. The chief cells of the parathyroid gland produce parathyroid hormone that increases the concentration of calcium ions in the blood. Oxyphil cells may be transitional chief cells.
Endocrine System (male)--anterior view 1. Pituitary gland 2. Parathyroid gland 3. Thymus gland 4. Pancreas 5. Testes 6. Adrenal glands 7. Thyroid gland
The endocrine system, involved in coordinating the activities of tissues throughout the body, acts by means of hor- mones. Hormones, made of amino acids or steroids, are released from endocrine cells at specific times and in precise amounts to act on target organs, often at some distance from their site of release. Hormones usually act by binding with special receptor sites on or inside target cells. Endocrine organs (often called endocrine glands) secrete only into the bloodstream. Endocrine hormones affect the nervous system, and many endocrine organs are stimulated or inhibited by nerve cells. The hypothalamus of the brain has an intimate connection with the chief organ of the endocrine system, the pituitary. This means that the endocrine and nervous systems share control of body functions: the nervous system usually controls activities occurring rapidly or in the short term, while the endocrine system controls slow or long-term changes. The organs involved in the male endocrine system are the pituitary, pineal, thymus, thyroid, parathyroids, adrenals, pancreatic islets, and testes. The testes produce hormones that control sexual function and secondary sexual characteristics.
Endocrine System (female)-anterior view 1. Pituitary gland 2. Parathyroid gland 3. Thymus gland 4. Pancreas 5. Ovaries 6. Adrenal glands 7. Thyroid gland
The organs involved in the female endocrine system include the pituitary, pineal, thymus, thyroid, parathyroids, adrenals, pancreatic islets, ovaries, and placenta (during pregnancy). The ovaries produce hormones that control sexual function and secondary sexual characteristics. The endocrine organs (or endocrine glands) secrete hormones that regulate growth. metabolism, sexul maturation, and other important body functions.
Pituitary Gland 1. Optic chiasm 2. Infundibulum hypothalamoneurohypo 3. Hypophyseal artery physeal tract 4. Anterior pituitary(adenohypophysis) 5. Posterior pituitary (neurohypophysis) 6. Hypophyseal portal system 7. Axon of hypothalamoneurohypo 8. Mammillary body 9. Hypothalamus 10. Neurosecretory cells
The pituitary gland (hypophysis) is a very small organ lying immediately below the hypohalamus of the brain. weighs only about V ounce (0.5 gram), but plays a very important role in the control of endocrine gland function throughout the body. The pituitary gland is divided into anterior and posterior lobes (the adenohypophysis and neurohypophysis, respectively). The different types of cells, which produce anterior lobe contains many growth hormone, prolactin, follicle-stimulating hormone, lutein- izing hormone, thyroid-stimulating hormone, adrenocorticotrophic hormone, and melanocyte-stimulating hormone. The poste lobe contains oxytocin and antidiuretic hormones, produced in the hypothalamus and transported to the pituitary within nerve fibers.