adrenal medulla/adrenaline * Paracrine - that secretes hormones that affect adjacent cells e.g. gastric mucosa/gastrin/gastric pits. * Autocrine – regulate their own avtivity by the secretion of hoirmone e.g. interstitial cells of testis/testosterone Each target cell in the body is regulated only by those hormones to which it has receptor molecules , and not y others.different cells may respond in different ways to the same hormone – the transduction machinery of different target cells ‘reads’ the hormone signal in different ways. Blood hormone concentrationare usually governed by negative feedback control – a reduction in concentration stimulates additional secretion and an increase in concentration inhibits further secretion.
Hypothalamus regulates the Pituitary Gland, by release of regulatory hormones -Negative feedback mechanism regulated How does the hypothalamus control the anterior pituitary? Hypothalamus produces Regulatory Hormones that are release by hypothalamic neurons into Portal Veins that descend into the Anterior Pituitary casueing it to either to release hormones or inhibit hormone release What is the hypophyseal portal system and why is it important? An extensive capillary network that surround endocrine cells of the Anterior Pituitary, provides an entry point into the blood stream for hormones secreted by the Anterior
The hormone that is not being produced is called ACTH, cortisol or aldosterone. Addison’s disease happens when the anterior pituitary gland produces excessive but in effective amounts of ACTH to the adrenal cortex. This hinders its ability to produce and release hormones. Symptoms include bronzing of skin, dehydration, fatigue, muscle weakness, loss of appetite, and weight loss. Addison’s disease is an autoimmune disease.
Homeostatic Imbalance/Unit 8 Assignment William Thornbury Introduction to Anatomy and Physiology SC121 Instructor: Eric D. Steelman, DHSc(c), MPH, MS, RLATG 10/17/14 Homeostatic Imbalance The endocrine system helps regulate and maintain various body functions by synthesizing (making) and releasing hormones, chemical messengers. The major areas of control and integration include responses to stress and injury, growth and development, absorption of nutrients, energy metabolism, water and electrolyte balance, reproduction, birth, and lactation. The endocrine system is composed of glands that release their hormones directly into the bloodstream for chemical signaling of target cells. Typically, the body synthesizes hormones in one part and transports it to another through the bloodstream or lymph. Endocrine glands have a rich blood supply through which hormones travel to reach their target organs.
The lymph ascends or descends to the left or right lymphatic duct. f. Describe the lymphatic system role with regard to lipids and lipid-soluble vitamins. The lymphatic system supports the lipids and vitamin A,D,E,K from the GI tract blood stream initiates specific immune responses. 3. What are the thymus gland functions?
Parietal cells (secrete HCI) and gastric glands (acetylcholine) are directly related to the formation of ulcers. D. Why does Zach’s G.I. tract need the substance that contributes to the formation of ulcers? How is this substance secreted by cells within the gastric pits? d. Zach’s G.I.
The hippocampus on the other side is responsible for the production of corticosteroids (chemicals that produce physiological responses to stimuli). How the mind creates memories is controlled by the hippocampus. So as to work efficiently, the amygdala and the hippocampus rely on each other greatly. The amygdala regulates the responses to stimuli and the hippocampus uses these responses in the formation of both short-term and long-term memories. Damage to the amygdala or hippocampus causes loss of emotions and memory respectively.
f. Describe the lymphatic system role with regard to lipids and lipid-soluble vitamins. The lymphatic system transports lipids and lipid-soluble vitamins from the GI tract to the blood. 3. What are the thymus gland functions? The thymus gland produces thymic hormone—thymosin—that matures lymphocytes as they pass through the gland.
a) thyroid hormones b) insulin and glucagon c) parathyroid hormone and calcitonin d) glucocorticoids and mineralocorticoids 5. Which of these organelles is concerned with digestion "within" the cell? a) lysosomes b) Golgi body c) mitochondria d) endoplasmic reticulum 11. After leaving the right ventricle, blood enters the a) aorta b) vena cavae c) pulmonary vein d) pulmonary
Explain the role the hypothalamus and pituitary gland have in the regulation of the endocrine system. What would happen if there were no negative feedback control on growth hormone and thyroid hormone? The hormonal secretion is controlled by negative feedback mechanisms. The stimulus triggers the production of hormone worse direct or indirect effects that reduce the intensity of the stimulus. The simplest case, endocrine activity may be controlled by humoral stimuli – changes in the composition of the exetracelluar fluid.