Human Anatomy And Physiology Of Endocrine System Pdf
File Name: human anatomy and physiology of endocrine system .zip
- Endocrine System Anatomy and Physiology
- Functions of the Endocrine System
- 17.1 An Overview of the Endocrine System
- An Overview of the Endocrine System
Human endocrine system , group of ductless glands that regulate body processes by secreting chemical substances called hormones. Hormones act on nearby tissues or are carried in the bloodstream to act on specific target organs and distant tissues. Diseases of the endocrine system can result from the oversecretion or undersecretion of hormones or from the inability of target organs or tissues to respond to hormones effectively.
Endocrine System Anatomy and Physiology
Communication within the human body involves the transmission of signals to control and coordinate actions in an effort to maintain homeostasis. There are two major organ systems responsible for providing these communication pathways: the nervous system and the endocrine system. The nervous system is primarily responsible for rapid communication throughout the body. In this way, neural communication enables body functions that involve quick, brief actions, such as movement, sensation, and cognition. In contrast, the endocrine system relies on only a single method of communication: chemical signaling Table 1.
Functions of the Endocrine System
Our body cells have dynamic adventures on microscopic levels all the time. For instance, when insulin molecules, carried passively along in the blood leave the blood and bind tightly to protein receptors of nearby cells, the response it dramatic: blood borne glucose molecules begin to disappear into the cells, and cellular activity accelerates. Despite the huge variety of hormones, there are really only two mechanisms by which hormones trigger changes in cells. Compared to other organs of the body, the organs of the endocrine system are small and unimpressive, however, functionally the endocrine organs are very impressive, and when their role in maintaining body homeostasis is considered, they are true giants. The major endocrine organs of the body include the pituitary, thyroid, parathyroid, adrenal, pineal and thymus glands, the pancreas, and the gonads. The posterior pituitary is not an endocrine gland in the strict sense because it does not make the peptide hormones it releases, but it simply acts as a storage area for hormones made by hypothalamic neurons. The parathyroid glands are mostly tiny masses of glandular tissue.
The pituitary gland is a part of your endocrine system. Its main function is to secrete hormones into your bloodstream. These hormones can affect other organs and glands, especially your:. The pituitary gland is small and oval-shaped. The hypothalamus is a small area of your brain. It controls the release of hormones from the pituitary gland. The anterior lobe of your pituitary gland is made up of several different types of cells that produce and release different types of hormones, including:.
If your institution subscribes to this resource, and you don't have a MyAccess Profile, please contact your library's reference desk for information on how to gain access to this resource from off-campus. Please consult the latest official manual style if you have any questions regarding the format accuracy. A hormone is a chemical that is produced by the body and has a specific regulatory effect on a target cell or organ. Classic endocrinology was concerned with the functions of anatomically defined glands such as the thyroid gland or the pituitary gland. It is now recognized that almost every organ secretes hormones and that endocrine cells may be dispersed throughout the body e. The more recent study of endocrinology encompasses all processes concerned with the physiology of hormones.
17.1 An Overview of the Endocrine System
If your institution subscribes to this resource, and you don't have a MyAccess Profile, please contact your library's reference desk for information on how to gain access to this resource from off-campus. Please consult the latest official manual style if you have any questions regarding the format accuracy. A hormone is a chemical that is produced by the body and has a specific regulatory effect on a target cell or organ. Classic endocrinology was concerned with the functions of anatomically defined glands such as the thyroid gland or the pituitary gland.
Numerous glands throughout the body produce hormones. The hypothalamus produces several releasing and inhibiting hormones that act on the pituitary gland, stimulating the release of pituitary hormones. Of the pituitary hormones, several act on other glands located in various regions of the body, whereas other pituitary hormones directly affect their target organs. Other hormone-producing glands throughout the body include the adrenal glands, which primarily produce cortisol; the gonads i. Many of these hormones are part of regulatory hormonal cascades involving a hypothalamic hormone, one or more pituitary hormones, and one or more target gland hormones.
An Overview of the Endocrine System
Communication is a process in which a sender transmits signals to one or more receivers to control and coordinate actions. Together, these two systems are primarily responsible for maintaining homeostasis in the body. The nervous system uses two types of intercellular communication—electrical and chemical signaling—either by the direct action of an electrical potential, or in the latter case, through the action of chemical neurotransmitters such as serotonin or norepinephrine. Neurotransmitters act locally and rapidly. When an electrical signal in the form of an action potential arrives at the synaptic terminal, they diffuse across the synaptic cleft the gap between a sending neuron and a receiving neuron or muscle cell.
Human Physiology pp Cite as. The biological role of the endocrine system is closely linked to that of the nervous system; the two together coordinate the functions of the other in some cases widely separated organs and organ systems. The distinguishing feature of the endocrine system is that its influence is exerted by way of a number of substances, the hormones. Chemically, the hormones are a nonuniform group; the range of compounds represented includes steroids, amino-acid derivatives, peptides and proteins. They have specific actions on these target organs, actions that as a rule cannot be produced by any other substance. Unable to display preview.
1. Describe the role and function of the anterior and posterior pituitary, hypothalamus, adrenal glands, endocrine pancreas, and thyroid gland within the endocrine.
Introduction to the Endocrine System
It provides a slower, but longer lasting coordination than the nervous system. The endocrine system uses chemical messages in the form of hormones- chemical substances that are secreted by cells into extracellular fluids and regulate metabolic activity. Target cells must have specific protein receptor in order to be affected by the hormone. Similarly, certain cells send chemical signals to other cells in the body that influence their behavior. This long-distance intercellular communication, coordination, and control is critical for homeostasis, and it is the fundamental function of the endocrine system.
The endocrine system consists of glands widely separated from each other with no physical connections Fig. Homeostasis of the internal environment is maintained partly by the autonomic nervous system and partly by the endocrine system. The autonomic nervous system is concerned with rapid changes, while endocrine control is mainly involved in slower and more precise adjustments. Although the hypothalamus is classified as a part of the brain rather than an endocrine gland, it controls the pituitary gland and has an indirect effect on many others. The ovaries and the testes secrete hormones associated with the reproductive system after puberty. The endocrine glands are explored in the early sections of the chapter. Problems that arise when abnormalities occur are usually caused by the over- or under-activity of endocrine glands and are explained in the final sections of the chapter.
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