endocrine system notes anatomy and physiology pdf Tuesday, May 25, 2021 6:46:44 PM

Endocrine System Notes Anatomy And Physiology Pdf

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Human endocrine system , group of ductless glands that regulate body processes by secreting chemical substances called hormones.

Endocrine System Anatomy and Physiology

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. Contrast the terms endocrine, paracrine, and autocrine. Define the terms hormone, target cell, and receptor. Understand the major differences in mechanisms of action of peptides, steroids, and thyroid hormones.

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. Once the neurotransmitters interact bind with receptors on the receiving post-synaptic cell, the receptor stimulation is transduced into a response such as continued electrical signaling or modification of cellular response.

What Are Glands in the Body?

Pituitary gland , also called hypophysis , ductless gland of the endocrine system that secretes hormones directly into the bloodstream. The pituitary gland lies at the middle of the base of the skull and is housed within a bony structure called the sella turcica, which is behind the nose and immediately beneath the hypothalamus. The pituitary gland is attached to the hypothalamus by a stalk composed of neuronal axons and the so-called hypophyseal-portal veins. Its weight in normal adult humans ranges from about to mg 0. In most species the pituitary gland is divided into three lobes: the anterior lobe, the intermediate lobe, and the posterior lobe also called the neurohypophysis or pars nervosa. In humans the intermediate lobe does not exist as a distinct anatomic structure but rather remains only as cells dispersed within the anterior lobe. Nonetheless, the anterior and posterior lobes of the pituitary are functionally, anatomically, and embryologically distinct.

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.

Pituitary gland

Glands are important organs located throughout the body. They produce and release substances that perform certain functions. Though you have many glands throughout your body, they fall into two types: endocrine and exocrine.

Hormone , organic substance secreted by plants and animals that functions in the regulation of physiological activities and in maintaining homeostasis. Hormones carry out their functions by evoking responses from specific organs or tissues that are adapted to react to minute quantities of them. The classical view of hormones is that they are transmitted to their targets in the bloodstream after discharge from the glands that secrete them. This mode of discharge directly into the bloodstream is called endocrine secretion. The meaning of the term hormone has been extended beyond the original definition of a blood -borne secretion, however, to include similar regulatory substances that are distributed by diffusion across cell membranes instead of by a blood 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.

Human endocrine system

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Сьюзан это выводило из себя, однако она была слишком самолюбива, чтобы пожаловаться на него Стратмору. Проще было его игнорировать. Хейл подошел к буфету, с грохотом открыл решетчатую дверцу, достал из холодильника пластиковую упаковку тофу, соевого творога, и сунул в рот несколько кусочков белой студенистой массы. Затем облокотился о плиту, поправил широкие серые брюки и крахмальную рубашку. - И долго ты собираешься здесь сидеть. - Всю ночь, - безучастно ответила Сьюзан. - Хм-м… - пробурчал Хейл с набитым ртом.

 Да, сэр, я… - Джаббе? - Фонтейн гневно поднялся.  - Какого черта вы не позвонили Стратмору. - Мы позвонили! - не сдавалась Мидж.  - Он сказал, что у них все в порядке. Фонтейн стоял, тяжело дыша. - У нас нет причин ему не верить.  - Это прозвучало как сигнал к окончанию разговора.

Отчаянное нажатие на кнопки неосвещенной панели ничего не дало: массивная дверь не поддалась. Они в ловушке, шифровалка превратилась в узилище. Купол здания, похожий на спутник, находился в ста девяти ярдах от основного здания АНБ, и попасть туда можно было только через главный вход. Поскольку в шифровалке имелось автономное энергоснабжение, на главный распределительный щит, наверное, даже не поступил сигнал, что здесь произошла авария. - Основное энергоснабжение вырубилось, - сказал Стратмор, возникший за спиной Сьюзан.  - Включилось питание от автономных генераторов. Это аварийное электропитание в шифровалке было устроено таким образом, чтобы системы охлаждения ТРАНСТЕКСТА имели приоритет перед всеми другими системами, в том числе освещением и электронными дверными замками.

3 Comments

Valentino M. 26.05.2021 at 15:06

1. Describe the role and function of the anterior and posterior pituitary, hypothalamus, adrenal glands, endocrine pancreas, and thyroid gland within the endocrine.

Ciamoscudab 27.05.2021 at 18:27

Figure Location of selected endocrine organs of the body. Pineal gland. Hypothalamus. Pituitary gland. Thyroid gland. Parathyroid glands. .

TabarГ© G. 30.05.2021 at 01:45

The endocrine system is a chemical messenger system comprising feedback loops of the hormones released by internal glands of an organism directly into the circulatory system , regulating distant target organs.

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