Ebook BRS Cell biology and histology (7th edition): Part 2
➤ Gửi thông báo lỗi ⚠️ Báo cáo tài liệu vi phạmNội dung chi tiết: Ebook BRS Cell biology and histology (7th edition): Part 2
Ebook BRS Cell biology and histology (7th edition): Part 2
chapter13Endocrine SystemI. OVERVIEW—THE ENDOCRINE SYSTEMA. The endocrine system is composed of several ductless glands, clusters of cells within cert Ebook BRS Cell biology and histology (7th edition): Part 2tain organs, and isolated single endocrine cells, known as the diffuse neuroendocrine system (DNES) cells, located in (he epithelial lining of the respiratory and gastrointestinal systems (discussed in chapters 15 and 16, respectively).8. Glands of the endocrine system include the pituitary gland (a Ebook BRS Cell biology and histology (7th edition): Part 2nd a region of the brain known as the hypothalamus), as well as the thyroid, parathyroid, adrenal, and pineal glands. Additional components of the endEbook BRS Cell biology and histology (7th edition): Part 2
ocrine system, such as the Islets of I.angcrhans, adipose tissue, female gonads, and male gonads, arc discussed in (he pertinent chapters.c. Function.chapter13Endocrine SystemI. OVERVIEW—THE ENDOCRINE SYSTEMA. The endocrine system is composed of several ductless glands, clusters of cells within cert Ebook BRS Cell biology and histology (7th edition): Part 2ivities.Hormones are chemical messengers that arc carried via (he bloodstream to distant target cells. They include low molecular weight water-soluble proteins, polypeptides, and amino acids (e.g., insulin, glucagon, follicle-stimulating hormone (FSTIJ) and lipid-soluble substances, principally the Ebook BRS Cell biology and histology (7th edition): Part 2steroid hormones (e.g., progesterone, estradiol, and testosterone).A.Water-soluble hormones interact with specific cell surface receptors on target ceEbook BRS Cell biology and histology (7th edition): Part 2
lls, which communicate a message (hat generates a biological response by (he cell.1G protein-linked receptors are used by some hormones (e.g., epinephchapter13Endocrine SystemI. OVERVIEW—THE ENDOCRINE SYSTEMA. The endocrine system is composed of several ductless glands, clusters of cells within cert Ebook BRS Cell biology and histology (7th edition): Part 2nger that evokes a target cell response.2Catalytic receptors are used by insulin and growth hormone. Binding of the hormone to the catalytic receptor activates protein kinases that phosphorylate target proteins.B.Lipid-soluble hormones diffuse across the plasma membrane of target cells and bind to s Ebook BRS Cell biology and histology (7th edition): Part 2pecific receptors in the cytosol or in the nucleus, forming hormone-receptor complexes that regulate transcription of deoxyribonucleic acid (DNA).2212Ebook BRS Cell biology and histology (7th edition): Part 2
22 BRS Cell Biology and HistologyIhe pituitary gland lies below the hypothalamus in a bony housing known as the hypophyseal fossa, a depression in thechapter13Endocrine SystemI. OVERVIEW—THE ENDOCRINE SYSTEMA. The endocrine system is composed of several ductless glands, clusters of cells within cert Ebook BRS Cell biology and histology (7th edition): Part 2he brain; it possesses nuclei that are structurally and functionally linked to the pituitary gland. The structural link is via a series of axons whose cell bodies are located in the supraoptic and paraventricular nuclei of the hypothalamus. These axons form the hypothalamo-hypophyseal bact and termi Ebook BRS Cell biology and histology (7th edition): Part 2nate in the pars nervosa of the pituitary gland, where they store and, when needed, release their hormones. The functional connection is via releasingEbook BRS Cell biology and histology (7th edition): Part 2
hormones that are synthesized in the arcuate, paraventricular(and medial paraventricular), periventricular, ventromedial, and dorsal nuclei of the hychapter13Endocrine SystemI. OVERVIEW—THE ENDOCRINE SYSTEMA. The endocrine system is composed of several ductless glands, clusters of cells within cert Ebook BRS Cell biology and histology (7th edition): Part 2system to a second capillary bed in the anterior lobe of the pituitary gland, leave the capillary bed, and bind to their respective target cells in the anterior pituitary.The pituitary gland is a relatively small gland, weighing only about 0.6 g in men and 1.2 g in women who are pregnant or who have Ebook BRS Cell biology and histology (7th edition): Part 2 given birth to two or more children. The pituitary is divided into two major subdivisions, the adenohypophysis and the neurohypophysis (Figure 13.1).Ebook BRS Cell biology and histology (7th edition): Part 2
Each subdivision is derived from a distinct embryonic analog, which is reflected in its unique cellular constituents and functions.A. The adenohypophchapter13Endocrine SystemI. OVERVIEW—THE ENDOCRINE SYSTEMA. The endocrine system is composed of several ductless glands, clusters of cells within cert Ebook BRS Cell biology and histology (7th edition): Part 2). The adenohypophysis is subdivided into the pars distalis, pars intermedia, and pars tuberalis.1The pars distalis is supported by a connective tissue capsule and framework. Il consists of irregular cords composed of two types of parenchymal cells, chromophilsand chromophobes, lying adjacent to fen Ebook BRS Cell biology and histology (7th edition): Part 2estrated capillaries.a.Chromophils (Figures 13.1 and 13.3)-1Overview. Chromophils are parenchymal cells that stain intensely because of their hormone-Ebook BRS Cell biology and histology (7th edition): Part 2
containing secretory granules. They synthesize, store, and release several hormones. They arc regulated by specific stimulatory and inhibitory hormonechapter13Endocrine SystemI. OVERVIEW—THE ENDOCRINE SYSTEMA. The endocrine system is composed of several ductless glands, clusters of cells within cert Ebook BRS Cell biology and histology (7th edition): Part 2l blood vessels originating in the median eminence.-2Types, chromophils are classified into two types, acidophils and basophils, depending on the dyes they bind using special histological stains. With hematoxylin eosin stain, the distinction between the two cell types is much less obvious.(a)Acidoph Ebook BRS Cell biology and histology (7th edition): Part 2ils (Tables 13.1 and 13.2) bind acidic dyes and often stain orange or red.They a re small cells of two subtypes: somatotrophsand mammotrophs.1SomatotrEbook BRS Cell biology and histology (7th edition): Part 2
ophs constitute about 50% of the chromophils and produce somatotropin (growth hormonel.Theyare stimulated by somatotropin-releasing hormone and are inchapter13Endocrine SystemI. OVERVIEW—THE ENDOCRINE SYSTEMA. The endocrine system is composed of several ductless glands, clusters of cells within cert Ebook BRS Cell biology and histology (7th edition): Part 2gh as 30%. Mammotrophs produce prolactin, which is stored in small secretory granules. They are stimulated by prolactin-releasing hormone and thyrotropin-releasing hormone (TRH)andare inhibited by dopamine (until re-identified that it W'as designated as prolactin-inhibiting hormone).(b)Basophils (Ta Ebook BRS Cell biology and histology (7th edition): Part 2bles 13.1 and 13.2) bind basic dyes and typically stain blue. They include three subtypes: corticotrophs, thyrotrophs, and gonadotrophs.1CorticotrophsEbook BRS Cell biology and histology (7th edition): Part 2
constitute about 10% of the chromophil population. They produce pro-opiomelanocortin (POMC) whose by-products are adrenocorticotropic hormone (ACTH),chapter13Endocrine SystemI. OVERVIEW—THE ENDOCRINE SYSTEMA. The endocrine system is composed of several ductless glands, clusters of cells within certchapter13Endocrine SystemI. OVERVIEW—THE ENDOCRINE SYSTEMA. The endocrine system is composed of several ductless glands, clusters of cells within certGọi ngay
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