Chapter 6: Endocrine System Flashcards
Influences the metabolic processes of the body.
Hormones
Are scattered throughout the body.
Endocrine glands
The glands are _______ thus, hormonal secretions are poured directly to the blood through the capillaries.
Ductless
The internal supporting framework of the endocrine glands
Reticular tissue
The endocrine gland is ________, thus provided with rich capillary networks among and between groups of secretory cells.
Highly vascular
The capillaries are _________ in which endothelial wall contains numerous pores or openings which are covered by very thin ________.
Fenestrated type. Diaphragms.
Development of endocrine system are from what origins.
Ectodermal, Mesodermal & Endodermal
Ectodermal in origin
Pituitary gland, Adrenal medulla & Pineal gland “PAP”
Mesodermal in origin
Leydig cells of the testes, Adrenal cortex & Theca internal cells of the ovary “LAT”
Endodermal in origin
Thyroid gland, Islets of Langerhans, Parathyroid gland & Parafollicular cells or C-cells “TIPP”
Pituitary gland develops from what sources
Infundibulum & Rathke’s pouch
Primitive of mouth cavity
Stomodeum
Ectodermal outpocketing of the stomodeum. Gives rise to adenohypophysis.
Rathke’s pouch
Anterior wall of the Rathke’s pouch gives rise to
Pars distalis & Pars tuberalis
Posterior wall of the Rathke’s pouch gives rise to
Pars intermedia
Downward extension of the diencephalon. Gives rise to neurohypophysis.
Infundibulum
Neurohypophysis is composed of
Pars nervosa(infundibular process), Infundibular stem/stalk & Median eminence of tuber cinereum “PIM”
Other name for pituitary gland
Hypophysis cerebri
_______ is a pea shaped glandular organ lodged in the _______ of the ________ of the body of the _______.
Hypophysis. Hypophyseal fossa. Sella tursica. Sphenoid.
Pituitary gland is connected by the _______ stalk to the base of the brain and is covered by a capsule of ________.
Infundibulum. Dense connective tissue.
Divisions of the hypophysis
Neurohypophysis & Adenohypophysis
Posterior part developed as a downgrowth from the floor of the __________.
Neurohypophysis. Diencephalon.
Anterior part derived from the Rathke’s pouch. An outgrowth from the __________ of the primitive oral cavity.
Adenohypophysis. Ectodermal roof.
Subdivisions of the Adenohypophysis
Pars Tuberalis, Pars Intermedia & Pars Distalis “TID”
Largest subdivision of adenohypophysis
Pars distalis
2 grouped categories of the cell in Pars distalis
Chromophobes & Chromophils
In chromophils, 2 types of cells based on affinity to stains
Acidophils & Basophils
Acidophils secrete
Prolactin & GH “PG”
Basophils secrete
FSH, LH, ACTH & TSH “FLAT”
Smallest and least numerous among the cells in the pars distalis. Since they are _____, their nuclei lie close to each other; and their cytoplasm is ______, thus hardly seen.
Chromophobes. Small. Scanty.
Chromophobes are also referred as ________, since some of them may differentiate into acidophils & basophils as the need arises.
Reserve cells
It is the most highly vascular portion of the hypophysis. It is formed of ___________ of cells that descend towards the pars distalis.
Pars tuberalis. Longitudianl column/cords.
No hormone isolated in this subdivision
Pars tuberalis
Cell types of the Pars tuberalis
Undifferentiated cells & Small basophils & acidophils
It is found between the pars distalis and the infundibular process. It is characterized by presence of _______ filled with colloid and lined by ______ epithelium, which are called ________.
Pars Intermedia. Follicles/Cyst. Columnar. Rathke’s cyst.
Hormone that causes the dispersion of melanin pigments in the ______ and increases the pigmentation of the skin. Secreted by?
Melanocyte Stimulating hormone. Melanoblast. Pars Intermedia.
Cells that are also found in the Pars Intermedia.
Polygonal Basophilic cells
It is formed of venules that connectbthe capillaries in the median eminence with the capillary sinusoids in the pars distalis.
Hypophyseal system
The ________ from the hypothalamus reach the pars distalis through _______.
Neurohormone. Nerve fibers.
The blood supply of the hypophysis is delivered from the _________, which are branches of
Superior hypophyseal arteries. Internal carotid & PCA.
It is thru the ________ that the releasing hormones from the hypothalamus reach the secretory cells of the pars distalis.
Hypophyseal portal circulation
Is formed of unmyelinated nerve fibers of the hypothalamo-hypophyseal tract, which are formed of axons of the neurons in the hypothalamic nuclei.
Neurohypophysis
In neurohypophysis, the axons descend through the _______ to the ________ and __________.
Median eminence. Infundibular stalk. Infundibular process.
Also found in the neurohypophysis, part of the pars nervosa. Cells with numerous processes and are considered as modified neuroglial cells.
Pituicytes
Are small, spherical structures containing neurohormones stored in pars _______ or in the infundibular process. These are neurosecretory materials secreted by the neurons in the hypothalamic nuclei and travel along the axons of these neurons to be stored and released from the ________ of the nerve fibers.
Herring bodies. Pars nervosa. Axolemma.
Hormones in the Pars nervosa
Pitocin(oxytocin) & Pitressin(ADH)
Secreted by the supraoptic nuclei of the hypothalamus. Increase water retention.
ADH (Pitressin)
Secreted by the paraventricular nuclei of the hypothalamus. Stimulates uterine contraction.
Oxytocin(Pitocin)
The gland is found in the anterior part of the neck, consisting of two lobes connected by a narrow _______, which crosses the trachea just below the cricoid cartilage.
Thyroid gland. Isthmus.
In thyroid gland, it has a _________ capsule that is continuous with the surrounding _________. The outer capsule is loosely adherent on its deep surface of another layer of moderately dense connective tissue that is intimately adherent to the gland.
Connective tissue. Cervical fascia.
The thyroid gland develops from the proliferation in the floor of the ________ between the ________ & _______, at a point layer indicated by the _________.
Pharynx. Tuberculum impar & copula. Foramen cecum.
The thyroid gland descends in front of the pharyngeal gut as a ________. This is connected to the tongue by a narrow canal, the ________, which later disappears.
Bilobed diverticulum. Thyroglossal duct.
In thyroid gland, the cystic remnants of the thyroglossal duct is called
Thyroglossal cyst
In thyroid gland, this gives rise to the ultimobranchial body, which later is incorporated in the thyroid gland.
5th pharyngeal pouch
The cells of the ultimobranchial body give rise to ____________ of the thyroid gland secreting _________.
Parafollicular/C-cells. Calcitonin.
The structural unit of the thyroid gland is the __________, which are lined by _______ and containing gelatinous _________. This represents the stored product of the secretory activity by the lining epithelium.
Spherical cystlike follicles. Simple cuboidal epithelium. Colloid.
The follicular cells are surrounded by a
Thin basal lamina
In the thyroid gland, the epithelial cells vary in height, but are commonly _______, ______ when the gland is hypoactive, _______ when it is hyperactive.
Cuboidal. Squamous. Columnar.
In the thyroid gland, nucleus is _______, _______ located, poor in ______ and contain _______ nuclei.
Spherical. Centrally. Chromatin. One or more nuclei.
Aside from the follicular cells, there are cells which are found singly or in groups wedged between the follicular cells and the lamina or between the thyroid follicles known as
Parafollicular cells
Parafollicular cells named based on its position, but with the discovery that they produce ________, they are now called ______. Other names are
Calcitonin. C-cells. Light cells, Mitochondria-rich cells & Ultimobranchial cells.
Decrease blood calcium level by the ______ or parafollicular cells through the secretion of _______.
Thyroid gland. C-cells. Calcitonin.
Synthesize, store and release hormones concerned with the regulation of metabolic by the follicular epithelial cells.
Thyroid gland
Hormones secreted in the thyroid gland are
Triiodothyroxine(T3) & Tetraidotyroxine(T4)
Development of the parathyroid gland: from the dorsal wing of the 3rd pharyngeal pouches.
Inferior parathyroid
Development of the parathyroid gland: from the dorsal wing of the 4th pharyngeal pouches.
Superior parathyroid
These are two pairs of glands which are small, __________ adhering to the posterior surface of the thyroid gland. A ________ separates them from the thyroid gland.
Parathyroid gland. Yellow-brown oval bodies. Connective tissue capsule.
Delicate __________ partially divide the gland into poorly definend lobules and still finer ones separate the epithelial cells into anastomosing cords & groups.
Connective tissue septa
The parenchyma of the parathyroid gland is composed of two types of cells
Oxyphil cells & Principal/Chief cells
Constant occurrence. Polyhedral cells with round nuclei, with loosely arranged chromatin giving a vesicular appearance, and basophilic cytoplasm.
Principal/Chief cells
Shape of Chief cells
Polyhedral w/ rounded nuclei
Cytoplasm of Principal cells
Basophilic
Appear only at the end of the first decade of life until puberty. Larger cells with smaller and darker nuclei and acidophilic cytoplasm.
Oxyphil cells
Size of oxyphil cells
Larger cells
Nuclei of oxyphil cells
Small and darker nuclei
Cytoplasm of the oxyphil cells
Acidophilic
Regulate calcium concentration by stimulating resorption of bone and reabsorption of calcium ions from ultrafiltration of the kidneys and with the aid of _______ absorption of calcium from the gut.
Parathyroid gland. Vitamin D.
Through the _______ secretion of _______, blood calcium level increases.
Principal cell. PTH.
About the ___ of development, mesothelial cells proliferate and later differentiate into large acidophilic structures forming the ___________ of the adrenal gland.
Adrenal cortex. 5th week. Primitive Fetal Cortex.
In adrenal cortex, shortly later a second wave of cells from the ________ penetrate and surround the original acidophilic mass. These cells will form the ________ of the adrenal gland.
Mesothelium. Definitive cortex.
Arises from the _________ cell. These cells invade the medial aspect and become cords and clusters forming the
Neural crest. Medulla of the adrenal gland.