where does the cortical reaction occur?
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What initiates the cortical reaction? Answers. Best Answer: The cortical reaction, also known as the zona reaction, occurs when a sperm cell unites with the egg's plasma membrane, altering the zona pellucida which prevents other sperm from binding to and entering the egg.The cortical reaction is exocytosis of the egg's cortical granules.Cortical granules are secretory vesicles that reside just below the egg's plasma membrane.he cortical reaction is exocytosis of the egg's cortical granules. Cortical granules are secretory vesicles that reside just below the egg's plasma membrane.
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The A to Z of Medical Terms The principal effectors of the stress response are localized in the paraventricular nucleus (PVN) of the hypothalamus, the anterior lobe of the pituitary gland, and the adrenal gland. This collection of structures is commonly referred to as the hypothalamic-pituitary-adrenal (HPA) axis (Figure 1) .
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Cortical blindness Cortical blindness is the total or partial loss of vision in a normal-appearing eye caused by damage to the brain's occipital cortex. Cortical blindness can be acquired or congenital, and may also be transient in certain instances. Acquired cortical blindness is most often caused by loss of blood flow to the occipital cortex from either unilateral or bilateral posterior cerebral artery blockage (ischemic stroke) and by cardiac surgery.
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How Vision Works The cells of the magnocellular and parvocellular layers project all the way to the back of the brain to primary visual cortex (V1). Cells in V1 are arranged in several ways that allow the visual system to calculate where objects are in space.
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Adrenal Insufficiency (Addison's Disease) Cortisol is normally produced by the adrenal glands, located just above the kidneys. It belongs to a class of hormones called glucocorticoids, which affect almost every organ and tissue in the body. Scientists think that cortisol has possibly hundreds of effects in the body.bout 70 percent of reported cases of Addisons disease are due to autoimmune disorders, in which the immune system makes antibodies that attack the body's own tissues or organs and slowly destroy them. Adrenal insufficiency occurs when at least 90 percent of the adrenal cortex has been destroyed.
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Cortical reaction In mammals the cortical reaction leads to a modification of the zona pellucida that blocks polyspermy; enzymes released by cortical granules digest sperm receptor glycoproteins ZP2 and ZP3 so that they can no longer bind spermatozoon.
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- The most common locations for the hyperintensities are the subcortical and periventricular white matter, optic radiations, basal ganglia and brain stem, in decreasing order of frequency. The lesions are hyperintense on T2, proton density, and FLAIR images and have well defined but irregular margins.he white matter of the brain is located in the central and subcortical regions of the cerebral and cerebellar hemispheres and accounts for about 60 % of the total brain volume. The white matter includes the major commissural tracts, the cortical association fibers, and all the cortical afferent and efferent fibers.
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Fertilization & Early Development Express the events and function of the acrosomal reaction. 1) Triggered by ZP3 2) Mediated by Ca++ 3) Involves fusion of acrosomal membrane with the plasma membrane, occurs when fertilin, a sperm glyco protein is exposed and mediates attachment to the egg plasma membrane (integrin, CD9). Communicate the events and function of the cortical reaction.
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- Again, the corticospinal tract begins in the motor cortex and descends into the internal capsule. The internal capsule, or projection fibers, link the cortex to the diencephalon, the brain stem, the cerebellum, and the spinal cord.
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All About Steroid Allergy Allergic reactions to systemic corticosteroids can occur as either immediate or non-immediate reactions. Immediate reactions most often occur within 30 to 60 minutes of the medication being taken, and symptoms may include urticaria and angioedema, asthma symptoms, and anaphylaxis.
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- 1 The cell bodies of the three neurons in a typical somatosensory pathway are located in the dorsal root ganglion, the spinal cord, and the thalamus, respectively.  A major target of somatosensory pathways is the postcentral gyrus in the parietal lobe of the cerebral cortex.
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Corticosteroids Systemic (Oral and Injectable) Naturally occurring corticosteroids, hydrocortisone (Cortef) and cortisone, are produced by the outer portion of the adrenal gland known as the cortex (hence the name, corticosteroid). mineralocorticoids (salt retaining) that regulate the balance of salt and water in the body.
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Monosaccharide With few exceptions (e.g., deoxyribose), monosaccharides have this chemical formula: C x (H 2 O) y, where conventionally x ≥ 3. Monosaccharides can be classified by the number x of carbon atoms they contain: diose (2) triose (3) tetrose (4), pentose (5), hexose (6), heptose (7), and so on.
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An Overview of the Adrenal Glands The adrenal cortex produces two main groups of corticosteroid hormones—glucocorticoids and mineralcorticoids. The release of glucocorticoids is triggered by the hypothalamus and pituitary gland. Mineralcorticoids are mediated by signals triggered by the kidney.
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- Organ: Parathyroid glands Target: bone, kidneys, small intestine Stimulus: decreased blood Ca2+ Cortisol Organ: Adrenal cortex Target: most tissues Stimulus: fat and protein
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Cortical reaction In contrast to the fast block of polyspermy which immediately but temporarily blocks additional sperm from fertilizing the egg, the cortical reaction gradually establishes a permanent barrier to sperm entry and functions as the main part of the slow block of polyspermy in many animals.n mammals, however, the extracellular matrix modified by the cortical reaction is the zona pellucida. This modification of the zona pellucida is known as the zona reaction. Although highly conserved across the animal kingdom, the cortical reaction shows great diversity between species.
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- The present study was conducted to determine the contribution of calcium release from intracellular stores to afferent and efferent arteriolar responses to Ang II and NE. Experiments were performed in vitro using the blood-perfused, juxtamedullary nephron technique combined with videomicroscopy.
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Chapter 28 â Lipids and Lipoproteins Hemoconcentration also occurs during postural shifts, dehydration, and a variety of pathophysiological conditions. During stress, hemoconcentration might occur by increased red blood cell mass, by acute changes in kidney function, or through hemodynamically induced fluid shifts (as might be expected with stress-related blood pressure increases).
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Definition of 'corticosteroid' Steroid hormones produced in the adrenal cortex are called corticosteroids. A corticosteroid is any one of a group of steroid hormones produced by the adrenal cortex that affect carbohydrate, protein, and electrolyte metabolism, and immune response. Corticosteroids are used to treat inflammatory and allergic diseases.
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Regulation of glucocorticoid release The regulation of glucocorticoid release is brought about by a highly sophisticated system of responses to a variety of stimuli. The origin of the stimulus to the diurnal release of corticotropin releasing factor (CRF) is undoubtedly located in the cen- tral nervous system.
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Cortisol in Urine  [en EspaÃ±ol] The cortisol level may show problems with the adrenal glands or the pituitary gland. Cortisol is made by the adrenal glands. Cortisol levels get higher when the pituitary gland releases adrenocorticotropic hormone (ACTH). Cortisol has many functions.
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- Definition of CORTICAL. 1. : of, relating to, or consisting of cortex.2. : involving or resulting from the action or condition of the cerebral cortex.— cor·ti·cal·ly \-k(ə-)lē\ adverb. ADVERTISEMENT.efinition of CORTICAL. 1. : of, relating to, or consisting of cortex. 2.
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- The chemoreceptors most sensitive to changes in the arterial PCO2 are located in the ventral area of the medulla oblongata, near the exit of the ninth and tenth cranial nerves.n increase in blood CO2 stimulates breathing indirectly by lowering the pH of blood and cerebrospinal fluid (CSF). This figure illustrates how a rise in blood CO2 increases the H+ concentration (lowers the pH) of CSF and thereby stimulates chemoreceptor neurons in the medulla oblongata.
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- All input to the basal ganglia circuit comes via the striatum. This input comes mainly. from motor cortical areas. Notice that the caudate (L. tail) appears twice in many frontal brain sections. This is because. the caudate curves around with the lateral ventricle. The head of the caudate is most anterior.
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What is cortisol? 24,005 Helpful Votes. 73 Followers. A. Cortisol is normally produced by the adrenal glands, located just above the kidneys. It belongs to a class of hormones called glucocorticoids, which affect almost every organ and tissue in the body. Scientists think that cortisol has possibly hundreds of effects in the body.
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Cortical reaction In most animals the extracellular matrix present around the egg is the vitelline envelope which becomes the fertilization membrane following the cortical reaction. In mammals, however, the extracellular matrix modified by the cortical reaction is the zona pellucida.