By Q. Kent. Wilson College.
Recall that during the follicular phase of the ovarian cycle order 100mg januvia with mastercard, the tertiary follicles are growing and secreting estrogen purchase januvia 100 mg on-line. At the same time order januvia 100mg with amex, the stratum functionalis of the endometrium is thickening to prepare for a potential implantation. The post- ovulatory increase in progesterone, which characterizes the luteal phase, is key for maintaining a thick stratum functionalis. As long as a functional corpus luteum is present in the ovary, the endometrial lining is prepared for implantation. Indeed, if an embryo implants, signals are sent to the corpus luteum to continue secreting progesterone to maintain the endometrium, and thus maintain the pregnancy. If an embryo does not implant, no signal is sent to the corpus luteum and it degrades, ceasing progesterone production and ending the luteal phase. Without progesterone, the endometrium thins and, under the influence of prostaglandins, the spiral arteries of the endometrium constrict and rupture, preventing oxygenated blood from reaching the endometrial tissue. As a result, endometrial tissue dies and blood, pieces of the endometrial tissue, and white blood cells are shed through the vagina during menstruation, or the menses. The first menses after puberty, called menarche, can occur either before or after the first ovulation. The Menstrual Cycle Now that we have discussed the maturation of the cohort of tertiary follicles in the ovary, the build-up and then shedding of the endometrial lining in the uterus, and the function of the uterine tubes and vagina, we can put everything together to talk about the three phases of the menstrual cycle—the series of changes in which the uterine lining is shed, rebuilds, and prepares for implantation. The timing of the menstrual cycle starts with the first day of menses, referred to as day one of a woman’s period. Cycle length is determined by counting the days between the onset of bleeding in two subsequent cycles. Because the average length of a woman’s menstrual cycle is 28 days, this is the time period used to identify the timing of events in the cycle. However, the length of the menstrual cycle varies among women, and even in the same woman from one cycle to the next, typically from 21 to 32 days. Just as the hormones produced by the granulosa and theca cells of the ovary “drive” the follicular and luteal phases of the ovarian cycle, they also control the three distinct phases of the menstrual cycle. Menses Phase The menses phase of the menstrual cycle is the phase during which the lining is shed; that is, the days that the woman menstruates. Recall that progesterone concentrations decline as a result of the degradation of the corpus luteum, marking the end of the luteal phase. Proliferative Phase Once menstrual flow ceases, the endometrium begins to proliferate again, marking the beginning of the proliferative phase of the menstrual cycle (see Figure 27. It occurs when the granulosa and theca cells of the tertiary follicles begin to produce increased amounts of estrogen.
Iron crosses the stinal mucosal cell by active transport purchase januvia 100 mg on line; then according to mucosal iron store buy discount januvia 100 mg line, it can either be available to transferrin to be transported to plasma or be stored in the mucosal cell as ferritin order januvia 100 mg without a prescription. Storage: Iron is stored primarily as ferritin in intestinal mucosal cells and in macrophages in the liver, spleen and bone. Elimination: Very small amount are execrated in stool by exfoliation of intestinal mucosal cells and trace amounts are execrated in bile, urine and sweat with total daily excretion not more than 1mg/day. Treatment of iron deficiency anemia consists of administration of oral or parenteral iron preparation. Oral Iron Therapy: Only ferrous salts should be used because of most efficient absorption. Ferrous sulfate, ferrous gluconate, ferrous fumarate are the most commonly used oral iron preparations. About 25% of oral iron given as ferrous salt can be absorbed; therefore 200-400mg elemental irons should be given daily to correct iron deficiency most rapidly. Side effects: Oral iron therapy can cause nausea, vomiting, epigastric discomfort, abdominal cramps, constipation and diarrhea. Parenteral iron therapy: Should be reserved for patient unable to tolerate or absorb oral iron. Patients with extensive chronic blood loss who can not be maintained with oral iron alone including patients with various post gastrectomy conditions, previous small bowel resection, inflammatory bowel disease involving proximal small bowel and malabsorption syndromes need parenteral iron therapy. Intravenous administration may result in very severe allergic reactions and thus should be avoided if possible. Side effect: include local pain, tissue staining, headache, light headedness, fever, arthralgia, nausea, vomiting, urticaria, back pain, bronchospasm, and rarely anaphylaxis and death. Acute iron Toxicity Is exclusively seen in young children who ingest a number of iron tablets and rarely seen in adults as a result of suicide or repeated blood transfusions. Signs and symptoms Necrotizing gastroenteritis with vomiting, abdominal pain and bloody diarrhea, shock, metabolic acidosis, coma Treatment Whole bowel irrigation. It is mainly obtained from animal products and serves as a co factor for essential biochemical reaction in humans. Excess vitamin B12 is transported to the liver for storage and excreted in the urine. Clinical uses - Vit B12 is used to treat or prevent deficiency of vit B 12 Deficiency of Vit B 12 results in: - Megaloblastic anemia - Neurological syndrome involving spinal cord and peripheral nerves Causes: The causes for Pernicious anemia are defective secretion of intrinsic factor necessary for absorption of vitB 12, partial or total gastrectomy, diseases that affect distal ileum, malabsoption syndrome e.
Ketone bodies are used as an alternative source of fuel cells employ to create a concentration gradient to ensure during starvation januvia 100mg otc. The kidneys also perform the final synthesis step of vitamin D production purchase januvia 100mg fast delivery, converting calcidiol to calcitriol cheap 100 mg januvia mastercard, the active form of vitamin D. If the kidneys fail, these functions are compromised or lost altogether, with devastating effects on homeostasis. The affected individual might experience weakness, lethargy, shortness of breath, anemia, widespread edema (swelling), metabolic acidosis, rising potassium levels, heart arrhythmias, and more. The urinary system, controlled by the nervous system, also stores urine until a convenient time for disposal and then provides the anatomical structures to transport this waste liquid to the outside of the body. Failure of nervous control or the anatomical structures leading to a loss of control of urination results in a condition called incontinence. This chapter will help you to understand the anatomy of the urinary system and how it enables the physiologic functions critical to homeostasis. It is best to think of the kidney as a regulator of plasma makeup rather than simply a urine producer. Because the glomeruli filter the blood based mostly on particle size, large elements like blood cells, platelets, antibodies, and albumen are excluded. The glomerulus is the first part of the nephron, which then continues as a highly specialized tubular structure responsible for creating the final urine composition. All other solutes, such as ions, amino acids, vitamins, and wastes, are filtered to create a filtrate composition very similar to plasma. The glomeruli create about 200 liters (189 quarts) of this filtrate every day, yet you excrete less than two liters of waste you call urine. Characteristics of the urine change, depending on influences such as water intake, exercise, environmental temperature, nutrient intake, and other factors (Table 25. For example, if you exercise or work outside, and sweat a great deal, your urine will turn darker and produce a slight odor, even if you drink plenty of water. This is good advice; however, it takes time for the kidneys to process body fluids and store it in the bladder. Another way of looking at this is that the quality of the urine produced is an average over the time it takes to make that urine. Normal Urine Characteristics Characteristic Normal values Color Pale yellow to deep amber Odor Odorless Volume 750–2000 mL/24 hour pH 4. Normally, only traces of protein are found in urine, and when higher amounts are found, damage to the glomeruli is the likely basis.