Mendelian disorder is the known disorder of a single gene
Answer:
When you sit on a plane for 6 hours without moving, blood accumulates in your veins, and the moment you get up, gravitational forces affect venous return, cardiac output, blood pressure, and venous pressure. That way, when you're sitting on a plane, the gravitational force is the same at the upper and lower extremities, such as the chest, abdomen, and legs, causing venous blood pressure and volume to be evenly distributed throughout the body. However, when one gets up, one becomes dizzy because of abnormal regulation of blood pressure. This is because gravity causes blood to accumulate in the lower extremities (veins of the legs and trunk). This lowers the blood pressure and the blood that the heart pumps. By causing blood to accumulate in the lower extremities, and as venous compliance increases, the veins expand with blood that causes the volume of blood to shift in the veins. This increases the volume and venous pressure in the lower extremities when standing. And the volume of thoracic venous blood is less and less central venous pressure. This leads to a decline in stroke volume. Cardiac output and mean arterial pressure also decrease as left ventricular stroke volume decreases, reducing pulmonary venous return. Decreased standing blood pressure, referred to as orthostatic or postural hypotension. Thus, lowering blood pressure decreases cerebral blood flow, which means less range of blood in the brain causing dizziness.
Explanation:
"Eukaryote" roughly translates as "truly nucleated" and refers to organisms with a membrane-bound nucleus.
Such membrane-bound organelles are thought to have arisen via the invagination of the cell's own plasma membrane.
Other organelles such as the mitochondria and the chloroplast are believed to have once existed as separate organisms, but which were engulfed by other cells, forming a symbiotic relationship.
Answer:
Estrogen and progesterone are both involved in preparing the endometrium for embryo implantation. Estrogen helps to ensure conception by increasing the amount of secretory glands in the uterus. Estrogen also increases blood supply to the endometrium.
Progesterone is crucial for embryo implantation and maintenance of pregnancy. Progesterone also enlarges secretory glands that produce carbohydrates, proteins and mucin that are required for embryo nourishment before implantation. Progesterone stabilizes endometrial muscles to prevent them from contracting during pregnancy.
Explanation:
- Estrogen and progesterone are steroid hormones of the reproductive system. Estrogen helps in conception whereas progesterone maintains pregnancy.
- Estrogen is secreted during the follicular phase of the menstrual cycle that promotes the growth and maturation of follicles in the ovary.
- Estrogen also induces oestrous behavior in females.
- Secreted by the corpus luteum, progesterone is also a steroid hormone, responsible for implantation of the embryo in the uterus.
