Answer:
Option B.
Explanation:
Cystic fibrosis is caused by a defective gene which causes the lungs and the digestive system to become clogged with sticky mucus resulting the inflammation of the lungs thereby causing difficulty in breathing.
Answer: 1. Blood enters the heart through two large veins, the inferior and superior vena cava, emptying oxygen-poor blood from the body into the right atrium of the heart. As the atrium contracts, blood flows from your right atrium into your right ventricle through the open tricuspid valve.
2. Plasma is the main component of blood and consists mostly of water, with proteins, ions, nutrients, and wastes mixed in. Red blood cells are responsible for carrying oxygen and carbon dioxide. Platelets are responsible for blood clotting. White blood cells are part of the immune system and function in immune response.
3.Within the bone marrow, all blood cells originate from a single type of unspecialized cell called a stem cell. When a stem cell divides, it first becomes an immature red blood cell, white blood cell, or platelet-producing cell.
4. Epinephrine and norepinephrine, hormones secreted by the adrenal medulla, raise blood pressure by increasing heart rate and the contractility of the heart muscles and by causing vasoconstriction of arteries and veins. These hormones are secreted as part of the fight‐or‐flight response.
Explanation:
distribution and functional relationships
Pernicious anemia produces red blood cells that are <u>large</u> and<u> vitamin B12</u> deficiency contributes to pernicious anemia.
Explanation:
When there is a lack of intrinsic factor, secreted in the parietal cells of the gastric mucosa or the stomach lining, vitamin B12 absorption from the stomach is affected.
Vitamin B12 is one of the key factors responsible for normal synthesis and maturation of fully functional red blood cells (RBCs).
The main function of the RBCs is to carry oxygen through hemoglobin to all parts of the body. In order to transport oxygen, the RBCs must be mature with normal shape (concave center and circular shape) and size.
When there is a lack of vitamin B12, the RBCs are not matured and immature, megaloblastic, large, irregularly-shaped red blood cells are formed and circulate in the blood. This also leads to macrocytosis of RBCs.
These cannot function as normal mature blood cells because of the irregular shape and cannot carry hemoglobin to transport oxygen.
