Answers chap.8
I. Answers A, B, and D are true statements, whereas C and E are false.
II. Answers B, C, and D are true statements, whereas A and E are false.
III. Answers A, B, and D are true statements, whereas C and E are false.
1. Castle demonstrated lack of intrinsic factor in patients with pernicious anaemia as early as in 1929. This factor is normally secreted by the parietal cells of the gastric mucosa together with HCl. The case described is classical pernicious anaemia with all severe symptoms and signs. The diagnose is confirmed by the megalocytic anaemia, with lack of HCl and low [vitamin B12] in the serum. The lack of vitamin B12 in the liver and the red bone marrow inhibits the methyl-malonyl Co-A mutase and spoils the purine-pyrimidine-DNA-synthesis. The inhibition of these two processes leads to the neurological and the haematological disorders in pernicious anaemia, respectively.
2. The oxygen capacity of the patients haemoglobin is (1.34 ml g-1× 63 g l-1) = 84 ml oxygen per l.
3. The cell rich bone marrow is filled up with immature stages of leucocytes, platelets and erythrocytes. They remain immature because of lack of maturity factor (vitamin B12). The leucopenia was causing frequent infections, and the thrombocytopenia was behind the bleeding tendency of the patient.
4. Physiologic adaptations to anaemia: 1) The falling red cell count leads to falling viscosity of the blood. The reduced viscosity can reduce the TPVR to less than half of the resting value, which is an appropriate event in order to ease the bloodflow. 2) A slight fall in systemic arterial pressure reduces the stimulus of the arterial baroreceptors. This is the reason for the rise in heart rate and cardiac output. 3) The low oxygen capacity of haemoglobin is compensated by an increased coronary bloodflow at rest, but during stair climbing the patient felt precordial pain (angina pectoris) caused by hypoxia. 4) The myocardial tissue suffer during long lasting, severe anaemia. This results in cardiac failure with oedema, large sore liver, and stasis of the neck veins. 5) The severely anaemic patient has an increased respiration and metabolic rate due to the large cardiac work, and a chronic rise in temperature is typical.
1.Three litres of lymphatic fluid are produced every day; the interstitial phase is supplied with (20 × 5) g of protein daily. The net gain is only 90 g protein, since 10 g returns to the Blood via the capillaries. Thus, the mean concentration of protein in mixed lymph is 90/3 = 30 g per l or 3 g per 100 ml.
2. Lymphatic fluid from the liver has a protein concentration equal to plasmas (6-8 g per 100 ml), which is at least twice as much as in the mixed (average) lymph.