Please help me with these. I am looking for not a very long answers to help me understand this topic better
1. What structural features of arteries and veins lead to an equilibrium in blood flow into and out of any given organ? Consider the relationship of flow to pressure and resistance in your answer (F=P/R).
2. Explain what is different and/or similar between the autonomic regulation of cardiac output and blood pressure.
In the following paragraphs I have explained the concepts of hemodynamics. Fishing-out the answer you require won't be difficult once you grasp the concepts. Also please refer to the attached PowerPoint Slides as referred in the material below.
First let me explain the equilibrium in blood flow. To understand the concept off equilibrium and how the structural features of arteries and veins affect that equilibrium we have to first understand the term cardiac output (CO), which means the rate of blood flow out of the heart (expressed in L/min). The heart is the central driver of the circulatory system and by the actions of constant contraction and relaxation the heart pumps blood throughout the whole body. Oxygenated blood from the heart first goes into the aorta, which is the largest artery of the body. Blood then goes into smaller and even smaller arterioles and then finally enters the capillaries. This is the region of micro-circulation. At the location of microcirculation oxygen, glucose and various enzyme substrates exchange with cells of the body take place. Capillaries pass blood to venules. Venules carry de-oxygenated blood to the right side of the heart from where it enters the lungs to get oxygenated again and to be circulated back to the body via the aorta (PowerPoint Slide #1).
A state of equilibrium is always maintained in normal circulation where the volume of oxygenated blood that is pumped out of the heart every minute (cardiac output) via aorta approximately equals to the volume of de-oxygenated blood that is returned back each minute via the veins to the heart. Since this equilibrium is maintained at every level of the circulatory system the velocity of blood flow at each level is determined by the cross-sectional area of that particular level and this is expressed by a simple mathematical equation (PowerPoint Slide #2):
v = Q/A
v = velocity (cm/s)
Q = blood flow (ml/s)
A = cross sectional area (cm2)
It is important to understand the Hagen-Poiseuille equation to understand vascular resistance, which means the force, required to move the blood across the circulatory system. Lets say you want to blow air through a cardboard tube (e.g. Kitchen Paper Roll). Lets say the length of the kitchen paper roll is "L" and the radius is "R" and lets imagine the kitchen paper roll is about 2 cm in radius. You realize that it is easy to take one breadth of air and blow into this roll. So you now ...
The material here explains the various concepts of Hemodynamics explaining the relationship among Blood flow (cardiac output), arterial pressure and resistance. Also is explained the mechanisms by which the autonomous system regulates blood pressure in situations when there is a fall in blood pressue.
Various Case Study Questions
You have helped me before and I learned a lot from your answers. Attached are misc case studies. I have done many for homework assignment, but these are the ones I struggled with. Please help. Thank you.
Answer the following clinical questions using your knowledge of basic anatomy and physiology obtained in this unit.
Case Study 3
A middle-aged college professor from Boston is in the Swiss Alps studying astronomy during his sabbatical leave. He has been there for two days and plans to stay the entire year. However, he notices that he is short of breath when he walks up steps and tires easily with any physical activity. His symptoms gradually disappear, and after two months he feels fine. Upon returning to the United States, he has a complete physical exam and is told that his erythrocyte count is higher than normal.
Attempt to explain this finding.
Will his RBC count remain at this higher-than-normal level?
Why or why not?
Case Study 4
A young child is diagnosed as having acute lymphocytic leukemia. Her parents cannot understand why infection is a major problem for Janie when her WBC count is so high. Can you provide an explanation to Janie's parents?
Case Study 7
A gang member was stabbed in the chest during a crack-related street fight. He was cyanotic and unconscious from lack of blood delivery to the brain. The diagnosis was cardiac tamponade.
What is cardiac tamponade and how does it cause the observed symptoms?
Case Study 9
Florida Santos, a middle-aged woman, is admitted to the coronary care unit with a diagnosis of left ventricular failure resulting from a myocardial infarction. Her history indicated the she was aroused in the middle of the night by severe chest pain. Her skin is pale and cold, and moist sounds are heard over the lower regions of both lungs.
Explain how the failure of the left ventricle can cause these signs and symptoms.
Case Study 13
Mrs. Johnson is brought to the emergency room after being involved in an auto accident. She is hemorrhaging and has a rapid, thready pulse, but her blood pressure is still within normal limits.
Describe the compensatory mechanisms that are acting to maintain her blood pressure in the face of blood loss.
Case Study 14
A 60-year-old man is unable to walk more than 100 yards without experiencing severe pain in his left leg; the pain is relived by resting for 5-10 minutes. He is told that the arteries of his leg are becoming occluded with fatty material and is advised to have the sympathetic nerves serving that body region severed.
Explain how such surgery might help to relieve this man's problem
Case Study 16
Mrs. Jackson, a 59-year-old woman, has undergone a left radical masectomy (removal of the left breast and left axillary lymph nodes and vessels). Her left arm is severely swollen and painful, and she is unable to raise it more tan shoulder height.
Explain her signs and symptoms.
Can she expect to have relief from these symptoms in time?
Case Study 17
A friend tells you that she has tender, swollen "glands" along the left side of the front of her neck. You notice that she has a bandage on her left cheek that is not fully hiding a large infected cut there.
Exactly what are her swollen "glands," and how did they become swollen?
Case Study 19
Some people with a deficit of IgA exhibit recurrent respiratory tract infections.
Explain these symptoms.
Case Study 20
Explain the underlying mechanisms responsible for the cardinal signs of acute inflammation: