34103229
Description
Flashcards by San Chhetri, updated more than 1 year ago
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Created by San Chhetri
over 3 years ago
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| Question | Answer |
| Suggest and explain what effect supraventricular tachycardia ( electrical signals leak from the atrial walls directly to the top of the ventricles.) might have on blood flow from the heart? | - less blood leaves heart (for each ventricular contraction - ventricles do not have time to fill (before contracting again) - blood flow around the body is reduced |
| Suggest why the foramen ovale (hole in the septum) is open in the fetus before birth | The fetus is not breathing as their lungs aren't functioning therefore it requires |
| State a difference between fetal haemoglobin and adult haemoglobin reason why this difference is essential to the fetus. | Difference: (fetal haemoglobin) higher affinity for oxygen Reason: (fetal haemoglobin) must be able to bind to oxygen, in lower partial pressure Difference: (fetal haemoglobin) contains gamma sub-units Reason: creates high(er) affinity for oxygen |
| Explain why tissue fluid does not contain erythrocytes | -gaps between endothelium cells (too) small - erythrocytes too large |
| Describe the role of haemoglobin in transporting oxygen around the body | - haemoglobin has high affinity for oxygen -oxygen binds to haemoglobin in, lungs / alveoli - This forms oxyhaemoglobin - oxygen released, in tissues / where needed or where respiration is occurring |
| Describe how the hydrogen carbonate ions are produced in the erythrocytes? | 1. carbon dioxide, enters / diffuses into, erythrocytes 2. carbon dioxide combines / reacts, with water this is assisted by the enzyme carbonic anhydrase, catalyses combination of carbon dioxide and water 3. This forms carbonic acid 4. (carbonic acid) dissociates to form hydrogencarbonate ions and, hydrogen ions |
| Name and explain this effect : "High concentrations of carbon dioxide in the blood reduce the amount of oxygen transported by haemoglobin" | Bohr effect or Bohr shift Explanation : This reduces affinity of Hb (haemoglobin) for oxygen , This occurs due to increased levels of carbon dioxide, such as when a person increases their exercise level, which causes an increased concentration of carbonic acid to be formed. |
| What is ment by the term health? | - mental and physical well-being with the absence of disease |
| Describe how the components of tobacco smoke can affect the cardiovascular system of smokers? | | Cause is nicotine | - increases stickiness of platelets - formation of blood clot -causes release of adrenaline - causes constriction of , arterioles -reduced , blood flow of the smoker Resulting in carbon monoxide / CO ; combining (permanently) with haemoglobin and forming carboxyhaemoglobin. Reducing oxygen carrying capacity of blood |
| Explain why the fetal haemoglobin curve is to the left of the adult haemoglobin curve | - The fetal placenta has low pO2 (partial pressure of oxygen) - adult (oxy)haemoglobin will, release O2 - fetal haemoglobin has higher affinity for oxygen |
| Describe and explain how substances that are dissolved in the blood plasma, such as oxygen or glucose, enter the tissue fluid from the capillaries ? | diffusion ; from high concentration to low concentration hydrostatic pressure in capillary higher than in tissue fluid |
| Explain why cartilage is essential in the trachea | provides strength & support, to keep, it trachea / airway, open |
| Suggest advantages of keeping the blood inside vessels | - maintain high, blood pressure - increase rate of, flow - blood moves faster -flow can be, diverted / directed to specific parts of the body |
| Describe and explain how the wall of an artery is adapted both to withstand and maintain high hydrostatic pressure. | To withstand pressure : walls of arterys are thick ; (thick layer of) collagen this provides strength endothelium is folded and therefor cannot be damaged by the pressue as it stretches To maintain pressure : Thick layer of elastic tissue, which can recoil the artery to go back to original size |
| Explain why the wall of the left ventricle is thicker than the wall of the left atrium | The left ventricle , requires more muscle to create more force, this is because left ventricle pumps blood further / pumps blood to all parts of body |
| Explain how pressure changes in the heart bring about the closure of the atrioventricular (bicuspid) valve | ventricular systole : ventricle walls / muscles , contracts, this raises ventricular pressure , ventricular pressure higher than atrial pressure , the pressure (movement) of blood generated by this contraction causes the valves to shut |
| Explain why the curve for fetal oxyhaemoglobin is to the left of the curve for adult oxyhaemoglobin. | - fetal haemoglobin has a higher affinity for oxygen than adult haemoglobin. - fetal Hb takes up oxygen in lower partial pressure of oxygen - placenta has low partial pressure of oxygen |
| Outline the benefits of the Bohr shift to actively respiring tissue | - actively respiring tissue needs / requires, more oxygen - for aerobic respiration / to release more energy - (Bohr shift) causes more oxygen to be released |
| Describe the roles of the sinoatrial node (SAN) and the atrioventricular node (AVN) in coordinating the cardiac cycle | SAN, is pacemaker , SAN sends impulse / wave of excitation, over atria (walls) ; AVN delays impulse ; (AVN) sends impulse down, septum / bundle of His / Purkyne fibres ; |
| State ways in which the wall of an artery is different from the wall of a vein. | Arteries have or are : - no valves - endothelium folded - more / thicker, muscle / elastic tissue / tunica media - more / thicker, collagen / tunica externa -artery wall being thicker |
| "Blood in the arteries has a high hydrostatic pressure." State how this hydrostatic pressure is generated in the heart | contraction of ventricle wall or muscles (ventricular systole) |
| Explain why the hydrostatic pressure of the blood drops as blood moves away from the heart ? | - The pressure is divided into smaller and more vessels -arteries, stretch or expand - loss of, fluid / plasma, from capillaries |
| Name the type of muscle found in the walls of the heart chambers | myogenic / cardiac |
| name the process that creates pressure inside the heart chambers | - atrial or ventricular systole or -Muscular contraction |
| State the meaning of the terms single circulatory system and closed circulatory system | single circulatory system: blood passes through the heart once for each, circulation/ cycle, of the body closed circulatory system: A closed circulatory system is comprised of the heart that pumps blood into the vessels to reach the tissues and organs. The exchange of gases in the bloodstream occurs between smaller vessels (capillaries) and tissues. |
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