Topic 11 Flashcards
Distinguish between arteries and veins in terms of structure and function
Blood moves faster through the arteries because they are thicker and stretchier and able to handle the higher pressure of blood moving through them. The veins are thinner and less elastic, moving higher amounts of blood over a longer period.
Describe the structure of an artery wall
The artery wall has 3 layers: Tunica intima (inner layer) the innermost layer of the artery which is made of tissue and is responsible for the exchange of gases and nutrients between the blood and surrounding tissues. Tunica media (middle) contains smooth muscle cells, elastin, collagen, and proteoglycans and is responsible for maintaining elasticity and withstanding high pressure. Finally, the tunica externa covers the blood vessel and anchors it in place in the body.
Distinguish between diastolic and systolic blood pressure.
Systolic blood pressure refers to the maximum blood pressure during contraction of the ventricles. Diastolic blood pressure refers to the minimum pressure recorded before the next contraction.
Describe the structure and function of capillaries
Capillaries are tiny blood vessels with thin walls in which O2 and CO2 exchange happens
Describe how blood is moved through veins, including the role of valves
Valves help move blood to the heart by opening when blood moves to the heart and closing when it might move backward
Distinguish between the pulmonary and systemic circulation systems.
Pulmonary circulation moves deoxygenated blood to the lungs to absorb oxygen and release CO2, it then flows back to the heart. Systemic circulation moves blood between the heart and body.
Describe the pathway that blood takes as it travels through the human heart.
The blood comes in through the superior and inferior vena cava, to the right atrium, to the tricuspid valve, into the right ventricle, to the pulmonary valve, to the pulmonary arteries, into the pulmonary veins, into the left atrium, to the mitral valve, to the left ventricle, to the aortic valve, and finally into the aorta.
Explain how the sinoatrial node (SA) controls the beating of the heart
The sinoatrial node generates an electrical stimulus which travels down the conduction pathways and causes the heart’s ventricles to contract and pump out blood
Describe the pressure changes in atria during the cardiac cycle
The blood pressure rises, pumping blood into the ventricles
Describe the pressure changes in ventricles during the cardiac cycle.
The pressure in the ventricles rises pushing open 2 semilunar valves and moving the pulmonary trunk and aorta into the ventricular ejection phase. After this, the ventricles relax.
Describe the pressure changes in the aorta during the cardiac cycle.
Aorta pressure declines due to the blood flow from the aorta to the periphery exceeding ventricular output
Describe the structure of an alveolus
Alveoli are ballon-shaped structures located at the end of the respiratory tree which expand during inhalation and shrinks during exhalation.
Explain the process of gas exchange in an alveolus
Gases pass through alveolar surfactant, alveolar epithelium, basement membrane, and capillary endothelium
Distinguish between type I and type II pneumocytes
Type 1 pneumocytes are flat and thin. Type 2 pneumocytes are cubic in shape.
Describe how the muscles in the chest cavity (diaphragm, internal intercostals, external intercostals) participate in ventilation.
As the diaphragm contracts, it increases the length and diameter of the chest cavity and thus expands the lungs.
Distinguish between fetal and adult hemoglobin in structure and function.
The fetal hemoglobin has 2 α chains and 2 y chains. The adult hemoglobin has 2 α and 2 β chains.
Explain the Bohr shift in terms of pCO2
Hypercapnia and acidosis both shift the curve to the right and hypocapnia and alkalosis both shift the curve to the left
Discuss the implications of the Bohr shift on metabolism and exercise.
The Bohr effect allows for better oxygen unloading during activity
Evaluate the pO2 of the following locations in the body: distal end of a working capillary, distal end of a resting capillary, the pulmonary artery.
Distal end of a working capillary (-30-40 mmHg), Distal end of a resting capillary (-40-50 mmHg), pulmonary artery (-40 mmHg)
Describe four levels of protein structure (review of the previous unit) about fetal and adult hemoglobin.
Fetal hemoglobin has a different primary structure than adult hemoglobin with gamma instead of beta chains but they have the same secondary and tertiary structures. The quaternary structure allows for higher oxygen affinity which is essential for fetal development.
