Human Anatomy MV 1 Flashcards
(35 cards)
Why is it important that oxygen binds loosely to hemoglobin?
It is important bc it allows hemoglobin to be an ideal transporter. This is bc oxygen must be able to associate and disassociate depending on the oxygen tension. Gases that bind in a too stable way are toxic, such as carbon monoxide.
What is the Septum and why is it important?
The septum divides the heart in two sections, the arterial and the venous part. The complete development of the septum is the last morphological step of the fetus. The septum allows for the division between oxygenated and deoxygenated blood.
What is the relationship between types of blood vessels and their histology?
As a general rule: the closer the vessel is to the heart the more pressure there is. This means that vessels such as the aorta have more elastic tissue and less smooth muscle than capillaries. Also smooth muscle is higher in capillaries because vasodilation and vasoconstriction is necessary during specific events.
How is blood flow out of an injury in respect to its position in the body?
The closer the injury to the heart the more the blood flow out of the injury is homogenous to the systolic and diastolic phases. Ex. Injury to the femoral artery. In contrast when you cut your finger the blood flow is slow and continuous.
What is Myocardial infarction?
It is caused by the occlusion of the coronary vessels, the ones that bring nutrient to the muscles of the heart. Most MIs are caused by fat based nutrition, diabetes and smoking. MIs also dependent on genetic predisposition.
What is cardiovascular adaptation?
Physiologically are hearts adapt to follow the requirements of the body. Cardiovascular transitory adaptations are those that occur after for example going up a flight of stairs. The heart will adapt to the situation making it easier and then after go back to its original state. Morpho-functional cardiovascular adaptations are those present in for example bikers. Their heart has increases in size due to the rigorous daily exercise.
What is the structure of the heart?
The outermost layer is the Epicardium which is a visceral layer part of the serous pericardium. Deeper is the Myocardium which is the cardiac muscle tissue. Within the Myocardium is a layer of fibrous skeleton. The innermost part is the Endocardium which is in contact with blood therefore it is lined by epithelium.
Anatomically speaking, where is the heart contained?
It is contained in the mediastinum, which is the central part of the thorax.
What is the mediastinum and how is it divided.
The mediastinum is delineated superiorly by the first rib, inferiorly by the diaphragm, posteriorly by the bodies of the vertebrae, anteriorly by the sternum and laterally by the pleura. The imaginary line that planes form the sternal angle to the cavity between T4 and T5 delineated the superior from the inferior mediastinum.
What are the three collateral arteries that origin from the aortic arch?
From the left: Left Subclavian artery, Left Common Carotid artery which goes into the neck and then bifurcates, and then Branchiocephalic artery.
Describe the path of the aorta?
The aorta arches at level T4 at the same level as the tracheal bifurcation. After the arch is descends with the esophagus on its left. While it descends the esophagus moves forward so the aorta can pass behind. The aorta passes the diaphragm at T12.
How does the head circulation drain?
Blood from the Braine drains into the sinuses, in the Confluence of sinuses. The sigmoid sinuses which is posterior then drains into the Interna Jugular vein.
Which arteries give blood to the brain?
Internal Carotid artery and Vertebral artery.
What is the path of the ICA?
The ICA climbs upward into the neck and enters the skull at the tip fo the Temporal pyramid. Once inside the skull in turns a little upwards and backwards for a few cm before giving off collaterals. The most important one being the Ophthalmic artery.
What is the only artery that can be seen from the outside?
Central Retinal artery.
What is the path of the vertebral arteries?
They move upward into the neck passing through the holes in each vertebra. After C1 they anastomoses and enter the skull through the great foramen as the Basilar artery.
What are the three openings to the right atrium?
The inferior and superior vena cava and the coronary circulation that empties into the coronary sinuses that ultimately empty in the right atrium.
What is the thebesian valve?
It is another valve that aids outflow to the right atrium. It is found around the coronary sinus.
What is the importance of trabeculae, where are they found and what are the different types?
Trabeculae help prevent the reversion of blood flow after the valves are closed. There are 3 types. Type 1, 2 and 3. They are found for example on the surface of heart ventricles.
What are the thicknesses of the LV, RV and interventricular septum?
LV is 8-12 mm and the RV is 3-5 mm. The Interventricular septum is thick like the LV and bulges toward the side of the RV because LV produces higher pressure than RV.
How are the valves during systole and diastole?
During systole the atrioventricular valves are closed and the semilunar are open. During diastole the atrioventricular valves are open and the semilunar are closed.
How is the blood flow of the RA and LA?
The RA receives blood from the superior and inferior vena cava, the blood then passes the tricuspid valve, makes a u turn and then leaves through the pulmonary valve and ultimately enter the pulmonary trunk. The LA receives blood from the pulmonary veins which then pass through the mitral valve, then make a u turn to pass the aortic valve and then finally enter the aorta.
How do the AV valves close?
When they are open the Chordae Tendinae are relaxed. Before the contraction of the ventricle a stimulus make the Chordae tense up. As the pressure in the ventricle increases the pressure itself finishes the closing of the valves.
What are cardiac tones?
They are the noise caused by the valves closing. The first tone is the closure of the AV which is tricuspid and bicuspid contemporary. The second tone is the closure of the semilunar valves.
