Anatomy of the CVS 1 & 2 Flashcards
What is the function of arteries?
To distribute from the heart
What is the function of the capillaries?
To exchange nutrients
What is the function of veins?
To collect and return blood to the heart
Where in the thoracic cavity does the heart lie?
In the middle mediastinum
What are the circulatory systems of the body?
Pulmonary, systemic, hepatic portal and lymphatic
Which vertebrae does the heart lie in front of in the recumbent position?
T5-T8
Where is the apex of the heart located?
The fifth left intercostal space in the midclavicular line
Which part of the heart makes up the base?
Left atrium
What is dextrocardia?
When the left part of the heart points towards the right
What lies anterior to the heart?
Sternum, costal cartilage and the thymus gland (in children)
What lies posterior to the heart?
Oesophagus, descending aorta and thoracic vertebrae 5-8
What lies latterly to the heart?
Lungs and phrenic nerve
What lies inferiorly to the heart?
Diaphragm
From inner to outer, what are the layers of the heart wall?
Endocardium, myocardium, epicardium (visceral pericardium), pericardial cavity, parietal pericardium and fibrous pericardium
What tissues are the endocardium and the epicardium made up of?
Epithelium, basement membrane and connective tissue
Which of the layers of the heart wall forms the valves?
Endocardium
What is the function of gap junctions?
Electrical communication
What is the function of desmosomes?
Binding myocytes together
Which layer of the heart wall contains the main coronary arteries?
Epicardium
Which structures prevent valve failure?
Chordae tendinae and papillary muscles
What are the three abnormalities that can occur in valves?
Incompetence (widening), stenosis (narrowing) and endocarditis (infection)
What is the name of the right atrioventricular valve?
Tricuspid valve
What is the name of the left atrioventricular valve?
Mitral valve
What type of valves are the pulmonary and aortic valves?
semilunar valves
What type of tissue is the cardiac skeleton made of?
Connective tissue
What are the functions of the cardiac skeleton?
Structural support and electrical insulation
How does the cardiac skeleton provide structural support?
Atrioventricular septum, roots of great vessels, anchorage for valves and myocytes/capillary network
In which areas does the cardiac skeleton provide electrical insulation?
From the atria to the ventricles and the myocardium from the great vessels
What are the attachments of the pericardium?
Central tendon of the diaphragm, sternum and the roots of the great vessels
What is the function of the serous pericardium?
To allow freedom of movement during the cardiac cycle
Do arteries or veins have a thicker tunica media and a thinner tunica adventitia?
Arteries
Which layers of blood vessels walls is missing in arterioles?
Tunica adventitia and the IEL
Which type of nerves provide the rich innervation of arterioles?
Sympathetic nerves
What is the local function of arterioles?
To control blood flow to the capillary bed
What is the systemic function of arterioles?
To control blood pressure
What is the only layer to the wall of a capillary?
Tunica intima
What are pericytes?
Incomplete layers of cells surrounding the basement membrane
What is the function of pericytes
They have contractile properties which help control flow of blood in the capillaries
Is blood pressure in the capillaries high or low?
Low
What are the three types of capillaries?
Complete, fenestrated and discontinuous
What are the features of continuous capillaries?
They can control what is exchanged, material must pass through or between the cells - selective transport mechanisms
Where can you find continuous capillaries?
Muscle
What are the features of fenestrated capillaries?
They have fenestrations (pores) with or without protein diaphragms
Where can you find fenestrated capillaries?
Endocrine glands, kidneys etc.
What are the features of discontinuous capillaries?
Gaps between the endothelial cells that allow free passage of fluid and cells
Where would you find discontinuous capillaries?
Liver, spleen and bone marrow etc.
What are sinusoids?
Larger diameter discontinuous capillaries
Where are sinusoids found?
Where large amounts of exchange takes place e.g. liver, some endocrine glands
What is the function of the arteriovenous shunts?
To bypass the capillary beds e.g. in thermoregulation
What features of a blood vessel wall are thin or absent in veins?
IEL, OEL T media
What is the function of the valves?
To prevent backflow
What are the features of superficial veins?
Thick walled and no surrounding support
What are the features of deep veins?
Thin walled and surrounding support from deep fascia and muscles
What are the features of lymph capillaries?
Blind ended, thin endothelium, no fenestrations, absent basal lamina and anchoring filaments
What is the name of the blood vessels that supply the bigger vessels?
Vasa vasorum
Where are the lymphatics found in the blood vessels?
In the T. adventitia
