Lecture 4 Flashcards
Anatomy of the heart - I
What is the function of the heart?
Pump
What is the function of the arteries?
Supply
What is the function of the veins / lymphatics
Drainage
What is the function of the capillaries?
Exchange
What is the vascular tissue made up of?
Connective tissue and cells
What are the cells of the vascular tissue?
Epithelia and muscle
The blood vascular system is a…?
closed supply drainage system, a continuous loop
The lymphatic (vascular) system is a…?
open-entry drainage system, a one way system
The left side of the heart is where…
Oxygenated blood circulates
The right side of the heart is where…
Deoxygenated blood circulates
What is pulmonary circulation?
Where deoxygenated blood exits from the right side of the heart and into the lungs to be oxygenated and return via the left side of the heart
What is systematic circulation?
Where oxygenated blood travels out of the left side of the heart and into the capillary beds. Here, the oxygen and nutrients is used and the blood returns to the right side of the heart, deoxygenated.
What happens in the lymph vascular system?
Fluid leaves the blood and enters the interstitium surrounding the capillary exchange surfaces.
What is the supply of the cardiovascular system?
The arteries are the only supply path
How are major arteries situated in the body?
Deep in the trunk or on flexor aspects of limbs. Natural reflexes are in place to protect and important structures (e.g. brain) are often supplied by more than one source.
What is the exchange network of the cardiovascular system?
Capillaries of varying degrees of permeability
What are the levels of permeability of capillaries?
Continuous < Fenestrated < Sinusoidal
What is the drainage system of the cardiovascular system?
Deep veins, Superficial veins, Lymphatics
How does the body ensure the amount of blood leaving an area is the same as the amount entering?
The cross-sectional area of veins is at least twice that of arteries
What is the shape of the heart?
It is blunt and cone shaped
What is the apex of the heart?
The pointed end, more inferior
What is the base of the heart?
The broad end, more superior
How is the heart rotated?
Left and tilted so base is more posterior and apex is more anterior
What is the anatomical location of the PMI of the heart?
Directly inferior to the midclavicular line between the 5th and 6th rib
Where is the thoracic cavity?
In the mediastinum
What is PMI?
Point of maximal impulse
How big is the heart?
Approximately that of a closed fist
What is the function of the aorta?
It pumps blood into the systemic circuit
What is the function of the superior vena cava?
Receives deoxygenated blood from the head, neck, chest, and upper limbs
What is the function of the right atrium?
Receives deoxygenated blood from the vena cava’s
What is the function of the right pulmonary veins?
Carries oxygenated blood from the right lung
What is the function of the opening of the coronary sinus?
Receives deoxygenated blood from the heart itself.
What is the function of the Atrioventricular valves?
Controls flow of blood from the atriums to the ventricles. Ensuring it only flows in one direction
Where is the atrioventricular tricuspid valve?
On the right side of the heart
Where is the atrioventricular bicuspid valve?
On the left side of the heart
What is the function of the inferior vena cava
Receives all deoxygenated blood from below the diaphragm
What is the function of the right ventricle
Pumps deoxygenated blood to the lungs
What is the function of the interventricular septum?
To separate the two ventricles
What is the function of the left ventricle
Pumps oxygenated blood to the systemic circuit
What is the function of the pulmonary (semilunar) valve?
Controls the flow of blood from the right ventricle to the pulmonary artery
What is the function of the left pulmonary veins?
Carries oxygenated blood from the left lung
What is the function of the left atrium?
Receives oxygenated blood
What are the atria of the heart?
Thin walled receiving chambers. One on left and one on right
The right atrium receives deoxygenated blood from…?
The superior vena cava, inferior vena cava and the coronary sinus
The left atrium receives oxygenated blood from…?
The four pulmonary veins
What are the layers of the heart wall?
Endocardium, Myocardium, Epicardium
What is the sac where the heat sits?
The pericardium
What is the function of the pericardium?
To protect and lubricate the heart in order to eliminate damage due to friction
What does the endocardium consist of?
Simple squamous epithelium cells called endothelium cells and a matrix of extracellular loose irregular fibrous connective tissue
What is the function of the endothelium cells?
To provide a non-stick layer to ensure blood does not coagulate and clot on the heart wall
What is the myocardium?
The muscle cells of the heart
What is the thickness of the left and right myocardial layer of the ventricles?
1.5cm and 0.5cm respectively
Why is the left myocardial layer thicker than the right?
More pumping pressure is required on the left to move the blood around the systemic circuit
What does the epicardium contain?
Visceral pericardium, blood vessels, loose irregular fibrous connective tissue and adipose
What are the layers of the pericardium?
Parietal pericardium (superficial), pericardium fluid, visceral pericardium (deep)
What is superficial to the parietal pericardium?
The fibrous pericardium
What structure is continuous between the pericardium and epicardium?
The visceral serous pericardium
