Cardiovascular System Flashcards
What is the heart?
A hollow muscle the pumps blood
What are blood vessels (vasculature)?
They carry blood
How much blood circulates the human body?
4-6 litres of blood circulates the human body
What side of the body is the heart apex on?
Left
What side of the body is the base of the heart on
Centre of body but near the right
Where is the heart located?
Within the thoracic cavity
Surrounded by the rib cage
The lungs are positioned on the left and right sides of the heart
The apex of the heart sits just above the diaphragm
Draw a cross section of the chest including the heart, ribs, lungs, trachea and diaphragm
See lecture notes
What is the size and orientation of the heart?
The heart is a hollow muscular organ and weights between 250 and 300 grams
The apex of the heart sits by the 5th intercostal space, above the diaphragm facing towards the right hip
The base of the heart is roughly 9cm long, facing towards the right shoulder
The majority of the heart is located to the left of the midline
Draw and label a diagram of the heart
See lecture notes
Describe the process of blood being pumped around the body
See lecture notes
Which part of the heart has a thicker muscular wall?
The left ventricle
What is the function of the septum?
To separate the two halves of the heart
What is the function of valves in the heart?
They ensure a one way flow around the heart
Prevent back flow of blood between chambers
Backflow can cause a stroke, heart failure, blood clots or cardiac arrest
What is the pericardium and what is the function of the pericardium?
It is a tough fibrous tissue
It protects the heart from physical damage and over-expansion
It anchors the heart at the right position
What is the endocardium?
Smooth squamous vascular endothelium
It minimises friction as the blood flows through the heart
What is the myocardium?
Striated muscles
Cardiomyocytes: branch and connect via inter calculated discs
Blood supply to the coronary arteries (the first branches off the aorta)
Draw and label a diagram showing the wall of the heart
See lecture notes
Pericardium on outside
Myocardium in middle
Endocardium on inside
What rate cardiac muscle cells called?
Myocytes
Describe myocytes
Striated appearance
All have a nucleus
Branch
Connect via intercalated disks
Intercalated discs contain two types of cell junctions; gap junctions and desmosomes
What are desmosomes?
Strong protein fibres
Composed of complexes of adhesion proteins found on the lateral side of the cells plasma membrane
It holds cardiac muscles together during contraction
Draw and label a diagram of a desmosome
See lecture slides
Are cardiac muscle cells excitable or contractile?
They can be both
Muscle cells communicate through gap junctions
Local ionic currents flow from one muscle to the next through gap junctions
Draw and label a diagram of the heart and show the direction of blood flow
See lecture notes
What is an artery?
Any vessel carrying blood away from the heart