Module 2 - Cardiovascular Flashcards
Describe the general organisation of the cardiovascular system.
- heart = pump
- arteries = supply path
- capillaries = exchange site
- Veins/Lymphatics = Drainage system
What is the cardiovascular organs made up of?
- vascular tissue
- connective tissues
- epithelial cells
- muscle cells
What are the differences between the blood vascular system and the lymphatic system?
Blood Vascular system - A closed supply and drainage system (a continuous loop)
Lymphatic system - An open-entry drainage (a one-way system)
What are the general principles of the cardiovascular system?
Supply side, Exchange network and Drainage
Describe the supply side.
- arteries are the only supply path
- placed in the body that will avoid injury
- carries blood at a high pressure/velocity
Describe the exchange network.
- capillaries of varying degrees of permeability
- different tissues have different capillaries
Describe the drainage.
- 3 pathways for drainage (deep veins, superficial veins and lymphatics)
- CSA of veins are at least twice that of arteries
What is the shape of a heart?
- cone shaped, blunt
- apex = pointed end
- base = broad end
Where does the heart sit?
- mediastinum
- 2/3 to the left of the midline
- rotated to the left and tilted posteriorly
- base sits near the 2-3 rib
- apex around the 5-6 rib and is sitting against PMI (point of maximal impulse)
What structure makes sure we have a left and right side of the heart?
Interventricular septum
What are the veins that connect to the right atrium and where do they get blood from?
- Superior vena cava - head, neck, chest and upper limbs
- Inferior vena cava - everywhere below the diaphragm
- Coronary sinus - from the heart itself
What are the layers of the heart wall?
Endocardium, Myocardium, Epicardium
what is the name of the sac where the heart sits?
Pericardium
What is the endocardium made up of?
- layer of SIMPLE epithelium for a non stick surface between the wall and the blood.
- small blood vessels
- loose fibrous connective tissue (FCT)
Why does the left ventricle have a thicker wall than the right?
Because it is pumping blood on a long journey around the body so needs a more powerful contraction compared to the right which is making a short journey to the lungs
What is the epicardium made up of?
- contains part of the pericardium called visceral pericardium
- blood vessels
- loose FCT, adipose
What are the the different layers of the pericardium?
Fibrous pericardium, parietal layer of serous pericardium, pericardial cavity and visceral serous pericardium
What is the name of the valve between the atrium and ventricle?
Atrioventricular valve (AV valve)
What is the function of the AV valves and what are the differences between the left and right side?
Function - prevent backflow of blood from ventricle to the atrium
Right - tricuspid valve
Left - bicuspid valve
What are the states of the heart when it’s contracting and not contracting?
Contracting = systole
Not contracting = diastole
What is the function of semilunar valves?
Prevent backflow of blood into the ventricles during diastole
What are the semilunar valves name on the left and right side?
Right = pulmonary valve Left = Aortic valve
What is the name of the muscle and the strand that is attached to the edge of the AV valve leaflet?
Papillary muscles and chordae tendineae
What is the function of the chordae tendineae and the papillary muscles?
Ensuring the leaflets don’t just open the other way by creating tension in the chordae tendineae
What is the function of myocardium?
continuously beating the heart
What is the structure of the cardiac muscle cell?
- Striated
- central nucleus
- interconnected with neighboring cells via intercalated disks (ICDs)
Why are the arrangement of sarcomeres different?
Because they’re short, stubby and have branching arms
What are the 3 different ways muscle cells are adhered together?
- Adhesion cells (actin to actin)
- Desmosomes (cytokeratin to cytokeratin)
- Gap junction (electrochemical communication)
What are the major arteries from the heart to the feet?
Ascending aorta > Aortic arch > descending thoracic aorta > abdominal aorta common iliac artery > external iliac artery > femoral artery > popliteal artery > posterior tibial artery > plantar arch.
What are the major veins from the feet to the heart?
Plantar venous arch > posterior tibial vein > popliteal vein > femoral vein > external iliac vein > common iliac vein > inferior vena cava.
What is the longest vein that joins at the femoral vein?
Great saphenous vein.
What are the three layers of a blood vessel?
- Tunica intima - inner layer
- Tunica media - middle layer
- Tunica adventitia - outer layer
What is the structure of the tunica intima and what are the layers composed of?
- Endothelium - simple squamous epithelium
- Sub-endothelium - fibrous connective tissue
- Internal elastic lamina - dense connective tissue, elastin
True or false: because the intima is thin it isn’t important in the heart.
False
Describe the tunica media.
- Smooth muscle
- Connective tissue - mainly elastin and collagen
- Thickness is proportional to vessel diameter and blood pressure.
Describe the tunica adventitia.
- Loose FCT with high amount of collagen and some elastin
- in large vessels it contains the vasa vasorum (vessels of the vessels)
- Lymphatics and autonomic nerves are found here
What is the function of arterioles?
determines the blood pressure
What is the function of capillaries?
Site of exchange between blood and tissues.
What are venules?
mono cuspid valve that makes sure that if blood runs back it creates a blockage.
What are the functions of veins?
- Low pressure but large volume transport system
- Capacitance vessels
What is the structure of the veins?
Intima, Media and adventitia but media is thinner and adventitia is the thickest layer.
What are the three different types of capillaries?
- Continuous capillaries
- Fenestrated capillaries
- Sinusoidal capillaries
What surrounds the capillaries?
- Basement membrane.
What is the differences between the different capillary types?
Continuous - brings red blooc cells as close to the wall as possible.
Fenestrated - has pore like structures (fenestrations) within the epithelial layer.
Sinusoidal - biggest capillary, intercellular gap within the endothelial layer and incomplete basement membrane.
What is the function of the lymph vascular system?
- Drains excess tissue fluid and plasma proteins from tissues and returns to blood.
- Filters foreign material from the lymph
- screens lymph for foreign antigens and provide an immune response.
- Absorbs fat from intestine and transports to blood.
What is the lymphatic system structure?
- Large, blinde ending capillaries.
- Larger (thin wall) collecting vessels have numerous valves to prevent backflow.
What are the vessels that takes the blood away and to the heart?
To the heart = venous/vein
Away from the heart = arterial/artery
What is the order of the chambers contractions?
Left & right atria - left and right ventricles.
What valves control the flow between the atria and ventricles?
Atrioventricular
What valves control the flow between the ventricles and the circulatory vessels?
Aortic and pulmonary
What is the initiator of the electrical signal?
sinoatrial node (SAN)
What allows the cells in the heart to communicate for a contraction?
gap junctions
