Cardiovascular System Flashcards
What are the two components of the cardiovascular system
Blood vascular system
Lymphatic System
What does the blood vascular system do, and is it closed or open?
It is a closed system that carries blood, starting at the heart, to the exchanges surfaces
What does the Lymphatic system do and is it an open or closed system?
It is an open-ended drainage system, fluid leaving the blood is drained back into the body via lymphatics
What is the supply side of the cardiovascular systeM?
Arteries are the only supply path and they are situated deep to avoid damage. They carry blood under high pressure
What is the exchange network of the cardiovascular system?
Capillaries
What are the 3 types of capillaries?
Continuous
Fenestrated
Sinusoidal
What are the 3 pathways for drainage in the cardiovascular system?
Deep veins
Superficial Veins
Lymphatics
What is the pointed end of the heart called?
Apex
What is the broad end of the heart called?
Base
Where does the base of the heart sit?
Along the plane of the intercostal space of the 2nd and 3rd ribs
Where does the apex of the heart sit?
In the midclavicular lines between the 5th and 6th ribs
Where does the tricuspid valve lie?
Between the right atruym and the right ventricle
Where does the pulmonary (semilunar) valve lie?
Between the right ventricle and the left pulmonary arteries
Where does the reoxygenated blood return to the heart?
Pulmonary veins into the left atrium
What structures drain into the right atrium?
Superior and inferior vena cava, and the coronary sinus - all with deoxygenated blood
What drains in the left atrium
Oxygenated blood via the four pulmonary veins
Whare the 4 layers of the heart?
Endocardium, myocardium, epicardium, and the pericardium
What is the function of the pericardium?
Lubricated sac which allows the heart to beat in a low abrasion environment
What makes up majority of the tissue structure of the heart?
Myocardium, or muscle
Which layer of tissue sits below the myocardium?
Endocardium
Which layer of tissue sits above the myocardium?
Epicardium
What is the purpose of FCT in the heart tissues?
To support the thin endothelium layer
Which ventricle wall is larger?
The Left has more pumping power
What is the epicardium mainly made up of?
Adipose tissue and blood vessels
What are the 3 layers of pericardium?
Fibrous pericardium, serous pericardium, and pericardial cavity
What is the function of the AV valves?
Prevent blood from returning to the atria via ventricular contraction
Where are the two AV valves located?
Tricuspid - right side
Bicuspid - left side
What is diastole?
Relaxed phase, allowing filling to occur
What is systole?
Contraction of the ventricles, allowing the pressure to go up in the chambers. LEaflets enter a closed position and, when there is enough pressure, the flood will spill into the outflow artery
What is the function of the semilunar valves?
Prevent blood from returning to the ventricles during filling (diastole)
What are the 2 semilunar valves and their locations?
Pulmonary (right)
Aortic (left)
How many cusps does a semilunar valve have?
3
How does a semilunar valve function?
Pushed open as the blood flows out of the heart, and closes as the blood starts to backflow back in
In diastole, which valves are opened and closed?
The AV valves are open and the semilunar valves re closed, allowing filling
IN systole, which valves are open and shut?
AV valves are closed, and semilunar valves are open, allowing blood to get ejected from the heart.
What is the function of the papillary muscles?
Hold the chordae tendineae
What is the function of the chordae tendineae?
To prevent the AV valve leafelts from folding back in the other direction
Why do the semilunar valves not have papillary muscles?
They are self-supporting
Describe the supply path of the right coronary artery?
Starts in the aorta, then runs around the right lateral margin around the heart. Supplies the right side of the heart
Describe the supply path of the anterior interventricular artery
Branches into the left coronary and the circumflex artery
Describe the supply path of the left coronary artery
Supplies the left side of the heart and branches off the anterior interventricular artery
Describe the supply path of the circumflex artery
Branches off of the anterior interventricular artery, supplies the rest of the body
What is the right side of the heart drained by?
Small cardiac vein
Which vein drains the left side of the heart?
Great cardiac vein
Where do the the small and great cardiac veins drain into?
COronary sinus
What is the function of the cardiac muscle?
Beating of the heart
Describe the structure of the cardiac muscle
Striated
Short
1/2 nuclei
Central nucleus
Organelles at the poles
How do cardiac muscle cells connect to each other?
Via intercalated disks (ICDs), this is found only in cardiac muscle
Describe the process of ICDs (3)
Actin between cells means that a sacromere can pull on a neighbouring cell (physical cell-to-cell propagation)
A desmosome is used to keep them together
Calcium spilled through neighbouring cells to propagate contractions
What is the purpose of the conduction system of the heart?
Increase the efficiency of the heart
Co-ordination
What are the parts of the heart’s conduction system?
AV node
SA node
Internodal pathways
AV bundle
R&L bundle braches
Purkinje Fibres
WHat is the function of a conduction cell?
Central nucleus
Mitochondria
Lots of gap junctions
Some desmosomes
Where is the Great saphenous vein located?
Superficial medial vein from the ankle to the groin
Where does the common iliac artery branch from?
Aorta
What does the external iliac artery branch off?
The common iliac artery
What are the 3 walls of blood vessels?
Tunica Intima
Tunica Media
Tunica Adventitia (Externa)
What are the 3 layers of the intima and their functions?
Endothelium (between free blood and the wall itself)
Sub-endothelium (Connective FCT that cushions the endothelium)
Internal elastic lamina (IEL) (Layer of elastin that acts as a rubber band for elastic recall
What i the structure and function of the tunica media?
Smooth muscle
Contains elastin and collagen
Thickness is proportional the blood pressure, e.g. thicker walls means more pressure
What is the structure and the function of the tunica adventitia (externa)?
Loose FCT forms tensile strands
VAsa Vasorum which supplies the blood vessel with its own blood supply
Lymphatics and autonomic nerves also found here
What is the thickest stucture in the artery?
Media
What is an arteriole?
Resistance vessel of the circulation which determines blood pressure
What is the function of a capillary?
Site of exchange between blood and tissues
What is a venule?
Smallest vein, start of collection drainage system
What are the 3 functions of a vein?
Low pressure, large volume transport
One-way (unidirectional) flow
Capacitance vessels
What is the shape of a vein?
Irregular, flattened, with large lumen and thin wall
What structure in the vein is thinner that that of the artery?
Media, because it contains muscle
What is the thickest layer of a vein?
Adventitia
What are the functional demands of a capillary?
Thin walls
Large cross sectional area of capillary bed
Slow and smooth blood flow