The Circulatory System Flashcards
Revision
What systems do the circulatory system consist of?
The cardiovascular system and lymphatic system.
What are the functions of the circulatory system?
Distribution of gases and other molecules for nutrition, growth and repair.
Chemical signalling (hormones)
Thermoregulation
Mediate inflammation and host defense responses.
(The lymph system also get rid of some of the body’s waste).
What are the three components that the cardiovascular system is comprised of?
Arterial System
Heart
Venous system
What is the role of the Arterial system?
All the arteries of the body carry blood away from the heart.
What is the role of the heart?
The heart’s role is to act as the pump of the cardiovascular system.
What is the role of the venous system?
All the veins of the body carry blood towards the heart.
What are the 2 main circulations that the cardiovascular system is divided into?
Pulmonary circulation
Systemic circulation
What is the role of the Pulmonary circulation?
this pumps oxygen depleted blood from the right side of the heart to the lungs and back to the left side of the heart.
What is the role of the systemic system?
It pumps oxygenated blood from the left side of the heart to capillary beds of organs and tissues back to the right side of the heart.
The heart is a muscular double pump. what are the two actions that the heart carries out?
Systole (contraction) and Diastole (relaxation)
Diastole is where the contraction dies and so the heart relaxes
What is the average pulse rate of a person?
70 beats per minute
What is the plural of atrium?
Atria
What is the biggest, chunkiest artery in the body?
Aorta
How many pulmonary veins are there?
4
How many vena cava’s are there?
There is a superior vena cava and an inferior vena cava.
How many layers does the heart have?
3
What are the names and types of tissues in each layer?
the external layer is the epicardium. Visceral serous pericardium
The middle layer is the Myocardium. Cardiac muscle layer.
The internal layer is the endocardium. Continuous with endothelium of blood vessels connecting with the heart.
What structure forms the right border of the heart?
Right atrium
What structure forms most of the anterior surface of the heart?
Right ventricle
What structure forms the posterior surface of the heart?
Left atrium
What structure form the left border of the heart?
Left ventricle
Is the myocardium the same all the way around the heart?
No it is thicker on the left than the right.
What is the role of cardiac valves?
They ensure uni-directional flow
Where is the pulmonary valve located?
between the right ventricle and pulmonary trunk
Where is the tricuspid valve located?
between the right atrium and right ventricle
The tricuspid valve slams shut and stops a back flow of blood into the right atrium.
Where is the aortic valve located?
between left ventricle and the aorta
Where is the mitral (bicuspid) valve located?
between right ventricle and pulmonary trunk The mitral (bicuspid) valve has to deal with large pressure of a strong flow of blood.
What is the name of the veins and arteries that exit and enter the heart?
Superior vena cava (SVC) Inferior vena cava (IVC) Aorta Pulmonary trunk Pulmonary veins (x4)
What are the four steps that talk you through the conduction system of the heart?
There is one normal route for electrical conduction in the heart:
- Electrical impulses starts spontaneously at SA node. Causing both atria to contract.
- Travels to AV node at atrioventricular septum. The AV node sandwiched between the atrium and the ventricle.
- Travels down right and left bundles in the interventricular septum.
- Spreads out to myocardium through conducting fibres. Causing both ventricles to contract.
What are the three layers that most blood vessels are comprised of?
Tunica Intima (internal) - endothelium Tunica media (middle) - smooth muscle and elastic fibres Tunica adventitia (external) - connective tissue
The bigger the artery the more elastic muscles and less muscle. The smaller the arteries, the more muscles, the less elastic fibres.
What the 7 key principles about arteries?
Often part of a neurovascular bundle (nerve, artery, vein)
High pressure (>120/80 mmHg)
Often named by anatomical location - (e.g. brachial artery, intercostal artery)
Round lumen
Pulsatile - you can see/take a pulse
Typically located deeper than veins
Carry oxygenated blood
What does proximal and distal mean?
Proximal means closer to the heart
Distal means away from the heart
What do arteries give rise to
branches