Lecture 4 Flashcards
What organ is described as a pump?
Heart
Describe the blood vascular system?
A closed supply and drainage system - continuous loop
describe the lymphatic (vascular) system?
An open- entry drainage system - one way system
Principles of the supply side?
Arteries are the supply path
Important structures often receive supply from two sources
Arteries change their name at each major branch
Where are arteries located?
Major arteries are situated to avoid damage… for example deep in the trunk or flexor aspects of limbs
principles of the exchange network?
Consists of capillaries of varying degrees and permeabilities…
Continuous (controlled-light)
Fenestrated (leaky)
Sinusoidal (very leaky)
Principles of the drainage system?
There are three pathways for drainage…
Deep veins
superficial veins
Lymphatics
What is one physical way in which veins differ from arteries ?
The cross sectional area of veins is twice that of arteries in order to shift the same volume of blood per second
Diseases associated with the blood vascular system?
Cardiovascular diseases such asd heart disease and stroke cause at least 50% f all deaths.
Disease associated with the Lymph Vascular system?
Spread of metastases (cancers)
Describe the structure of the heart?
Blunt, cone shaped Pointed end - Apex Broad end - Base Size of approx a closed fist Rotated left (base tilted posteriorly)
List the layers of the heart wall ?
Endocardium
Myocardium
Epicardium
Endocardium?
Thin layer within, made up of squamous epithelium, loose irregular fibrous connective tissue, (small) Blood vessels, Purkinje fibres and prevents blood clotting
Myocardium?
Layer of Muscle. The heart is a muscular organ therefore the Myocardium is the largest layer.
Epicardium?
Outermost layer upon the heart.
Contains visceral pericardium, large blood vessels lose irregular FCT, adipose
Pericardium?
Serous membrane - A closed cavity (lubricated sac) and protective layer which the heart sits in
Location of the heart?
Sits within our chest in the thorax flanked by the two pleural cavities in a space called the mediastinum
What is the point of maximal intensity?
Where the apex beat can be observed. This is due to the apex being tilted and positioned so that it is bagning anteriorly against the chest wall.
How many chambers does the heart have?
4, two chambers ( an atrium and a ventricle) associated with the right pump supplying the pulmonary circuit and two chambers associated with the left ;pump supplying the systemic circuit.
What does the right atrium do?
Receiving chamber - receives deoxygenated blood from the periphery.
What does the right ventricle do?
Pumping chamber - contraction
what does the left atrium do?
Receiving chamber - receives oxygenated blood
What does the left ventricle do?
Pumping chamber - contraction
What is the superior vena cava?
A large vein that drains all the venous blood from the head, neck, chest and upper limbs. It drains into the superior aspect of the right atrium
