B2 - The Circulatory System Flashcards
What is the purpose of the Circulatory System?
It enables the transportation of substances around the body
What is the purpose of the heart?
It is a muscular pump that makes blood move
What is the purpose of blood vessels?
They are tubes that carry blood
What is blood?
A transportable substance
Why is blood classified as tissue?
As it is a collection of similar cells carrying out a similar function
What are the main components of blood?
Plasma (water), Glucose, Urea, Hormones and Antibodies
What percentage of blood is red and white?
Red = 45% White = 65%
What are the structural features of a red blood cell?
It has a flexible membrane (makes it capable of squeezing through capillaries)
It’s shape is referred to as a ‘bi-concave disc’ (large surface area which is able to pick up substances like oxygen quicker)
There is no nucleus so there is more room for Haemoglobin so it can carry more oxygen
What are the features of a white blood cell?
It has a large multi lobed nucleus that produces antibodies
Name the 11 main features that make up the heart
Superior Vena Cava Inferior Vena Cava Right Atria Left Atrium Right Ventricle Left Ventricle Septum Aorta Pulmonary Vein Pulmonary Artery Valves
Describe the structural features of a vein
Lumen Size - Large Vessel Wall - Thin Blood - Deoxygenated Blood Flow - Towards the heart Pressure of Blood - Low Valves - Yes to prevent backflow
Describe the structural features of an artery
Lumen Size - Small Vessel Wall - Very thick Blood - Oxygenated Blood Flow - Away from the heart Pressure of Blood - High Valves - No
Describe the structural features of a capillary
Lumen Size - Large comparatively Vessel Wall - 1 cell thick Blood - Both Blood Flow - Both Pressure of Blood - Low Valves - No
What happens at a capillary bed?
The exchange of substances occurs (e.g. glucose, carbon dioxide, oxygen et cetera)
