THE CIRCULATORY SYSTEM Flashcards
Explain why the human circulatory system is described as a ‘double circulatory system’?
Because it consists of 2 circuits joined together.
The 1st circuit pumps deO2 blood —) lungs to take in 02 & returns OXGEN blood —-) heart
The 2nd circuit pumps 0XYGEN blood around all other organs of the body &returns deOXGEN blood—) heart
how is the HB controlled?
By a group of cells located in the RA wall that ACTS AS A PACEMAKERR
Name 1 adaptation of the arteries?
They have thick elastic fibres to stretch and spring back
Explain why the walls of the capillaries are 1 cell thick
Capillaries carry blood= close to cells= to exchange substances with them.
Having thin walls = inc rate at which substances can diffuse across them by shortening the diffusion distance
What does haemoglobin do?
absorbs oxygen, combines with oxygen to make OXYHAEMAGLOBIN
Explain how WBC’S are adapted to their function?
Phagocytes- can change shape and engulf microbes in a process called PHAGOCYTOSIS
lymphocytes- produce antibodies to fight microbes off or produce antitoxins to neutralise any toxins produced by the microbe.
Structure of platelets
Small fragments of cells with no nucleus
Function of platelets
Help blood clot at a wound
Explain why a blockage in the coronary arteries could damage the patient’s heart muscle?
Restricts the blood flow to heart muscle, leading to a lack of oxygen reaching it
Suggest and describe a method of treatment a doctor might recommend to the patient?
Doctor might recommend a STENT. Stents are tubes that are inserted inside arteries to keep them open —) To MAKE SURE THAT BLOOD CAN PASS THROUGH TO THE HEART MUSCLE
Explain how statins prevent / slow progression of CHD
Reduce amount of ‘bad’ cholesterol present in the blood stream—–) slowing down rate of FATTU DEPOSITS FORMING IN THE CORONORY ARTERIES
a Patient is offered statins. Suggest one reason he may not wish to take them.
SIDE EFFECTS:
headache.
dizziness.
feeling sick.
