Use the most suitable human biology terms to fill each of the spaces to complete the passage.
Circulation and Lymph
Blood is made up of watery fluid called __________ in which is found ________________________ (red blood cells), ____________________ (white blood cells) and __________________ (platelets).
Blood transports ____________ and ________________ to the cells. It also carries __________________________ and other wastes of metabolic processes from the cells to their sites of excretion.
Blood also produces ______________________ as one line of defence against foreign bodies.
The body’s transport system is made up of two parts: blood and lymph. Blood is carried around the body in several types of vessels: ________________ carry blood away from the heart;
______________________ (vessels of only a single cell thickness) allow the exchange of gases and food and wastes between the blood stream and the body cells;
________ carry blood back towards the heart. Arteries and veins have similar structures, but veins have a thinner ________ than arteries, making them less elastic and prone to collapse.
Not all fluids are able to be carried by the blood stream. Most body fluids which leave the circulation are returned to the general circulation via the __________________ system.
This fluid, called __________, differs from blood plasma in that it has no blood cells or blood proteins. Lymph is collected by small blind-ended tubes which drain into larger and larger tubes.
They ultimately empty into the circulatory system just above the heart at the right subclavian duct and the thoracic duct.
Arterial blood is pumped around the body by the action of the __________________________ which forces blood into already full arteries.
The distinct beat caused by blood dilating the artery wall is called the __________ and corresponds to the contraction of the heart.
Once blood reaches the capillaries, the pressure drops to almost zero.
The return of lymph is achieved by a method similar to venous return.
The return of venous blood relies on:
- the contraction of ________________ muscles to squeeze the walls of the veins;
- the action of ____________ which prevent the backflow of blood;
- the pressure difference in the thoracic cavity due to breathing;
- and the pressure of blood being forced onward by the oncoming stream of blood from arteries and capillaries.
The heart is a double pump, each side completely separated into two chambers, an ____________ and a ________________.
Oxygenated blood enters the ________ atrium from the __________________ veins coming from the lungs.
It passes into the ________ ventricle, from which it is discharged through the __________ to the body circulation.
The __________ atrium receives deoxygenated blood from the ________________ circulation and discharges it into the __________ ventricle,
from which it is sent to the _________ (through the _________________ arteries) for oxygenation and discharge of ________________________.
It is the ____________________ which serve as the force pumps.
The __________ act as receiving chambers only, and their contraction, which sends the final portion of the blood into the ventricles, is comparatively slight.
____________ are located at the entrance and exit of each ventricle. The sounds heard when listening to the heart are due to the closure of
the ________________________________ and __________________ valves. The heart and blood vessels are lined with a continuous membrane called
the ____________________. The term ______________ is applied to the muscular tissue of the heart.
Inside the heart is a pacemaker called the ________________________________ node which starts the contraction of the atria.
Another node, the ________________________________ node, controls the contraction of the ventricles.
The pressure exerted by the heart as it contracts is called ________________ pressure.
This is measured using an instrument called a ________________________________. Mark it!
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