Chapters 7 and 8- Blood and circulation and Respiratory system Flashcards
What are the functions of blood?
- transporting oxygen and nutrients to all cells of the body
- transporting CO2 and other waste products away from cells
- transporting hormones
- distributing heat and maintaining body temp
- maintaining water content
What are the 4 components of blood?
red blood cells, white blood cells, plasma and platelets
How does O2 get transported throughout the blood?
3% of oxygen is carried in the plasma, 97% is carried in a combination of haemoglobin molecules, which are found in only red blood cells
How is nutrients transported throughout the blood?
dissolved into the blood plasma. Nutrients are the essential elements and molecules that are obtained from the food we eat. Inorganic nutrients are transported as ions
How are wastes transported throughout the blood?
metabolic wastes are substances produced in cells that cannot be used and would be harmful if accumulated. Some important wastes include urea, creatinine and uric acid
What are the functions of RBC’s?
transports oxygen and other nutrients throughout the body
How does CO2 get transported throughout the blood?
- 8% is dissolved into plasma and carried in solution
- Another 22% combines with the globin part of haemoglobin molecule to form a compound (carbaminohaemoglobin)
- The remaining 70% is carried in the plasma as bicarbonate ions
What are the functions of WBC’s?
fight infections and produce immune responses
What is the function of platelets?
important in blood clotting to prevent excessive bleeding in wounds
What is the function of plasma?
transport essential substances and contain proteins that assist with blood clotting
what is a simple definition fo the heart?
the pump that pushes blood throughout the body
what are the 3 types of blood vessels?
arteries, capillaries and veins
what is the function of arteries?
carry blood away from the heart
what is the function of the capillaries?
tiny vessels that carry blood between cells
what is the function of veins?
carry blood back towards the heart
what is pulmonary circulation?
the portion of the circulatory system which carries deoxygenated blood away from the right ventricle
what is systematic circulation?
the portion of the circulatory system which carries blood to body cells and tissues and picks up CO2 and waste products
how does blood flow change?
by changing the output of blood from the heart and by changing the diameter of the blood vessels supplying the tissues
what is the cardiac cycle?
(heartbeat)- the sequence of events that occurs in one complete beat of a heart
what are the contractions and relaxations of the heart called?
systole and diastole
what is vasoconstriction?
the contraction of a blood vessel- reduces diameter of an artery thus reducing blood flow to an organ
what is vasodilation?
when the muscle relaxes to increase blood flow to an organ
what are venules?
small veins that capillaries join into
what are vasodilators?
substances that produce a local widening or dilation of arterioles
what is blood clotting?
formation of a blood clot
what is coagulation?
formation of a blood clot?
what are clotting factors?
chemical substances in blood plasma that are essential for blood clotting
what is fibrin
an insoluble protein in the form of threads; form blood clots by forming blood cells, platelets and plasma together in a mesh
what is clot retraction?
contraction of the fibrous threads of a blood clot
what is serum?
blood plasma without the clotting substances, squeezed out of a blood clot during clot retraction
what is the lymphatic system?
a system of vessels that drains excessive fluid from the tissues
what are lymph nodes?
an oval shaped structure found on the lymphatic vessels; involved in protection against infection
what are lymphatic vessels?
a large vessel that collects lymph from the lymph capillaries
what is lymph?
the colourless fluid that circulates through the lymphatic vessels to be returned to the blood
what is the ABO blood group system?
a system of classifying blood types according to the antigens on the surface of the RBC’s
what is an antigen?
any substance capable of causing the formation of antibodies when introduced into the tissues
what is an antibody?
a substance produced in the response to a specific antigen; it combines with the antigen to neutralise or destroy it
what is a blood transfusion?
a transfusion transfers blood, or one of the components of blood, from one person to another
why is mixing blood types extremely dangerous?
if blood types are incompatible, they can cause the erythrocytes to clump together or aggulitnate
what is a whole blood transfusion?
blood taken from the donor but with a chemical added to prevent clotting
what are red cell concentrates?
a component of blood used in transfusions; produced by spinning blood in a centrifuge
what are platelet concentrates?
a component of blood used in transfusions
what is cryoprecipitate?
a blood product used in transfusions; produced by freezing the plasma and thawing it slowly
what is immunoglobulins?
a group of proteins (antibodies are an example)
what is an autologous transfusion?
when the patient’s own blood is used
what is the respiratory system?
the system specialised for the intake of oxygen and the removal of CO2 KNOW HOW TO LABEL
what is the membrane that covers the surface of the lungs?
pleura
what is the thin layer of fluid between the two layers of membrane?
pleural fluid
what are bronchioles?
very fine tubes that the bronchi branch into
what are the tiny air sacs that bronchioles open up into?
alveoli
why is the alveoli important?
they are the exchange surface for respiratory gases
what is each alveolus surrounded by?
a network of blood capillaries
why are lungs well suited for their gas exchange?
- millions of alveoli have enough surface area to exchange large amounts of gases in short periods of time
- the blood vessels provide as much blood flow as possible close to the alveolus which helps maintain a difference in concentrations of oxygen and CO2
- the thin membrane surrounding the alveolus enables gas molecules to travel easily through the blood vessels
- because the lungs are positioned deep inside the body it prevents excessive evaporation of the fluid that surrounds and protects the lungs
- due to respiratory muscles, air is always flowing in and out of the lungs- always a difference in concentrations fo oxygen and CO2
what is inspiration?
breathing in / inhaling
what is expiration?
breathing out / exhaling
what is the process of inspiration?
- external intercostal muscles contract- rib cage goes up and out
- diaphragm contracts- chest cavity extends down
- increase in lung volume
- air flows from high outside body to low inside lungs
- breathes in
what is the process of exhalation?
- external intercostal muscles relax- rib cage goes down and inwards
- diaphragm relaxes chest cavity- pushes up
- decrease in lung volume
- air flows from high inside lungs to low outside
- breathes out
- during forced breathing = internal intercostal muscles contract
what is gas exchange?
the blood within the capillaries that surround the alveoli have a low concentration of oxygen (used by body cells- arteries) the oxygen therefore dissolves into the moisture on the inside of the alveoli and diffuses through the membrane
what are the percentages of O2 and CO2 concentration of inspired and expired air?
O2- inspired air = 20.95%
expired air = 15.8%
CO2- inspired air = 0.04%
expired air = 4.3%
what is emphysema?
a disease of the lungs that damages the alveoli; caused by long term exposure to irritants
what is lung cancer?
growth of a tumour in the lungs
what are lung infections?
pneumonia- a lung infection that causes fluid and mucus to build up in the alveoli, causing difficulty breathing
tuberculosis- a lung infection caused by the bacterium mycobacterium tuberculosis
what is asthma?
an allergic condition that causes narrowing of the airways and difficulty breathing
