B4 Blood Vessels And The Heart Flashcards
What are the main components in blood
Plasma
Red blood cells
White blood cells
Platelets
Function of red blood cell
Carries oxygen and delivers it throughout our body
How red blood cells adapted to their function
They are small and flexible so they can fit through narrow vessels
Why do red blood cells need large surface area
For absorbing oxygen
Why does it help if blood cells don’t have nucleus
More room to carry oxygen
What is the structure of red blood cells?
Small
Disc-shaped
No nucleus
Function of white blood cell
Helps the body fight infection and other diseases
What is the structure of white blood cells?
They have a nucelus
Bigger than red blood cells
No definite shape
How white blood cells are adapted to their function
Can change shape to squeeze out of blood vessels
What can white blood cells produce
Antibodies and antitoxins
Name the 2 types of white blood cell and explain how they fight disease
Phagocytes - engulf (‘eat’) pathogens
Lymphocytes - create antibodies which destroy pathogens
What are the three main types of blood vessels
Arteries, veins, capillaries
Arteries
Carries blood pumped away from the heart
Veins
Returns blood to the heart
Capillaries
Allow fast exchange/diffusion of substances
Structure of an artery
Thick collagen, elastin & muscle wall
Narrow lumen
How does capillaries walls being 1 cell thick increase rate of diffusion
Decreases distance over which diffusion occurs
Why are artery walls thick
Have to withstand high blood pressure from the heart
Structure of vein
Thin muscle & elasin wall
Wide lumen
Have valves
Why do veins need bigger lumen then arteries
To help blood flow
Why do thick layers of muscle and elastic fibres help the arteries
Makes them strong and allows them to stretch and spring back
Why don’t veins need thick walls like arteries
Veins has lower blood pressure
Why do veins have valves
To help keep the blood flowing in the right direction
Structure of capillary
Very small blood vessel with thin-walled vessels composed of a single endothelial layer
Why do capillaries have permeable walls
So substances can diffuse in and out
Function of plasma
Takes nutrients, hormones and proteins to the parts of the body that need it
Stent
Tube constructed of a metallic alloy or a polymer
Statin
Drugs that can lower your cholesterol
Advantages of stents
Help blood flow
Stops heart attacks
Improve symptoms such as shotness of breath
Disadvantages of stents
Bleeding
Blood clot inside stent
Stroke
Advantages of statin
Reduce a person’s chance of having a heart attack or stroke
Disadvantages of statin
Dizziness
Feeling sick
Feeling physically tired
Function of platelets
To prevent and stop bleeding
Structure of platelets
Tiny fragments of cells
NO nucleus
They cause blood to clot
Where is the pancreas
Between stomach and large intestine
Where is the liver
Next to the stomach
Bigger than pancreas
Function of plasma
Takes nutrients, hormones and proteins to the parts of the body that need it
What is the structure of blood plasma
Straw yellow liquid
Where does a stent go
Tube which is inserted into a (blocked) coronary artery to widen the artery and allow more blood to flow.
How is the thorax (top part of your body) separated from lower part
Separated by diaphragm
Process of blood clotting
Constriction of the blood vessel
Formation of temporary platelet plug
Activation of coagulation cascade
Formatiom of final clot
Importance of a double circulatory system
Ensures body always has a dedicated supply of oxygen
Improves body efficiency
What is meant by humans having a ‘double circulatory system’?
The heart is an organ that pumps blood around the body in a double circulatory system
The right ventricle pumps blood to the lungs where gas exchange takes place
The left ventricle pumps blood around the rest of the body
What is the double circulatory system made from
Heart, blood vessels and blood
Ways in which the heart can stop functioning efficiently
High blood pressure
Main structure of human heart
4 chambers
Left atrium and right atrium (top)
Left and right ventricles (bottom)
Function of left and right ventricle
Right ventricle - pumps oxygen-poor blood to the lungs
Left ventricle - recieves oxygen-rich blood from the lungs
Function of left and right atrium
Right atrium - recieves oxygen-poor blood from the body
Left atrium - recieves blood full of oxygen from the lungs
What are the 2 top chambers of the heart called
Left and right atria (singular atrium)
What are the 2 bottom chambers of the heart called
Left and right ventricles
What is your resting heart controlled by
Group of cells in the right atrium wall
Describe the pathway of blood through the heart
Vena cava –> right atrium –> right ventricle –> pulmonary artery –> Pulmonary vein –> left atrium –> left ventricle –> aorta
What type of blood do arteries (usually) carry?
Oxygenated blood
What type of blood do veins (usually) carry?
Deoxygenated blood
Which blood vessel carries deoxygenated blood into RHS of the heart?
Vena Cava
Which blood vessel carries oxygenated blood into the LHS of the heart?
Pulmonary vein
Function of heart
Pumps blood and oxygen around the body
Delivers waste products back to the lungs to be removed
Examples of problems that can develop in blood vessels in the human heart
Angina
Heart attacks
Heart failure
Why an irregular heartbeat is detrimental to health
Arrhythmias can damage the heart, brain or other organs
Heart transplant
Replacement of a faulty/diseased heart with that of one donated by another person
Why would someone use an artificial heart
If donor organs are not available
It is a mechanical device that can pump blood for a person who has a failed heart
When would an artificial valve be used
When the valve becomes faulty this could prevent the valve from opening fully, or the heart valve might develop a leak
Why people may have objections to heart transplants
If they are too ill or frail to cope with the surgery and aftercare
What happens on alveoli
Gas exchanges
How alveoli are adapted
Thin walls provide gases with a short diffusion distance
Moist walls - gases dissolve in the moisture
What happens during gas exchange in lungs
When the blood reaches body cells oxygen is
released from the red blood cells and diffuses into the body cells
At the same time, carbon dioxide diffuses out of the body cells into the blood it’s then carried back to the lungs.
Name the 3 main ways of treating heart disease?
Statins
Heart transplant
Mechanical devices: valves, stents, pacemakers
Pacemaker
Group of cells that maintain a heartbeat
Desrcibe the process of ventilation
Movement of air through passages between the atmosphere and the lungs
Function of valves in veins
Valves prevent the back-flow of blood
Coronary arteries
Arteries that supply the heart muscle with oxygen and glucose for respiration
How can blocked coronary arteries lead to heart disease
In coronary heart disease layers of fatty material build up inside the coronary arteries, narrowing them
This reduces the flow of blood through the coronary arteries, resulting in a lack of oxygen for the heart muscle.
How a natural pacemaker maintains the heart beat
Sinus node generates a new electrical impulse which spreads out through the heart’s upper chambers
Diamater of red blood cell
Approximately 7 to 8 μm
-6 7 to 8 x 10 m
How to view blood under a light microscope and recognise components
Place a drop of blood onto a microscope slide
Add a drop of stain to the blood to make cells easier to see
Place coverslip over drop of blood
Sliding it slightly along the microscope slide will spread out the blood cells making them easier to see
How would you estimate heart rate
Count number of beats in 15 seconds
Multiply this number by four to calculate beats per minute
How is the structure of the heart related to its function
Right ventricle walls are thinner, as this ventricle only pumps blood a short distance to the lungs
Left ventricle, which has much thicker walls, to generate enough force to pump oxygenated blood throughout the rest of the body
How an artificial pacemaker regulates an irregular heartbeat
Pacemakers send electrical pulses to help your heart beat at a normal rate and rhythm
Why a person may need an artificial pacemaker or an artificial heart
To help your heart chambers beat in sync so your heart can pump blood more efficiently to your body
Treatments of heart problems
Stents
Statin
Bypass surgery
Best way to treat coronary heart disease
Stents
How does oxygen travel to the blood (gas exchange system)
Air is breathed into lungs through the trachea (windpipe)
The trachea divides into two tubes called the bronchi
The bronchi divides into many tubes called bronchioles
The bronchioles divide until they end up in tiny air sacs called alveoli
List main structures of gas exchange
Alveoli
Trachea
Bronchiole
Diaphragm
Function of trachea
Allow passage of inspired and expired air into and out of the lung.
Function of brionchiole
Delivers air to a diffuse network of around 300 million alveoli in the lungs
Function of diaphragm
Helps you inhale and exhale (breathe in and out)
Process of ventilation
Inhalation (breathing in)
Oxygen from inhaled air diffuses across thin walls of alveoli into the blood
Carbon dioxide diffuses from the blood into alveoli to be exhaled
Exhalation (breathing out)
Describe breathing in
Diaphragm contracts —–> chest cavity expands ——> air pressure drops ——–> air enters lungs
Describe breathing out
Diaphragm relaxes —–> chest cavity contracts ——> air pressure rises ——–> air exits lungs
Process of gas exchange
Air enters lungs
Oxygen diffuses into blood
Carbon dioxide diffuses out of blood
Oxygen transport
Carbon dioxide removal
Explain the differences between the composition of inhaled and exhaled air
Inhaled air contains 21% oxygen
Exhaled air cintains 16% oxygen
Inaheld air contains 0.04% CO2
Exhaled air contains 4% CO2
Inhaled air contain 78% nitrogen
Exhaled air contain 78% nitrogen
