Organization in Animals TOPIC 2 Flashcards
Why do cells differentiate and become specialised
Because the organisms develop different ways of exchanging materials
Define tissues
A group of cells with similar structure and functions
Define organs
Groups of tissues that preform a particular function
What does epithelial tissue do
it lines the inside of organs
What does muscular tissue do
it contracts and relaxes to bring about movement
What do glandular tissues do
Make and secrete chemicals like enzymes and hormones
Define organ system
Different organs combine to form organ systems to carry out major functions in the body
Define organisms
An organism is made up of organ systems that work together
Define Cell
The smallest unit of all living organisms that are the basic building blocks of all living organisms
Define Organelle
A specialized structure inside a cell that carries out a specific function within the cell
Why do multicellular organisms have a double circulatory system
To ensure all the nutrients are delivered to all the cells and that waste products are efficiently removed
Why can’t multicellular organisms not just rely on diffusion
Because the distance molecules need to travel is too big and the rate of delivery and removal would be too slow to meet the cells demands
What are the three components that make up the circulatory system
- heart
- blood vessels
- blood
What does the heart do in the circulatory system
the muscle contracts to generate a force to move the blood
What do the blood vessels do in the circulatory system
they are tubular structures that carry blood through all organs and tissues of the body
What does the blood do in the circulatory system
It is the transport medium that carries nutrients and hormones to the tissues and organs and removes the waste products from them
What is meant by double circulatory system
The blood passes through the heart twice per complete circuit around the body
What are the two routes the blood has to take to complete a circuit around the body
- The pulmonary circuit
- The systemic circuit
What is the pulmonary circuit
Where deoxygenated blood passes from the right ventricle to the lungs and then back to the heart oxygenated
What is the systemic circuit
where oxygenated blood passes from the left ventricle to the rest of the body and then returns to the heart deoxygenated
How is cardiac muscle different to skeletal muscle
- It never fatigues
- It doesn’t need impulses from the nervous system to contract - the heart does it itself
Why does the heart contract
to generate a force that moves the blood around the body in a double circulatory system
What happens to the blood when it goes to the lungs
Gas exchange occurs
Where are valves present in the heart
- between the atria & the ventricles
- at the start of the aorta
- at the end of the vena cava
What is 1
aorta
What is 2
superior vena cava
what is 3
pulmonary artery
What is 4
pulmonary vein
What is 5
Right atrium
what is 6
valves between the atrium and the ventricle
What is 7
Right ventricle
What is 8
Inferior vena cava
what is 9
Pulmonary artery
What is 10
Pulmonary veins
What is 11
left atrium
What is 12
valves between the atrium and ventricle
What is 13
valves at the start of the aorta
what is 14
left ventricle
What does the aorta do
carries high oxygen blood to the arteries
What does the vena cava do
Carries high carbon dioxide blood back to the heart
What does the pulmonary artery do
Carry high carbon dioxide blood to the lungs
What does the pulmonary vein do
Carries high oxygen blood from the lungs to the heart
What do the coronary arteries do
deliver oxygen and nutrients to the cardiac muscle cells that make up the heart walls
What does the left side of the heart do
receive the oxygenated blood
What does the right side of the heart do
Receives the deoxygenated blood from the right atrium
What tissues is the heart made up of
- cardiac muscle tissue
- nervous tissue
What is the function of the nervous tissue in the heart
to pass tiny electrical impulses along the nervous tissue causing the muscle cells to contract
What are the specialized cells called that cause the heart to contract called
the pacemaker
What does the pacemaker control
the natural rate of the heartbeat
Why would someone need an artificial pacemaker
If they were born or develop problems with their pacemaker so their heartrate is not controlled properly.
Where is the pacemaker located
on the right atrium wall
How are arteries adapted
- thick walls ~ withstand high pressure
- elastic tissue ~ walls strech when blood is forced
- narrow lumen ~ maintain high blood pressure
Which artery doesn’t carry oxygenated blood
Pulmonary artery
how are capillaries adapted
- one cell thick walls ~ reduce diffusion distance
- gaps ~ allows larger molecules to exchange
What is the function of a cappillary
- exchange nutrients into the plasma (glucose)
- exchange waste products into the plasma (carbon dioxide)
How are veins adapted
- thin walls ~ low blood pressure
- Valves ~ maintain correct direction of flow
- wide lumen ~ reduce resistance between blood and walls
Which vein doesn’t carry deoxygenated blood
Pulmonary vein
What does CHD stand for
Coronary heart disease
what is CHD caused by
a blockage in the coronary arteries
What blocks the coronary arteries
layers of fatty material building up in the walls
What are the impacts of a blockage in the coronary arteries
- narrowing
- reduced blood flow
- lack of oxygen for the heart muscle
What are the symptoms of CHD
- chest pain
- shortness of breath
- heart attack
What are some risk factors for CHD
- age
- family history
- smoking
- diabetes
- high blood cholestrol
What are stents used for
to keep the coronary arteries open
What is a stent
A metal mesh that is inserted into an artery to keep the lumen of the artery open by pushing the wall outwards
How is a Stent inserted
- A catheter is used to insert a balloon which is inflated ~ opening artery
- The stent is then inserted and the balloon deflated
- Catheter and balloon are removed
Why would someone have a stent fitted
When an artery narrows due to fatty deposits in the artery or natural narrowing due to age
What are the advantages of stents
- Lowers risk of heart attack for people with CHD
- Quick effective operation with quick recovery
What are the disadvantages of stents
- complications can occur during surgery (heart attack)
- Risk of infection from operation
- Risk of blood clot ~ lead to stroke or heart attack
What do statins do
Lower blood cholesterol levels
What does lowering blood cholesterol levels do
Slow down the rate of fatty material deposited
What do statins reduce
LDL levels
What do statins increase
HDL levels
What does HDL and LDL stand for
- High-density lipoprotein
- Low-density lipoprotein
What does LDL cholesterol do
carry fat to the artery wall and increase the amount of fat deposited in the artery wall
What does HDL cholesterol do
carry fat away from the artery wall and decrease the amount of fat deposited
What are the advantages of statins
- reduces risk of strokes, CHD and heart attacks
- may prevent other diseases
What are the disadvantages of statins
- Must be taken regularly over a long period of time (get forgotten)
- Negative side effects
- Not immediate effect
What negative side effects do statins cause
- headaches
- kidney failure
- liver damage
- memory loss
What are causes of faulty heart valves
- heart attack
- infection
- old age
What is the function of the heart valves
maintain the blood flow in one, correct direction
What do atrio-ventricular valves do
Prevent backflow of blood from ventricles to atria
What do semilunar valves do
prevent back flow of blood from the blood vessel to the ventricles
What are the consequences of faulty valves
- blood doesn’t circulate as efficient and effectively
- low oxygen supply ~ breathless
- fatal ~ death
What can faulty heart valves be replaces by
Using biological or mechanical valves
What is the difference between biological and mechanical valves
mechanical values are man made
biological valves are from other humans or animals
What are mechanical valves made from
titanium and polymers
What animals can biological heart valves come from
cattle or pigs
What are advantages of mechanical heart valves
- last very long
- very efficient
- permanent
- no ethical issues
- more cell respiration
What are the disadvantages of mechanical heart valves
- require anticoagulants for life ~ due to risk of clotting
- Open heart surgery needed
- unsuitable for growing person (children)
- risk of infection
What are the advantages of biological heart valves
- no medication needed
- fully effective
- more cell respiration
What are the disadvantages of biological heart valves
- need replacing after 15 years
- risk of infection
- risk of clotting
why have scientist developed artificial hearts
- Shortage of donor hearts in UK
- extends patients life (bides time)
- to allow the heart to rest
How do artificial hearts work
It is a mechanical device hat supplies the valves. It doesn’t generate a force, that is generated by an external power source
What are advantages of artificial hearts
- compensates shortage of donor hearts
- less likely to be rejected ~ metal and plastic isn’t foreign
- no need to tissue match ~ its plastic
- no immunosuppressants
- gains time
What are the disadvantage of artificial hearts
- sizing
- surgery can lead to bleeding and infection
- temporary
- blood flow is not smooth
- anticoagulants to thin blood
- may fail
- not natural
- battery pack inconvenience
What is blood an example of
A tissue
Describe plasma
liquid component of blood
what is the function of plasma
carries:
- red blood cells
- white blood cells
- platelets
- nutrients (glucose, amino acid)
- waste products (CO2, urea)
around body
Describe how red blood cells are adapted
- biconcave shape ~ increase surface area = more oxygen absorbed
- no nucleus ~ more room for oxygen
- contains hemoglobin ~ binds the oxygen
What is the function of a red blood cell
carry oxygen bound to haemoglobin
What is the equation for red blood cells
oxygen + haemoglobin -><- oxyhaemoglobin
what is the other word for red blood cell
erythocyte
describe how a white blood cell is adpted
- produces antibodies ~ break down pathogens
- produces antitoxins ~ break down toxins
- carries out phagocytosis ~ kills harmful molecules
What is phagocytosis
The process white blood cells carry out to engulf bacteria or toxins, breaking them down to harmless products
describe platelets
- small fragments of cells
- no nucleus
What is the function of platelets
start the clotting process by forming a mesh over the wound to trap blood cells
What can lack of platelets lead to
excessive bleeding and bruising
What are blood products
components of blood prepared from donated blood
Where are blood products prepared
in transfusion centres
Why are blood components used
Because patients usually require a specific component of blood so its a waste to give a patient blood they may not need ~ this is called blood component therapy
What are advantage of using blood component therapy
- more patients treated
- does of required component can be optimized
- more cost effective and efficient
What is the use of packed red blood cells
To restore oxygen carrying capacity - anaemia & blood loss
What is the use of fresh frozen plasma
treating patients with excessive bleeding
What is the use of platelets
Treating or preventing bleeding in patients with low platelet counts
Why are scientists trying to make artificial blood
Because whole blood has a short shelf life
What is artificial blood referred as
A blood substitute
What are the characteristics of any good blood substitute
- no rejection
- long shelf life
- easy to store & transport
- no infections
- good at transporting oxygen
What is important to make sure when saline is transferred
It has to be without any air bubbles
