2.2 Animal Tissues, Organs and Systems Flashcards
What substance carries the different components of blood around the body?
Plasma
What substances are transported by plasma ?
• Red blood cells
• White blood cells
• Platelets
• Carbon dioxide
• Urea
• Products of digestion
What is plasma ?
A yellow liquid within blood that transports substances around the body
What is the purpose of red blood cells in blood ?
Transport of oxygen around the body
How are red blood cells adapted for their function?
• Biconcave shape - increased surface area to volume ratio.
• No nucleus - more room for haemoglobin to bind to oxygen.
• Contain haemoglobin - binds to oxygen.
What is the purpose of white blood cells in blood ?
They form part of the immune system , which protects the body from invading pathogens
How are white blood cells adapted for their function ?
• Have a nucleus - contains DNA which codes for proteins
• Can produce antibodies
• Can produce antitoxins
• Can engulf and digest pathogens (phagocytosis)
What is the purpose of platelets in blood ?
Platelets are small cell fragments which aid the clotting of blood at the site of a wound.
Why is the function of platelets inportant ?
• Platelets aid in the process of blood clotting .
prevents bacteria from entering the wound.
What is coronary heart disease ?
Coronary heart disease occurs when the coronary arteries that supply the heart muscle become blocked with a buildup of fatty material.
This restricts the supply of oxygen to the heart, possibly leading to a heart attack or death.
What is a stent and how does it work ?
A stent is a metal mesh tube that is inserted into a blocked artery so that it remains open.
The stent is inflated using a balloon, which is later removed to allow blood to flow freely.
What are the adv and disadvantages of stents ?
Advantages
• Insertion can be carried out without general anaesthetic
• Quick recovery time
• Lower the risk of a heart attack
Disadvantages
Risk of postoperative infection
• Risk of blood clots at site of stent
What are statins ?
Statins are drugs which reduce the level of LDL (bad) cholesterol which contributes to the development of coronary heart disease.
What are the adv and disadvantages of statins ?
Advantages
• Reduce risk of strokes, coronary heart disease and heart attacks
• Increase level of HDL (good) cholesterol
Disadvantages
• Have to be taken continuously
• May have side effects
• Effect may not be immediate
What is a heart bypass surgery ?
A surgery where blocked coronary arteries are replaced with sections of veins taken from other parts of the body.
What are the consequences of leaky heart valves?
Blood flows in the wrong direction, causing the heart to become less efficient. Patients may become breathless and die as a result.
What type of valves can replace leaky valves?
• Mechanical - made of metal or polymers
• Biological - taken from animals (pigs, sometimes humans)
What are the adv and disadvantages of mechanical valves?
Advantages
• Last for a very long time
Disadvantages
• Need to take medication to prevent blood clotting around valve
What are the advand disadvantages of biological valves?
Advantages
• Work very well - no medication required
Disadvantages
• Only lasts 12-15 years
What is the purpose of an artificial heart ?
Artificial hearts are intended to support a patient’s heart while they wait for a suitable donor heart.
What are the adv and disadvantages of artificial hearts ?
Advantages
• Less likely to be rejected by immune system
• Allows damaged heart to rest to help recovery
Disadvantages
• Risk of infection due to surgery
• Risk of blood clots
• Have to take blood-thinning drugs
What is health ?
Health is the state of physical and mental wellbeing
What is a communicable disease?
A disease caused by a pathogen which can be transmitted from one person to another eg. The flu
What is a non-communicable disease?
A disease the can not be transmitted from person to person eg. Cancer
How can diet affect health ?
• Too little food / lack of nutrition - anaemia, vitamin deficiencies.
• Too much food / too much unhealthy food - obesity, type 2 diabetes.
How can stress affect health ?
Prolonged stress is linked to a wide range of health problems including heart diseases, cancers and mental health issues.
How can life situations affect health ?
Many life factors such as location, gender, financial status, ethnic group and healthcare provision can impact a person’s mental and physical health.
Give examples of how health problems can interact
• Infection with certain viruses can lead to cancer eg. hepatitis infections can lead to liver cancer.
• A compromised immune system (eg. due to cancer) can lead to a higher risk of infection with communicable diseases.
• Immune reactions caused by a pathogen can trigger allergic reactions.
• Problems with physical health can lead to mental health issues.
What is a risk factor ?
A risk factor is an aspect of a person’s lifestyle or a substance found in the body or the environment which can increase the risk of a disease.
What is a casual mechanism ?
A mechanism which demonstrates how one factor boilogically influences another
How do diet , smoking and exercise affect the development of cardiovascular disease?
• Diet: high levels of LDL cholesterol causes arteries to become blocked, increasing blood pressure and the risk of a heart attack.
• Smoking: nicotine increases heart rate; other chemicals damage the artery lining and increase blood pressure.
• Exercise: lowers blood pressure, reducing strain on the heart.
How does obesity affect the development of Type 2 diabetes ?
• Obesity is strongly linked with the onset of type 2 diabetes - a disease in which the body stops responding to insulin.
How does alcohol affect liver and brain function ?
• Excessive long-term alcohol use may lead to liver cirrhosis (scarring of the liver).
• Increases risk of liver cancer.
• Damages brain tissue and nerve cells.
How does smoking affect the development of lung disease and lung cancer?
• Tar in tobacco can damage the alveoli of the lungs, leading to chronic obstructive pulmonary disease (COPD).
• Tar also damages the cells which line the lungs, leading to lung cancer.
How do smoking and alcohol affect unborn babies ?
• Carbon monoxide from tobacco smoke reduces the amount of oxygen the foetus receives, which can lead to premature birth or stillbirth.
• Alcohol passes across the placenta and damages the developing foetus. Once born, the baby may have a number of deformities and health problems as part of foetal alcohol syndrome.
How do carcinogens affect the development of cancer ?
lonising radiation is a type of carcinogen which can cause mutations in DNA, potentially leading to cancer.
What is cancer ?
Cancer is the development of a tumour as a result of uncontrolled cell division.
What is a benign tumour ?
• A tumour that is contained in one location, usually within a membrane.
• They are not cancerous and do not invade other parts of the body.
• Can grow large very quickly - may cause damage to another organ.
What is a malignant tumour ?
• A tumour that can spread around the body via the blood and lymphatic system.
• Can invade other tissues (metastasis).
• Cells divide more rapidly and have a longer lifespan.
• Disrupts healthy tissues and may lead to death.
Give examples of factors which can lead to cancer
• Genetics - certain genes increase the risk of breast and ovarian cancer
• Smoking
• Obesity
• lonising radiation - UV light and X-rays
• Viral infections - HPV and cervical cancer
What are villi ?
Villi are cells in your small intestine which absorb nutrients into the bloodstream.
Their hair-like shape means they have a large surface area, maximising the rate of absorption.
They contain microvilli which increases the surface area of the cell, usually for absorption
What is carcinogens ?
Chemicals and other agents that can cause cancer
