animal tissues, organs and systems Flashcards
what is the main function of the digestive system
to digest food and absorb the nutrients obtained from digestion
what is the role of the pancreas and the salivary gland in the digestive system
the pancreas and the salivary glands are glands which produce digestive juices containing enzymes
what is the role of the stomach in the digestive system
produces hydrochloric acid - which kills bacteria present and provides the optimum acidic pH for the protease enzyme to function
what is the role of the small intestine in the digestive system
the small intestine is the site where the soluble food molecules are absorbed into the blood stream.
what is the role of the liver in the digestive system
produces bile (stored in the gallbladder) which emulsifies lipids and allows the lipase enzyme to work more efficiently.
what is the role of the large intestine in the digestive system
absorbs water from undigested food, producing faeces.
what is the role of enzymes in the digestive system
they act as biological catalysts that speed up the rate of biological reactions (the breaking down of food) without being used up
how does the shape of an enzyme affect its function
enzymes have a specific active site which is complementary to their substrate
what is metabolism
the sum of all the reactions in a cell or an organism
what types of metabolic reactions do enzymes catalyse
- building larger molecules from smaller molecules e.g glucose to starch
- changing one molecule to another e.g glucose to fructose
- breaking down larger molecules into smaller molecules e.g carbohydrates to glucose
what is the lock and key hypothesis of enzyme function
the shape of the enzyme active site and the substrate are complementary, so can bind together to form an enzyme-substrate complex
how does temperature affect enzyme action
up to a certain point, increasing temperature increases enzyme action, as molecules have higher kinetic energy. above a certain temperature, the shape of the active site is altered and the enzyme becomes denatured, so it can no longer catalyse the reaction. The optimum temperature is around 37 degrees
how does pH affect enzyme function
the optimum pH for most enzymes is 7 (except from proteases in the stomach) if the pH is too extreme, the shape of the active site may be altered and the enzyme may no longer work.
where are carbohydrates produced in the body?
- amylase - salivary gland and pancreas
- maltase - small intestine
where are proteases produced in the body?
- pepsin - stomach
- others - pancreas and small intestine
where are lipases produced in the body?
pancreas and small intestine
what is the role of carbohydrate in the digestive system
carbohydrate break down carbohydrates into monosaccharides and disaccharides. amylase breaks down starch into maltose, and maltase breaks down maltose into glucose.
what is the role of proteases in the digestive system
proteases break down protein into amino acids
what is the role of lipases in the digestive system
lipases break down lipids into fatty acids and glycerol
how are the products of digestion used
they are used to build bigger molecules such as carbohydrates and proteins. glucose is used as a substrate in respiration
where is bile made up and stored in the body
bile is made by the liver and stored in the gall bladder
what is the role of bile in the digestive system
- bile is an alkaline substance which neutralises the hydrochloric acid secreted by the stomach.
- bile emulsifies lipids to form droplets- this increases the surface area for the lipase enzyme to work on
what is the purpose of the circulatory system
carries oxygen and other useful substances to the bodily tissues and removes waste substances
how does the double circulatory system work
- one pathway carried blood from the heart to the lungs - where the gaseous exchange of oxygen and carbon dioxide takes place
- one pathway carried blood from the heart to the tissues
where does the blood pumped by the right ventricle go
the lungs
where does the blood pumped by the left ventricle go
body tissues
why is the double circulatory system important
it makes the circulatory system more efficient, for example oxygenated blood can be pumped around the body at a higher pressure by the left ventricle
how many chambers does the heart have and what are they called
- right atrium, right ventricle, left atrium, left ventricle
why is the wall of the left ventricle thicker
the left ventricle has to pump blood at a higher pressure around the whole body
what are the four main blood vessels associated with the heart
pulmonary vein, pulmonary artery, aorta, vena cava
what is the role of the aorta and what side of the heart is it on
left, carries oxygenated blood from the heart to the body
what is the role of the pulmonary vein and what side of the heart is it on
left, carries oxygenated blood from the lungs to the heart
what is the role of the vena cava and what side of the heart is it on
right, carries deoxygenated blood from the body to the heart
what is the role of the pulmonary artery and what side of the heart is it on
right, carries deoxygenated blood from the heart to the lungs
what is the purpose of valves in the heart
to prevent the back flow of blood
what is the purpose of coronary arteries
supply the heart muscle with oxygenated blood
describe the process of blood flow through the heart
- blood enters the right atrium via the vena cava, and the left atrium via the pulmonary vein
- the atria contract, forcing blood into the ventricles and causing valves to shut
- after the ventricles contract, blood in the right ventricle enters the pulmonary artery (to the lungs) and blood in the left ventricle enters the aorta (to the body)
what is the approx value of natural resting heart rate
70 bpm
how can an abnormal heart rhythm be treated
using an artificial pacemaker, which sends out electrical signals to correct the heart’s rhythm
how is heart rate controlled
heart rate is controlled by a group of cells in the right atrium which act as a pacemaker, they release waves of electrical activity which cause the heart muscle to contract
what are the three types of blood vessel in the body
arteries, veins, capillaries
how are arteries adapted for their function
thick muscular walls to resist high pressure;
thick elastic layer, allows arteries to stretch and recoil to withstand high pressure
how are veins adapted for their function
wide lumen, enables low pressure;
valves, prevent backflow of blood
how are capillaries adapted for their function
function: enable transfer of substances between the blood and tissues
1. walls are one cell thick, meaning short diffusion path
2. permeable walls, substances can diffuse across
3. narrow lumen, blood moves slowly, meaning more time for diffusion
how would you calculate the rate of blood flow
volume of blood / number of minutes
where are the lungs found in the body
in the thorax, protected by the ribcage and separated from the rest of the abdomen by the diaphragm
what 6 tissues and organs make up the gas exchange system
- trachea
- intercostal muscles
- bronchi
- bronchioles
- alveoli
- diaphragm
explain how the lungs are ventilated by the action of intercostal muscles
intercostal muscles contract,
ribcage moves upwards and outwards,
diaphragm flattens and volume of the chest increases,
increased volume results in decreased pressure,
air is drawn into lungs down pressure gradient.
(the inverse happens when air moves out of the lungs)
describe how gas exchange occurs at the alveoli
oxygen diffused from the alveoli into the capillary bloodstream down its concentration gradient;
carbon dioxide diffuses from the capillary into the alveoli down its concentration gradient
describe how alveoli are adapted for gas exchange
- small and arranged in clusters (large surface area)
- rich blood supply (maintains concentration gradient)
- thin alveolar wall (short diffusion pathway)
how would you calculate breathing rate
number of breaths / number of minutes
what substance carries the different components of blood around the body
plasma
what 6 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 different substances e.g rbc/wbc around the body
what is the purpose of red blood cells in the blood
to transport 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)
contains 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 (fights infections)
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
to clot the blood
why is the function of platelets important
prevents excessive bleeding,
scab formation after the clot has dried prevents bacteria from entering the wound
what is coronary heart disease
the build of fatty materials in the coronary arteries stopping the blood flow, which restricts the supply of oxygen to the heart, which can lead to heart failure/stroke/death.
what is a stent and how does it work
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 advantages of using stens
lowers the risk of heart attack, quick recovery time, insertion can be carried out without general anaesthetic
what are the disadvantages of using stens
risk of infection post-operative, risk of blood clots at site of stent
what are statins
drugs which reduce the level of LDL (bad) cholesterol which contributed to the development of CHD.
what are the advantages of using statins
reduces risk of strokes, CHD and heart attacks, increased levels of HDL (good) cholesterol
what are the disadvantages of using statins
has to be taken continuously, may have side effects, effects may not be immediate
what is a heart bypass surgery
a surgery where blocked coronary arteries are replaced with sections of veins 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 types of valves can replace leaky valves
mechanical- made of metal or polymers
biological- taken from animals (pigs or sometimes humans)
what are the advantages of advantages of mechanical valves
lasts for a very long time
what are the disadvantages of advantages of mechanical valves
need to take medication to prevent clotting around valve
what are the advantages of advantages of biological valves
works very well- no medication required
what are the disadvantages of advantages of biological valves
only lasts 12-15 years
what is the purpose of an artificial heart
intends to support a patient’s heart while they wait for a suitable donor’s heart
what are the advantages of advantages of artificial hearts
less likely to be rejected by immune system
allows damaged heart to rest to help recovery
what are the disadvantages of advantages of artificial hearts
risk of infection due to surgery
risk of blood clots
have to take blood-thinning drugs
what is health
the complete state of mental and physical well-being
what is a communicable disease
a disease caused by a pathogen which can be transmitted from one person to another e.g flu
what is a non-communicable disease
a disease which cannot be transmitted from one person to another e.g cancer
how can diet affect health
too little food/ lack of nutrients - 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, cancer 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 e.g hepatitis infections can lead to liver cancer;
a compromised immune system (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
an aspect of a person’s lifestyle or 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 biologically influences another
how does diet 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
how does smoking affect the development of cardiovascular disease
nicotine increases heart rate; other chemicals damage the artery lining and increase blood pressure
how does exercise affect the development of cardiovascular disease
lowers blood pressure, reducing strain on the heart
how does obesity affect the development of type 2 diabetes
obesity is a major risk factor for developing type 2 diabetes because it can lead to insulin resistance. The more body fat a person has, especially around the abdomen, the more likely their cells are to become resistant 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/cancer
tar in tobacco can damage the alveoli of the lungs, leading to chronic obstructive pulmonary disease ;
tar also damages the cells which line the lungs, leading to lung cancer
how does 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 / stillbirth;
alcohol passes across the placenta and damages the developing foetus. once born, the baby may have a umber of deformities and health problems as a part of foetal alcohol syndrome
how do carcinogens affect the development of cancer
ionising radiation is a type of carcinogen which can cause mutations in DNA, potentially leading to cancer
what is cancer
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
smoking,
genetics (increase risk or breast/ovarian caner),
obesity,
ionising radiation (UV light /X-rays),
viral infections (HPV/ cervical cancer)
