pathway test Flashcards
The three parts of the circulatory system are what?
The three parts of the circulatory system are the blood, the blood vessels, and the heart.
On each side of the heart, the atrium and ventricle are separated by what?
valve
which ventricle is the thickest and why?
The left ventricle has thicker walls because it has to pump blood all the way around the body.
Which blood vessel carries deoxygenated blood from the heart to the lungs?
The pulmonary artery
Which blood vessel carries oxygenated blood from the heart to the body?
aorta
Pacemaker cells are found in which chamber of the heart?
Right atrium
what do arteries always do?
(Blood)
They carry blood away from the heart
what does the coronary arteries supply the heart muscle?
The coronary arteries supply the heart muscle
with oxygen and nutrients.
what is the function of arteries ?
carries blood away from the heart
what is the function of veins ?
to carry blood from the body (or lungs) back to the heart.
what is the function of capillaries? (3)
exchange substances with cells (nutrients and oxygen)
take away waste products (CO2)
and they connect your arteries and veins
key facts about capillaries. (4)
- really small
- lower blood pressure (which gives the blood time to exchange things with the tissue)
- single cell thick
- permeable
key facts about veins (6)
- low pressure
- joined up with many tiny capillaries
- has valves
- has the biggest lumen
- has small layer of elastic fibres + smooth muscles (wall surrounding the lumen)
- one cell thick
how to calculate backflow
how much blood/time
key facts about arteries (4)
- high pressure because just pumped out from the ventricle.
- strong - thick layer of muscle tissue
- elastic - thick layer of elastic tissues
- narrow lumen - which keeps the blood pressure high.
why are capillary walls so thin?
allows easy exchange of oxygen, carbon dioxide, water, other nutrients and waste products to and from blood cells
What are the nutrients that are exchanged between the blood in the capillaries and the body tissues?
Amino acids
Glucose
Which substances are waste products that are exchanged between the blood in the capillaries, and the body tissues?
urea
carbon dioxide
Which substances are exchanged between the blood in the capillaries, and the body tissues?
Carbon dioxide
Glucose
Oxygen
Urea
In which order does blood flow through the three types of blood vessels?
Heart ➔ arteries ➔ capillaries ➔ veins ➔ heart
role of red blood cell?
to carry oxygen to our lungs so that our cells can use it in cellular respiration
permeable
Permeability is the ability of a material to allow the passage of molecules
partially permeable
meaning its selectively permeable, i.e. being permeable to only certain molecules and not to all molecules.
what make the red blood cells red?
haemoglobin
what does haemoglobin do?
combines oxygen to become oxyhaemoglobin.
once the O2 finished travelling then the oxyhaemoglobin can split back into just haemoglobin and oxygen again so they are free to diffuse into our tissues
red blood cell adaption
- has no nucleus - means more space for haemoglobin and oxygen
- shaped like a biconcave disk - LSA for absorbing oxygen.
ways white blood cell defend us from the pathogens (3)
- phagocytosis - engulfs or consume the pathogen (microorganism)
- produce antibodies - bind onto pathogen + help destroy them
- antitoxins- neutralises any toxins that the pathogens produce
key points of platelets(3)
- small fragments of cell
- no nucleus
- float about in the blood
platelets function
wait in blood until you get a cut.
they rush to the wound and act like a glue to patch up the hole
this is called ‘clotting’
what does platelets prevent
- decrease loss of blood
- stops microorganisms in as it can cause an infection
what do plasma carry 8+
- all other blood cell.
Nutrients: glucose, amino acids, fatty acids, and glycerol
Waste products: carbon dioxide and urea
Other substances: hormones, antibodies
What is the role of blood plasma?
To carry substances and cells around the body
what is coronary heart disease
- coronary arteries which supply blood to heart muscles start to get blocked by the build up of fatty material
this causes the lumen to become narrower
so less blood can flow through
meaning less oxygen reaches the heart muscle
and as the heart needs lots of O2 it causes strain to the heart which becomes a heart attack.
coronary heart disease treatment
- stents - expandable tube that we can place inside the arteries to hold them open which ensures the blood can keep flowing
- statin is a medicine
- alters the balance of cholesterol (LDL and HDL)
advantaged and disadvantages of using a stent to heal coronary heart disease
- quick surgeries
- effective for a long time
-require surgery that always has risk (heart attack or infection)
- small risk of the patient later developing a blood clot near the stent (thrombosis)
advantaged and disadvantages of using a statin to heal coronary heart disease
- reduces risk of not only coronary heart disease but also diseases like stroke and heart attack
- has to be taken regularly for years.
- can cause side effects like headache and kidney failure
what if the valve gets damaged or weakened ?
replace it with a biological or mechanical valve
- require surgery (risk of blood clot)
name three things that make up the
cardiovascular system
heart
blood
blood vessels
Which chemical process supplies the majority of the energy required for the contraction of muscle tissue?
Aerobic respiration
What are two problems that may be caused by faulty heart valves?
Not enough blood can pass though the valve
Blood can pass backwards through the valve
The drug digitalis originated from plants known as _________. It is used to treat heart conditions such as heart failure.
foxgloves
Stages of drug development (4)
Stage 1 - Test the drug on human cells and tissues.
Stage 2 - Test the drug on live animals.
Stage 3a - Test the drug on healthy volunteers to find the maximum dosage before side effects occur.
Stage 3b - Test the drug on patients that suffer from the relevant disease, to find the optimum dosage.
Why is it important that new medicinal drugs undergo testing before they are used?
To make sure they are an effective treatment
To determine the optimum dose
To make sure they are safe to use
In a double blind trial, who knows who is given the trial drug, and who is given the placebo?
Only the researcher
Patients in clinical trials are often given a placebo.
What is a placebo?
A substance or treatment that contains no active drug
Medical trials often use placebos, and are double-blind.
Why is it important for medical trials to be double-blind?
To avoid any bias by the patients and/or researchers
If patients know they received the drug they may be more likely to report side effects
If researchers know who has been given the real drug then they may pay closer attention to those patients
what definition of osmosis do we need to know?
Osmosis is the net movement of water molecules across a partially permeable membrane from a region of higher water concentration to a region of lower water concentration
In living organisms, the partially permeable membrane is usually the ___________
Cell membrane
What would happen to red blood cells if they were placed in pure water?
They would gain water and swell
A microscope is designed to…
A microscope is designed to…
…magnify small objects so that they appear larger.
What is the definition of magnification?
how many times larger the image is than the object?
What is the pathway of light through a microscope?
Light source ➔ stage ➔ microscope slide ➔ object ➔ objective lens ➔ body tube ➔ eyepiece lens ➔ eye
what are the 2 microscopes?
light microscope
electron microscopes
disadvantages of light microscope (2)
- not good enough to study subcellular structure
- any details less that 0.2um will appear blurry
advantages of light microscope (3)
easy to use
relatively cheap
colour
disadvantages of electron microscope
very expensive
hard to use
no colour
advantages of electron microscope
higher magnification and resolution
order the units of conversion - low to high and name the things
(3)(3)(2)(1)(1)
nanometre
- glucose(0.1 - 0.5)
- glucose (1)
- virus (100)
micrometre
- bacteria, animal and plant cell (10-100)
- hair (100)
millimetre
- insects
- objects (mostly cm)
metre
- planes
kilometre
- mountain
how to work out the image size
Image size = object size x magnification
what is the definition of an endothermic reaction?
these are reactions that take energy from the surrounding to take place
- e.g. LIGHT FROM SUN
In what part of the cell does photosynthesis take place?
In chloroplasts
What is the word equation for photosynthesis?
Carbon dioxide + water ➔ glucose + oxygen
What is the chemical symbol equation for photosynthesis?
6CO2 + 6H2O ➔ C6H12O6 + 6O2
Which type of reaction is photosynthesis?
Photosynthesis is an endothermic process because it requires energy (from the sun).
What can the glucose make during photosynthesis be used for?
- Stored as starch for later
- Respiration
How do plants get the carbon dioxide required for photosynthesis?
It diffuses from the air into the leaves via stomata
How do plants get the water required for photosynthesis?
It diffuses from the soil into the root hair cells by osmosis
What makes starch a useful long term storage molecule?
- It can easily be broken down when needed
- It is insoluble in water
- It is compact
One use of glucose is to make amino acids.
What else do plants need to make amino acids?
Nitrate ions
What are the main uses of glucose in plants? (5)
Cellular respiration - break down the glucose to release energy
Make cellulose - which is used to make strong cell walls
Make starch - which is used to store glucose for a later time
Make amino acids - which are used to make proteins
Make lipids - these store the energy as fats or oils for later use
What useful energy transfer or conversion happens overall in photosynthesis?
Light ➔ chemical
Photosynthesis converts light energy from the sun into chemical energy in the chemical bonds of glucose molecules.
which cells are eukaryotic or prokaryotic
animal and plant - eukaryotic
bacteria - prokaryotic
