Human Tissues, Organs and Organ Systems Flashcards
Order these from smallest
to largest: organ, cell,
organism, tissue, organ
system
Cell, tissue, organ, organ
system, organism
What is tissue?
A group of specialised cells with
similar structure performing the
same function
What is an organ?
An aggregation of tissues that
perform a specific function; e.g.
the stomach is an organ made of
muscular tissue to churn the
contents, epithelial tissue to
cover the inside and outside of
the stomach and glandular tissue
to produce digestive enzymes
What is an organ
system?
A collection of organs that
perform a specific function
Name the components of
the digestive system
Salivary glands, oesophagus,
stomach, pancreas, liver, small
intestines, large intestines
What is the function of
saliva?
Lubricate food so it is easier to
swallow.
Contains amylase to start
digesting carbohydrates.
What is the oesophagus?
A 20cm long tube that connects
the mouth to the stomach.
What is the anus?
Opening at the end of the digestive system.
What is the function of
the stomach?
Releases protease. Ensures pH at 2-3 so
protease works at optimum.
What is the function of
the liver?
To produce bile which is then stored in
the gall bladder.
What is the function of
bile?
To emulsify fats – break up large fat
drops into small fat droplets. Bile is
alkaline so it also neutralises stomach
acid
What is the function of
the small intestines?
To absorb soluble foods into the blood
stream; this is where digestion occurs
What is the function of
the pancreas?
Produces carbohydrase, protease,
lipase.
What is the function of
the large intestines?
Absorb water and salts from the
undigested food producing faeces
What are villi?
Finger-like1cell-thick projections of the
lining of the small intestines to increase
the surface area for an increased rate of
diffusion/absorption of nutrients into the
blood stream. One cell thick to shorten
the diffusion distance. Good blood supply
to maintain diffusion gradient.
What is peristalsis?
Walls of the digestive system have rings
of muscles around them which contract
behind the bolus (ball of food) to push it along
What are carbohydrates
broken down into?
Glucose molecules
What are proteins broken
down into?
Polypeptides first which are
further broken down into amino
acids
What are lipids (fats) broken
down into?
Fatty acids and glycerol.
What is a substrate?
The molecule on which an enzyme acts.
What is the active site of an
enzyme?
The region of the enzyme that
binds to the substrate.
What is the lock and key
principle?
Enzymes are specific for each
substrate. The substrate fits
into the active site like a key
fits into a lock to help break
substrate bonds.
What happens to enzymes at
high temperatures/extreme
pH?
They denature. The shape of
the active site is permanently
distorted.
Why don’t enzymes work well
at very low temperatures?
Kinetic energy too low.
How do you test for starch?
Add iodine which will turn blue-
black if starch is present.
How do you test for glucose?
Add 10ml of Benedict’s
solution (blue) to 1ml of
sample. Warm. A red-brick
precipitate will form.
How do you test for proteins?
To 2ml of sample add 2ml of
Biuret solution. If a protein is
present the colour will change
to light lilac purple. If no
protein is present, the colour
will be cloudy blue.
How do you test for fats/lipids?
Half fill a test tube with water. Add 1 drop of sample. Shake the test tube. If a fat is present, an emulsion will form.
What is an artery?
A large blood vessel that carry
oxygenated blood away from
the heart.
What is a vein?
A large blood vessel that
returns deoxygenated blood to
the heart.
What is a capillary?
A blood vessel that joins
arteries and veins. Substances
pass through capillary walls to
and from the surrounding cells.
What does the right atrium do?
Receives blood from the body
What does the vena cava do?
Returns blood from the body.
What does the right ventricle
do?
Pumps blood from the heart to
the lungs.
What does the left ventricle
do?
Pumps blood from the heart to
the body.
What does the left atrium do?
Receives blood from the lungs.
What do the pulmonary veins
do?
Return oxygenated blood from
the lungs to the heart.
What is the job of the
pulmonary artery?
Carry deoxygenated blood
from the heart to the lungs.
What does the aorta do?
Carry oxygenated blood at high pressure from the heart to the body.
How many chambers does the
heart have?
4 – left atrium, right atrium, left
ventricle, right ventricle
Which chambers are the
ventricles?
The bottom ones.
How does the heart prevent
blood flowing back from the
ventricles into the atria?
Valves prevent the backflow of
blood.
Which has a thicker wall – a
ventricle or an atrium?
Ventricle
Which has a thicker wall, an
artery or a vein?
Artery. They carry blood at
high pressure.
Which contain valves, arteries
or veins?
Veins.
Which are wider, veins or arteries?
Veins
What are the three
components of blood?
White blood cells, red blood
cells, plasma.
What is haemoglobin?
The protein in red blood cells
that can temporarily bind with
oxygen to carry it around the body.
What is oxyhaemoglobin?
The substance formed when
oxygen binds to haemoglobin.
How are red blood cells
adapted to perform their
function?
No nucleus and biconcave to
increase SA to carry oxygen.
What are platelets?
Cell fragments. These join
together to make a scab and
release clotting factors which
turn fibrinogen into fibrin. This
then forms a mesh that traps
platelets to form a scab.
What is blood plasma?
A straw-coloured liquid in
which blood cells and platelets
are suspended in. Glucose,
carbon dioxide, amino acids,
urea all are dissolved in
plasma.
What are coronary arteries?
Arteries that supply the heart
muscle with oxygenated blood.
What is Atherosclerosis?
A medical condition resulting
from an unhealthy lifestyle that
reduces the flexibility of
arteries due to a build up of
fatty material in the coronary
arteries.
What is Cholesterol?
A biological molecule needed
for cell membranes which can
also lead to atherosclerosis if
found in high concentration in
blood.
What is a heart attack?
When there is a blockage in
the coronary arteries leading to
the death of some heart
muscle tissue.
What is a heart bypass?
A small section of artery is
moved from one part of the
body to short-circuit the
blockage in the coronary
artery.
What is a stent?
A small mesh that is inserted
into an artery to keep it open
and allow blood to flow
through.
How do you know you might
have a faulty valve?
You are breathless, feel tired,
feel dizzy and have chest pain.
What happens when you have
a faulty valve?
It is replaced using an artificial
or a donor valve.
What do doctors do when
someone suffers heart failure?
Heart or heart-lung transplant.
Use a pacemaker.
How do you prevent heart
problems?
Eat a balanced diet
Do regular exercise
Reduce stress
Seek help for mental and
physical difficulties.
What is the meaning of the
term malignant?
Malignant tumour cells are
cancers. They invade
neighbouring tissues
and spread to different parts of
the body in the blood where
they form
secondary tumours.
What is the meaning of the
term benign?
Benign tumours are growths of
abnormal cells which are
contained in
one area, usually within a
membrane. They do not invade
other parts of
the body.
What are the symptoms of
cancer?
A lump formed by the tumour.
Unexplained bleeding, a long-
term cough, a loss of weight
without dieting.
What are the causes of cancers?
Smoking, too much alcohol,
viruses (e.g. HPV), genetic
disorders inherited from
parents, ionising radiation,
environmental pollutants,
obesity, age.
What is a risk factor?
An aspect of your lifestyle or
substance in your body that
increases the risk of a disease
developing.
What does the word causation
mean?
The act of making something
happen. Some risk factors can
cause diseases.
What does the word
correlation mean?
When an action and outcome
are linked but the action does
not necessarily cause the
outcome.
What is a carcinogen?
A cancer-causing substance,
e.g. tar, asbestos, UV light, X-
rays.
What are alveoli?
Tiny air sacs found in the lungs
through which gases exchange
between blood and air.
What factors affect the rate of
diffusion?
-the difference in
concentrations (concentration
gradient)
-the temperature
-the surface area of the
membrane.
How do you increase the
exchange of material?
Have a larger surface area. Thin membrane for a short diffusion path. Efficient blood supply. Increased ventilation.
The larger the surface area :
volume ratio, the…..
Faster the exchange of
materials.
