B3 Flashcards
(72 cards)
what are epithelial cells
they line any surface that is in contact with the external environment and line the surface of internal organs eg. the lungs
what are the two types of epithelial tissue that line the lungs?
squamous epithelium and columnar epithelium
explain what columnar epithelium cells are
cilliateed columnar epithelium cells line the upper airway (trachea and bronchi),
they have a lot of mitochondria
the cilia move mucus away from the lungs which prevent any inhaled particles causing infection.
what do goblet cells produce?
they produce / release sticky mucus onto the surface of the epithelium which acts as an lubricant
what does the mucus layer do?
it helps to trap any unwanted particles that are present in the air that you breathe
what are cilia
they are tiny hairs on the outer surface of epithelial cells, they waft back and fourth to move surface mucus out of lungs
squamous epithelium cells
they are very flat and thin with egg-shaped nuclei, often one cell thick
what is chronic obstructive pulmonary disease (COPD)
it includes multiple conditions and is more common in smokers as substances in smoke damages the lungs.
what does cigarette smoke cause?
it causes cilia columnar epithelium to slow and stop beating and eventually die so mucus builds up, which clogs the arteries and which causes more coughing that ruptures the thin alveolar epithelial cells and destroys them, this reduces the area for gas exchange and provides a good environment for pathogens to grow
why do ciliated columnar cells contain many mitochondria ?
they have cilia that move particles or mucus eg. in the lungs they move inhaled particles out of the lungs. in order to keep moving, the cilia need a lot of energy, which is provided by respiration, which occurs in the mitochondria
what are blood cells line with
epithelial tissue
what is meant by the term tissue
a group of similar or specialised cells carrying out a specific function
state the type of epithelial tissue found in both alveolar and endothelial tissue
squamous
when do blood clots form?
when there is damage to tissue, if there is a damage to an artery and a clot forms it can result in health-related problems.
what are blood vessels lined with?
endothelial tissue
what is endothelial tissue made up of
it is made up of a single layer of flat, long cells, which are orientated lengthways in the direction of blood flow. their function is to provide a smooth covering surfacec so blood can flow easily over them
arteries
Carry blood away from the heart to tissues of the body
They have thick muscular walls to carry blood at high speed
carry blood at high pressure
do not contain valves
veins
Carry blood from the tissues of the body into the heart
carry blood at lower pressure than the blood in arteries.
thinner walls than arteries
have valves to prevent backflow
capillaries
Capillaries have thin walls which allow them to effectively perform their function of allowing substances to easily and quickly diffuse or pass throuhg them.
they are much thinner than arteries and veins, as their walls are made up of only a single layer of endothelial cells, the flat cells that line all blood vessels.
are arteries made up of the same tissue?
yes but in different proportions
they both have an outer layer of connective and elastic tissue, but is thicker in veins to prevent collapse of the vessel.
their middle layer is made of smooth muscles, connective and elastic tissue, but is thicker in arteries to maintain bp.
the inner layer is mad of endothelial tissue
capillaries only have an endothelium
what is atherosclerosis
it is the disease process that leads to coronary heart disease and strokes
fatty deposits can either block an artery or increase its chance of being blocked by a blood clot.
how can endothelial tissue lining of artery become damaged?
smoking and high blood pressure
artieries become narrow and the loss of elasticity restricts blood flow whcih increases blood pressure
what does cigarette smoke contain?
it contains many toxic chemicals, which can lead to atherosclerosis, the thickness of the blood increases which causes fatty deposits to build up on the walls of arteries and increases the risk of clotting.
smoking also increases blood pressure and heart rate, which causes damage to the endothelium.
describe endothelial tissue and explain how it is adapted to its function
endothelial tissue is made up of a single layer of long, flat cells, oreintated lengthways to the direction of blood flow. as they are flat, the surface is smooth which allows blood to flow more easil.
the diffusion distance is small, so substances can diffuse easily in and out of blood vessels into the surrounding tissue.