stuff i cant remeber Flashcards
mitosis definition
cell decision in eukaryotic cells, cell divides to produce two new identical copies
mitosis process
normal boy cell has 4 chromosomes, copy of each chromosome is made (8), chromosomes become shorter and spindles start to appear, chromosomes line up at centre of cell, spindles draw chromosome copies to opposite ends of cell, cytoplasm and cell wall starts to divide, 2 new cells form each with 4 a chromosomes called daughter cells
White blood cell, phagocyte
slightly bigger than RBC, has a lobed nucleus
white blood cell, lymphocyte
has a large nucleus
blood plasmid
straw coloured liquid
platelets
fragments invoked in clotting the blood
haemoglobin
consist of 4 polypeptide chains known as globins, attached to each chair is an iron-containing molecule know as haem
artery function
carry blood away from heart
artery structure
thick walls, small lumen, thick layer of muscles and elastic fibre
artery colour of blood
red, oxygenated
artery pressure
high
does the artery have valves?
no
vein function
to carry blood toward the heat
vein structure
relatively thin walls, large lumen, often have valves
colour of blood in veins
red/purple, deoxygenated
pressure in veins
low
cappillary function
connects arteries to veins in organs, exchange substances by diffusion
capillary structure
walls a single cell thick, tiny vessel with narrow lumen, very small
blood colour in capillary
changes from bright red to dark red
pressure in capillaries
low
are there valve sin capillaries?
no
the heart
made of cardiac muscle, pumps blood around the body, coronary arteries supply heart with oxygen and glucose for respiration releasing energy for contraction of heart
route of the blood
deoxygenated blood-vena cava, right atrium, tricuspid valve, right ventricle, semi-lunar valves, pulmonary artery.
oxygenated blood- pulmonary vein, left atrium, tricuspid valves, left ventricle, semi lunar valves, aortia
pacemaker
resting heart rate control by a group of cells in right atrium walls acting as pacemaker
artificial pacemakers correct irregularities I heart rate
CHD
fat try build up in coronary arteries narrow ing and reducing blood flow which can result in cardiac arrest or heart attack
CHD treatment
a ballon can be inserted with a stent which opens the blockage
faulty valves
valves can become faulty preventing it from opening fully or the heart valve might develop a leak, faulty valves can be replaced
advantages/disadvantages of mechanical valves
last a long time, but you have to take me medicine for rest of life
advantages/disadvantages of biological valves
patient does not need medication, only lasts around 15 years, maybe challenge religious beliefs
the cardiac cycle
heart beat begins when heart muscles Relaxand blood flows into the atria, atria contracts and valves open allowing blood into ventricles, ventricles contract causing blood to leave heart through arteries
cycle repeats int self
artificial heart advantages/disadvantages
keeps patient alive, no waiting for donor, can live relatively normL life till transplant, blood clots can form and drugs are needed to prevent, heavy and noisy
heart transplant advantages/disadvantages
permanent solution, can live normal life, need anti-reject meds, body may reject transplant, takes long time
statins
reduce blood cholesterol levels, slows down rate of fatty materials deposit, reduces risk of CHD
inhalation action and exhalation
diaphragm contracts and flatterns
intercostal muscles internal relax-external contact, volume of thoracic cavity increases, air pressure in thoracic cavity decreases, air is drawn into thoracic cavity
exhalation is opposite
how does temperature affect rate of digestion
as temperature increases, so does rate of digestion until optimum then drops off
xylem
cells- dead, made of lignin (strong)
direction of transpirt- up from roots to leaves
substance transported- water and mineral
phloem
cell- living, have sieve plates
direction of transport- from where made to rest of plant
substance transported- dissolved sugars
stomata
open and close controlled by guard cells, in the day it’s open for plant to photosynthesise (guard vells become turgid), in the night it’s closed as photosynthesis can’t take place so they lose water causing it to close
transpiration
loss of water through the stomata by evaporation ,stream is constant movement of water molecules
best of its warm, dry and windy
measured with photometer
