topic 2 - organisation Flashcards
what is a tissue? (bio)
a tissue is a group of similar cells that work together to carry out a particular function
what is a organ?
an organ is a group of different tissues that work together to perform a certain funtion
what is an organ system?
an organ system is a group of organs working to perform a particulate function
heart and lungs pumping oxygenated blood
what do glands do?
glands makes and puts out hormones that do a specific job in your body
the digestive system
the stomach - where food is digested
the liver - produces bile
the small intestine - where food is digested and soluble food molecules are absorbed
the large intestine - where water is absorbed
lungs.
the lungs are in the thorax, that’s the top part of the body. the diaphragm separates the thorax and the abdomen. the lungs are protected by the rib cage.
the air u breathe goes into the trachea then splits into two tubes called bronchi, which splits into smaller tubes called bronchioles which go into alveoli
what is alveoli
alveoli is where gas exchange happens. there are millions of these tiny sacs in the lungs
the circulatory system
heart to lungs
lungs to heart
heart to body
body to heart
blood flow through the heart
vena cava into right atrium right atrium into pulmonary artery pulmonary artery into lungs lungs into pulmonary vein pulmonary vein into left atrium left atrium into left ventricle left ventricle into aorta
arteries
blood vessels which carry blood away from heart. Carries blood at high pressure. artery walls are strong and elastic. has a small lumen
capillaries
arteries branch into capillaries. they are one cell thick to allow diffusion to happen more easily.
veins
capillaries join up to form veins. they carry blood to the heart. low pressure. has a large lumen. also has valves which stop back flow
structure of leaf structure
epidermal tissue - covers the whole plant
palisade mesophyll tissue - where most photosynthesis happens
spongy mesophyll tissue - has spaces which allow gases to diffuse in and out of the cells
meristem tissue - found at tips of shoots and roots, is able to differentiate changes in environment
phloem
made of elongated living cells with small pores in end walls to allow cell sap to flow through. transport goes in both directions - this is called translocation
xylem
made of dead cells joined end to end. strengthened by lignin. carries water and moves in one direction - roots to leaves. this is called the transpiration stream
what can transpiration be effected by?
light intensity
temp
air flow
humidity
guard cells
they surround stoma. kidney shape. when the plant has water, they go plump and turgid which opens them up for gas exchange.
when the plant doesn’t have enough water the cells go flaccid which allow them to close in order to stop water vapour escaping.
health
health is the state of physical and mental well being
communicable disease
diseases which spread from person to person. they can be caused by bacteria, viruses, parasites and fungi.
non- communicable disease
diseases which cannot spread between people and animals. cancer is an example
cardiovascular disease
used to describe diseases to the heart. a common one is coronary heart disease.
statins
drugs which reduce cholesterol present in bloodstream, LDL cholesterol - low density. however it’s a long term drug and someone can easily forget to take it and there are side effects such as headaches, kidney failure, liver damage, and memory loss.
artificial hearts
used if there are no donors available. not usually a permanent fix.
enzymes
a biological catalyst - increases the speed of a reaction, without being changed or used up in the reaction
