Common Systems Flashcards
What does haemoglobin do
In red blood cells and makes them red, when it goes into the lungs it reacts with oxygen to make oxyhemoglobin and when it gets to where oxygen is needed it reacts back to oxygen and haemoglobin to the oxygen can diffuse out.
What is blood made of and functions
55% plasma, carries dissolved substances ,C02, food substances and hormones.
White blood cells <1%, used in immune system, make antibodies that fight foreign cells and kill diseases.
Red blood cells 45%, carries 02 around body, disk shape for higher surface area so higher surface area to volume ratio meaning more space for diffusion and no nucleus for more space to have more 02
Where and what is bile
Something that is used to break down large bits of fat into smaller pieces that the lipase then beak down into smaller soluble substances. Also used to neutralise substances leaving the stomach and going into the small intestine for the so enzymes can work. Made in liver and stored in gall bladder where it is released Into the small intestine when it’s needed
What is the pentadactyl limb structure
A 5 fingered structure that is common in many animals such as Humans, whales and horses suggesting we had a common ancestor and have evolved into separate species. Consists of humerus, radius and ulna, carpals and phalanges.
What is a fossil
The remains of organisms that lived thousands or millions of years ago
Why are fossils useful
They help scientists discover organisms that once lived in the past and they can use them for evidence such as backing evolution
What the processes are in growth
When a cell splits into two and when those two grow bigger
What does differentiate mean
When a cell changes and become specialised for a specific purpose
What are and where are meristem
This area is found in the tips of plants. It is an area where the cells keep dividing and elongate for growth
What are special about cells in meristem
After they have grown and become older, they can differentiate into any plant cell
Similarities and differences in growth in plants and animals
Similarities
Both grow through cell division
Difference
Animals stop growing, plants always grow
Adult stem cells can only differentiate into certain cells, meristem cells can become anything
Why is haemoglobin so important
Without it in red blood cells, there won’t be anything for the oxygen to react with so it won’t enter the blood meaning nothing will work as there is no oxygen int he body
What is an organ
Something with a group of specialised tissue used to carry out a specific function
What is the cycle of blood
Goes from tissues as de oxygenated blood, into heart which pumps it into the lungs
Become oxygenated blood and goes back to the heart
Pumps it around the body to tissue
Cycle starts again
What is the superior and inferior vena cava and what do they do
Superior vena cava brings blood from upper body to the heart
Inférieur vena cava brings blood from lower body to the heart
What is the septum
A piece of muscle separating the halfs of the heart
Why are there valves in the heart
To stop backwards blood flow
What happens to blood in the right side of the eart
Deoxygenated blood is taken into the right atrium by one of the vena cava
When the atrium is full, it contracts, pushing the blood into the right ventricle
When this is full, it contracts and pushes the blood into the pulmonary artery
This carries on into the lungs where it become oxygenated
What happens to blood in the left side of the heart
Blood goes from the lungs into the pulmonary vein which takes it into the left atrium
When the atrium is full, it contracts and forces the blood into the left ventricle
When the ventricle is full, it pushes blood into the aorta which is a large blood vessel which carries the blood around the body.
Why is the muscle in the left of the heart thicker than the right
Because the right only has to push blood into the lungs but the left side has to push it around the whole body
What are blood vessels
Tubes in the body that carry blood around the body
What are the 3 types of blood vessels
Veins
Arteries
Capillaries
What are veins and features
They carry de oxygenated blood (apart from pulmonary vein) to the heart. They are wide and have thin walls as the blood flows slowly as there isn’t much pressure
What are arteries and features
Apart from the pulmonary artery, they carry oxygenated blood away from the heart to the tissues. They have thick walls as they need to be under high pressure for the blood to reach every part of the body
What are capillaries and feature
They are small, single cell walled blood vessels that allow substances such as oxygen to diffuse from the blood and into tissue. They connect arteries to veins
What are the parts of the alimentary canal and what do they do
Mouth - takes in food, chews it into a bolus, amalease break down starch into sugars
Oesophagus - peristalsis pushes the bonus to the stomach in a wave
Stomach - acid and enzymes digest the food, peristalsis churns it into a thick paste. Mostly protein digestion
Pancreas - makes and releases the digestive enzymes
Small intestine - enzymes break large insoluble molecules into smaller soluble ones, these are absorbed into the blood by villi
Gall bladder - bile is made and then stored in the liver
Large intestine - rest of the undigested food passes through this to the anus, water is réabsorbes leaving just poo
Liver - once molecules in small intestine have been absorbed by the blood, the blood is processed by the liver, some molecules are made smaller, some made larger, bile is also sometimes used on fats
Anus - where poo leaves the body
What are the three main types of food molecules
Carbohydrates
Proteins
Fats
What enzyme breaks up starch and what into and where are they found
Carbohydrases such as amylase which breaks them down into simple sugars such as glucose which can be absorbed. It is present in saliva and in the pancreas and small intestine
What enzymes break down proteins, what into and where are they
Proteases, trypsin and pepsin. Pepsin is in the stomach and works best in low pH and trypsin is in the small intestine and works best at high pH. They break proteins down into amino acids which can be absorbed into the body to make new proteins
What acids break down fats, where are they, what they do
Lipases break down fats into fatty acids and glycerol
What is bile for and why is it important
2 uses
Used to physically break down large globules of fats and oils into smaller ones. It emulsifiers the fat. This is important as it increases the surface area, making it easy for the lipases.
It is also alkaline and is released into the small intestine, this neutralises the acidic matter from the stomach making it more alkali and suitable for enzymes such as trypsin
How does digested food enter the blood
It diffusés into the blood thorough villi
Why are villi finger shaped
To give them a large surface area for more efficient absorption of digested food. If the small intestine was smooth, like in coeliac disease, not much absorbtion would happen and you would become very thin
Why do villi need a good capillary network
So the blood in the villi always has a lower concentration of food molecules than in the small intestine as it is always being moved away, this creates a steep concentration gradient so diffusion happens fast.
What are probiotics
Friendly bacteria that are beneficial to you
What are plant stenol esters
Oily substances found in plants. They stop the intestines absorbing choloestrol which can help reduce risk of heart problems
What are prebiotics
Substances our body can’t digest but they act as food fro probiotics and encourage there growth. They are ingested in tablets and are shown to have health benefits.
