Human Health and Physiology Flashcards
What do carbohydrates do?
Used in respiration to convert glucose to energy
Surplus sugar converted to glycogen and stored in cells
Name the different carbohydrates
Sucrose, glucose fructose lactose starch
What do proteins do?
-meat and fish
Repair body cells, growth if cells and human protein such as haemoglobin enzymes and antibodies
What does fibre do?
Not digested helps constipation and absorbs poison
What does water do?
Hydration, medium for chemical reactions, transporting substances, cooling body down and removing excretory substances
Where is vitamin A found and what does it do?
-fat soluble, cheese, egg, oily fish and liver
Skin, immune system and vision in dim light
What does vitamin D do and where is it found?
-fat soluble, oily fish, milk and eggs
Absorb calcium which helps strengthen teeth and bones
Where is Vitamin C found and what does it do?
-Water soluble, oranges kiwi fruit peppers broccoli and Brussel sprouts
Immune system, wound healing, iron absorption and maintains connective tissue
If you have too little of vitamin A what happens?
Poor vision, weak immune system, poor growth
If you have too much vitamin A what happens?
It is stored in the liver and becomes toxic
If you have too little vitamin C what happens?
Poor iron absorption leads too anaemia
Poor wound healing, Bleeding gums, Weakened immune system, poor connective tissue this leads to scurvy
If you have too little vitamin D what happens?
Poor calcium absorption leads to softer bones and therefore rickets
What happens when you have too little calcium?
Softer bones and teeth and poor blood clotting
What happens when you have too little iron?
Less haemoglobin, less oxygen carried round to cells therefore less respiration and less energy released which leads too anaemia
Where is calcium found and what does it do?
-milk, cheese, cabbage, broccoli, soya beans
Muscle contraction, blood clotting and strengthen teeth and bones
Where is iron found and what does it do?
-liver, meat, beans, nuts and dried apricot
Makes haemoglobin and does cell reactions
Where is sodium chloride found and what does it do?
-salt
Maintains the fluid balance in the body
What is diffusion?
The net movement of particles from a high concentration to a low concentration
What is osmosis?
The net movement of water molecules from a high concentration to a low concentration across a partially permeable membrane
What happens to cells if they are put in pure water?
They would burst as they are continually diffusing
What happens to cells if they are put in salty water?
The cells would shrink as all the water would diffuse out of them
What does a ribosome do?
Produce proteins such as haemoglobin, enzymes and antibodies
What does the mitochondria do?
Release energy in aerobic respiration
What causes an enzyme to become denatured?
It changes shape so the active site is lost
What is a person who studies cells called?
Cytologist
Whats an advantage of storing glucose in an insoluble form?
Glycogen will not draw water into the cell during osmosis and will not diffuse out of the cell because it insoluble
How is energy measured?
Energy content (J/g) = volume of water x temperature rise x 4.2J / weight of food (g)
What is the Benedict test?
Shows how much sugar is in a substance
- Put substances being tested into a boiling tube
- Add Benedict solution
- Heat in water bath for 5-10 minutes
- If it goes from blue ti murky green to yellow/orange/red this shows the presence of simple sugar
What is the biuret test?
Test for protein
1. Add biuret solution into the boiling tube to a substance
2. If it goes from blue to mauve it shows the presence of protein
( not instantaneous)
How do you test for vitamin C?
- Put vitamin solution to a test tube
- Add DCPIP drop by drop to vitamin C solution
- Shake tube gently every time you add a drop
- Add DCPIP solution until the blue colour of final drop does disappear
What is the iodine test?
Its the test for starch
- Put substances into spotting tile
- Add a few drops of iodine
- Colour changes from orange to blue to black
Why are omega 3 and 6 and fatty acids in our diet?
They prevent heart disease
What happens before digestion?
Large pieces of food must be broken down into tiny particles this increases surface area
Where is fat broken down?
Its broken down physically into droplets by bile in the small intestine
What enzymes digest carbohydrates?
Carbohydrases
What enzyme digest proteins?
Protease
What enzymes digest fats?
Lipase
What do proteins get broken down into?
Amino acids
What does starch get broken down into?
Glucose molecules
What do lipids get broken down into?
Fatty acids and glycerol
Name the types of teeth?
Incisors
Pre-molars
Canines
Molars
Name the parts of the tooth?
Pulp cavity Enamel Dentine Cement Nerve endings Blood vessels and nerves
Name the properties of the enamel?
Very hard
Can dissolve in acid
Too much erosion and the dentine could be damages eventually exposing the pulp then the tooth aches are stimulated because of the nerve endings being exposed
What is saliva?
An alkaline liquid produced in the salivary glands
- it helps neutralise acids in the mouth
- dissolves soluble food without it the food would be hard to swallow
- contains amylase which starts the digestion of starch
How do you reduce the effect if acid?
- don’t eat acidic food such as cola
- drink water with acidic food ti wash away sugar and acid
- clean teeth before meals to remove bacteria - bacteria digest sugar in the food and produce acid
- brush teeth afterwards to remove food particles
How do you swallow?
Reflex action - occurs when tounge pushes the food to the back of your mouth
Epiglottis - tiny flap which covers the wind pipe as you swallow
Oesophagus - slimy mucus in saliva helps food slip down the throat
What is peristalsis?
A series of wave like muscle contractions that move food to different areas in the gut
How does the gut digest food?
- Salivary gland and pancreas and gut lining contain specialised cells which produce digestive enzymes
- the digestive juices containing enzymes pass into the gut where they are mixed with food
- to hell the mixing process the muscular walls of the gut contract and relax this is called peristalsis
- the squeezing action of peristalsis bring the enzymes in contact with the food molecules
- once mixed the conditions must be right for the enzymes to work
In the mouth, what is the name of the enzyme? Where is it produces and what does the enzyme do?
Amylase
Salivary gland
Starch to sugar
Likes alkaline conditions
In the stomach, what is the name of the enzyme? Where is it produced? And what does it do?
Protease
Cells in stomach lining
Turns protein to amino acids it also stores them
It prefers alkaline conditions
In the small intestine, what is the name of the enzyme? Where is it produced? What does the enzyme do?
Carbohydrases
- pancreas and cell lining of small intestine
- converts carbohydrates to simple sugars
Protease
- pancreas and cell lining of small introduced
- converts protein into amino acids
Lipase
- pancreas and cells in lining of small intestine
- fats are converted into fatty acids and glycerol
What does the stomach do?
Acts the bag to hold food so we don’t have to eat every half hour
Activates protease
Kills microbes swallowed with food
Cells are protected by a layer of mucus
What is bile?
- made in liver and stored in gall bladder
- enters small intestine through bile duct
- the alkaline salts neutralise stomach acids so that the enzymes from the pancreas can work effectively
What is emulsification?
Where bile breaks fat down into small droplets
How is the small intestine designed to absorb soluble food?
- covered in villi which increases surface area
- rich blood supply which produces a steep concentration gradient
- one cell thick wall so there is a short diffusion distance this increases the rate of diffusion
- lymph system
- microvilli these are folds in the cell surface membrane to increase the surface area of the intestine
What is assimilation?
The movement of food molecules into cells
What happens to food which cannot be stored?
Excess amino acids cannot be stored so they are carried to the liver and broken down this is called deamination and ammonia is produces the liver converts ammonia into urea which is excreted in the urine
What is cystic fibrosis?
- a disease which causes the body to produce a thick sticky mucus
- covers the surface of the villi preventing efficient absorption of nutrients
- block pancreatic duck so that digestives cannot reach the duodenum from the pancreas
What is coeliac disease?
- triggered by a protein called gluten
- gluten causes the immune system ti attack the villi
- reduces the surface area of the villi available for absorbing food
Why is blood important to the human body?
Carries around important substances that need to go to our cells and they carry away waste substances
What are the three blood cells?
Red blood cells
White blood cells
Platelets
What kind of red blood cell produces antibodies?
Lymphocytes
What kind of red blood cells engulf pathogens?
Phagocytes
What happens when the blood vessels break?
Platelets release enzymes which set of a chain of reactions
Final reaction involves a soluble blood protein called fibrinogen which is changed in to fibrin by an enzyme
This traps blood cells forming a clot
What does the national blood service do?
Collects, screens, processors, delivers blood to hospitals for surgery and other medical treatments
What happens of the wrong blood group is given?
The red blood cells clump together which can be fatal
What are blood groups determined by?
They are determined by the antigens found on the surface of the cell membrane so when foreign blood cells enter the body the antibodies from the white blood cells attack the foreign red blood cells
Why is O a universal donor?
Because it has no antigens on the surface on their cell membrane
Why do burns victims dehydrate rapidly?
The skin is damaged so the water evaporates quickly from the damaged skin cells so plasma transfusion given to maintain body fluid balance
What happens when there is a lack of haemoglobin?
Is causes anaemia if there is a lack of haemoglobin therefore less o2 carried around to cells so less aerobic respiration so less energy so more tired
What do valves do?
They open to let blood through and close to stop back flow
When is blood pressure at its highest?
When it comes out of its heart
- larger arteries help maintain the pressure by stretching then the blood branches in smaller blood vessels called arterioles then the blood pressure decreases when until it reaches blood pressure then it slows. In the capillaries the blood pressure is slower so soluble molecules can get out
What is angina?
Chest pains caused by blockages in the arteries
What causes a stroke?
When there is a blood clot goes in the brain so oxygen doesn’t get to the brain thus causing brain damage
What is the name of the person who records heart pulsing?
Cardiac physiologist
What is the resting heart rate controlled by?
A group of cells in the right atrium called the pace maker
How does a electric pace maker work?
Generates electrical pulse which stimulates the heat to beat regularly, it fits under the skin in the chest and is attached to the heart by 1 or 2 wires
Who did the first transplant?
Christiaan Bernard in 1967
- survived for 18 days before eventually dying of a lung infection
How does a heart work outside the body?
- attached to a heart-lung machine
- machine has a pump and a oxygenation system in order to circulate blood to all body cells in an operation the blood must be kept warm and free from contamination
How does a organ care system work?
- Donor heart is placed in a sterile chamber which keeps the organ at body temperature
- Blood from the heart donor is oxygenated and combined with nutrients and pumped into the heart through the aorta which keeps it beating
- Blood flows through heart leaving pulmonary artery
What happens when you breath in?
Intercostal muscles contract pulling up the ribcage and the diaphragm contracts and flattens this increases the volume of the thorax and decreases the internal pressure so air is drawn in
What happens when air is inhaled?
It is cleaned and warmed
- in the nose large particles are filtered out by hair and mucus
- tiny particles and bacteria are trapped by mucus lining of air tubes
What are cilia?
Tiny hair on the surface of air tubes
- these beat to move mucus up the throat to be coughed or swallowed
What does cigarette smoke do to cilia?
Destroys cilia, so the mucus accumulates in the lungs therefore the smoker has to cough to remove it
How is the alveoli efficient in gas exchange?
Good blood supply to maintain concentration gradient
Thin walls to increase rate of diffusion
Spherical shape gives a large surface area for diffusion
What happens if there is too much carbon dioxide in the blood?
The blood is slighly acidic as carbon dioxide is acidic, this is detected by pH receptors which signal the brain to increase the breathing rate, when pH rises the breathing rate will slow down
How does an artificial lung work?
- Patient is connected to the device and there blood will pass through it
- The blood will be in close contact with a flow of air
- Gas exchange will occur in the device ( the device will be made of materials that do not cause the blood to clot )
- The oxygenated blood will then return to the patients blood stream
Where is breathing coordinated?
Respiratory centre in the brain
What is deamination?
Where waste proteins in the liver are broken down to form amino acids
