8. cells, tissues, organs and systems

Question 1

cells

Answer 1

cells are basic units of life, every organism in the planet is made of many cells.
inside cells there are an intricate network of different structures that all work together to allow the cell to function.

Question 2

what is a tissue?

Answer 2

groups of cells that are organised together to carry out a function.

c.lumnar cells lining the intestine they are specialised for absorption of nutrients.

the stomach is made of mucus membrane, muscle tissue and a layer of tissue covering the abdomen.

Question 3

what is an organ

Answer 3

organs are groups of tissues working together to preform the same function. e.g heart, liver, kidney, spleen etc

Question 4

what is a system

Answer 4

systems are a group of organs work together at a particular function.
-respiratory system
- digestive system
- endocrine system
- excretory system (kidney + lungs)
- nervous system
- lymphatic system
- skeletal/muscular system
- lategumentary system (skin, nails hair)
- cardiovascularq system

Question 5

mammalian nutrition overview

Answer 5

mammals require food as a source of energy and building materials.

Question 6

main food groups;

Answer 6

• carbohydrates (made of carbon, hydrogen , oxygen)
  (carbohydrates are build from monosaccharides - glucose)
• proteins (carbon, hydrogen, oxygen, nitrogen)
• fats (carbon, hydrogen, oxygen)
• vitamins and minerals

Question 7

food that are source of carbohydrates;

Answer 7

bread, pasta, potatoes
> carbohydrates required for fuel as a source of energy.

Question 8

sources of protein

Answer 8

> proteins are made from amino acids linked together by peptide
bonds.
meat and egg are good sources of protein, mainly used for growth and repair. Protein can be used as a source of energy (last resort).

Question 9

fats;

Answer 9

> fats are made of glycerol and fatty acids.
dairy products; butter/cheese are source of fat.
fats are rich in energy ~ provide twice as much energy per gram
as carbohydrates

Question 10

fats are essential for a number of functions;

Answer 10

• component of cell membrane
• some hormones (steroid hormones)
• fatty layers for insulation
• protection (fat pads)
• fat soluble vitamins

Question 11

vitamins and minerals;

Answer 11

• very small quantity of vitamins & minerals are required by the body, however there are essential for many functions.
• many enzyme reactions require vitamins and minerals
• if a shortage of a particular vitamin or enzyme occurs, it can cause detrimental change to body function.
• a lack of iron results in anaemia (lack of red blood cells)

Question 12

diseases associated with lack of minerals;

Answer 12

> vitamin A - poor eyesight
vitamin B - beri ben
vitamin B3 - pellagra
vitamin b12 - pernicious anaemia
vitamin E - poor reproductive health, muscle wasting
vitamin K - required for blood clotting
vitamin D - required to absorb calcium from the gut (if lack of vit D can lead to rickets)
vitamin C - can lead to scurvy (bleeding gums)

Question 13

the need for digestion;

Answer 13

the human gut (alimentary canal) runs from the mouth to the anus. the food we eat must be broken down into small soluble molecules so it can enter the body.

salts, monosaccharides & alcohol do not digest, they pass directly into the bloodstream.