Tissues

1. Squamous
   1. Structure

      Anmerkungen:

      • Squamous epithelial tissues are found in the capilaries and are flat single cells attached to a basement membrane. They do not give any protection but are vital in the role of diffusion, they are found in the alveolar sacs and the capillaries.
   2. Function

      Anmerkungen:

      • Squamous epithelial tissue allows the diffusion of substances ie in the alveolar sacks it allows the transfer of o2 and co2 to pass through for us to be able to breathe and secrete co2 from out system.
2. Cuboidal
   1. Structure

      Anmerkungen:

      • The structure of cuboidal epithelial tissue is also single layered cells on a basement membrane but is slightly thicker than squamous epithelium but again does not give much protection. It is cube shaped and can be found in the kidneys and glands.
   2. Function

      Anmerkungen:

      • The cuboidal epithelial tissue is also useful in diffusion of substances and hormones secreted from the glands ie, adrenalin, thyroxine.
3. Cilated Columnar
   1. Structure

      Anmerkungen:

      • Columnar and cilated columnar epithelial tissue is charecterised by little hair like structures in the top layer. these are called cilia. The cilated epithelium is found in the tissue lining the respiratory tract. So the lungs and also the digestive tract like stomach and small intestine. 
   2. Function

      Anmerkungen:

      • The goblet cells within secrete mucus to be able to trap dust and bacteria then the microvilli or cilia then move it along and then out of the body protecting us from sickness.

1. Structure

   Anmerkungen:

   • Stratisfied squamous epithelial tissue is flat cells the top layers being dead cells. They are arranged in many layers on a basal membrane which is cuboidal. Only one layer is in contact with the basement membrane the rest of the layers are stuck to each other. This is our skin.
2. Function

   Anmerkungen:

   • Keratinised epithelial tissue.. skin. protects our blood, bones and tissues inside our bodies. The top layer sheds creating household dust. Our skin also secretes sweat and is the largest organ in our body.

1. Structure

   Anmerkungen:

   • Two or more cell layers It also has a cuboidal under layer underneath, they create new cells that can be replaced regularly as the outer layer of non-keratinised skin is sloughed off through friction and has fewer layers of dead flat cells.
2. Function

   Anmerkungen:

   • Non-keratinised skin lines moist areas of the body like the mouth and oesophagus it doesn't shed like keratinised and loses its top layer through friction. The cells that line are thicker and are perfect for the mouth as they can withstand more abrasion. The main roll of this kind of tissue is to lubricate and for protection.

1. Structure

   Anmerkungen:

   • Smooth muscle cells are shaped like a rugby ball. When relaxed they are quite flat but when contracted they become fatter in shape. Smooth muscle can be found in the stomach. and oesophagus.
2. Function

   Anmerkungen:

   • Smooth muscle is not under our conscious control. They are contolled by the autonomic nervous system and when we eat they automatically contract and release to digest our food.

1. Structure

   Anmerkungen:

   • Cardiac muscle is located in the heart. The muscle is striated and is fist sized. It is myogenic which means it does not need nerves to beat continuously. It has many fibres and nuclei so it is able to send and receive messages from the brain quickly so it is able to continuously beat but the speed is determined by the hormones and homeostasis of the rest of the body.
2. Function

   Anmerkungen:

   • The function of the heart muscle is to pump oxygenated blood around the body giving life energy and oxygen to the body tissues, deoxygenated blood is bought back to the heart via the superior and inferior vena cava so the heart can pump it to the lungs to collect more oxygen completing the cycle.

1. Structure

   Anmerkungen:

   • Skeletal muscle is under control of the motor nerves. And needs nerves to trigger the contraction and release of the muscles to enable us to move. Skeletal muscle is long and striated (stripey) and fiberous. There are 600 muscles in the human body and located the full length and breadth of the entire body.
2. Function

   Anmerkungen:

   • The function of skeletal muscle is to receive messages from the somatic nervous system to enable us to move ie walking, lifting our arms and picking things up.

1. Structure

   Anmerkungen:

   • Is very similar to areolar but contains more fat cells. to stop over stretching of the skin. Found in the same places also.
2. Function

   Anmerkungen:

   • The extra fat cells serve to insulate, protect and store energy. there is a this layer that protects the heart. too much fat around the heart would be detrimental its a very fine balance.

1. Structure

   Anmerkungen:

   • Areolar is sticky and white and binds muscle fibres, blood vessels and nerves. its is stretchy and contains elastin and collagen.
2. Function

   Anmerkungen:

   • Areolar is what makes tissue stretchy, you would find it in the skin and in the muscles and it is what makes skin stretchy and flexible. 

1. Structure

   Anmerkungen:

   • Bones are found throughout the body and make up the skeletal system. Bones have a hard, dense outer layer and a soft spongey inside filled with bone marrow. It also has a strong blood supply and are filled with blood vessels that run through them.
2. Function

   Anmerkungen:

   • Bones are connected and are strong enough for us to be able to stand and walk with the help of muscles. Our bones also protect some of our most vital organs like the brain and lungs. The bone marrow inside the bones is vital in the production of red and white blood cells made from the stem cells within the marrow.

Anmerkungen:

• Cartilage is a strong flexible structure, it is a connective tissue and can be found all over the body ie the nose and the ears. Unlike bone cartilage does not have a blood supply that runs through it.

1. Structure

   Anmerkungen:

   • Cartilage is  bendy and flexible usually white or milky in  colour and can be found in many parts of the body ie nose, ears, knee and is a connective tissue with little or no blood supply.
2. Function

   Anmerkungen:

   • The function of cartilage is to provide strength and flexibility to parts of our body. 

1. Structure

   Anmerkungen:

   • Blood is made up of red blood cells and white blood cells, plasma and platelets. It is a thick fluid and the brightness of the red colour is determined by the amount of oxygen it is carrying. Blood is found throughout the entire body.
2. Function

   Anmerkungen:

   • Our blood acts as a transport system within our body. It carries o2 and co2 around the body to where it needs to be. It also transports medicines and hormones. 

1. Function

   Anmerkungen:

   • To send and receive messages from the central nervous system down to the peripheral nervous system and back creating a circuit of information for the entire body. 
2. Structure

   Anmerkungen:

   • The neurons are nerve cells and are larger than neuroglia and contain a nucleus, cytoplasm, cell membrane and nerve endings. They are the message system for the body from the central nervous system to the peripheral nervous system and back.

1. Function

   Anmerkungen:

   • The function of neuroglia is to support the role and function of the neurons so they are able to better fulfil their role. They also help to give sustenance to the neurons, ie oxygen and nutrients.
2. Structure

   Anmerkungen:

   • Neuroglia are the supporting cells that do not transmit nerve impulses. They support neurons in many ways though and are much smaller in size than neurons and are found dotted around neurons. They are found in the brain and spinal cord.