Tissues

Annotations:

• Tissues are a collection of cells that work together in order to do certain things.

1. Epithelial
   1. Simple
      1. Squamous
         1. Structure

            Annotations:

            • Single layer of flat cells in contact with the basal lamina of the epithelium. Blood vessels are lined by simple squamous epithelium. This epithelium is permeable and is found where small molecules need to pass quickly through membranes.
         2. Function

            Annotations:

            • It lines the cavities and surfaces of blood vessels and organs throughout the body.
      2. Cuboidal
         1. Structure

            Annotations:

            • Can withstand more trauma than simple squamous epithelium. Found on the surface of ovaries, the walls of renal tubules and parts of the eye and thyroid.
         2. Function

            Annotations:

            • Allows substances to pass through by diffusion, e.g. water in the kidney tubules. It also specializes in secreting substances, e.g. medicines in the kidney tubules.
      3. Ciliated columnar
         1. Structure

            Annotations:

            • Thin tissue with hair like structures on it. It can be found in our respiratory tract and fallopian tubes for women. They contain goblet cells which secrete mucous.
         2. Function

            Annotations:

            • Moves mucus and other substances. It performs the function of moving particles and fluid over the epithelial surface in the structures such as the trachea, bronchial tubes and nasal cavities.
   2. Compound
      1. Keratinised
         1. Structure

            Annotations:

            • The layers on the top are flat cells that are dead and filled with protein called keratin.
         2. Function

            Annotations:

            • The layers underneath are cuboidal, and continually divide to replace the surface cells that become house dust.
      2. Non-Keratinised
         1. Structure

            Annotations:

            • This is found lining moist cavities or tubes within the body, e.g. the mouth and oesophagus.
         2. Function

            Annotations:

            • Cells on the surface are sloughed off through friction and are replaced by news cells made from the cuboidal cells underneath.
2. Muscle

   Annotations:

   • Muscle is controlled by motor nerves which are found in the somatic nervous system.
   1. Skeletal
      1. Function

         Annotations:

         • It produces skeletal movement. The muscles in the body move the bones of the skeleton by their connective tissue attachments. The skeletal system maintains posture, body position and body temperature.
      2. Structure

         Annotations:

         • Skeletal muscles are attached to bones and contract and relax to cause movement of the bones they are attached to. The skeletal muscle consists of two types of tissues which are Contractile tissue and Supporting tissue.
   2. Smooth
      1. Structure

         Annotations:

         • The structure of smooth muscle cells are similar to a rugby ball shape. Smooth muscle cells are fatter when contracted.
      2. Function

         Annotations:

         • It is controlled by nerves in the autonomic nervous system. The smooth muscle is not under conscious control and is controlled by the autonomic nervous system. It can be found in stomach wall and the bladder wall.
   3. Cardiac
      1. Structure

         Annotations:

         • The cardiac muscle is only found in the heart and it not under conscious control. Cardiac muscle is made up of many interlocking cardiac muscle cells that give the tissue its properties.
      2. Function

         Annotations:

         • The fibres are interconnected in order for them all to contract at the same time. It is capable of being myogenic which means it can contract without any nervous stimulation.
3. Nervous
   1. Neurones (motor neurones and sensory neurones)

      Annotations:

      • The nervous system is a thin cell. The function of a neuron cell is to transmit information which means its an integral part of the body's nervous system. Neurons are able to network together and transmit information throughout the body using electrical and chemical signals. Nervous tissue can be found in the brain, spinal cord and peripheral nerves.
4. Connective
   1. Blood
      1. Structure

         Annotations:

         • Blood contains plasma which is a liquid that contains dissolved substances, cells and cell fragments. Red blood cells transport oxygen, white blood cells protect against disease and platelets help the blood to clot.
      2. Function

         Annotations:

         • Blood carries O2 and CO2 (oxygenated and deoxygenated blood). The function of blood is to carry nutrients, waste products and hormones around the body. There are many different types of white blood cells which are all involved in protecting the body from infection.
   2. Cartilage
      1. Structure

         Annotations:

         • It is made up of specialized cells called chondrocytes. There are no blood vessels in the cartilage.
      2. Function

         Annotations:

         • Cartilage makes the nose bendy and the ears flappy. It also provides structure and flexibility.
   3. Bone
      1. Structure

         Annotations:

         • Bone is hard living tissue made up of calcium salts deposited around protein fibres.
      2. Function

         Annotations:

         • The bone in the centre contains blood vessels and bone marrow that contains stem cells that can become red blood cells or white blood cells. The bone protects us, gives flexibility and enables movement.
   4. Areolar
      1. Function

         Annotations:

         • It binds muscle groups, blood vessels and nerves together. It contains collagen and elastin fibres which makes it stretchy.
      2. Structure

         Annotations:

         • This is a sticky white material
   5. Adipose
      1. Function

         Annotations:

         • This protects, insulates and stores energy.
      2. Structure

         Annotations:

         • This is similar to Areolar but has more fat cells.