Question

3. Briefly describe striated and smooth muscles with their functions.(3marks)​

Answer 1

Answer:

Muscle tissue is a soft tissue that composes muscles in animal bodies and gives rise to muscles' ability to contract.

There are mainly three types of muscle tissue:-

1)Skeletal(Striated) Muscle:

Structure: Skeletal muscle is called "striated" because of its appearance consisting of light and dark bands visible using a light microscope. A single skeletal muscle cell is long and approximately cylindrical in shape, with many nuclei located at the edges (periphery) of the cell.

Function:

Movement of the skeleton under conscious control, including movement of limbs, fingers, toes, neck, etc.

Movement of tissues of facial expression under conscious control, e.g. ability to smile and to frown.

2)Smooth(Non-Striated) Muscle:

Structure: Unlike Skeletal and Cardiac muscle tissue, Smooth muscle is not striated. Smooth muscle fibres are small and tapered - with the ends reducing in size, in contrast to the cylindrical shape of a skeletal muscle. Each smooth muscle fibre has a single centrally located nucleus.

Function: Contractions of smooth muscle constrict (i.e. narrow = reduce the diameter of) the vessels they surround. This is particularly important in the digestive system in which the action of smooth muscle helps to move food along the gastrointestinal tract as well as breaking the food down further. Smooth muscle also contributes to moving fluids through the body and to the elimination of indigestible matter from the gastrointestinal system.

3)Cardiac(Semi-Striated) Muscle:

Structure: Cardiac muscle fibers are striated, branched (sometimes described as Y-shaped), and have a single central nucleus. These fibers are attached at their ends to adjoining fibers by thick plasma membranes called intercalated discs.

Function: Pumping of blood through the heart: Alternate contraction and relaxation of cardiac muscle pumps

De-oxygenated blood through the Right Atrium and Right Ventricle to the lungs, and oxygenated blood through the Left Atrium and Left Ventricle to the aorta, then the rest of the body.