- The cell is the smallest thing that is classified as a living thing and is often celled the building block of life.
- All the cells have a membrane that envelops the cell, separates its interior from its environment and maintains the electric potential of cell.
- The cell membrane is said to be semi-permeable and it can either let a substance (molecule or ion) pass through freely, pass through to a limited extend or not pass through at all.
- The biological information contaied in an organism is encoded in its DNA sequence.
- The extracellular fluid contains large quantities of sodium ions (Na+) and small amount of potassium (K+), whereas the intracellular fluid has more concentration of potassium when compared to sodium.
- As a result of phenomenon known as sodium-potassium pump, more sodium ions are transported to the extracellular fluid (ECF) and comparatively less potassium ions are transported in to the intracellular fluid (ICF).
- Under polarized state, the inside of cell is less positive than outside and cells is said to be in negative potential state called “resting potential”. This potential is about – 70 mV to -90 mV.
- The condition in which the inside of the cell to be more positive than outside is called action potential and it is about +20mV to +40 mV.
- The cell showing a resting potential is called polarized cell and when it is genes action potential is called a depolarized cell.
- The function of cardiovascular system is the transportation of oxygen , other essential chemical compounds and blood.
- The circulatory system consists of heart and the blood vessels including arteries veins etc.
- Pulmonary circulation is a short loop from the heart to the lungs and back again.
- Systemic circulation sends blood from the heart to all other parts of our body and back again.
- Heart is a complex pumping organ which receives blood from different parts of the body into the atria and pumps it to the various body parts from ventricles.
- Structurally the heart is divided into right and left parts. Each part has two chambers called atrium and ventricle.
- The right and left atria receive the blood entering the heart and right and left ventricles pump the blood out of the heart.
- The heart has four valves. They are tricuspid valve, bicuspid valve, pulmonary valve and aortic valve.
- Heart muscles continuously generate impulses in such a way that it causes rhythmic contraction and relaxation of heart chambers in a specific sequence.
- There are small groups of specialized neuromuscular cells in the myocardium which, initiate and conduct impulses of contraction over the heart muscle.
- There are three types of blood vessels in the circulatory system of human called arteries, veins and capillaries.
- The function of arteries is to carry the oxygenated blood away from the heart
- Veins carry the blood to the heart which is to be oxygenated whereas capillaries are the smallest blood vessels.
- The nervous system of our body is a vital system since it coordinates the functions of various organs.
- The central nervous system consists of the brain and spinal cord whereas the peripheral nervous system is composed of sensory neurons and the neurons that connect them to the brain.
- The central nervous system is the largest part of the nervous system. Two major parts of CNS are the brain and spinal cord.
- The cerebrum is the largest part of the brain and constitutes about 80% of brain. The cerebrum consists of right and left hemispheres.
- Cerebellum coordinates all the muscular movements. It also enables a person to maintain his balance and is called ‘small brain’.
- The major part of brain stem is called medulla oblongata. It is the lowest section of the brainstem. It can regulate the work performed by the heart.
- The main functions of hypothalamus are temperature regulation, fluid regulation, metabolism etc. Also Hypothalamus has centers for hunger, thirst, sleep, sexual drive, subjective feelings, emotions etc.
- The spinal cord serves as a conductor of impulses to and from the brain to the various organs.
- The basic property of neurons is the ability to transmit electrical signals called nerve impulses is response to any stimuli.
- A neuron has a cell body, a very long axon sheathed in myelin and many tiny branches called dendrites.
- Dendrites are tiny branches on the cell body and at the ends of all neurons. The dendrites from one cell do not actually touch the dendrites of any other cell.
- The axons carry electric impulses from one part of the body to another.
Author Bio: The Author of this article, Sreejith is writing articles on Ultrasound Transducer Working and Electronics and Communications