The eye is a complex sensory organ that allows us to see the world around us. The eye works by gathering light from the environment and converting it into electrical signals that can be interpreted by the brain. The basic structure of the eye includes the cornea, iris, pupil, lens, retina, and optic nerve. The cornea is the transparent outer layer of the eye that helps to focus incoming light. The iris is the colored part of the eye that regulates the amount of light that enters the eye through the pupil, which is the black circular opening in the center of the iris. The lens is a clear, flexible structure located behind the iris that helps to focus light onto the retina. The retina is a thin layer of tissue that lines the back of the eye and contains photoreceptor cells called rods and cones. These cells convert light into electrical signals that are sent to the brain via the optic nerve. The rods are responsible for the low light vision and detecting motion, while the cones are resp
The Cardiac event that occurs from the beginning of one heartbeat to the beginning of the next is called the cardiac cycle. The action potential travels rapidly through both atria and then through the AV bundle into the wall of ventricles. Because of the special arrangement of the conducting system from the atria to the ventricles, there is a delay of more than 1/10th a second between the passage of the cardiac impulse from the atria into the ventricles. this allows the atria to contract ahead of the ventricles, thereby pumping blood into the ventricles before the strong ventricular contraction begins. Thus the atria are the primer pumps for the ventricles, and ventricles then provide the major source of power for moving blood through the vascular system. The process of heartbeat begins from the time of embryonal development. Once the heartbeat starts, it continues thought out life (inherent capacity). In the resting stage of man in 1 minute, the heartbeat around 72 times and during t