There are several factors which affect normal vision and eyesight. These factors include diet, heredity, environmental factors including exposure to artificial light, age, etc. Hormones can also affect our vision considerably.
The flow of blood in the capillaries is controlled by structures called precapillary sphincters. These structures are located between arterioles and capillaries and contain muscle fibers that allow them to contract. When the sphincters are open, blood flows freely to the capillary beds of body tissue.When the sphincters are closed, blood is not allowed to flow through the capillary beds. Fluid exchange between the capillaries and the body tissues takes place at the capillary bed.hen the sphincters are open, blood flows freely to the capillary beds of body tissue. When the sphincters are closed, blood is not allowed to flow through the capillary beds. Fluid exchange between the capillaries and the body tissues takes place at the capillary bed.
Capillaries- Small vessels that take nutrients and oxygen from arteries to cells, carry waste products from cells to veins. Blood Flow Through the Heart Systemic/General Circulation: Entire process of blood traveling from the heart through the body and back again. Objectives: Identify the structure and function of the circulatory system. The Circulatory System Controls circulation of blood and lymph through the body 2 interrelated subsystems Cardiovascular Lymph Vascular Components The Heart- Cone shaped muscular organ located in the chest cavity. Pericardium- Tough outer membrane that encases the heart. Left Atrium-Upper left chamber of the heart. AKA left auricle.