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Evolutionary tree of life Animation

By: HWC, Views: 3018

An evolutionary tree of life that reflects mainstream thinking about the connections among major lineages (bya = billions of years ago, mya = millions of years ago). By about 3.8 billion years ago, chemical and molecular evolution had produced the first living cells. The first major divergenc...

Basic rhythm - control centers in medulla oblongata, spirograph and normal tidal cycle

By: HWC, Views: 9132

• Normal ventilation is rhythmic and involves continuous cycles of inspiration and expiration. • Various regions of the brain closely regulate this rhythmic pattern of ventilation. • The rhythmicity area in the medulla regulates the basic rhythm of ventilation. • The medullary rhy...

Proteins

By: HWC, Views: 8340

Living things must accomplish a great number of tasks just to get through a day, and these tasks are accomplished by a diverse range of biological molecules. In the range of tasks that molecules accomplish, however, proteins reign supreme. Almost every chemical reaction that takes place in living...

Virtual Tour of the Eye Animation

By: Administrator, Views: 12024

Eye Composed of special anatomical structures that work together to facilitate sight: Cornea Pupil Lens Vitreous body Light stimulates sensory receptors (rods and cones) in the retina or innermost layer of the eye. Vision is made possible through the coordinated actions of nerves that co...

Head and Neck Movement Animation

By: Administrator, Views: 360

Interestingly, head and neck muscles are the first ones that the baby can control. A baby can hold his head up before he can sit erect. The muscles of the head and neck perform many important tasks, including movement of the head and neck, chewing and swallowing, speech, facial expressions, an...

Methods that regulate pH

By: HWC, Views: 9444

• The blood flow redistributes fluids that have different pH values between body regions. • The regulation of the blood pH is important to maintain homeostasis. • Blood pH is regulated by: • Chemical buffers. • The respiratory system. • The urinary system. • All thes...

Structures that affect circulation - heart and MABP

By: HWC, Views: 8864

■ BP is defined as the systolic BP over the diastolic BP. ■ MABP = diastolic BP + 1/3 (systolic BP - diastolic BP). ■ MABP accounts for diastole lasting longer than systole; mean is not equidistant between the two pressures.

Cardiac Cycle (Part 1 of 4)

By: Administrator, Views: 12344

Blood Flow through the atrium.

Immune responses Animation

By: HWC, Views: 6191

Overview of interactions in antibody-mediated and cell-mediated immunity Animation The antibody mediated immune response begins when a naive B cell encounters antigens from a pathogen, such as a bacterium. The B cell binds, processes, and displays this antigen. It is now an antigen-presenti...