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Anatomy and Chemical Makeup of a Single Hair (Animation)

By: HWC, Views: 5943

The hair's outer cuticle surrounds hair cells filled with tough keratin macrofibrils. Each macrofibril consists of smaller microfibrils. A microfibril is made up of three keratin polypeptide chains. The chains are linked together by disulfide bonds. A hair consists of keratin chains held...

Nerve Type Animation (Part 2)

By: Administrator, Views: 316

Used to describe neuronal processes conducting impulses from one location to another. Nerve fibers: - Nerve fibers of the PNS are wrapped by protective membranes called sheaths. - Myelinated fibers have an inner sheath of myelin, a thick fatty substance, and an outer sheath or neurilemma compo...

Apicomplexan life cycle Animation

By: HWC, Views: 2060

Malaria is caused by the sporozoan, Plasmodium. It is transferred to humans by mosquitoes. When an infected mosquito feeds, infective sporozoites move from her salivary glands into the human body. The bloodstream carries the sporozoites to the liver. Here, they reproduce asexually and...

Vasectomy

By: Administrator, Views: 10908

Vasectomy Procedure: (A) The spermatic cords are located as they ascend from the scrotum. (B) The vas deferens are severed. (C) A 1 cm section is removed. (D) The cut ends cannot reconnect thereby preventing the passage of sperm cells and providing surgical sterilization.

Cellular Defects - Osteoblasts, Osteoclasts and Osteocytes

By: HWC, Views: 7341

■ Metabolically active bone-building cells that secrete astroid. ■ Cover surfaces of newly formed bone and respond to growth stimuli ■ Less responsive to growth factors as the body ages. ■ Contribute to hone loss once their reproductive and biosynthetic potential lessens....

Neurosynapse Animation

By: Administrator, Views: 10708

In the nervous system, a synapse is a structure that permits a neuron (or nerve cell) to pass an electrical or chemical signal to another neuron or to the target effector cell. Synapses are essential to neuronal function: neurons are cells that are specialized to pass signals to individual tar...

Gas exchange - partial pressure, locations, external and internal respiration

By: HWC, Views: 7901

▪ In a mixture, each individual gas exerts a pressure that is proportional to the concentration of that gas within the mixture. • This part of the total pressure is called a "partial pressure". • A gas moves along the part of the pressure gradient determined by its own concentration. ...

Exocytosis - secretion

By: HWC, Views: 7767

Exocytosis is another method of vesicular transport that moves large volumes Of fluid or chemicals out of the cell. It is a process by which a cell transports secretory products through the cytoplasm to the plasma membrane. A examples of cellular secretory products: 1. Secreted protein - enzym...

Pressure Flow Model Animation

By: HWC, Views: 7014

This apparatus of beakers A and funnels simulates the flow of a sucrose solution in the phloem of a plant. The funnels and connecting tube represent a sieve tube of the phloem. Differentially permeable membranes cap the funnels at the source and sink ends, allowing water, but not sucrose, to cros...