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Anatomy and Chemical Makeup of a Single Hair (Animation)

By: HWC, Views: 7131

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: 339

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: 3244

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...

Second Stage of Labor and Delivery

By: Administrator, Views: 592

During labor forceful contractions move the fetus down the birth canal and expel it from the uterus. Signs and symptoms that labor is about to start can occur from hours to weeks before the actual onset of labor. Braxton Hicks contractions Irregular contractions that begin in the second trim...

Vasectomy

By: Administrator, Views: 12019

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.

First Stage of Labor and Delivery Video

By: Administrator, Views: 12004

During labor forceful contractions move the fetus down the birth canal and expel it from the uterus. Signs and symptoms that labor is about to start can occur from hours to weeks before the actual onset of labor. Braxton Hicks contractions Irregular contractions that begin in the second trim...

Cellular Defects - Osteoblasts, Osteoclasts and Osteocytes

By: HWC, Views: 8513

■ 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: 11883

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: 9036

▪ 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. ...