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Muscle Fatigue and Recovery

By: HWC, Views: 7520

• After prolonged activity, muscle contraction weakens, and the muscle enters a state of fatigue. • Fatigue results from in muscle cells, such as: • Inadequate release of calcium ions • Depletion of energy sources • Lack of oxygen • Build up of lactic acid other metabolic w...

B cells and antibodies

By: HWC, Views: 8525

What Are Antibodies? Antibodies, also known as immunoglobulins, are Y-shaped proteins that are produced by the immune system to help stop intruders from harming the body. When an intruder enters the body, the immune system springs into action. These invaders, which are called antigens, can be vi...

Plant Defense Mechanisms from Pathogens

By: HWC, Views: 7198

Plants and pathogens have coevolved such that pathogens can recognize plants by the sugars, or other molecules, they produce. Plants, in turn, can recognize pathogens by the molecules they produce. The ability to recognize pathogens allows plants to activate defense systems that can prevent wides...

Labor and Childbirth - The Three Stages of Labor: Dilation, Expulsion & Placental مراحل الولادة

By: HWC, Views: 8185

Regulation of labor and birth - effects of estrogen and oxytocin on onset of labor • Just prior to birth, high placental corticotropin-releasing hormone levels stimulate the production of more estrogen. • High estrogen levels overcome the inhibitory effects of progesterone on uterine sm...

Decubitus Ulcer

By: Administrator, Views: 10887

Pressure ulcers, also known as bedsores, decubiti, decubitous ulcers, pressure injuries, and pressure sores, are localized damage to the skin and/or underlying tissue that usually occur over a bony prominence as a result of usually long-term pressure, or pressure in combination with shear or fric...

Transferring genes into plants Animation

By: HWC, Views: 5099

Researchers extract DNA from an organism that has a trait they want to introduce into a plant. The genetic donor can be a bacterial cell, a plant cell. or even an animal cell. The desired gene will be transferred into a plasmid, a small circle of bacterial DNA. The gene is cut out of th...

How Broken Bones Repair Themselves

By: Administrator, Views: 404

Bone healing, or fracture healing, is a proliferative physiological process in which the body facilitates the repair of a bone fracture. Generally bone fracture treatment consists of a doctor reducing (pushing) displaced bones back into place via relocation with or without anaesthetic, stabili...

Energy sources - types

By: HWC, Views: 7927

• The amount of ATP stored in a skeletal muscle cell can only provide muscular activity for two to three seconds. • Muscle cells must be able to generate additional molecules of ATP to continue contracting. • Muscle cells can generate ATP from several processes: • Phosphogen syste...

SNP Polymorphysim Microarray Chip - How to Test a Person's DNA

By: HWC, Views: 7050

To test a person's DNA, a researcher first needs a source of tissue. Most of the cells in a blood sample are red blood cells, which lack nuclei, but there are also a number of white blood cells, which do contain nuclei and chromosomal DNA. If we could see a particular DNA sequence in these cel...