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Mechanisms of capillary exchange

By: HWC, Views: 9465

■ The primary role of capillaries is to permit the exchange of nutrients and wastes between the blood and tissue cells (via interstitial fluid). ■ Oxygen and nutrients move from the blood to the cells. ■ Carbon dioxide and other wastes move from the cells to the blood. The three ba...

Definition of heart rate

By: HWC, Views: 9491

• Heart rate is determined by the rate of depolarizations of the sinoatrial (SA) node. • Cardiac output is directly proportional to heart rate, the greater the heart rate the greater the cardiac output. • Changes in heart rate are associated with exercise, stress or injury. Nervous ...

Allergic Rhinitis

By: Administrator, Views: 12059

Allergic rhinitis, also known as hay fever, is a type of inflammation in the nose which occurs when the immune system overreacts to allergens in the air. Signs and symptoms include a runny or stuffy nose, sneezing, red, itchy, and watery eyes, and swelling around the eyes. The fluid from the nose...

Primary and secondary response to infection

By: HWC, Views: 9121

• Pathogens enter the body by penetrating the non-specific barriers in the skin and mucus membranes. • Pathogens first encounter macrophages and natural killer cells that carry out phagocytosis and cytolysis respectively. • A pathogen's first encounter with the immune system can promo...

Neurotransmission at chemical synapses & Excitory and inhibitory potentials

By: HWC, Views: 9243

• A series of events occur at chemical synapses in order to communicate with the adjacent cell. • The action potential arrives at the presynaptic membrane. • The depolarization phase of the action potential opens voltage gated Ca+ channels. • increased inflow of Ca+' into the cyto...

Inflammation Animation

By: Administrator, Views: 12367

Inflammation is caused by a number of physical reactions triggered by the immune system in response to a physical injury or an infection. Inflammation does not necessarily mean that there is an infection, but an infection can cause inflammation.

Autonomic Nervous System Animation

By: Administrator, Views: 12612

Parasympathetic Division Works to conserve energy and innervate the digestive system. When activated, it: stimulates the salivary and digestive glands. decreases the metabolic rate. slows the heart rate. reduces blood pressure. promotes the passage of material through the intestines along...

Multiple Sclerosis Animation

By: Administrator, Views: 12559

Multiple sclerosis (MS) is a demyelinating disease in which the insulating covers of nerve cells in the brain and spinal cord are damaged. This damage disrupts the ability of parts of the nervous system to communicate, resulting in a range of signs and symptoms, including physical, mental, and so...

Rh blood type and complications during pregnancy & Fertilization

By: HWC, Views: 6722

Complications can arise if an Rh- woman is impregnated by an Rh+ man. The fetus maybe Rh+. During childbirth, some of the fetal Rh+ cells may leak into the maternal bloodstream. The woman's immune system views the Rh+ as foreign and makes antibodies against it. If the woman becomes pr...