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Barriers - eye structures, digestive mucosa, respiratory mucosa & genitourinary mucosa

By: HWC, Views: 6898

• Eyebrows, eyelids, eyelashes and conjunctiva serve to trap microbes preventing their invasion. • Tearing (lacrimation) is a protective mechanism that washes away microbes that attempt to enter the eyes. • Salts, mucus, and lysozymes in tears neutralize substances and bacteria. â€...

Cellular defenses (natural killer cells, phagocyte types & process of phagocytosis)

By: HWC, Views: 6510

• Lymphocytes that rapidly defend against abnormal (cancer) or virus-infected cells. • Found in blood, spleen, lymph nodes, and red bone marrow. • Lack receptors for binding with specific antigens. • Act upon cells displaying abnormal MHC antigens. • NK cells destroy cells in ...

Inflammation and Fever

By: HWC, Views: 7135

• Inflammation is an immune response that can occur anywhere in the body, but is observed most frequently on the skin. • It provides early protection by preventing infection from spreading to other parts of the body. • Inflammation also promotes repair of damaged tissues. Inflammat...

B cells and antibodies

By: HWC, Views: 7482

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...

Heart sounds

By: HWC, Views: 6529

During a normal, healthy heartbeat, or what we call a cardiac cycle, the top two chambers of the heart, called the atria, contract simultaneously. Then, as they relax, the bottom two chambers, called the ventricles, contract. This explains what happens during a cardiac cycle, but what it doesn't ...

Stroke volume

By: HWC, Views: 6665

Preload definition • Preload is the degree of stretch of cardiac muscles cells prior to contraction. • The amount of stretch is related to the end-diastolic volume[EDV]. • Increased return blood flow from the veins increases end-diastolic volume. Cardiac muscle sarcomeres stretch and ...

Reflex arc construction

By: HWC, Views: 6563

• Somatic reflexes are the rapid, predictable, and automatic responses of skeletal muscle to changes in stimuli. • A reflex arc is the pathway followed by the nerve impulse producing the reflex. • Reflex arcs include: • Sensory receptor • Sensory neurons • Integrating c...

Rena arc construction

By: HWC, Views: 6606

• Somatic reflexes are the rapid, predictable, and automatic responses of skeletal muscle to changes in stimuli. • A reflex arc is the pathway followed by the nerve impulse producing the reflex. • Reflex arcs include: • Sensory receptor • Sensory neurons • Integrating cen...

Stretch reflex & Tendon reflex

By: HWC, Views: 6399

• The stretch reflex is a response to the stretching of muscles. It is monosynaptic and ipsilateral. • Stretching stimulates receptors in the muscle spindle of the agonist (stretched) muscle. • One or more action potentials are generated by the receptors and propagate along the axon of ...