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Retina

By: Administrator, Views: 10972

Eye Composed of special anatomical structures that work together to facilitate sight: Cornea Pupil Lens Vitreous body Light stimulates sensory receptors (rods and cones) in the retina or innermost layer of the eye. Vision is made possible through the coordinated actions of nerves that co...

Conduction of action potentials

By: HWC, Views: 7894

• Action potentials must be rapidly conducted over long distances in order for the nervous system to communicate with other cells. • Propagation of an action potential uses processes similar to those that generate the potential at the trigger zone. • a When a graded potential reaches ...

Definitions of stroke volume, preload definition & Factors influencing stroke volume

By: HWC, Views: 7528

• Stroke volume is directly correlated with cardiac output-the greater the stroke volume the greater the cardiac output. • Stroke volume represents the difference in the amount of blood between: • the volume in the ventricles at the end of diastole (end-diastolic volume EDV); • the ...

Types of antimicrobial substances (interferons & complement protein)

By: HWC, Views: 7766

• Found in blood and interstitial fluids. • Discourage microbial growth. • Include interferon and complement proteins. • Produced and released by virus-infected lymphocytes. • Enter new cells and inhibit viral replication. • Act against a large variety of viruses (non-speci...

Electrocardiogram Examination

By: Administrator, Views: 10582

An electrocardiogram (ECG or EKG) is a test that checks how your heart is functioning by measuring the electrical activity of the heart. With each heartbeat, an electrical impulse (or wave) travels through your heart. This wave causes the muscle to squeeze and pump blood from the heart. Sinoat...

Hormonal regulation of pregnancy - weeks 17 through 38

By: HWC, Views: 7995

• Estrogens increase uterine blood flow, maintaining the endometrium during pregnancy. • High levels of estrogen and progesterone inhibit the synthesis of milk. Progesterone inhibits myometrial contractions of the uterus to prevent premature birth. • Relaxin inhibits myometrial contract...

Factors that influence muscle tension - Sarcomere length and force, understretched and overstretched

By: HWC, Views: 7764

• Muscle tension generated through the contraction of muscle cells provides the force necessary for the muscular system to function. • The amount of tension produced depends on several factors: • Sarcomere length Frequency of stimulation • Motor unit size • Recruitment of moto...

Mitosis step-by-step

By: HWC, Views: 5733

During interphase, the chromosomes will be duplicated in preparation for mitosis, which divides the chromosomes, and cytokinesis, which divides the cell's cytoplasm. In early prophase, the duplicated chromosomes begin to condense. Each chromosome consists of two sister chromatids joined at the...

Isovolumetric VC, Ventricular ejection, Isovolumetric & Passive ventricular filling

By: HWC, Views: 7696

• Isovolumetric means that blood volume does not change. • Ventricular blood volume and cell length remain constant. • With valves closed and contraction continuing, ventricular pressure continues to rise. • Ventricular pressure rises above arterial pressure. • Increased ventr...