Search results for: 'cardiac cycle'

Watch Later 1:19

By: HWC, Views: 7587

• ECG: Graph of the voltage changes that occur during the cardiac cycle. • Readings are taken by electrodes placed on the surface of the body. • Electrodes detect voltage changes caused by the electrical activity of the heart. • P wave = atrial excitation (atrial depolarization). ...

Watch Later 2:58

The primary factors that affect circulation - MABP, CO and SVR

By: HWC, Views: 8070

Introduction Blood flow is determined by the relative intensities of factors that drive and resist moving blood. • Cardiac output (CO) equals the mean arterial blood pressure (MABP, a driving force) divided by systemic vascular resistance (SVR, a resisting force). • Hormones and the cen...

Watch Later 2:08

Structures that affect circulation - heart and systolic/diastolic BP

By: HWC, Views: 7664

• Heart generates blood pressure. • Arterioles produce resistance thereby regulating blood flow to tissues. • Veins store blood; kidneys regulate blood volume; both affect venous return and cardiac output. ■ Contractions of the ventricles determine blood pressure, which drives th...

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Female Reproductive System - Hormonal regulation (GnRH) الجهاز التناسلي للأنثى - التنظيم الهرموني

By: HWC, Views: 8167

• There is a complex interaction between the anterior pituitary gland, the hypothalamus, the ovaries and the uterus that leads to the monthly changes that women experience during their monthly reproductive cycle. • Two monthly cycles constitute these changes: • Ovarian cycle. • Uter...

Watch Later 1:36

Calvin cycle (The light-independent reactions )

By: HWC, Views: 7490

The light-independent reactions of photosynthesis occur in the stroma of the chloroplast. Carbon dioxide enters the leaf through tiny pores or stomata and diffuses into the chloroplast. The first stage of the Calvin cycle is the attachment of a carbon dioxide molecule to a 5-carbon ribulose bi...

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Stroke volume - afterload definition & hypertension

By: HWC, Views: 7201

• Pressure (or other resisting force) that ventricles must overcome to push open semilunar valves and eject blood. ▪ Normally, the left ventricle blood pressure must overcome arterial pressure in the aorta. ▪ Abnormally high blood pressure, or hypertension, increases aortic pressure w...

Watch Later 2:18

Contraction and Relaxation Animation

By: Administrator, Views: 10654

Muscles are responsible for movement. The types of movement are: - Locomotion, when chemical energy is changed into mechanical energy. - Propulsion of substances through tubes, as in circulation and digestion. - Changes in the sizes of openings, as in the contraction and relaxation of the iris...

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HIV Infection: Viral life cycle

By: HWC, Views: 7091

The series of steps that HIV follows to multiply in the body. The process begins when HIV encounters a CD4 cell. The seven steps in the HIV life cycle are: 1) binding; 2) fusion; 3) reverse transcription; 4) integration; 5) replication; 6) assembly; and 7) budding. Many viruses f...

Watch Later 2:24

Epinephrine/NE (heart rate, altered blood flow, glycogenolysis & bronchodilation)

By: HWC, Views: 7676

• Stressors trigger increased sympathetic stimulation from the hypothalamus to the chromaffin cells of the adrenal medulla. • This causes the immediate release of epinephrine and norepinephrine (NE). • Epinephrine/NE binds to the cardiac muscles of the heart. • Cardiac muscle cells ...

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