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The Pressure Flow Model in a Plant

By: HWC, Views: 8685

The vascular system of plants has two transport tissues, called xylem and phloem. Xylem transports water and minerals, while phloem transports a variety of dissolved substances, including sugars and amino acids, throughout the plant. Water in the xylem always moves up, in the direction from th...

Pressure Flow Model Animation

By: HWC, Views: 8619

This apparatus of beakers A and funnels simulates the flow of a sucrose solution in the phloem of a plant. The funnels and connecting tube represent a sieve tube of the phloem. Differentially permeable membranes cap the funnels at the source and sink ends, allowing water, but not sucrose, to cros...

Labor and Delivery - Transition

By: Administrator, Views: 334

The last part of active labor – when your cervix dilates from 8 to a full 10 centimeters – is called the transition period because it marks the shift to the second stage of labor. This is the most intense part of labor. Contractions are usually very strong, coming every two and a half to t...

Neural regulation of blood pressure - baroreceptor and chemoreceptor reflexes

By: HWC, Views: 9641

• The nervous system regulates blood pressure with two reflex arcs: baroreceptor and chemoreceptor. ■ Baroreceptors (pressure) and chemoreceptors (chemical) are located in the carotid sinus and aortic arch. • Carotid sinus reflex helps maintain normal blood pressure in brain. • Ba...

Gas exchange - driving force

By: HWC, Views: 9339

• The respiratory system is responsible for the movement of gases involved in cellular metabolism. • Oxygen is used up and carbon dioxide is generated during the aerobic breakdown of glucose and other fuel molecules in order to produce ATP. • Three important continuous physiological pro...

Energy Flow - Trophic Levels and Food

By: HWC, Views: 8930

All of these relationships between different species are founded on one thing: energy. Organisms get food in order to get energy, which is used by the organism for growth, maintaining health, and reproduction. We can classify the members of a community according to how they obtain food. Produc...

Five phases of cardiac cycle & Atrial contraction

By: HWC, Views: 9418

1. Atrial contraction (atrial systole). 2. Isovolumetric (ventricular) contraction. 3. Ventricular ejection. 4. Isovolumetric (ventricular) relaxation. 5. Passive ventricular filling. Beginning of cardiac cycle • Prior to atrial contraction: • Atria and ventricles are relaxed....

Types of Shock (Part 2 of 2)

By: Administrator, Views: 11978

Shock is a life-threatening condition in which delivery of oxygen to the organs is low, causing organ damage and sometimes death. Blood pressure is usually low.

Structures that affect circulation - venous return

By: HWC, Views: 9201

• Venous return directly affects cardiac output. • Increased venous return leads directly to greater cardiac output whereas decreased return contributes to decreased output. • Venous return depends on: • Blood volume regulation by the kidneys. • Venous tone. • Skeletal muscl...