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Structures that affect circulation - venous return

By: HWC, Views: 7557

• 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...

Exercise and cardiac output

By: HWC, Views: 7461

• Cardiac output: • Maintains blood flow throughout the body. • Measure of blood volume ejected from the heart over a given time. • Determined by multiplying heart rate by stroke volume (CO = SV x HR). • Heart rate: Number of beats/min. • Stroke volume: Amount of blood eject...

Simple Diffusion - Ion transport

By: HWC, Views: 7739

In the process of diffusion, a substance tends to move from an area of high concentration to an area of low concentration until its concentration becomes equal throughout a space. Ions must diffuse through membrane pores or gated channels. Pores are always open. More pores allow more ions...

Simple Diffusion - gases and nonpolar compounds transport

By: HWC, Views: 8035

Gases and some molecules can diffuse through the phospholipid bilayer because they are small or non-polar. Oxygen gas. Carbon dioxide gas. Lipid based hormones. Plasma membranes are selectively permeable: The lipid bilayer is always permeable to small, nonpolar, uncharged molecules ...

Bacteriophage (Virus) - Mice Experiment

By: HWC, Views: 7443

Also known as phages, these viruses can be found everywhere bacteria exist including, in the soil, deep within the earth's crust, inside plants and animals, and even in the oceans. Bacteriophages (phages) are viruses of bacteria that can kill and lyse the bacteria they infect. ... The lethalit...

Acid-base imbalances - compensation of metabolic acidosis and alkalosis

By: HWC, Views: 7983

1. Metabolic acidosis: • Few HC03- ions are present so blood pH becomes acidic. • Compensation is increased respiratory rate and more CO2 is removed from the blood. • Blood pH returns to normal. 2. Metabolic alkalosis: • Many HC03- ions are present so blood pH becomes alkaline...

What is an ecosystem?

By: HWC, Views: 7552

An ecosystem is a community of organisms and their environment. The community forms the living component of the ecosystem. These are called the 'biotic' factors, which means all of the living things in the ecosystem. The environment forms the nonliving component of the ecosystem, such as ...

Hormonal feedback loop components

By: HWC, Views: 7826

The endocrine system maintains many body conditions within normal limits with feedback loops. Each endocrine feedback loop maintains homeostasis using the following components: ■ Stimulus - a change in a body condition. ■ Production cell - an endocrine cell that produces a hormone after b...

Enzyme-Catalyzed Reactions

By: HWC, Views: 7180

S P Substrate in great excess ([S] -- [E]) (More correctly [S] -- KM, but more on this later) Zero order rate equation: v = k where k is the zero-order rate constant (with respect to substrate). (More correctly [S] -- KM, but more on this later) Substrate forms complex with enzyme. ...