Chapter 42: Gas Exchange and Circulation

Diffusion

________ αt the respiratory surface, where 02 moves from 1e air or water into the blood and C02 moves from 1e blood into 1e air or water, along their concentration gradients.

tiny sacs

The lungs of mammals, in contrast, are finely divided into ________ called alveoli.

cellular respiration

In tissues, where ________ has led to low 02 levels and high C02 levels, gas exchange occurs between blood and cells.

thin muscular sheet

The change in volume is caused by a downward motion of the ________ called the diaphragm and an expansion of the rib cage.

Solubility

________ of the gas in the aqueous film lining the gas exchange surface.

blood cells

White ________ (also called leukocytes) are part of the immune system.

tube

A(n) ________ known as the trachea (not to be confused with the tracheae of insects) carries the inhaled air to narrower ________ called bronchi.

Platelets

________ are cell fragments that act to minimize blood loss from ruptured blood vessels.

interstitial fluid

A(n) ________ that enters the lymphatic ducts is called lymph.

Lungs

________ are internal organs that are used for gas exchange.

Veins

________ are thin- walled vessels that return blood to the heart.

Capillaries

________ are vessels whose walls are just one cell thick, allowing an exchange of gases and other molecules between blood and tissues.

Arteries

________ are tough, thick- walled vessels that take blood away from the heart.

Small arteries

________ are called arterioles.

Larger veins

________ also contain one- way valves, which are thin flaps of tissue at prevent any backflow of blood.

Partial pressure

________ is the press of a particular gas in a mixture of gases.

heart valves

If ________ are damaged or defective, the resulting backflow can be heard through a stethoscope and is called a heart murmur.

Ficks law of diffusion

________, states that the rate of diffusion of a gas depends on five parameters:

Diffusion

________ in the tissues, where 02 moves from the blood into the tissues and C02 moves from the tissues into the blood, along their concentration gradients.

In fact, the fluid is collected in the lymphatic system

a collection of thin-walled, branching tubules called lymphatic vessels that permeate all tissues

Ventilation

The movement of air or water through a specialized gas exchange organ, such as a lung or gill