Modern Biology Chapter 46 : Gas Exchange, The Respiratory System

Physiological Respiration is the process by which animals

Exchange gases with their surroundings

Physiological represents how they

Take in O2 from environment, deliver it to the body cells, and remove CO2 from body cells and deliver it to the environment

Cellular Respiration includes all the ___________ _______ that lead to the production of _______ in _____________ of animals cells - where what is used?, and what is released?

Oxidative Reactions
ATP in Mitochondria
O2 is Used and CO2 is released

What is Diffusion?

Molecules move from High Contration to Low Concentration regions

The gas animals tkae depend on their respiratory medium of?

Water, Air, or Both

The layer of epithelial cells acts as an?

Interface between body and respiratory medium, where molecules exchange

That layer of epithelial cells will be known as the?

Respiratory Surface

Breathing is known as the?

Exchange of gasses with the respiratory medium

Two primary adaptations help animals maintain what? This will maximize what?

Difference of concentration between gases outside and inside the respiratory surface, maximizing the rate of gas exchange

The two primary adaptations are?

Ventilation and Perfusion

Ventilation is the

Flow of respiratory medium over external side of respiratory surface

Perfusion is the flow of

Blood or other body fluids on internal side of respiratory surface

The respiratory surface must be? Why is that?

-Wetted

-Gas exchange will occur only if the surface is wet

What are ways for Respiratory Surface to be wetted?

By respiratory medium or thin film of water

Why couldn’t gas exchange work?

O2 and CO2 cannot cross cell membrane as dry gasses, so they must dissolve

What are the two main Respiratory Media?

Water and Air

Water hold less _______ than air?, what is that content affected by?

Oxygen, Affected by Temperature and Solutes

What does Water take more than Air?

More energy to move Water

Air holds a? (Hint: It’s a List)

-High O2 Content
-Low Density
-Low Viscosity (Reduce energy required for ventilation)

Gas Molecules will diffuse faster in?

Air

What is the main drawback of Air as a Respiratory Media

Respiratory Surface can dry out, due to animals losing water during breathing

In all animals the exchange of gas molecules across the Respiratory Surface occurs by?

Simple Diffusion

Respiratory Surfaces have what structural properties that favor high rate of diffusion?

-Large surface areas

-They are thin
(Rate of Diffusion= Surface Area/ thickness of surface

Rate of diffusion can become higher with?

Large concentration gradients and increasing temperature

Go back for Fick’s Law of Diffusion

Most animals that live in water exchange gasses through? and Aquatic Mammals exchange though?

-Skin or Gills
-Lungs

Most animals that live in land will exchange gasses through? (Hint: Their are three)

-Lungs

-Sometimes Gills

-A Tracheal System

What are the Advantages of the Extended Body Surface of a Flatworm?

The flattened and elongated body surface allows direct contact of respiratory surface with respiratory medium

Disadvantages of Extended Body Surfaces?

-Must always be in a wet environment

-Respiratory surface is not well protected

-Diffusion must go directly to cells, so organism must be thin

Gills and Lungs have the purpose of?

Increasing surface area of the Respiratory Surface

What will it form to increase the surface area?

-Branched Structures/Tubes
-Fingerlike & Platelike projections
-Folds
-Pockets
-Air Sacs

In water breathing animals, gills are ________ of the body - they will _________________ (Hint: First is a single word, second is a sentence)

Evaginations
Extend outward into respiratory Medium

In terrestial animals, lungs are __________ of the body surface, deep in the ________________ where they are less susceptible to ________

Invaginations
Body Interior
Drying Out

Work on Slide 15 to 19

For Fish they use a Mouth-Operculum Pump, what is that?

Mouth Opens —→ Water Flows in
Mout Closes + Operculum Opens —→ Water Flows out Gill Filaments

What structures in fish gills provide the surface for gas exchange?

Gill arches support gill filaments, which contain lamellae — thin, high‑surface‑area structures where oxygen diffuses into blood

What is countercurrent flow in fish gills?

The blood under the respiratory surface and Water over the gills move/flow in opposite directions, maintaining a constant oxygen gradient

Countercurrent Exchange uses a?

One-way flow of water over the gills to maximize exchange

What would occur if the water is more highly oxygenated than the blood along the gill filament?

O2 diffuses from water into blood across entire respiratory surface

Countercurrent exchange is top tier because it will efficiently?

Remove 80-90% of water’s O2 content

Countercurrent Exchange Concept

Insects breathe air through their?

Air-conducting tubes known as Tracheae

Trachea are ____________ of the outer epidermis of the animals reinforced by _______ ____ ________ - the material of the exoskeleton

Invaginations, Rings of Chitin

Go over slide 24

Lungfish and Mature Amphibians use what breathing process

Positive Pressure Breathing

Positive Pressure Breathing

Animals push air into the lungs by increasing pressure in mouth cavity (gulping motion)

Reptiles and Mammals fill their lungs by using

Negative Pressure Breathing

Negative Pressure Breathing

Muscular expansion of the chest/lungs lowers internal pressure, pulling air into the lungs.

Diagram for Positive Pressure Breathing

Go over slide 28-29

Nasal Passages

Chamber in which air is moistened, warmed, and filtered and in which sound resonates

Pharynx (Throat)

Airway connecting nasal passages and mouth with Larynx; enhances sounds, also connects with esophagus

Epiglottis

Closes off larynx during swallowing

Larynx (Voice Box)

Airway where sound is produced

Trachea

Airway connecting larynx with two bronchi that lead to lungs

Lung

Lobed,elastic organ of breathing that exchanges gases between internal environment and outside air

Bronchi

Increasingly branched airways leading to alveoli fo lung tissue

Mouth

Supplemental Airway

Pleura

Double-layered membrane separating lugns from wall of throacic cavity

What does the fluid between the layers of the Pleura do?

Lubricate breathing movements

Intercostal muscles Skeletal

Muscle between ribs that contract to fill and empty lungs

Diaphragm

Muscle sheet between chest cavity and abdominal cavity that contracts to fill lungs