Respiratory System

Dalia ElmeligeDjenaba Dureas Rachel Geshay

What is respiration?Respiration- is the sequence of events that results in gas exchange between the body’s cells and the environment.

How do we respire?

For those on land (terrestrial creatures): Step 1- Ventilation: (i.e. breathing) includes inspiration (entrance of air into the lungs) and expiration (exit of air into the lungs).Step 2- External Respiration: is a gas exchange between the air and the blood within the lungs. Blood then transports oxygen from the lungs to the tissues (with the presence of a respiratory pigment called hemoglobin)Step 3- Internal Respiration: is gas exchange between the blood and the tissue fluid. The blood then transports carbon dioxide to the lungs

Basically: AIR Blood in the Lungs Blood transports oxygen to tissues Exchange gases with tissue fluid Blood takes CO2 back to the lungs

Visualize

The need for Gas Exchange and Ventilation in Humans

Cell respiration releases energy in the form of ATP so that this energy can be used inside the cell. Cell respiration occurs in the mitochondria and cytoplasm of cells. Oxygen is used in this process and carbon dioxide is produced.

Gas exchange is the process of swapping one gas for another. It occurs in the alveoli of the lungs. Oxygen diffuses into the capillaries from the air in the alveoli and carbon dioxide diffuses out of the capillaries and into the air in the alveoli. (Diffusion)

Ventilation is the process of bringing fresh air into the alveoli and removing the stale air. It maintains the concentration gradient of carbon dioxide and oxygen between the alveoli and the blood in the capillaries (vital for oxygen to diffuse into the blood from the alveoli and carbon dioxide out of the blood into the alveoli). (alveoli discussed later)

THEREFORE…humans must take in oxygen from the air and release carbon dioxide which is…….

6.4.1 Distinguish between ventilation, gas exchange and cell respiration.

6.4.2 Explain the need for a ventilation system.

• To maintain the concentration gradients of oxygen and carbon dioxide in the alveoli. • The body needs oxygen to make ATP via cell respiration.• The body needs to get rid of carbon dioxide which is a product of cell respiration.• Oxygen needs to diffuse from the alveoli into the blood. Carbon dioxide needs to

diffuse from the blood into the alveoli.• To do so there must be a high oxygen concentration and a low carbon dioxide

concentration in the alveoli. • A ventilation system makes this possible by getting rid of the carbon dioxide in the

alveoli and bringing in more oxygen.

Basically so we don’t die of CO2 poisoning and so we can have oxygen to function.

Requirements for External Respiration

For External respiration to be effective the gas exchange region must be1) Moist2) Thin3) Large in relation to the size of the body

-Some animals are shaped in a way that their surface can be the gas exchange area (planarians)-Complex animals have specialized external respiration surfaces (gills, lungs)

-Diffusion of oxygen and CO2 during respiration is enhanced by vascularization (presence of many capillaries)

-and delivery of oxygen to cells is promoted when there is a presence of respiratory pigments like hemoglobin

No matter what the external respiration surface is or how gases are delivered, in the end oxygen is taken to the mitochondria where cellular respiration takes place.

Otherwise you are dead.

Gas ExchangeAP wants you to know….

Respiratory structures are adapted for gas exchange in air or water:-Gills are adapted for respiration in water-Trachea and lungs for terrestrial respiration-Gas Exchange takes place across a moist surface

Many types of surfaces have evolved for gas exchange-The body surface may be adapted for gas exchange-Tracheal tube systems of arthropods deliver air directly to the cells-Gills of aquatic animals are respiratory surfaces -Terrestrial vertebrates exchange gases through lungs.

According to www.dotsonscience.com/apoutlines.htm

External Gas-Exchange Surfaces

Many types of surfaces have evolved for

gas exchange

Planaria, or flatworms, have a large surface area in comparison to their size , this makes it possible to exchange gases directly with their environment.

The body surface may be adapted for gas exchange

Gas Exchange takes place across a moist

surface

Tracheal tube systems of arthropods deliver air directly to the cells

The earthworm keeps its surface moist by secreting mucus and other fluids. In addition to tubular structures of some worms may be vascularized for gas exchange.

Gills are adapted for respiration in water

Gills of aquatic animals are respiratory surfaces

Gills- are finely divided vascularized of the body surface, they extract oxygen from a watery environment.

Fish

The Gills Of Fish• Water is drawn into the mantle cavity, where it passes through the gills• The action of specialized appendages located near the mouth keep the

water moving• Mouth and opercula cause ventilation, when mouth open opercula closes,

then the mouth opens and opercula closes drawing the water through. • Opercula= gill covers• The gills are composed of filaments that are folded into plate like lamellae.• Fish use countercurrent exchange- to transfer oxygen from the

surrounding water into their blood. • Flows over lamellae in gills • Concurrent flow means that the oxygen rich water and oxygen poor blood

are flowing in the same direction and causing equilibrium • Countercurrent flow means that the two fluids flow in opposite directions.

Allows oxygen rich water and oxygen rich blood to meet and about 80-90% of dissolved oxygen is extracted.

http://www.youtube.com/watch?v=XEIRlw5rCUk

http://www.youtube.com/watch?v=cVFqME-NW9s

Insects

Trachea and lungs for terrestrial respiration

Insects have a system of tubes called tracheae through which oxygen is delivered directly to the cells without entering the blood.

The Tracheal System of Insects• Hemolumph (blood and lymph) flows freely through most indects making

circulation ineffecient. • Many insects adapted for flight so they need a steady supply of oxygen for flight

muscles• Trachea- are tiny air tubes that take oxygen directly to the cell to overcome the

ineffeciency pf their blood flow• Trachea branch into many thin tracheoles that almost every single cell is near

one. • Air enters the trachea through small openings called spiracles.• Trachea expand and contract drawing air into them much like lungs.• Air moves to the smaller tracheoles which take air to the cells and gas exchange

takes place.• A tracheal system is an adaptaion to breathing air.• Marine insects use diffusion to allow oxygen to reach their tracheal system

rather then spiracles

Visualize

TerrestrialTerrestrial vertebrates exchange gases through

lungs.

Lungs – are vascularized outgrowths from the lower pharyngeal region

• The human respiratory system includes all of the structures that conduct air in a continuous pathway to and from the lungs

• The lungs lie deep in the thoracic cavity to keep from drying up.

• Air is filtered as it goes through the nose, pharynx, trachea, and the bronchi to the lungs so that it is free of debris, warmed and humidified.

• Nose hairs and cilia act as filters.• Cilia beat upward in bronchi and trachea to get debris

such mucus, dust and occasional food that went down the wrong way back intot he throat.

• The hard and and soft pallets separate the nasal cavities from the mouth.

Going down…• Air and food passages cross in the pharynx. Has the advantage of letting

you breathe through your mouth in case your nose is plugged up.• Air passes from the pharynx through the glottis, an opening in the

larynx, or voice box.• Vocal Cords- located at the edge of the glottis are flexible and pliable

bands of connective tissue that vibrate and produce sound when air is expelled past them.

• Larynx and trachea remain open at all times• Larynx held open by 9 cartilages among them the Adam’s apple• Trachea held open by a series of c-shaped cartilages • Epiglottis- is a flap of tissue that closes to protect the glottis when food

is being swallowed.

Down…

• Trachea divides into two primary bronchi.• Bronchi branch into smaller passages in the

lungs called bronchioles.• Bronchioles end in in air pockets, or sacs,

called alveoli. • Internal gas exchange happens in the alveoli

between the air in the alveoli and the blood in the capillaries.

Lungs

• AP Summary:-The airway conducts air into the lungs.- Gas exchange occurs in the alveoli of the lungs- Ventilation is accomplished by breathing- Gas exchange takes place in the alveoli - Gas exchange takes place in the tissues- Respiratory pigments increase capacity for oxygen transport- Carbon Dioxide is transported mainly as bicarbonate ions - Breathing is regulated by respiratory centers in the brain- Hyperventilation reduces carbon dioxide concentration.

Trachea Songhttp://www.youtube.com/watch?v=8lCqtdF95H0

FYE: (entertainment and education)

Visualize

6.4.4 Draw and label a diagram of the ventilation system, including trachea, lungs, bronchi, bronchioles and alveoli.

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6.4.3 Describe the features of alveoli that adapt them to gas exchange.

• Great numbers increase the surface area for gas exchange.• Walls of alveoli made up of single layer of thin flattened epithelial cells as well as the walls of the capillaries . The thin walls allow for short distance in gas exchange. • Diffusion distance is small allowing rapid gas exchange. • Covered by a dense network of capillaries which have low oxygen and high carbon dioxide concentrations. This allows oxygen to diffuse into the blood and carbon dioxide to diffuse out of the blood. • Moist surface for the solution of gases, Fluid also prevents the sides of alveoli from sticking together.

Visualize And know how to label this too….