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LET’S DISCUSS

The respiratory system consists of a set of organs and tissues involved in the uptake of oxygen from the atmosphere and the release of carbon dioxide generated during aerobic respiration.

This gas exchange is also called breathing, or external respiration. It plays a crucial role in maintaining our body’s oxygen supply and removing waste gases.

RESPIRATORY SYSTEM

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OXYGEN TRAVEL

This flowchart simplifies a complex process that captures the essential steps involved in oxygen transport and gas exchange within the respiratory system.

Air enters through the nose or mouth. It passes through the pharynx and larynx. The trachea carries air down into the bronchi.

The bronchi divide into smaller bronchioles. These bronchioles lead to clusters of alveoli in the lungs.

In the alveoli, oxygen diffuses into the bloodstream. Carbon dioxide diffuses out of the bloodstream into the alveoli.

The diaphragm relaxes, pushing air out of the lungs. Air exits through the trachea, larynx, and either the nose or mouth.

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RESPIRATORY ORGANS

The nose serves as the primary entry point for air. Inside the nose, we find the nasal cavity, which filters incoming air, removing dust and particles; warms and humidifies the air before it reaches the lungs; and contains olfactory receptors for our sense of smell.

NOSE AND NASAL CAVITY

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RESPIRATORY ORGANS

The mouth can also serve as an alternate entry point for air. The oral cavity plays a minor role in respiration but is essential for speech and swallowing.

If the nasal passages are blocked, breathing through the mouth becomes essential.

MOUTH AND ORAL CAVITY

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RESPIRATORY ORGANS

The pharynx connects the nasal cavity and mouth to the trachea. It serves as a common pathway for both air and food.

The epiglottis, a flap-like structure in the pharynx, prevents food from entering the trachea during swallowing.

PHARYNX (THROAT)

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RESPIRATORY ORGANS

The larynx is a tough, flexible segment of the respiratory tract that connects the pharynx (the back of the nose and throat) to the trachea (windpipe).

It allows air to pass through it while preventing food and drink from blocking the airway.

LARYNX

(VOICE BOX)

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RESPIRATORY ORGANS

The trachea is a wide, hollow tube that connects the larynx to the bronchi (airways) of the lungs. Its primary function is to enable airflow to and from the lungs. This preparation ensures that the air entering the lungs is at an optimal temperature and humidity level for efficient gas exchange.

TRACHEA (WINDPIPE)

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RESPIRATORY ORGANS

The bronchi are the main airways into the lungs. When you breathe, air enters your body through your mouth or nose and passes through the larynx and trachea. The trachea branches into a bronchus in each lung.

The bronchi are equipped with tiny, hair-like structures called cilia. Cilia help move mucus out of your lungs, keeping the bronchi clean and healthy.

BRONCHI

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RESPIRATORY ORGANS

Bronchioles are small, branching air passages inside the lungs. They serve as conduits for air, connecting the larger bronchi to the alveoli

Alveoli are where gas exchange occurs: oxygen enters the bloodstream, and carbon dioxide is removed during exhalation. Bronchioles deliver air to a diffuse network of approximately 300 million alveoli.

BRONCHIOLES

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RESPIRATORY ORGANS

Alveoli are tiny, air sacs located at the end of the bronchioles. These structures play a crucial role in gas exchange during breathing.

In the alveolus, oxygen molecules move through a single layer of lung cells, entering the bloodstream. Simultaneously, carbon dioxide (CO₂) molecules pass from the bloodstream into the alveolus.

ALVIOLI

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LET’S DISCUSS

During external respiration, oxygen-rich air enters the alveoli during inhalation.
Oxygen molecules diffuse across the thin alveolar walls into the bloodstream, where they bind to hemoglobin in red blood cells.
Simultaneously, carbon dioxide (produced by cellular metabolism) diffuses from the blood into the alveoli.
During internal respiration, oxygen is delivered to body tissues, and carbon dioxide is removed from the tissues and transported back to the lungs for exhalation.

GAS EXCHANGE

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During external respiration, oxygen-rich air enters the alveoli during inhalation.

Oxygen molecules diffuse across the thin alveolar walls into the bloodstream, where they bind to hemoglobin in red blood cells.

Simultaneously, carbon dioxide (produced by cellular metabolism) diffuses from the blood into the alveoli.

During internal respiration, oxygen is delivered to body tissues, and carbon dioxide is removed from the tissues and transported back to the lungs for exhalation.

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PERFORMANCE TASK

Students will demonstrate an understanding of the respiratory system, including its key organs and the process of gas exchange.
Students will apply their knowledge to create an informative product.

Goals:

Students take on the role of biologists exploring the intricate world of the respiratory system.

Roles:

The audience for this project includes their peers and teachers.

Audience:

Your mission is to create an educational resource that explains the importance of the respiratory system and how it works.

Situation:

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PERFORMANCE TASK

Product: An informative poster or digital presentation.
Performance: Students will present their posters or slides to the class, explaining the respiratory system’s key components and gas exchange process.
Purpose:

Educate others about the respiratory system.
Highlight the significance of healthy respiratory habits.
Foster curiosity and interest in biology.

Goals:

Grade 8 Science: Understand the structure and function of the respiratory system.
Grade 8 Health: Promote healthy respiratory practices.
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Standards:

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CRITERIA	EXCELLENT (10 POINTS)	GOOD (7-9 POINTS)	SATISFACTORY (4-6 POINTS)	NEEDS IMPROVEMENT (1-3 POINTS)
KNOWLEDGE OF ORGANS	Demonstrates an in-depth understanding of each respiratory organ’s structure and function.	Accurately describes the role of most organs (nose, pharynx, larynx, trachea, bronchi, lungs).	Provides basic descriptions of organ functions.	Shows minimal knowledge of respiratory organs.
GAS EXCHANGE EXPLANATION	Clearly explains the gas exchange process in the alveoli, including oxygen uptake and CO₂ removal.	Describes gas exchange with reasonable clarity, mentioning alveoli and their role.	Provides a basic overview of gas exchange but lacks depth.	Gas exchange explanation is unclear or incorrect.
USE OF TERMINOLOGY	Uses precise scientific terminology effectively.	Utilizes relevant terms appropriately.	Some use of terminology, but may be imprecise.	Limited use of relevant terminology.
VISUAL AIDS AND CREATIVITY	Incorporates engaging visuals (diagrams, labeled structures) to enhance understanding.	Includes relevant visual aids (e.g., diagrams).	Visuals are minimal or lack creativity.	No visual aids or creativity evident.
OVERALL PRESENTATION	Well-organized and engaging presentation.	Presentation is organized and informative.	May lack organization or engagement.	Minimal effort in presentation.

HOW WILL IT BE GRADED?