Biology Chapter: Specialized Exchange Surfaces

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Questions and Answers

What is a primary reason multicellular organisms require specialised exchange surfaces?

To enhance cellular respiration efficiency

To increase their surface area for photosynthesis

To facilitate digestion of larger food particles

To compensate for a lower surface area to volume ratio (correct)

Which characteristic is NOT a feature of an efficient exchange surface?

Good blood supply or ventilation

Thin membrane

Thick barrier to diffusion (correct)

Large surface area

What structure separates the lungs from the abdominal area?

Rib cage

Trachea

Diaphragm (correct)

Bronchioles

How are the trachea and bronchi similar in structure?

Both contain smooth muscle and are lined with ciliated epithelium Signup and view all the answers

What role do the external and internal intercostal muscles play in the respiratory system?

They contract to raise and lower the rib cage Signup and view all the answers

What prevents friction between the rib cage and lungs during breathing?

Lubricating substance secreted by the pleura Signup and view all the answers

What feature of the alveoli facilitates efficient gas exchange?

Large surface area and thin walls Signup and view all the answers

What adaptation allows the trachea to allow passage for food while maintaining airways?

Incomplete cartilage rings Signup and view all the answers

What is the role of ciliated epithelium in the respiratory system?

To facilitate the movement of mucus to prevent infection Signup and view all the answers

Which of the following structures contains cartilage?

Trachea Signup and view all the answers

During inspiration, what happens to the diaphragm?

It contracts and flattens Signup and view all the answers

What is the primary function of goblet cells in the respiratory system?

To secrete mucus that traps pathogens Signup and view all the answers

How do elastic fibers contribute to ventilation?

They stretch during inhalation and recoil during exhalation Signup and view all the answers

What occurs during the process of expiration?

Diaphragm relaxes and rises Signup and view all the answers

What device is used to measure lung volume?

Spirometer Signup and view all the answers

What happens to the pressure inside the thorax during inspiration?

It decreases, creating a pressure gradient Signup and view all the answers

What does vital capacity refer to?

The maximum volume of air that can be inhaled or exhaled in a single breath Signup and view all the answers

How can breathing rate be calculated using a spirometer?

By counting the number of peaks or troughs in a minute Signup and view all the answers

What is the primary function of gill filaments in bony fish?

To facilitate gas exchange Signup and view all the answers

What feature of fish gills allows for efficient gas exchange?

Counter current flow of blood and water Signup and view all the answers

What action starts the ventilation process in fish?

Opening the mouth and lowering the floor of the buccal cavity Signup and view all the answers

Why can't fish survive long out of water?

Their gills stick together without water flow Signup and view all the answers

What is the role of the operculum in bony fish?

To act as a pump that regulates water flow Signup and view all the answers

How do insects transport oxygen to their tissues?

Through direct diffusion to tissues Signup and view all the answers

Study Notes

The Need for Specialized Exchange Surfaces

Multicellular organisms have lower surface area to volume ratios than single-celled organisms, necessitating specialized exchange surfaces
Specialized exchange surfaces provide efficient transport of gases, nutrients, and waste products

Features of an Efficient Exchange Surface

Large Surface Area: Increases the area for diffusion, examples include root hair cells and folded membranes in mitochondria
Thin: Reduces the distance over which substances need to diffuse, allowing for quicker exchange
Good Blood Supply/Ventilation: Maintains a steep concentration gradient to facilitate diffusion

Mammalian Gaseous Exchange System

Lungs: Composed of two structures within the chest cavity with a large surface area
Rib Cage: Protects the lungs
Lubricating Substance: Prevents friction between the rib cage and lungs during breathing
Intercostal Muscles: External muscles raise the rib cage during inhalation, internal muscles lower the rib cage during exhalation
Diaphragm: Separates the lungs from the abdominal area, contracts to flatten during inhalation and relaxes to dome upwards during exhalation
Airways: Include the nose, trachea, bronchi, and bronchioles, facilitating air passage
Alveoli: Tiny sacs filled with air where gas exchange occurs

Structures and Functions of Mammalian Gaseous Exchange System

Cartilage: Provides support to the trachea and bronchi, prevents collapse during exhalation
Ciliated Epithelium: Lines the bronchi, bronchioles, and trachea, moves mucus towards the throat to prevent lung infections
Goblet Cells: Produce mucus to trap bacteria and dust, reducing infection risk
Smooth Muscle: Contracts to constrict airways, regulating airflow to and from alveoli
Elastic Fibres: Stretch during inhalation and recoil during exhalation, assisting airflow

Ventilation

Inspiration (Inhalation): External intercostal muscles contract, diaphragm flattens, increasing thorax volume and decreasing pressure, drawing air into the lungs
Expiration (Exhalation): Internal intercostal muscles contract, diaphragm relaxes, decreasing thorax volume and increasing pressure, forcing air out of the lungs

Spirometer

Purpose: Measures lung volume
Function: A person breathes into an airtight chamber, causing it to move up and down, producing a trace on a graph for analysis
Vital Capacity: Maximum volume of air inhaled or exhaled in one breath
Tidal Volume: Volume of air breathed in and out at rest
Breathing Rate: Number of breaths per minute, determined by counting peaks or troughs on the spirometer trace
Residual Volume: Air always present in the lungs
Inspiratory Reserve Volume: Additional volume of air that can be inhaled beyond tidal volume
Expiratory Reserve Volume: Additional volume of air that can be exhaled beyond tidal volume

Ventilation and Gas Exchange in Bony Fish

Fish Adaptations: Small surface area to volume ratio, impermeable skin necessitate specialized gas exchange systems
Gills: Four pairs of gills supported by arches
Gill Filaments: Projections along each arch containing lamellae for gas exchange
Countercurrent Flow: Water and blood flow in opposite directions across the lamellae, maximizing gas exchange efficiency
Ventilation: Requires continuous unidirectional water flow
Buccal Cavity: Fish open their mouths and lower the buccal cavity floor to draw water in, then raise the floor to increase pressure and force water over the gills
Operculum: Acts as a valve and pump, regulating water flow

Ventilation and Gas Exchange in Insects

Lack of Transport System: Oxygen must be transported directly to respiring tissues

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Description

This quiz explores the necessity and characteristics of specialized exchange surfaces in multicellular organisms, emphasizing their efficiency in gas and nutrient transport. It also delves into the mammalian gaseous exchange system, focusing on the structure and function of lungs and related features.