BIOS 255 Week 6 Respiratory System-Anatomy

Student Name

Chamberlain University

BIOS-252: Anatomy & Physiology II with Lab

Prof. Name

Date

Respiratory System – Anatomy

Learning Objectives

Identify the gross anatomical features of the respiratory tract.
Trace the flow of air into and out of the lungs.
Explain how Boyle’s Law relates to intrapleural and alveolar air pressures during respiration.
Define and differentiate pulmonary volumes.

Introduction

The respiratory system is an essential physiological system responsible for the exchange of gases between the external environment and the body. When air enters through the nasal or oral cavity, it travels sequentially through the pharynx, larynx, trachea, bronchi, and eventually reaches the alveoli within the lungs. The process of inhalation occurs when thoracic cavity volume increases, leading to reduced pressure in the lungs compared to atmospheric pressure, thereby drawing air inward. This change is explained by Boyle’s Law, which links pressure and volume in closed systems.

The lungs are enclosed within the thoracic cavity and protected by the pleural membrane, a double-layered structure that allows smooth expansion during breathing. Pulmonary function can be measured using spirometry, which provides data on various lung volumes such as tidal volume and inspiratory reserve volume. Understanding these principles highlights the critical role of the respiratory system in sustaining life.

Assignment

Part 1

Students are expected to engage in interactive activities on Anatomy.TV to explore the upper and lower respiratory tracts, pulmonary ventilation, lung capacities, and functional measurements.

Steps to Access Anatomy.TV:

Go to the Resources tab.
Navigate to Library > Library Resources – Database A-Z > Anatomy.TV.
Select the assigned system and explore the relevant sections.
Complete the interactive activities provided.

Part 2

Students will complete the Respiratory Anatomy Lab Report after finishing the Anatomy.TV exercises.

Respiratory Anatomy Lab Report

Purpose

The purpose of this laboratory exercise is to investigate the structure and function of the respiratory organs, understand the mechanics of respiration, apply Boyle’s Law to pulmonary physiology, and identify different forms of respiration.

Procedure

The lab requires students to:

Identify structures of the respiratory system.
Trace the flow of air through the respiratory tract.
Relate thoracic cavity changes to air movement.

Data and Details

a. Functions of the Respiratory System

Function	Description
Gas Exchange	Supplies oxygen to cells and removes carbon dioxide.
Pulmonary Defense	Filters, humidifies, and protects against pathogens.
Acid-Base Regulation	Maintains blood pH through carbon dioxide control.
Metabolic Functions	Processes bioactive materials, such as angiotensin-converting enzyme (ACE).

b. Anatomy of the Larynx
The larynx contains several cartilaginous structures that protect the airway and aid phonation:

Thyroid cartilage: Commonly known as the Adam’s apple, provides structural support.
Cricoid cartilage: Forms a complete ring below the thyroid cartilage.
Epiglottis: Leaf-shaped flap preventing aspiration of food into the airway.

Questions

a. Boyle’s Law
Boyle’s Law explains that at a constant temperature, pressure and volume of a gas are inversely related. During inhalation, the thoracic cavity expands, increasing lung volume and reducing pressure, which draws air into the lungs.

b. Thoracic Cavity Volume and Pressure
When the diaphragm contracts and flattens, thoracic cavity volume increases. This reduction in intrapulmonary pressure allows atmospheric air to flow into the lungs. Relaxation of the diaphragm reverses the process, expelling air during exhalation.

c. Role of Surfactant in the Lungs
Pulmonary surfactant reduces surface tension in the alveoli, preventing alveolar collapse and facilitating efficient gas exchange. Without surfactant, respiratory distress and impaired lung function may occur.

d. Pulmonary Volumes

Pulmonary Volume	Definition
Tidal Volume (TV)	Volume of air inhaled or exhaled during normal breathing.
Inspiratory Reserve Volume (IRV)	Additional volume that can be inhaled beyond a normal breath.
Expiratory Reserve Volume (ERV)	Additional air that can be exhaled after normal expiration.
Residual Volume (RV)	Air remaining in lungs after maximal exhalation to prevent collapse.

Discussion

a. Anatomic Dead Space
Anatomic dead space represents the portion of the airway (trachea, bronchi, bronchioles) where no gas exchange occurs. Although air fills these structures, oxygen and carbon dioxide exchange takes place only in the alveoli.

b. Difficulties in the Lab
One challenge during the lab was manipulating the 3D model of the respiratory system. Enhanced interactivity and user-friendly software would improve comprehension and accessibility.

Reflection

This lab provided valuable insights into the mechanics of respiration. I gained a clearer understanding of ventilation, the role of the diaphragm, and the importance of surfactant in maintaining alveolar function. Additionally, I learned about the carina, a ridge at the bifurcation of the trachea into the right and left primary bronchi, which plays an important role in airway reflexes during respiration.

Grading Rubric for Lab Report Activity

Deliverable	Points
Part 1: Lab activities/simulation	10
Part 2: Lab report and responses
– Purpose	2
– Procedure	2
– Data and Details	5
– Questions	4
– Discussion	2
– Reflection	5
Total	30

References

American Thoracic Society. (2020). Pulmonary function testing guidelines. ATS Publications.

Guyton, A. C., & Hall, J. E. (2021). Textbook of medical physiology (14th ed.). Elsevier.

BIOS 255 Week 6 Respiratory System-Anatomy

Marieb, E. N., & Hoehn, K. (2019). Human anatomy & physiology (11th ed.). Pearson.

West, J. B. (2020). Respiratory physiology: The essentials (11th ed.). Wolters Kluwer.