Anatomy & Functions of the Respiratory System Flashcards
Respiratory System
Main Function
- Responsible for conducting gas exchange between the body & the environment
Gas Exchange provides the body with gas (O2) & removes waste gas (CO2)
Anatomy & Functions
Nose/External Nose
Upper Respiratory Tract
Anatomy:
- Nasal Cavity - Inner space of the nose
- Nasal Septum - wall that divides nasal cavity into two halves to form the nostrils
Functions:
- Nostrils - allow entry/exit of air to/from the body
- Nasal hairs filter out large particles/debris from the air before it enters the respiratory tract
Anatomy & Functions
Nasal Cavity
Upper Respiratory Tract
Anatomy:
- Behind the nose, extends from the nostrils to the back of the throat
- Divided into two halves by nasal septum
Functions:
- Produces mucous membrane
- Mucous membrane - contains goblet cells, conchae, meatuses, and cilia that help to filter, warm, & humidify the air before it enters the lungs
- Goblet cells - produce mucus to trap dust/dirt/other particles in air
- Mucus helps to humidify & warm air as it moves through nasal cavity
- Conchae - 3 bony projections in each nasal cavity that increase surface area of mucous membrane
- Meatuses - narrow passageways between conchae that help slow down and filter air
- Cilia - hair-like structures that move in coordinated motions to move mucus/debris towards the back of throat
Humidification maintains homeostasis of the airway
Anatomy & Functions
Nasal Septum
Upper Respiratory Tract
Anatomy:
- Wall of cartilage that divides the nose into two equal sections
- Main components: perpendicular plate of ethmoid bone in posterior part, vomer bone in center, and septal cartilage in anterior part
Function:
- Covered with a mucous membrane, containing cilia and goblet cells , similar to rest of nasal cavity to aid in inspiration and expiration
Anatomy & Functions
Pharynx
Upper Respiratory Tract
Anatomy:
- Divided into 3 parts: nasopharynx, oropharynx, & laryngopharynx
Function:
- Muscular tube that connects nasal & oral cavity to larynx and esophagus
- Serves as common pathway for air and food
- When swallowing food or liquid, the epiglottis (a flap of cartilage) closes off the trachea (tube leading to respiratory tract) to prevent choking
Anatomy & Functions
Nasopharynx
Upper Respiratory Tract
Anatomy:
- Region of the pharynx at back of nose and above soft palate
Function:
- Connects nasal cavity to rest of the respiratory system
- Drainage channel for Eustachian tubes, which connect middle ear to back of nose, equalizing air pressure on both sides of eardrum
Anatomy & Functions
Oropharynx
Upper Respiratory Tract
Anatomy:
- Central region of pharynx between roof of the mouth and upper edge of epiglottis
- Connects oral cavity to rest of the respiratory system
- Moves food from the mouth to the esophagus by contracting the muscles in the back of the throat
- Regulates breathing by providing an open pathway for air to travel from the mouth to the lungs
Function:
- Connects oral cavity to rest of the respiratory system
- Helps move food from the mouth to the esophagus by contracting the muscles in the back of the throat
- Helps to regulate breathing by providing an open pathway for air to travel from the mouth to the lungs
Anatomy & Functions
Laryngopharynx
Upper Respiratory Tract
Anatomy:
- Lower region of pharynx that lies between soft palate and hyoid bone
- Connects and divides into the larynx and esophagus
Function:
- Serves as a passageway for both food and air
- During swallowing, larynx is lifted and epiglottis closes off the entrance to trachea, allowing food and liquid to pass through esophagus and into stomach
Anatomy & Functions
Larynx
Upper Respiratory Tract
Anatomy:
- Located in the neck, between the base of the tongue and the trachea
- Made up of several cartilages, including the thyroid cartilage (Adam’s apple) & cricoid cartilage
- Contains the glottis, the opening through which air passes
- More commonly known as the ‘voice box’; when speaking, the voice box opens, and when not speaking, the voice box closes
- Vocal cords are two folds of tissue in the larynx that vibrate to produce sound; located inside the glottis
Function:
- Helps regulate the flow of air in and out of the lungs during breathing
- Protects the airways during swallowing by closing off the trachea with the epiglottis
- Plays a role in coughing, sneezing, & clearing the airways
- Involved in maintaining airway resistance during respiration, which helps prevent the collapse of the airways
- Maintains the pressure in the thorax, which is important for the function of the heart & lungs
Anatomy & Functions
Trachea
Lower Respiratory Tract
Anatomy:
- More commonly known as the windpipe
- Runs from the larynx to above the lungs
- Divides into two large branches behind the sternum called primary bronchi which enter each lung
- Trachea and bronchi are made from smooth muscle & cartilage which allows the airways to contract and expand during inspiration and expiration
Function:
- Connects the larynx to the lungs
- Pathway for air to enter and exit the lungs
- Lined with cilia and goblet cells that help to trap and remove foreign particles and microorganisms from the respiratory tract
Anatomy & Functions
Lungs
Lower Respiratory Tract
Anatomy:
- Paired organs within the chest cavity on either side of the heart
- Protected by rib cage
- Sit on top of the diaphragm muscle, a muscle fixed to the lower ribs, sternum, and lumbar vertebrae
- Covered by two layers of plurae; visceral (outer surface of lungs) and parietal (inner surface of chest cavity)
- The plural cavity is the space between the two plurae which contains a lubricating intrapleural fluid
- Conduct gas exchange through the bronchi in each lung
Function:
- Brings oxygen into the body and exhales carbon dioxide; respiration
The visceral and parietal plurae are usually “stuck” to each other, which is why when our lungs intake oxygen, we can notice it because our chest expands as well
Anatomy & Functions
Bronchi & Bronchioles
Lower Respiratory Tract
Anatomy:
- Made of cartilagenous tissue
- Tree-like structure; starts with main trunk (bronchi) which splits into two large segments (primary bronchi) which then diverges into smaller branches (bronchioles)
- Terminal bronchioles (smallest branches of bronchi) contain alveolar sacs, the primary site of gas exchange
Function:
- Cartilage tissue allows airway to contract and expand during respiration
- Pathway for air to enter and exit the lungs
- Lined with cilia and goblet cells that help to trap and remove foreign particles and microorganisms from the respiratory tract
Anatomy & Functions
Alveoli/Alveolar Sacs
Lower Respiratory Tract
Anatomy:
- Alveolar sacs contain individual alveoli within the sac
- Alveoli are grape-like structures at the end of each terminal bronchiole
- Provide a large surface area for gas exchange to occur
- Total surface area of about 70 square meters in the average adult
- Each alveoli is wrapped with capillaries, which are how the body gets oxygen to every location, and how carbon dioxide is delivered from anywhere to the lungs
- The surface of the membrane of the alveolus and capillaries is called the respiratory membrane
Function:
- Primary site of gas exchange within the respiratory system
- Oxygen from inhaled air diffuses through the alveolar walls and into the blood
- Carbon dioxide produced by the body’s cells diffuses out of the blood and into the alveoli to be exhaled
Anatomy & Functions
Diaphragm
Lower Respiratory Tract
Anatomy:
- Dome-shaped muscle
Function:
- Separates the thoracic cavity from the abdominal cavity
- Contracts downward during inspiration, increasing the volume of the thoracic cavity
- Relaxes during expiration and elasticity of lungs pushes air out
