The Respiratory System (Revision) Flashcards
1
Q
Divisions of the Respiratory System
A
Conducting Division
- Transports air to the lungs
- Nasal cavity
- Pharynx
- Larynx
- Trachea
- Bronchi
Respiratory Division
- Where gas exchange occurs
- Alveoli
- Respiratory bronchioles
2
Q
Key Structures of the Respiratory System
A
Nasal Cavity
- Conchae and meatuses
- Warm, humidify, and filter incoming air
- Internal nares opens into nasopharynx
Pharynx
- Nasopharynx
- Oropharynx
- Laryngopharynx
Larynx
- Unpaired cartilages (epiglottis, thyroid, cricoid)
- Ligaments that stabilize the structure
Trachea
- A tube supported by cartilages
- Connects larynx to the bronchi
- Trachealis smooth muscle
Alveoli
- Tiny air-filled pockets
- Site of gas exchange
3
Q
Lung Anatomy
A
Lobes
- Right lung has three lobes
- Left lung has two lobes
- Left lung is longer, displaced leftward
- Cardiac impression in the medial margin
Pleural Membranes
- Each lung surrounded by parietal and visceral pleura
- Creates a pressure gradient, reduces friction
- Pulmonary ligament: attaches lung to mediastinum
4
Q
Quiet Inhalation
A
Diaphragm
- Contracts and moves downward
- Increases the volume of the thoracic cavity
External Intercostal Muscles
- Muscles between the ribs contract
- Elevates the rib cage
- Increases the thoracic volume
Air Pressure Change
- Thoracic cavity volume increases
- Pressure inside the cavity decreases
- Creates negative pressure
- Draws air into the lungs
5
Q
Forced Inhalation
A
In addition to diaphragm and intercostal muscles
- Scalene Muscles: Located in the neck, elevate the first two ribs
- Sternocleidomastoid Muscles: Located in the neck, raise the sternum
6
Q
Quiet Exhalation
A
- Passive process
- Diaphragm and intercostal muscles relax
- Thoracic cavity volume decreases
- Pressure inside the cavity increases
- Pushes air out of the lungs
7
Q
Forced exhalation
A
Abdominal Muscles
- Contract to push the diaphragm upward
- Decreases thoracic volume
Internal Intercostal Muscles
- Pulls the ribs down and inward
- Decreases thoracic volume
8
Q
Features of the Alveoli
A
- Alveolar Walls: Squamous epithelial cells (type I alveolar cells) and specialized cells (type II alveolar cells)
- Surfactant: Reduces surface tension, prevents alveolar collapse, aids in lung expansion
- Elastic Fibers: Allows stretching during inhalation and recoiling during exhalation
9
Q
Ribs
A
Structure
- 12 pairs of curved bones
- Form the rib cage
- Provides structural support and protection for the thoracic cavity
Types
- True Ribs (1-7): Attach directly to the sternum via costal cartilage
- False Ribs (8-10): Attach indirectly to the sternum through the cartilage of the rib above
- Floating Ribs (11-12): Do not attach to the sternum, connected to the vertebrae
Function
- Protect vital organs (heart and lungs)
- Assist in respiration by expanding and contracting the thoracic cavity
10
Q
Vertebrae (Back bones of the spine)
A
Structure
- 33 vertebrae categorized into five regions
- Cervical (7)
- Thoracic (12)
- Lumbar (5)
- Sacral (5 fused)
- Coccygeal (4 fused).
Function
- Provide structural support
- Protect the spinal cord
- Allow for flexibility and movement
Features
- Intervertebral Discs: Cartilaginous pads for shock absorbers
- Spinous and Transverse Processes: Muscles and ligaments attach, aiding movement and stability
- Vertebral Foramen: Central hole for the spinal cord to pass through
11
Q
Sternum
A
Structure
- Flat bone located in the center of the chest
- Three parts: the manubrium, body, and xiphoid process
Function
- Anchors the ribs through costal cartilage
- Provides protection to the heart and lungs
Features
- Manubrium: Upper portion, articulates with the clavicles and the first two pairs of ribs
- Body: Middle portion, where most ribs attach
- Xiphoid Process: Lower portion, small and pointed, attachment point for muscles and ligaments
