Anatomy & Physiology Exam 2

What is the correct order of airflow through the respiratory system?

Nasal/oral cavity -> pharynx -> larynx -> trachea -> bronchi -> lungs

What are two entry points of the respiratory system?

Nasal cavity and oral cavity

What is the pharynx?

A muscular tube that connects the nasal/oral cavities to the larynx

What is the larynx?

A structure located between the pharynx and trachea that houses the vocal folds

What is the trachea?

A tube that carries air from the larynx to the bronchi

What is the bronchi?

Two main branches of the trachea that lead into each lung

What is the primary function of the lungs?

Gas exchange (oxygen in, carbon dioxide out).

What are the 3 main functions of the larynx?

Airway protection, respiration, and phonation (voice production)

How does the larynx protect the airway?

Closes during swallowing to prevent food/liquid from entering the lungs

What role does the larynx play in speech?

Houses vocal folds that vibrate to produce sound

What are the two main cavities of the respiratory system?

Thoracic cavity and abdominal cavity

What separates the thoracic and abdominal cavities?

The diaphragm

Where is the trachea located?

Anterior to the esophagus and extends from larynx to bronchi

What shape is the trachea?

C-shaped cartilage rings

Why are tracheal rings C-shaped?

Allows flexibility and space for the esophagus to expand

What membrane completes the open part of the trachea?

Trachealis muscle (posterior membrane)

The trachea divides into what two structures?

Primary bronchi

Bronchi divide into smaller tubes called what?

Bronchioles

What are the tiny air sacs at the ends of bronchioles?

Alveoli

Where does gas exchange occur?

In the alveoli

What is gross anatomy of the lungs?

Large spongy organs divided into lobes

How many lobes does the right lung have?

3 lobes

How many lobes does the left lung have?

2 lobes

Why does the left lung have fewer lobes?

Space for the heart

What are the pleura?

Membranes surrounding the lungs

What are the 2 layers of pleura?

Visceral pleura and parietal pleura

Function of pleura?

Reduce friction and allow smooth lung movement

What is pleural linkage?

The coupling of lung movement to chest wall movement via pleural fluid

What is pneumothorax?

Collapse of lung due to air entering pleural space

What is the conducting zone?

Passages that move air (no gas exchange)

What structures are in the conducting zone?

Nose -> pharynx -> larynx -> trachea -> bronchi -> bronchioles

What is the respiratory zone?

Area where gas exchange occurs

What structures are in the respiratory zone?

Alveoli

How many cervical vertebrae are there?

12

How many thoracic vertebrae?

12

How many lumbar vertebrae?

5

What is the sacrum?

Fused vertebrae at the base of the spine

What is the coccyx?

Tailbone

What is the atlas?

C1 vertebra (supports skull)

What is axis?

C2 vertebra (allows head rotation)

What is the vertebral foramen?

Opening for spinal cord

Function of intervertebral discs?

Shock absorption and flexibility

What are the 3 articulation points of ribs?

Vertebral body, transverse process, sternum

What are components of pelvic girdle?

ilium, ischium, pubis

What is the iliac crest?

Top ridge of ilium

What is the pubis symphysis?

Joint connecting pubic bones

What bones make up the pectoral girdle?

Clavicle and scapula

What are the 3 parts of the sternum?

Manubrium, body, xiphoid process

Parts of a rib?

Head, neck, tubercle, shaft

How do ribs attach dorsally?

To vertebrae

How do ribs attach ventrally?

To sternum via costal cartilage

How many muscles are involved in quiet inspiration?

2

Main muscle of quiet inspiration?

Diaphragm

Second muscle of quiet inspiration?

External intercostals

How many muscles are involved in forced inspiration?

9

What happens during forced inspiration?

Additional muscles elevate rib cage to increase lung volume

Is quiet expiration active or passive?

Passive

What causes quiet expiration?

Elastic recoil of lungs and relaxation of diaphragm

How many muscles are involved in active expiration?

7

What happens during active expiration?

Muscles contract to force air out

Why is the diaphragm essential for breathing?

It creates negative pressure to draw air into lungs

What happens when diaphragm contracts?

Moves downward -> thoracic cavity expands

What happens when diaphragm relaxes?

Moves upward -> air pushed out

Diaphragm: Origin

Xiphoid process, lower 6 ribs, lumbar vertebrae

Diaphragm: Insertion

Central tendon

Diaphragm: Function

Primary muscle of inspiration; contracts and flattens to increase thoracic volume

External Intercostals: Origin

Inferior border of rib above

External Intercostals: Insertion

Superior border of rib below

External Intercostals: Function

Elevate ribs -> increase thoracic cavity (quiet inspiration)

Sternocleidomastoid: Origin

sternum (manubrium) and clavicle

Sternocleidomastoid: Insertion

Mastoid process of temporal bone

Sternocleidomastoid: Function

Elevates sternum -> assists in forced inspiration

Scalenes: Origin

Cervical vertebrae

Scalenes: Insertion

First and second ribs

Scalenes: Function

Elevate upper ribs -> assist forced inspiration

Subclavius: Insertion

Clavicle

Subclavius: Function

Stabilizes clavicle and assists in elevating rib cage

Pectoralis Major: Origin

Clavicle, sternum, upper ribs

Pectoralis Major: Insertion

Humerus

Pectoralis Major: Function

Assists forced inspiration when arms are fixed; elevates rib cage

Pectoralis Minor: Origin

Ribs 3-5

Pectoralis Minor: Insertion

Scapula (coracoid process)

Serratus Anterior: Origin

Upper 8-9 ribs

Serratus Anterior: Insertion

Medial border of scapula

Costal Levator (Levatores Costarum): Origin

Transverse processes of vertebrae

Costal Levator (Levatores Costarum): Insertion

Rib below

Costal Levator (Levatores Costarum): Function

Elevate ribs -> assist inspiration

Serratus Posterior Superior: Origin

Upper thoracic vertebrae

Serratus Posterior Superior: Insertion

Upper ribs (2-5)

Latissimus Dorsi: Insertion

Humerus

Latissimus Dorsi: Function

Assists forced expiration (can compress rib cage)

What is the primary force driving quiet expiration?

Elastic recoil of the lungs

What structures contribute to elastic recoil of the lungs

Elastic fibers in lung tissue and alveoli

How do alveoli contribute to quiet expiration?

They recoil after being stretched, pushing air out

What happens to the diaphragm during quiet expiration?

It relaxes and moves upward

What happens to the rib cage during quiet expiration?

It moves downward and inward

What causes the diaphragm to move upward and during expiration?

Relaxation and pressure from abdominal contents

What happens to thoracic cavity volume during quiet expiration?

It decreases

Rectus Abdominis: Origin

Pubic crest and pubic symphysis

Rectus Abdominis: Insertion

Xiphoid process and costal cartilages of ribs 5-7