Respiratory Anatomy

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Questions and Answers

What type of joints does each rib form?

Two costovertebral joints

One costotransverse joint

One costovertebral joint

Two joints: one costovertebral and one costotransverse (correct)

What is the function of the conchae in the nasal cavity?

To increase surface area and warm the air (correct)

To produce mucus to moisturize the air

To detect odors in the air

To filter out large particles from the air

What is the name of the flap of cartilage that prevents food and drink from entering the trachea?

Epiglottis (correct)

Laryngeal cartilage

Glottis

Uvula

Which part of the pharynx is posterior to the oral cavity and inferior to the level of the soft palate?

Oropharynx Signup and view all the answers

What is the name of the tube that air travels through to reach the lungs?

Trachea Signup and view all the answers

What is the purpose of the laryngeal cartilage?

To surround and protect the larynx Signup and view all the answers

What is the name of the system of airways that allow passage of air into the lungs?

Tracheobronchial tree Signup and view all the answers

What is the boundary between the oral cavity and the nasal cavity?

Hard palate Signup and view all the answers

What happens to the air after it passes through the larynx?

It enters the trachea Signup and view all the answers

Why do we sometimes choke on food or drink?

Because the trachea and oesophagus are not separated Signup and view all the answers

What is the purpose of the thoracic cage?

All of the above Signup and view all the answers

Which of the following structures is NOT part of the sternum?

Costal cartilage Signup and view all the answers

Where is the sternal angle located?

At the level of the T4 vertebrae Signup and view all the answers

Which ribs articulate with the body of the sternum?

Ribs 3-6 Signup and view all the answers

What is the name of the depression on the superior aspect of the manubrium?

Jugular notch Signup and view all the answers

Which of the following structures articulates with the medial ends of the clavicles?

Manubrium Signup and view all the answers

What is the level of the T10 vertebrae?

Level of the xiphoid process Signup and view all the answers

What is the function of the costal cartilages?

Both b and c Signup and view all the answers

Which nerve innervates the diaphragm?

Phrenic nerve (C3, C4, C5) Signup and view all the answers

What are the three areas of attachment of the diaphragm?

Costal cartilages, lumbar vertebrae, and xiphoid process Signup and view all the answers

What is the effect of diaphragm contraction on the thoracic cavity?

Increase in vertical size Signup and view all the answers

Which of the following structures passes through the diaphragm at the T8 level?

Inferior vena cava Signup and view all the answers

What is the function of the external intercostal muscles?

To elevate the ribs Signup and view all the answers

Which muscle is NOT an accessory muscle of inhalation?

Rectus abdominis muscle Signup and view all the answers

What is the arrangement of the neurovascular bundle in the intercostal spaces?

Vein, artery, nerve Signup and view all the answers

What is the name of the movement of the ribs during inspiration?

Bucket handle movement Signup and view all the answers

What is the function of the internal intercostal muscles?

To draw adjacent ribs nearer together Signup and view all the answers

What is the central tendon of the diaphragm?

A tendinous part of the diaphragm Signup and view all the answers

What is the primary function of the trachealis muscle?

To allow the trachea to expand and contract Signup and view all the answers

Why are the tracheal rings shaped like 'C' rather than complete circles?

To accommodate the position of the esophagus Signup and view all the answers

How many secondary bronchi are found in the left lung?

2 Signup and view all the answers

What is the composition of surfactant secreted by Type 2 pneumocytes?

A mixture of fats and proteins Signup and view all the answers

What characteristic distinguishes the right bronchus from the left bronchus?

The right bronchus is wider and shorter Signup and view all the answers

What type of epithelium lines the majority of the respiratory tree from the nasal cavity to the bronchi?

Pseudostratified columnar ciliated epithelium Signup and view all the answers

What happens to inhaled foreign objects in the bronchi?

They are more likely to get lodged in the right bronchus Signup and view all the answers

What is the primary role of Type 1 pneumocytes in the alveoli?

To facilitate gas exchange Signup and view all the answers

What does widening or distortion of the carina typically indicate?

Possible cancer in the lymph nodes Signup and view all the answers

Which structure is directly responsible for trapping pathogens in the respiratory tract?

Ciliated cells Signup and view all the answers

Which ribs are classified as true ribs?

Ribs 1-7 Signup and view all the answers

What distinguishes atypical ribs from typical ribs?

Atypical ribs have unique features not seen in other ribs. Signup and view all the answers

How do ribs 8-10 articulate with the sternum?

Indirectly through the costal cartilages of superior ribs. Signup and view all the answers

What is the role of the costal groove found on typical ribs?

It protects blood vessels and nerves. Signup and view all the answers

Which of the following statements about rib anatomy is correct?

Ribs 11 and 12 have no tubercles or necks. Signup and view all the answers

What is the primary function of the rib cage?

To protect internal thoracic organs. Signup and view all the answers

Which rib is characterized by a single facet for articulation?

Rib 1 Signup and view all the answers

How many costal cartilages connect with the sternum?

Seven Signup and view all the answers

What structural feature do all thoracic vertebrae possess regarding ribs?

They possess both superior and inferior demi-facets. Signup and view all the answers

What characterizes the left lung compared to the right lung?

Longer and narrower than the right lung Signup and view all the answers

Which structure is located at the hilum of the lungs?

Nerves, arteries, veins, and bronchi Signup and view all the answers

How many bronchopulmonary segments are found in the right lung?

10 Signup and view all the answers

What is the primary function of pulmonary arteries?

Deliver deoxygenated blood to capillaries around the alveoli Signup and view all the answers

Where do bronchial veins on the left side drain into?

Accessory hemiazygos vein Signup and view all the answers

What is the main role of the diaphragm in respiration?

Separating the thoracic and abdominal cavities Signup and view all the answers

Which fissure is found only in the right lung?

Horizontal fissure Signup and view all the answers

What does the term 'costal surface' refer to?

The surface adjacent to the rib cage Signup and view all the answers

Which of the following structures is involved in the drainage of the right bronchial veins?

Azygos vein Signup and view all the answers

What is the purpose of bronchoscopy?

To visually inspect airways and lungs Signup and view all the answers

At what gestational age does surfactant production typically begin in a developing fetus?

24-28 weeks Signup and view all the answers

What is the primary function of the lungs?

Oxygenating blood Signup and view all the answers

Which cell type primarily promotes mucus motility in the larger airways?

Ciliated cells Signup and view all the answers

What distinguishes the visceral pleura from the parietal pleura?

Surrounds and is attached to the lungs Signup and view all the answers

What is the consequence of being born prematurely with insufficient surfactant?

Respiratory Distress Syndrome (RDS) Signup and view all the answers

Which of the following describes the histology of the proximal conducting zone airways?

Pseudostratified columnar epithelium Signup and view all the answers

How many lobes does the right lung have?

3 lobes Signup and view all the answers

What structure separates the thoracic cavity from the abdominal cavity?

Diaphragm Signup and view all the answers

What is the preferred term for the space between the parietal pleura and visceral pleura?

Pleural cavity Signup and view all the answers

What type of epithelium is commonly found in the bronchioles?

Simple cuboidal epithelium Signup and view all the answers

Study Notes

The Thoracic Cage (Rib Cage)

The thoracic cage is made up of:
- Sternum (breastbone)
- 12 pairs of ribs
- Thoracic vertebrae
Its purpose is to provide structure and protect thoracic contents (heart and lungs)
The thoracic cage has the ability to change its volume of space during inhalation/exhalation to allow lungs to expand

The Sternum

The sternum (breastbone) consists of:
- Manubrium
- Body
- Xiphoid process
Sternal angle (angle of Louis) is located at the level of T4 vertebrae
The superior aspect of the manubrium is concave, producing a depression called the jugular notch

Ribs

There are 12 pairs of ribs, classified as:
- True ribs (1-7): articulate directly with the sternum
- False ribs (8-10): do not articulate directly with the sternum
- Floating ribs (11 and 12): have no anterior connection with other ribs or the sternum
Typical ribs have a head, neck, and body (shaft)
Atypical ribs (1, 2, 10, 11, and 12) have variations on this structure

Costovertebral Joints

The ribs articulate posteriorly with the thoracic vertebrae
Each thoracic vertebra has two demi-facets on either side of its vertebral body
The demi-facets articulate with the heads of two different ribs
Each rib forms two joints: costovertebral joint and costotransverse joint

The Respiratory System

The respiratory system can be divided into upper and lower parts:
- Upper: nose, nasal passages, paranasal sinuses, pharynx, and larynx above the vocal cords
- Lower: larynx below vocal cords, trachea, bronchi, bronchioles, and lungs
The nasal cavity:
- Air enters the nose via the nasal cavity
- Conchae increase surface area and spin the air to warm and moisten it
The oral cavity:
- Acts as an air inlet in addition to the nasal cavity
- Lies inferior to the nasal cavity, bordered superiorly by the hard palate and soft palate
The pharynx:
- Can be divided into three parts: nasopharynx, oropharynx, and laryngopharynx
- Serves as a common passageway for air and food

The Tracheobronchial Tree

The trachea, bronchi, and bronchioles form the tracheobronchial tree
The trachea bifurcates into the left and right primary bronchi
The bronchi have characteristic hyaline cartilage rings
The left and right primary bronchi divide further into secondary bronchi, and then tertiary bronchi

The Bronchi

Each tertiary bronchus gives rise to many terminal bronchioles
Terminal bronchioles give rise to respiratory bronchioles
Each respiratory bronchiole ends in an acinus of clustered alveoli

Epithelial Types Recap

Pseudostratified columnar ciliated epithelium lines the trachea and bronchi
Simple columnar to simple cuboidal epithelium lines the bronchioles
Simple squamous epithelium lines the alveoli

The Alveoli

The alveolar wall has a different structure than the bronchioles
Type 1 pneumocytes are responsible for gas exchange
Type 2 pneumocytes secrete surfactant, which decreases surface tension and helps keep alveoli open
Surfactant production begins in the developing fetus at around 24-28 weeks gestation### Descending Aorta
The descending aorta transports blood to the thorax, abdomen, pelvis, and lower limbs.
It is divided into two parts: thoracic aorta and abdominal aorta.
The thoracic aorta gives rise to bronchial arteries, which supply the trachea and bronchial tree.
The abdominal aorta begins at the diaphragm and extends to the common iliac arteries.

Vasculature

The trachea and bronchial tree receive blood supply from the thoracic aorta through bronchial arteries.
Bronchial veins drain into the accessory hemiazygos vein on the left and the azygos vein on the right, which ultimately drain into the Superior Vena Cava (SVC).

Lymphatics

The inferior tracheobronchial lymph nodes can become enlarged and distort the carina, indicating pathology.
Bronchoscopy involves traveling down the trachea to enter a main bronchus, and cancer cells can metastasize to the inferior tracheobronchial lymph nodes.

Diaphragm

The diaphragm is the most important muscle of respiration, separating the thoracic and abdominal cavities.
It is comprised of two domes and is peripherally muscular, with a central tendon.
The diaphragm is innervated by the phrenic nerve (C3, C4, C5) and has three areas of attachment: costal cartilages, lumbar vertebrae, and the xiphoid process of the sternum.
The parts of the diaphragm that arise from the vertebrae are known as the right and left crura.

Movement of Diaphragm

Contraction of the diaphragm results in a downward movement of the central tendon, increasing the vertical size of the thoracic cavity during inhalation.
Relaxation of the diaphragm allows it to return to its resting position, decreasing the vertical size of the thoracic cavity during exhalation.
The diaphragm's movement is often described as a "bucket handle" movement, with the diaphragm increasing thoracic volume in three planes during inspiration.

Openings in the Diaphragm

There are three major openings in the diaphragm that allow the oesophagus, inferior vena cava, and aorta to pass from the thoracic to the abdominal cavity.
These openings occur at specific levels: IVC at T8, oesophagus at T10, and aorta at T12.

Intercostal Spaces

The intercostal spaces are numbered according to the rib superior to them and contain intercostal muscles that help move the ribs during breathing.
There are three layers of intercostal muscles: external, internal, and innermost.

Intercostal Muscles

External intercostal muscles are the most superficial layer, running from the inferior border of one rib to the superior border of the rib below, and contract to elevate the ribs.
Internal intercostal muscles are the middle layer, running from the superior border of one rib to the inferior border of the rib above, and contract to draw adjacent ribs together.
Innermost intercostal muscles are the deepest layer, separated from the other two layers by the neurovascular bundle, and have the same attachment points and action as internal intercostal muscles.

Neurovascular Supply to Intercostal Spaces

Each intercostal space has a separate neurovascular bundle that runs along the inferior aspect of the rib in the costal groove.
The neurovascular bundle contains the intercostal vein, intercostal artery, and intercostal nerve, always in that arrangement (superior to inferior).

Accessory Muscles of Respiration

Accessory muscles of inhalation include the sternocleidomastoid muscle, pectoralis minor muscle, and scalene muscles.
Accessory muscles of exhalation include the external oblique muscle, internal oblique muscle, transversus abdominis muscle, and rectus abdominis muscle.

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Description

Learn about the thoracic cage, also known as the rib cage, and its components. Understand its purpose and how it functions during inhalation and exhalation.