Muscles of Expiration and Diaphragm Anatomy

Questions and Answers

Which ribs are classified as true ribs?

Ribs 1-7 (correct)

Ribs 11-12

Ribs 6-12

Ribs 8-10

What is the primary function of the thoracic wall?

To allow for limb movement

To support the neck

To facilitate digestion

To protect thoracic and abdominal organs (correct)

Which of the following muscles is primarily involved in passive inspiration?

Internal intercostals

Serratus anterior

Diaphragm (correct)

External intercostals

Which ribs are considered atypical?

1st and 2nd ribs Signup and view all the answers

What role does the intercostal muscle play during forced inspiration?

Elevates the ribs Signup and view all the answers

Which structure mediates the communication between the thoracic cavity and the neck?

Superior thoracic aperture Signup and view all the answers

During passive expiration, what happens to the diaphragm?

It relaxes and depresses the ribs Signup and view all the answers

Which type of joint allows for the articulation between the ribs and the vertebrae?

Costovertebral joint Signup and view all the answers

Which structure is NOT found in the contents of the rectus sheath?

External iliac artery Signup and view all the answers

What is the correct relationship of the deep inguinal ring in terms of anatomical structure?

Evagination of transversalis fascia Signup and view all the answers

Which umbilical fold covers the remnants of the urachus?

Median umbilical fold Signup and view all the answers

Where does direct inguinal hernias typically occur?

Medial to the inferior epigastric vessels Signup and view all the answers

Which statement best describes the pathway of the testes during fetal development?

They relocate from the dorsal abdominal wall through the inguinal canal. Signup and view all the answers

What forms the lateral umbilical folds?

Epigastric vessels Signup and view all the answers

Which structure is part of the posterior wall of the inguinal canal?

Transversalis fascia Signup and view all the answers

Which anatomical feature is associated with indirect inguinal hernias?

Lateral to the inferior epigastric vessels Signup and view all the answers

The gubernaculum in males functions to tether which structure during descent?

Testis Signup and view all the answers

What component is NOT part of the spermatic cord?

Inferior epigastric artery Signup and view all the answers

What is the primary function of the visceral pleura?

To cover the lungs Signup and view all the answers

Which part of the parietal pleura covers the internal surfaces of the thoracic wall?

Costal part Signup and view all the answers

Where is the sternal line of pleural reflection located?

At the transition from costal to mediastinal pleura anteriorly Signup and view all the answers

What marks the bifurcation of the trachea into the main bronchi?

Sternal angle Signup and view all the answers

What type of blood vessel carries blood to a bronchopulmonary segment?

Lobar arteries Signup and view all the answers

Which lymphatic flow goes directly to bronchopulmonary lymph nodes first?

Superficial plexus Signup and view all the answers

What is the role of the transverse abdominis muscle?

Compresses and supports abdominal viscera Signup and view all the answers

Which structure is responsible for connecting the visceral and parietal pleura?

Pleural sleeve Signup and view all the answers

Which muscle is primarily responsible for flexing the trunk?

Rectus abdominis Signup and view all the answers

What type of fascia lies between the internal aspect of the thoracic wall and the parietal pleura?

Endothoracic fascia Signup and view all the answers

What is the function of the intersegmental veins?

To drain blood from adjacent bronchopulmonary segments Signup and view all the answers

What happens to the rectus abdominis muscle below the arcuate line?

Only the transversalis fascia covers it posteriorly Signup and view all the answers

Which of the following reeives lymphatic drainage from the superficial plexus of the lungs?

Tracheobronchial nodes Signup and view all the answers

What is the primary role of the diaphragm during inspiration?

It contracts to increase lung volume. Signup and view all the answers

Which muscle is primarily involved in forced expiration?

Internal intercostal muscles Signup and view all the answers

What structure can be found at the T8 vertebral level?

Caval opening Signup and view all the answers

Which component provides motor supply to the diaphragm?

Phrenic nerve Signup and view all the answers

What is the function of the greater splanchnic nerve?

It facilitates the synapse in the celiac ganglia. Signup and view all the answers

How does the diaphragm affect thoracic pressure during expiration?

It contracts, decreasing thoracic volume, thus increasing pressure. Signup and view all the answers

What is the main source of sensory innervation for the diaphragm?

Phrenic nerve Signup and view all the answers

Which arteries supply the anterior intercostal spaces?

Internal thoracic arteries Signup and view all the answers

What type of innervation do the pulmonary plexuses mainly contain?

Parasympathetic and sympathetic Signup and view all the answers

What role do intercostal nerves play in the thoracic wall?

They supply both motor and sensory innervation. Signup and view all the answers

Which ribs are associated with the subcostal groove for intercostal vessels?

Lower 6 to 7 ribs Signup and view all the answers

Which structure does NOT pass through the aortic hiatus?

Esophagus Signup and view all the answers

What is the correct relationship of the phrenic nerve to the diaphragm?

It both supplies motor and sensory functions. Signup and view all the answers

What communicates between intercostal nerves and the sympathetic trunk?

Rami communicantes Signup and view all the answers

During expiration, how does the pressure in the lungs compare to atmospheric pressure?

Lung pressure is greater than atmospheric pressure. Signup and view all the answers

Study Notes

Thoracic Wall Anatomy and Function

Thoracic wall protects thoracic and abdominal organs, provides attachment for upper limbs, neck, and muscles of respiration.
Mediates internal pressure during inspiration and expiration.
Comprised of 12 pairs of ribs, sternum, 12 thoracic vertebrae, and intercostal spaces.
Ribs classified as True (1-7), False (8-10), and Floating (11-12).

Rib Characteristics

Typical Ribs (3-9): Crest of the head between vertebral articular facets, articulates with costal cartilage.
Atypical Ribs:
- 1st rib: Unique structures including scalene tubercle and subclavian grooves.
- 2nd rib: Larger tuberosity for serratus anterior.
- 11th and 12th ribs: Minimal features, only head and facet.

Muscles of Respiration

Diaphragm: Dome-shaped structure; contracts during inspiration, expands thoracic cavity volume and reduces lung pressure. Relaxes during expiration, compressing the thoracic cavity.
Intercostal Muscles:
- External intercostals: Elevate ribs during forced inspiration.
- Internal intercostals: Assist with forced expiration by depressing ribs.
Accessory Muscles of Respiration: Include scalene, SCM, and pectoralis minor for forced respiration.

Nerve and Vessel Anatomy

Phrenic Nerve: Motor supply to diaphragm, arises from C3-C5 spinal nerves.
Pericardiophrenic Vessels: Supply diaphragm from the internal thoracic artery.

Intercostal Arteries and Veins

Anterior Intercostal Arteries: Supply from thoracic aorta through internal thoracic arteries.
Posterior Intercostal Arteries: Directly from thoracic aorta.
Venous Return: Anterior intercostal veins drain into internal thoracic vein; posterior intercostal veins drain into the azygos system.

Pleura and Lung Anatomy

Visceral Pleura: Covers lungs, adheres to all surfaces; Parietal Pleura: Lines the pulmonary cavity, attaching to thoracic wall, mediastinum, and diaphragm.
Four parts of parietal pleura: Costal, Mediastinal, Diaphragmatic, and Cervical.
Surface Projections of the lungs vary by rib levels.

Bronchopulmonary Segments

Trachea bifurcates into right and left main bronchi, which lead to lower lobar bronchi and bronchopulmonary segments.
Pulmonary Artery Pathway: Blood flows from the pulmonary trunk to bronchopulmonary segments through lobar and segmental arteries.

Lymphatic Drainage

Lymphatics from lungs grouped into superficial and deep plexuses; drain into tracheobronchial lymph nodes.
Superficial plexus drains visceral pleura and lung tissue; deep plexus targets bronchi and connective tissue.

Abdominal Wall Anatomy

Layers of Abdominal Wall: Skin, superficial fascia (Campers and Scarpa), investing fascia (various muscle layers), endoabdominal fascia, and peritoneum.
Flat abdominal muscles arranged effectively to compress abdominal viscera and stabilize trunk posture.

Rectus Sheath and Surgical Anatomy

Formed by aponeuroses of flat abdominal muscles, with contents including rectus abdominis and epigastric vessels.
Above and below the arcuate line, different layers are penetrated during incisions.

Inguinal Canal and Hernias

Inguinal Rings: Deep ring (transversalis fascia) and superficial ring (external oblique aponeurosis).
Hernias:
- Direct inguinal hernia occurs medial to inferior epigastric vessels.
- Indirect inguinal hernia occurs lateral to these vessels.

Testes and Ovaries Development

Testes migrate from the abdominal wall to the inguinal canal and down to the scrotum; ovaries descend similarly into the lesser pelvis with gubernaculum involvement.
Spermatic cord includes ductus deferens, blood vessels, nerves, and lymphatics; female gubernaculum gives rise to ovarian and round ligaments.

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Description

This quiz covers the key muscles involved in forced and labored expiration, including the diaphragm and various intercostal and abdominal muscles. Test your knowledge on the anatomy and functions of these essential respiratory structures.