Muscular Triangle and visceral space

Muscular Triangle, and visceral space

In this part of neck, structures like the thyroid gland and trachea are routinely examined by clinicians. Surgical procedures are commonly performed. All doctors must therefore have a good knowledge of anatomy of this part.

Objectives
By the end of this lab students are expected to be able to
1. Describe the boundaries, roof, floor and content of muscular triangle
2. Discuss the formation, course and termination of anterior jugular vein
3. Compare the position of the 4 infrahyoid muscles & their nerve supply.
4. Describe different parts of thyroid gland
5. Identify the major structures related to thyroid gland
6. Discuss the fascial coverings of the gland (true and false capsules)
7. Describe the course of the three arteries supplying the thyroid gland and their relation to external and recurrent laryngeal nerves.
8. Locate the parathyroid glands
9. Discuss the structure, location and relation of trachea and esophagus
Lab check list
A- Muscular Triangle
? Boundaries
? Anterior: Anterior median line, from hyoid bone to suprasternal notch.
? Posterosuperior: Superior belly of the omohyoid.
? Posteroinferior: Anterior border of sternocleidomastoid.
? Roof
? Investing layer of deep cervical fascia.
Note: Anterior jugular vein lies within superficial fascia over the roof.
? Floor (pretracheal fascia covering 3muscles)
? Sternothyroid
? Sternohyoid
? Thyrohyoid.
B- Visceral space
1. Thyroid gland
2. Parathyroid gland
3. Trachea
4. Esophagus
Practical Anatomy LAB 5 Dr. Firas M. Ghazi
2
1- Thyroid gland
? Parts and Features
? Right and left Lobes
- Apex
- Base
- Lateral (superficial) surface
- Medial surface
- Posterior (posterolateral) surface
? Pyramidal lobe
? Isthmus
? Levator glandulae thyroideae
? Capsule
? True
? False
- Ligament of berry
? Relations
? Relations of the Lobes
? Relations of the Isthmus
? Blood Supply
? Superior thyroid artery
? Inferior thyroid artery
? Thyroidea ima
Anatomy jewel: Enlarged Thyroid may extend backward, as the capsule is thin posteriorly, compressing the adjacent structures without forming a visible swelling on the front of the neck.
Anatomy jewel: Thyroid gland moves up and down during swallowing because its capsule is attached to laryngeal cartilages and hyoid bone, which moves up and down during swallowing. Thus thyroid swellings can be distinguished clinically from other swellings in the region of the neck.
2- Parathyroid Glands (4)
? Location
? Closely related to the posterior border of the thyroid gland (within its fascial capsule)
? Two superior and two inferior
? Blood Supply
? Superior and inferior thyroid arteries.
Practical Anatomy LAB 5 Dr. Firas M. Ghazi
3
3- Trachea (Cervical part)
? Start : C6
? C-shaped rings (D-shape)
? Trachealis muscle
? Relations:
? Anterior:
o Anterior jugular veins and jugular venous arch
o Isthmus of thyroid 2nd-4th tracheal rings
o Thyroidea ima and inferior thyroid veins
o Sternothyroid
o Sternohyoid
? Posterior:
o Esophagus
o Recurrent laryngeal nerve.
? On each side:
o Lobe of thyroid gland
o Carotid sheath.
4- Esophagus (Cervical part)
? Total length: 25 cm
? Extent: pharynx to stomach
? Start: C6
? Relations
? Anterior:
o Trachea
? Posterior:
o Prevertebral fascia
? Lateral:
o Lobe of the thyroid gland
o Carotid sheath
Home work:
A 35-year-old woman underwent surgery for thyroid gland nodule 2weeks earlier, complains of hoarseness of voice and choking while drinking liquids. She is suspected of having recurrent laryngeal nerve injury.
Q:
1- What is the anatomical explanation for her symptoms?
2- How is the nerve related?
3- Is there a difference in course of left and right recurrent nerves?