What is the Difference Between Pars Tensa and Pars Flaccida

The main difference between pars tensa and pars flaccida is that pars tensa thickens superiorly, whereas pars flaccida thickens inferiorly. 

Pars tensa and pars flaccida are two general regions of the tympanic membrane. Its function is to separate the outer ear from the middle ear.      

Key Areas Covered

1. What is Pars Tensa
– Definition, Facts, Features
2. What is Pars Flaccida
– Definition, Facts, Features
3. Similarities Between Pars Tensa and Pars Flaccida
– Outline of Common Features
4. Difference Between Pars Tensa and Pars Flaccida
– Comparison of Key Differences
5. FAQ: Pars Tensa and Pars Flaccida
– Answers to frequently asked questions

Key Terms  

Pars Flaccida, Pars Tensa

What is Pars Tensa

Pars tensa is a general region of the tympanic membrane or eardrum. It is large and composed of three layers. They are skin, fibrous layer, and mucosa. Also, pars tensa contains a thick periphery that forms a fibrocartilaginous ring. It is called Gerlach’s ligament or annulus tympanicus. The central part of the pars tensa is the umbo. It tends inward at the tip of the malleus. Also, a fibrous layer occurs in the middle of the pars tensa. It contains circular, radial, and parabolic fibers.

Figure1: Tympanic Membrane    

What is Pars Flaccida

Pars flaccida is the other part of the tympanic membrane. It is relatively fragile and small in size. Also, it lies above the lateral process of the malleus. Additionally, it occurs between the anterior and posterior malleal folds between the notch of Rivinus. On the other hand, it consists of two layers. The first layer appears slightly pinkish in the hue.

Figure 2: Pars Flaccida 

Similarities Between Pars Tensa and Pars Flaccida

• Pars tensa and pars flaccida are two regions of the tympanic membrane. They occur with malleolar prominence. 

Difference Between Pars Tensa and Pars Flaccida

Definition

Pars tensa refers to a part of the tympanic membrane occurring below the malleolar prominence. In contrast, pars flaccida refers to a part of the tympanic membrane occurring above the malleolar prominence. 

Occurrence

Pars tensa occurs below the malleolar prominence, while pars flaccida occurs above the malleolar prominence. 

Thickening

Pars tensa thickens superiorly, while pars flaccida thickens inferiorly. 

Taution

Pars tensa is taut while pars flaccida is not taut. 

Texture

Pars tensa is relatively fragile, while pars flaccida is thick.

Size

Pars tensa is small, while pars flaccida is large.

Layers

Pars tensa consists of three layers: skin, fibrous tissue, and mucosa, while pars flaccida consists of two layers.  

FAQ: Pars Tensa and Pars Flaccida

What are pars tensa and flaccida layers?

Pars tensa is the large portion of the tympanic membrane. Also, it remains stretched to a maximum. Pars flaccida is the other portion of the tympanic membrane. However, it remains less stretched. On the other hand, it contains organized radial and circular fibers. 

What is the pars tensa and pars flaccida retraction?

The two parts of the eardrum include pars tensa and pars flaccida. The main part of the eardrum is pars flaccida. In comparison, pas flaccid is a small part of the eardrum. Both parts of the eardrum can be retracted. Retraction pocket is another name for retracted segment. 

What is the structure of the pars tensa?

The three parts of pars tensa are the epidermal layer, lamina propria, and mucosal epithelial layer. The fibrous layer of the pars tensa contains a large amount of type II and type III collagen. Also, it contains a small amount of type I collagen.

Conclusion

In brief, pars tensa and pars flaccida are two parts of the tympanic membrane. Their function is to separate the outer ear from the middle ear. Pars tensa occurs below the malleolar prominence, and it is taut. Also, it is small. It is composed of three layers. They are the skin, fibrous tissue, and mucosa. In comparison, pars flaccida occurs above the malleolar prominence. The thickening of the pars flaccida occurs inferiorly. However, it is not taut. Additionally, it is thick and large. Therefore, their structure is the main difference between pars tensa and pars flaccida.          

References:

1. Szymanski A, Toth J, Ogorevc M, et al. Anatomy, Head and Neck, Ear Tympanic Membrane. [Updated 2023 May 8]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2023 Jan-.

Image Courtesy:

1. “Blausen 0328 EarAnatomy” By BruceBlaus – Own Work (CC-BY 3.0) via Commons Wikimedia
2. “View-normal-tympanic-membrane” By Madhero88 – Own Work (CC-BY SA 3.0) via Commons Wikimedia