Question

multiple choice question

which describes a pennate muscle?

feather-like and fasciculi insert obliquely into the tendon.
ring-shaped and fasciculi surround body openings.
broad at one end and narrow at the opposite end
thick in the middle with narrow tapered ends

Explanation:

Analyze the question and options

The question asks for the description of a pennate muscle. Let's evaluate each option based on anatomical definitions of Skeletal Muscle Shapes:

• Option 1: "Feather-like and fasciculi insert obliquely into the tendon."
• The term "pennate" comes from the Latin word pinna, meaning feather. In a pennate muscle, the fascicles (fasciculi) are arranged obliquely (at an angle) to a central tendon, resembling the barbs of a feather. This matches the definition of a pennate muscle.

• Option 2: "Ring-shaped and fasciculi surround body openings."
• Using the Skeletal Muscle Shapes knowledge point, this describes a circular (or sphincter) muscle, such as the orbicularis oculi.

• Option 3: "Broad at one end and narrow at the opposite end."
• This describes a convergent (or triangular) muscle, such as the pectoralis major.

• Option 4: "Thick in the middle with narrow tapered ends."
• Using the Fusiform Muscle knowledge point

$$ \text{This describes a fusiform muscle, such as the biceps brachii.} $$

Select the correct answer

Based on the analysis, the first option correctly describes a pennate muscle.

Answer:

• (A) Feather-like and fasciculi insert obliquely into the tendon. (Correct answer)
• (B) Ring-shaped and fasciculi surround body openings.
• (C) Broad at one end and narrow at the opposite end.
• (D) Thick in the middle with narrow tapered ends.