Panniculus carnosus
Encyclopedia
The panniculus carnosus is a part of the subcutaneous tissue
s in the study of animal anatomy. It is a layer of striated muscle deep to the panniculus adiposus
. In humans the platysma muscle of the neck, palmaris brevis in the hand, and the dartos muscle in the scrotum are described as a discrete muscle of the panniculus carnosus. Some of the muscles of facial expression in the head are part of the panniculus carnosus. In other parts of the body, the layer is vestigial, and may be absent or may exist only as microscopic, disconnected fibers.
In other animals, the panniculus carnosus is more extensive. A grazing animal may twitch the panniculus carnosus to frustrate the attempts of a bird to perch on its back. This is known as twitching the withers. For another example, the panniculus carnosus in the echidna
covers almost its entire body, enabling it to change its shape to a certain degree, most characteristically by rolling into a ball and presenting its spines to a potential predator.
Subcutaneous tissue
The hypodermis, also called the hypoderm, subcutaneous tissue, or superficial fascia is the lowermost layer of the integumentary system in vertebrates. Types of cells that are found in the hypodermis are fibroblasts, adipose cells, and macrophages...
s in the study of animal anatomy. It is a layer of striated muscle deep to the panniculus adiposus
Panniculus adiposus
The panniculus adiposus is the fatty layer of the subcutaneous tissues, superficial to a deeper vestigial layer of muscle, the panniculus carnosus.It includes structures that are considered fascia by some sources but not by others....
. In humans the platysma muscle of the neck, palmaris brevis in the hand, and the dartos muscle in the scrotum are described as a discrete muscle of the panniculus carnosus. Some of the muscles of facial expression in the head are part of the panniculus carnosus. In other parts of the body, the layer is vestigial, and may be absent or may exist only as microscopic, disconnected fibers.
In other animals, the panniculus carnosus is more extensive. A grazing animal may twitch the panniculus carnosus to frustrate the attempts of a bird to perch on its back. This is known as twitching the withers. For another example, the panniculus carnosus in the echidna
Echidna
Echidnas , also known as spiny anteaters, belong to the family Tachyglossidae in the monotreme order of egg-laying mammals. There are four extant species, which, together with the platypus, are the only surviving members of that order and are the only extant mammals that lay eggs...
covers almost its entire body, enabling it to change its shape to a certain degree, most characteristically by rolling into a ball and presenting its spines to a potential predator.