Meaning & use
pectinate muscles
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Meaning
nounpluraltechnicalspecialistbiologymedical
The parallel muscular ridges on the inner wall of the heart's atria, especially the right atrium.
Grammar: Always used in the plural; the singular 'pectinate muscle' is rare and mainly appears in technical descriptions of a single ridge.
Patterns
- the pectinate muscles of the heart
- pectinate muscles in the atrium
The pectinate muscles give the inner surface of the atrium a ridged, comb-like appearance.
In the right atrium, the pectinate muscles are more prominent than in the left atrium.
The electrical signal spreads quickly through the pectinate muscles to help the atria contract together.
Common combinations
- pectinate muscles of the atrium
- The pectinate muscles of the atrium are visible as parallel ridges.
- right atrial pectinate muscles
- The right atrial pectinate muscles are larger and more numerous.
- pectinate muscle ridges
- The pectinate muscle ridges increase the surface area inside the atrium.
Synonyms and how they differ
- musculi pectinati
- The Latin anatomical term used in formal medical texts; it means the same thing but is not used in everyday English.
Word family
- pectinate adjective
- Shaped like a comb; used in anatomy and biology to describe comb-like structures.
- pectin noun
- A substance found in fruit that makes jam set; unrelated in meaning but from the same root meaning 'comb' or 'stiff'.
Commonly confused: pectinate muscles or papillary muscles? pectinate muscles or pectoral muscles?
pectinate muscles vs papillary muscles
These are different heart muscles attached to the valve flaps in the ventricles, not the ridges in the atria. Learners often mix up the two terms.
pectinate muscles vs pectoral muscles
These are the chest muscles (pecs), not heart structures. The similar beginning 'pect-' can cause confusion.
Practice
Where are the pectinate muscles found?
Choose one answer.
Pectinate muscles are ridges in the atria of the heart. Option 0 describes papillary muscles, option 2 describes pectoral muscles, and option 3 describes unrelated smooth muscle.
Make it your own
Write a sentence using “pectinate muscles”, then check it and compare it with the examples above.