Respiratory Muscles Flashcards
Muscles of respiration (name, attachments, innervation, and function)
- External Intercostal Muscles
- Internal Intercostal Muscles
- Rectus Abdominus
- Transverse Abdominus
- External Oblique
- Internal Oblique
External Intercostal Muscles
(attachments, innervation, and function)
11 muscles
Origin = lower edge of one rib Insertion = upper ridge or rib below
Elevates ribcage & INSPIRATION
Thoracic (T1-11) & Spinal nerves at each level
Internal Intercostal Muscles
(attachments, innervation, and function)
11 muscles (deep to EIM)
ORIGIN = Lower edge of one rib
INSERTION = upper ridge of rib below
Runs at right angles (from inner>outer)
Depresses rib cage + EXPIRATION
Rectus Abdominis
(attachments, innervation, and function)
Attaches to: pubic symphysis and pubis bone, xiphoid process, and costal cartilage 5-7
Pulls rib & sternum down, compresses viscera, expiration
THoracic Spinal nerves (T5-11) + subcostal nerve from T12
Transverse Abdominis
(attachments, innervation, and function)
Runs horiontally
Attachments: thoracolumbar fascia, xiphoid process, internal surfaces (7-12), iliac crest, linea alba, pubic crest & simphysis
Compresses adominal viscera, expire
Innervated by T7-T11, T12, and L1
External Oblique
(attachments, innervation, and function)
Attachments:
- Xyphoid process
- External surfaces of ribs 5-12
- Linea alba
- Pubis bone
- Anterior portion of iliac crest
Innervated by T7-12
Pulls lower ribs downward, compresses abdominal viscera, and helps with expiration
Internal Oblique
(attachments, innervation, and function)
Attachments:
- Xyphoid process
- Inferior borders of ribs 10-12
- Thoracolumbar Fascia
- Linea alba
- Pubic symphysis
- Anterior portion of iliac crest
Innervated by T7-12
Pulls lower ribs downward, compresses abdominal viscera, and accessory muscle of expiration
Layers of Respiratory Muscles
MOST SUPERFICIAL
- External Oblique
- Internal Oblique
- Transverse Adbdiminus
MOST DEEP
How do abdominal muscles change expiration?
Abdominal contents are incompressible, so when these muscles contract, they push abdominal contents upwards and inwards, which pushes the diaphragm UP.
This reduces vertical dimensions of the ribcage and pulls ribs down… EXHALE!
Diaphragm
(attachments, innervation, and function)
Origin
- Internal edges of lower rib cages
- Ribs 7-12 and costal cartilages
- Xiphoid process of sternum
- Lumbar vertebrae (L1-L4)
Inserts @ Central tendon
Innervated by Phrenic Nerve (C3, C4, C5) and is primarily autonomic
Main muscle of inspiration, as it changes the thoraxin all dimensions
