Anatomy strucutres/muscles Flashcards
Pectoralis major attachment, insertion and action
Attachment: clavicle and upper 6 ribs
Insertion: Upper humerus
Adduction of arm (humerus), internal rotation of arm
Pectoralis minor attachment and action
Attachment: ribs 3-5
Insertion: Coracoid process of scapula
Protracts the scapula (antero-inferiorly)
Serratus anterior attachment, action and innervation
Attachment: ribs 1-8
Insertion: Scapula
Protracts the scapula (antero-inferiorly)
Innervation - long thoracic nerve
What are the accessory muscles of breathing?
Sternocleidomastoid, pectoralis major, trapezius, scalene, pectoralis minor and serratus anterior
What is the orientation of the external intercostals, internal intercostals and innermost intercostals?
External - antero-inferiorly (down and in)
Internal- postero-inferiorly (down and out)
Innermost- postero-inferiorly (down and out)
Muscles in inspiration
The diaphragm and external intercostal muscles contract, increasing intrathoracic volume.
External intercostals pull the ribs superiorly and laterally.
Lungs expand with the thoracic wall due to surface tension.
Muscles in Active Expiration (contraction and relaxation)
(passive expiration is just due to recoil of the lungs)
The diaphragm and external intercostal muscles relax
Internal intercostals contract, pulling the ribs inferiorly, decreasing intrathoracic volume, expelling air from the lungs (as the lungs recoil)
Describe muscles used in
1) Normal, quiet breathing
2) Vigorous breathing
3) Very vigorous or forced breathing
Normal- Inspiration is active, expiration is passive. Mainly driven by movement of diaphragm (and recoil of lungs)
Vigorous- Both inspiration and expiration are active. Intercostal muscles become important. (Internal intercostals are used for active expiration)
Very vigorous/forced - accessory muscles of breathing contribute to movement of the ribs and aid ventilation
Attachment, insertion, innervation and function
Sternocleidomastoid
Attachment- sternum and clavicle
Insertion- mastoid process
Innervation- Accessory nerve
Function- Rotation of the neck
Boundaries of anterior triangle of the neck
Anteriorly- midline of the neck
Posteriorly- anterior border of sternocleidomastoid
Superiorly- lower border of the mandible
Structure in the anterior triangle of the neck
- Trachea and larynx
- Thyroid and parathyroid glands
- Suprahyoid muscles
- Infrahyoid muscles
- Common carotid artery, external carotid artery
- Internal jugular vein
- Branches of CN7,9,10,11,12
Boundaries of the posterior triangle of the neck
Anteriorly- posterior border of sternocleidomastoid
Posteriorly- anterior border of trapezius
Inferiorly- clavicle
Structures in the posterior triangle of the neck
- Subclavian artery and vein
- External jugular vein
- Accessory nerve
- Phrenic nerve
- Roots of the brachial plexus
What are the suprahyoid muscles and their collective actions? (extrinsic larynx muscles)
Geniohyoid, mylohyoid, stylohyoid, digastric
When they contract, they raise the hyoid bone and larynx for speech and swallowing
What are the infrahyoid muscles and their collective actions? (extrinsic larynx muscles)
Sternohyoid and omohyoid (superficial)
Sternothyroid and thyrohyoid (deep)
When they contract, they draw the hyoid bone and larynx inferiorly during speech and swallowing
What are the types of muscles in the walls of the pharynx?
An outer layer of circular muscle and inner layer of longitudinal muscle
The outer circular muscle layer has 3 constrictor muscles, superior, middle and inferior.
The 3 unpaired cartilages of the larynx
Epiglottis, thyroid cartilage and cricoid cartilage
The 3 paired cartilages of the larynx
Arytenoids, cuneiform and corniculate
What are the intrinsic muscles of the larynx and their functions
What are their innervations?
Cricothyroid muscle- tips the thyroid cartilage anteriorly and inferiorly to place tension on the vocal cords
Posterior cricoarytenoids- they abduct the vocal cords and open the rima glottidis
Transverse arytenoids- they adduct the vocal cords and close the rima glottidis
Recurrent laryngeal nerve- all intrinsic muscles except cricothyroid
Superior laryngeal nerve- cricothyroid
What are the muscles of the anterior compartment of the thigh? What is their innervation? What is their main function?
Quadriceps femoris- Rectus femoris, vastus medialis, vastus intermedius, vastus lateralis
Sartorius, iliopsoas, pectineus
They primarily act as extensors of the knee (some act on the hip joint)
They are innervated by the femoral nerve (L2-L4)