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)
What is the prime extensor of the knee?
Quadriceps femoris
What are the attachments and insertions of all of the quadriceps femoris muscles?
Innervation
Prime extensors of the knee
Rectus femoris attachment - AIIS, can also contribute to flexion of the hip
Vastus lateralis attachment- linea aspera
Vastus medialis attachment - linea aspera
Vastus intermedius attachment - anterior aspect of the femoral shaft
Insertion- All 4 muscles converge on the quadriceps tendon which runs over the patella to insert on the tibial tuberosity via the patellar ligament
Innervation- femoral nerve
Sartorius attachment, insertion and function
Innervation
Attachment- ASIS
Insertion- medial aspect of proximal tibia (crosses both hip and knee joints)
Function- flexes and laterally rotates the hip joint, flexes the knee joint (but it is not a prime mover)
Innervation- Femoral nerve
Iliopsoas attachment, insertion and function
Innervation
Psoas major- transverse processes of L1-L5 vertebrae
Iliacus- Origin is iliac fossa
Insertion- both converge via a common tendon onto the lesser trochanter of the femur
Function- prime flexor of the hip joint
Innervation- femoral nerve
What is the prime flexor of the hip joint?
Iliopsoas
Pectineus attachment, insertion and function
Innervation
Attachment- superior pubic ramus
Insertion- just inferior to the lesser trochanter on the femur
Function- flexes and adducts the hip joint
Innervation- femoral nerve
What are the muscles of the medial compartment of the thigh? What is their innervation? What is their main function?
Adductor brevis
Adductor longus
Adductor magnus
Gracilis
Obturator externus
Innervated by obturator nerve (L2-L4)
Primarily act as adductors of the hip (the adductors play an important role in normal gait)
What is the attachment and insertion of adductor brevis and longus? What lies between them?
Function
Innervation
Adductor brevis
Attachment- Body of pubis
Insertion- Linea aspera (higher point than longus)
Adductor longus
Attachment- Body of pubis
Insertion- Linea aspera (lower point than brevis)
- Flexion and adduction of hip joint for both
The obturator nerve lies between them. Innervated by obturator nerve
What are the 2 parts of the adductor magnus and what are their attachments and innervations?
Adductor part -
Attachment- inferior pubic ramus
Insertion- linea aspera
Adducts hip joint
Innervation- Obturator nerve
Hamstring part
Attachment- ischial tuberosity
Insertion- adductor tubercle
Extension of hip joint
Innervation- Tibial nerve
Gracilis: attachment, insertion and function
Innervation
Most medial muscle
Attachment: pubic bone
Insertion: medial aspect of tibia
Function: weak flexor and adductor of the hip. Weak flexor of the knee (not prime mover)
Innervation: obturator nerve
Obturator externus: attachment, insertion and function
Innervation
Attachment: external surface of the obturator membrane
Insertion: Femur (near greater trochanter)
Function: It stabilises and laterally rotates the hip joint.
Innervation: obturator nerve
Order of contents of femoral triangle
Nerve, artery, vein from lateral to medial
What are the superficial gluteal muscles? What are their innervations?
Inferior gluteal nerve- Gluteus maximus
Superior gluteal nerve- Gluteus medius, gluteus minimus, tensor fascia latae
Attachment, insertion, function, innervation
Gluteus maximus
Attachments- posterior parts of posterior surface of ilium, the sacrotuberous ligament and sacrum
Insertion- iliotibial tract (a few fibres to the gluteal tuberosity)
Function- Extensor of the hip (important for standing from sitting position)
Also lateral rotator of the hip
Innervation- inferior gluteal nerve
Attachment, insertion, function, innervation
Gluteus medius and gluteus minimus
Gluteus minimus is deep to gluteus medius which is deep to gluteus maximus.
Attachment- anterior parts of the posterior surface of ilium
Insertion- greater trochanter
Function- Medially rotate and abduction of the hip (kind of attached to the top of the greater trochanter in a way)
Innervation- superior gluteal nerve
Which are the 2 muscles important in normal gait? How do they act?
Gluteus medius and minimus.
When we stand on one leg, the muscles in the limb that we are standing on hold the pelvis ‘level’ so it does not tilt.
If the muscles are paralysed, it would result in a limp as the pelvis will tilt in the direction of the foot of the ground
Attachment, insertion, function, innervation
Tensor fascia latae
Attachment- ASIS
Insertion- iliotibial band (which inserts on the lateral part of proximal tibia)
Function- stabilise the knee when extended and flexes the hip joint (but not prime mover)
Innervation- superior gluteal nerve
What are the deep gluteal muscles? What is their function? What is their innervation?
Piriformis, superior and inferior gemelli, obturator internus, quadratus femoris
Function- stabilise and laterally rotate the hip joint
Piriformis - nerve to piriformis - S1, S2
Superior gemellus- Nerve to obturator internus (L5-S1)
Inferior gemellus- Nerve to quadratus femoris (L4/5-S1)
Obturator internus- nerve to obturator internus
Quadratus femoris- nerve to quadratus femoris
Attachment, insertion, function innervation- Piriformis
Why is it a significant muscle?
Attachment- anterior surface of the sacrum (passes through greater sciatic foramen)
Insertion- greater trochanter
Function- lateral rotator of the hip
Important- the nerves of sacral plexus lies over it, the sciatic nerve emerges below its inferior border
Innervation- branches of sacral plexus (S1-S2, don’t need to know)
Attachment, insertion, innervation, function
Superior gemellus
Attachment- Ischial spine
Insertion- Greater trochanter
Function- lateral rotation of hip
Innervation- Nerve to obturator internus (L5-L1)
Attachment, insertion, innervation, function
Inferior gemellus
Attachment- Ischial tuberosity
Insertion- Greater trochanter
Function- Lateral rotation of the hip joint (stabilising)
Innervation- Nerve to quadrator femoris (L4-S1)
Attachment, insertion, innervation, function
Obturator internus
Attachment- Pubis and ischium and obturator foramen (passes through lesser sciatic foramen)
Insertion- Greater trochanter
Function- Lateral rotation of the hip joint (stabilising)
Innervation- Nerve to obturator internus (L5-S1)
Attachment, insertion, innervation, function
Quadratus femoris
Attachment- Ischial tuberosity
Insertion- Quadratus tuberosity on intertrochanteric crest
Function- Lateral rotation of the hip joint
Innervation- Nerve to quadratus femoris (L4-S1)
What are the posterior thigh muscles?
Semimembrinosus, semitendinosus, biceps femoris, hamstring part of adductor magnus
Which are the hamstring muscles?
What is their collective function?
Semimembranosus, semitendinosus and long head of biceps femoris
Extension of the hip and flexion of the knee
Attachment, insertion, function, innervation
Semimembranosus and semitendinosus
Attachment- Ischial tuberosity
Insertion- medial aspect of proximal tibia
Function- Extension of the hip, flexion of the knee
Innervation- tibial nerve
Attachment, insertion, function, innervation
Biceps femoris
Short head and long head
Attachment- Linea aspera, ischial tuberosity
Insertion- both heads form a common tendon which inserts on the head of the fibula
Short head function- Flexion of the knee
Innervation- common peroneal
Long head function- extension of the hip, flexion of the knee
Innervation- tibial
What do muscles in the anterior thigh do?
Flex the thigh at the hip joint and extend the leg at the knee joint
What do muscles in the medial thigh do?
Adduct the thigh at the hip joint
What do muscles in the posterior thigh do?
Extend the thigh at the hip joint and flex the leg at the knee joint
