A+P: Lecture 2 Flashcards
Shoulder/glenohumeral joint Type
Ball-and-socket joint
Describe the shoulder/glenohumeral joint
- Large, hemispherical head of humerus fits in small, shallow glenoid cavity of scapula
- Articular cartilage & capsule contain synovial fluid for lubrication
What is the most freely moving joint in the body? what is the catch?
The shoulder, but it is the most unstable joint
What is the glenoid labrum & function?
- fibrocartilaginous rim around glenoid cavity
- Helps to add depth to shallow cavity
What are the reinforcing ligaments of the shoulder?
- Coracohumeral ligament
- 3 capsular glenohumeral ligaments
–> superior, middle, inferior
What is the function of these capsular glenohumeral ligaments?
main stabilizing aspect on the anterior aspect of the shoulder
What contributes most to joint stability of the shoulder?
Reinforcing muscle tendons
What is considered the “superstablizer” of the shoulder & function?
- Tendon of long head of biceps brachii
- Secures humerus to glenoid cavity
Muscles of the rotator cuff
- supraspinatus
- infraspinatus
- subscapularis
- teres minor
What makes up the elbow joint?
Humerus articulates w/ radius & ulna
What does the annular ligament do?
surrounds head of radius
What are the two capsular ligaments of the elbow & their function?
- Medial ulnar collateral ligament (MUCL): mostly connects the humerus to the ulna
- Lateral collateral ligament (LCL): contains the radial LCL, ulnar LCL, & annular ligament
Which bone articulates with the humerus distally?
The ulna
Describe the annular ligament?
a band that goes from ulnar to ulnar; surrounds radial head but attaches to the ulnar; keeps radius attached to the ulnar. Stabilizes
Prime mover for shoulder flexion
Deltoid - anterior fibers
Prime mover for shoulder extension
Latissimus dorsi & deltoid - posterior fibers
Prime mover for shoulder abduction
Deltoid
Prime mover for shoulder adduction
pectoralis major & latissimus dorsi
Prime mover for shoulder medial rotation
subscapularis
Prime mover for shoulder lateral rotation
Infraspinatus & teres minor
Prime mover for forearm elbow flexion
- biceps brachii
- brachialis
Prime mover for forearm elbow extension
triceps brachii
Prime mover for forearm pronation
pronator quadratus
Primer mover for wrist flexion
- flexor carpi radialis
- flexor carpi ulnaris
- flexor digitorum superficialis
Primer mover for finger extension/abduction
extensor digitorum
What type of joint is the hip joint?
ball-and-socket
What does the femur articulate with?
the acetabulum
Describe the ROM for the hip joint
Good ROM, but limited by the deep socket
Describe acetabular labrum
rim of fibrocartilage that enhances depth of socket
Are hip dislocations common or rare?
rare
Ligament of head of femur
- one of the deepest ligaments in the hip joint
- Slack during most hip movements, so not important in stabilizing
- Does contain artery that supplies head of femur in babies
Why is the ligament of head of femur so important in babies?
it contains some arteries that supply the head of the femur
Other 3 reinforcing ligaments of the hip
- Iliofemoral ligament (Y-shaped) limits overextension
- Pubofemoral ligament limits abduction & overextension at hip
- Ischiofemoral ligament (posterior runs anteriorly) & limits overextension
General description of the knee joint
Consists of 3 joints surrounded by single cavity w/ ~12 bursae
3 joints of the knee
- Femoropatellar joint
- Lateral joint & Medial joint
–> collectively called the tibiofemoral joint
Describe the Femoropatellar joint
- Plane joint
- Allows gliding motion during knee flexion
Describe the tibiofemoral joint
- Joint b/t femoral condyles & lateral
& medial menisci of tibia - Hinge joint that allows flexion, extension & some rotation when knee partly flexed
Function of menisci
provide cushion & shock absorption
Describe/Function of the ACL
- Attaches to anterior tibia
- Prevents forward sliding of tibia & stops hyperextension of knee
- Deepest ligament
Which test is used to assess the ACL?
Anterior Draw Test: see if the tibia will move anteriorly
Describe/Function of the ACL
- Attaches to posterior tibia
- Prevents backward sliding of tibia & forward sliding of femur
Function of LCL & MCL
prevent rotation when knee is extended
Prime mover for hip flexion
Iliopsoas
Prime mover for hip extension
gluteus maximus & biceps femoris
Prime mover for hip abduction
gluteus medius
Prime mover for knee flexion
- biceps femoris
- semitendinosus
- semimembranosus
Prime mover for knee extension
rectus femoris & vastus muscles
Prime mover for ankle plantar flexion
Gastrocnemius & Soleus
Prime mover for dorsiflexion
Tibialis anterior
Prime mover for ankle inversion
tibialis posterior
Prime mover for toe flexion
flexor digitorum longus
Prime mover for toe flexion (big toe)
Flexor hallicus longus
Prime mover for toe extension
extensor digitorum longus
Prime mover for toe extension (big toe)
extensor hallicus longus
What happens to our ligaments & tendons as we age?
shorten & weaken
Most people at what age have some degree of OA?
70s
What is key to postponing joint problems?
full ROM exercise
The brachial plexus & upper limb is formed by
Formed by C5–C8 & T1
Four major branches of this plexus from proximal to distal
- Roots
- Trunks
- Divisions
- Cords
The brachial plexus supplies most of the…
motor & sensory innervation of the upper extremity
Describe the Roots (anterior rami) & terminal nerves. (DRAW)
- Axillary C5, C6,
- Musculocutaneous C5,C6
- Median C5,C6, C8, T1
- RadialC7
- Ulnar C8, T1
Axillary gives its proximity to the___ & is susceptible to damage w/___.
- surgical neck of the shoulder
- fractures of the humerus
Axillary
Motor:
Sensory:
-Motor: deltoid & teres minor muscles
- Sensory: skin of shoulder
Musculocutaneous
Motor:
Sensory:
- Motor: muscles of anterior arm (think flexion)
- Sensory: terminates as lateral cutaneous n. of forearm
Median nerve doesn’t ____. It goes through the ___.
- innervate anything in the arm
- carpal tunnel
Median
Motor:
Sensory:
-Motor: muscles of the hand (flexion of the anterior hand)
- Sensory: some skin of hand
Ulnar
Motor:
Sensory:
- Motor: 1½ muscles in anterior forearm, most intrinsic muscles of hand
- Sensory: some skin of hand
Damage to this nerve can cause “wrist drop”
radial nerve
Radial
Motor:
Sensory:
- Motor: all muscles of posterior arm & forearm
- Sensory: skin of posterior arm,
forearm & hand
What does the lumbar plexus innervate?
anterior thigh (hip & knee flexors) & medial thigh (adductors)
What does the femoral nerve innervate?
the quadriceps & skin of anterior thigh & medial surface of leg
(goes right under inguinal ligament)
What does the obturator nerve pass through?
the obturator foramen to innervate adductor muscles of medial thigh
(runs through obturator foramen & inguinal ligament)
Pathway of sacral plexus?
greater sciatic foramen inf–> piriformis muscle–> post compartment of the thigh–> popliteal fossa–> splits into nerves which are found in the posterior thigh
The sacral plexus serves
the gluteal muscles & posterior thigh muscles (i.e. hamstrings)
Sciatic nerve function
Innervates hamstring muscles, adductor magnus & most muscles in leg & foot
The sciatic nerve is composed of what 2 nerves?
tibial & common fibular
Cervical
Ventral Rami:
Major Nerves:
C1- C4
- Phrenic
Brachial
Ventral Rami:
Major Nerves:
C5-T1
- Axillary, musculocutaneous, median, radial, ulnar
Lumbar
Ventral Rami:
Major Nerves:
L1-L4
- femoral, obturator
Sacral
Ventral Rami:
Major Nerves:
L4-L5
- Sciatic
The thigh has how many compartments?
3
- anterior, posterior, medial
The lower leg has how many compartment?
4
- ant, lateral, posterior deep, posterior superficial
