anatomy I - MIDTERM 1

what are the axio-appendicular muscles ?

-pectoralis major
-pectoralis minor
-serratus anterior
-subclavius

pectoral region makes up what ?

makes up the anterior chest

what is the pectoral region comprised of ?

-muscle
-fascia
-fat

what does the pectoral region provide ?

provides useful open-chain and closed-chain functions

OPEN-CHAIN: distal segment is FREE on fixed proximal segment (bench press)

CLOSED-CHAIN: distal segment is FIXED on moving proximal segment (push ups- humerus fixed, shoulder moving over it)

can the pectoral region affect posture ?

yes, if dysfunctional

abduction ROM is measured using what as a landmark ?

mid axillary line

what other line are used for descriptors for surface anatomy ?

-anterior median line (going down middle body in front)
-scapular planes
-posterior median line (going down middle of back)

coracoid process of scapula

acromion process of scapula

anterior surface of medial border of scapula

lateral border of scapula

what is the most common site for clavicle fracture ?

middle 1/3 of the clavicle

what kind of action, activity, or motion causes a clavicular fracture ?

-indirect force transmitted from outstretched hand through the bones of the forearm & arm to the shoulder during a fall

-fall directly on the shoulder

when the clavicle fractures, what does the displacement look like ?

-sternocleidomastoid M. elevates the medial fragment of the bone

-trapezius M. is unable to hold the lateral fragment up, resulting in shoulder drop

**the end of the superiorly directed fragment is prominent**

what is a dermatome ?

a segment of skin innervated by a spinal segment

motions of the shoulder

-abduction/adduction
-flexion/extension
-internal rotation/external rotation
-horizontal abduction/horizontal adduction
-scaption

what is the muscle pierced by under the fascial layer ?

several cutaneous nerves

what are the boundaries of the deltopectoral triangle ?

clavicle (superior)
pectoralis major (medial)
deltoid (lateral)

what travels through the deltopectoral triangle ?

the celphalic vein (travels w deltoid branch of thoracoacromial artery)

what opens at the deltopectoral triangle ?

clavipectoral fascia opens here

first branch of axillary artery contains what ?

superior thoracic artery

second branch of axillary artery contains what ?

-thoracoacromial artery
-lateral thoracic artery

third branch of the axillary artery contains what ?

-anterior circumflex humeral artery
-posterior circumflex humeral artery
-subscapular artery

what is the axilla ?

-main highway from head/neck/thorax/ to the upper limb
-"armpit"

what are the sides to the pyramid within the axilla ?

-anterior border= pectoralis major

-posterior border= lats, teres major, subscapularis

-medial border= serratus anterior

-lateral border= humerus

-apex= superior aspect of acromion process and under

-floor/base= axillary fascia/skin/adipose tissue

why are there not a lot of structures under the axilla ?

allows for more ROM

why is the axillary fascia highly vascularized ?

for protection, this is where all blood/nerves get through

when does the subclavian artery become the axillary artery ?

after it passes 1st rib

when does the axillary artery become the brachial artery ?

after passing the inferior border of teres major

what are the muscles of the axillary region ?

pect major
pect minor
teres major
teres minor
lat dorsi
serratus anterior
biceps brachii
coracobrachialis
subscapularis

what is the orientation of the brachial plexus ?

1. passes through the axilla
2. wraps around the axillary artery
3. branches of the brachial plexus spread out throughout the neck, chest, upper thorax & arm

where does the brachial plexus emerges from ?

-spine at C5-T1
-emerges from between the anterior and middle scalene muscles in the neck

what is the brachial plexus made up of ?

anterior rami

where does the brachial plexus pass under ?

passes under the clavicle into the axilla

3 muscular men, assassinate, 5 rats, 4 mice, 3 ok uncles

musculocutaneous N= C5, C6, C7

axillary N= C5, C6

radial N= C5, C6, C7, C8, T1

median N= C6, C7, C8, T1

ulnar N= C7, C8, T1

peripheral nerve innervation

segments of skin supplied by individual peripheral branches

winged scapula

-medial border sticking out
-long thoracic nerve damage

upper brachial plexus injury

"erbs palsy"

-upper brachial plexus injury (superior trunk)

-waiters tip (int. rotated and hanging at side)

-C5, C6

lower brachial plexus injury

"klumpke's palsy"

-lower brachial plexus injury (inferior trunk)

-claw hand

-arm raises too much over body, unable to extend

-C8, T1

radial nerve injury

"saturday night palsy"

-hyperabduction

-fall asleep w arm up

supraspinous ligament

travels along tip of spinous processes
-resists flexion/over spreading of spinous process
-C7 and below is the supraspinous ligament

nuchal ligament

-broad dense ligament spanning from spinous processes to skin
-C7 and above is the nuchal ligament

types of acromion

type I= forms straight angle (best for tendon to run under)

type II= small curve

type III= hook (can damage tendon)

what is the triangle of auscultation good for ?

to listen for breath/lung sounds bc just the ribs there

what is the triangle of auscultation made of ?

trapezius
lat dorsi
medial border of scapula

force couple (ex: scapula)

the scapula can rotate upward and downward due to multiple muscles working together

what does the rotator cuff act as ?

acts as a stabilizer for the GH joint during movement

what is the most common rotator cuff muscle tear ?

supraspinatus

-hypovascular zone

-runs under acromion process= narrow space

the quadrangular space

long head triceps
teres minor
humerus

the triangular space

teres minor
teres major
long head triceps

what travels through the triangular space ?

circumflex scapular artery

what travels through the quadrangular space ?

axillary nerve and posterior circumflex humeral artery

fascia and septa

-fascia surrounds regions under skin
-fascia separates compartments
-compartments are functional units

what muscle is working when doing a chin up ?

biceps brachii

what muscle is working when doing a pull up ?

brachialis

is musculocutaneous nerve motor, sensory or both ?

-motor (flexing)
-sensory (lateral forearm) - turns into lateral cutaneous N