Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Anatomy - Upper limb > L5: Musculo-neuro-vascular systems of pectoral and dorsal regions > Flashcards

L5: Musculo-neuro-vascular systems of pectoral and dorsal regions Flashcards

1
Q

what is a muscle

A

Muscle is a contractile tissue consisting of cells called myocytes
Muscles cross at least one joint; i.e., each end of muscle attached to different bones

“Origin” – Proximal attachment*Usually remains fixed during movement
“Insertion” – Distal attachmentUsually, the part that moves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

how do muscles work

A

Skeletal muscle consists of:
-Myocytes (muscle fibres)
-Bundled into fascicles
-Bundled into muscle

Myocytes contract (shorten) when they are activated by nerves (neurons)
Induces contraction of myofibrils with muscle cells via the sliding filament mechanism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

myocyte activation

A

Electrical signals (nerve impulse) travels along nerves, towards muscles
1.Electrical signal triggers release of acetylcholine (ACh) neurotransmitter from the end of the nerve cell
2.Neurotransmitter (ACh) travels across neuromuscular junction where it binds to ACh receptor on muscle cell
3.Triggers muscle action potential and muscle contraction

Muscles consist of many myocytes
*Many myocytes contracting together produces strong muscular movement

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

brachial

A

relating to, or situated in the arm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

plexus

A

a network of anastomosing or interlacing blood vessels or nerves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

brachial plexus

A

is the system of nerves that emerge lateral to the spinal chord and :
- allow motor nerves send their signals from brain to upper limb muscles
- allow sensory nerves send their signals back to the brain

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

brachial plexus; intro

A

spinal nerves leave spine through spaces between vertebrae

brachial plexus formed by C5-T1 spinal nerves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

brachial plexus- sections

A

Roots - 5 > C5-T1
Trunks - 3 > sup, mid, inf
Divisions - 6 > anterior , posterior
Cords - 3 > lat, medial, post

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

movements of the scapula

A

elevation + depression
protraction + retraction
upward + downward rotation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

scapular movers or stabilisers (6 muscles)

A

muscles that connect the scapula to the axial skeleton

dorsal region [back];
1. trapezius
2. levator scapulae
3. rhomboid minor
4. rhomboid major

pectoral region [front of chest]
5. pectoralis minor
6. serratus anterior

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

trapezius; origin

A

large diamond shaped superficial muscle of the back
developed in rowers

origin:
-external occipital protuberance
-nuchal ligament
-spinous process of C7-T12 vertebrae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

trapezius; insertion

A
  • spine of scapula
  • acromion of scapula
  • lateral 1/3 of clavicle
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

trapezius; innervation

A

spinal accessory nerve
aka cranial nerve 11

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

trapezius; actions

A
  • powerful retractor of scapula [rowing]
  • elevates scapula [upper fibres]
  • depresses scapula [lower fibres]
  • upward rotation of scapula [upper fibres]
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

levator scapular; origin

A

small muscles from neck vertebrae to medial superior scapula. deep to trapezius

origin: transverse processes of C1-4 vertebrae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

levator scapular; insertion

A

superior part of medial border of scapula

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

levator scapular; innervation

A

dorsal scapular nerve [C4-5]

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

levator scapular; actions

A
  • elevates medial border of scapula
  • downward rotation of scapula
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

rhomboid minor; origin

A

deep to trapezius, superior to rhomboid major
spinous process of C7-T1
vertebrae

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

rhomboid minor; insertion

A

medial border of scapula, root of spine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

rhomboid minor; innervation

A

dorsal scapular nerve (C4-5)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

rhomboid minor; actions

A
  • retracts scapula
  • downward rotation of scapula
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

rhomboid major; orign

A

deep to trapezius, inferior to rhomboid minor

origin: spinous process of T2-T5 vertebrae

24
Q

rhomboid minor; insertion

A

medial border of scapula (inferior 2/3)

25
rhomboid minor; innervation
dorsal scapular nerve (C4-5)
26
rhomboid minor; actions
- retracts scapula - downward rotation of scapula
27
dorsal scapular nerve
formed from spinal nerve roots C4-5 Passes inferiorly, medial to medial border of scapula Innervates: - levator scapula - rhomboid minor - rhomboid major
28
pectoralis minor; origin
deep to pectoralis major origin: anterior surface of ribs 3-5
29
pectoralis minor; insertion
coracoid process of the scapula
30
pectoralis minor; innervation
medial pectoral nerve (C8-T1)
31
pectoralis minor; actions
protracts and stabilises scapula by pulling it antero-inferiorly onto posterior thoracic wall
32
medial pectoral nerve
arises from medial cord of brachial plexus formed by contributions from spinal nerve roots C8-T1) passes inferiorly deep to pectoralis minor providing innervation
33
serratus anterior; origin
between scapula and posterior thoracic wall origin: medial border of scapula, anterior surface
34
pectoralis minor; insertion
individual muscle slips that insert into anterolateral surface of ribs 1-8
35
pectoralis minor; innervation
long thoracic nerve (C5-7)
36
pectoralis minor; actions
- protracts and stabilises scapula by pulling it anteriorly against the thoracic wall - very important in pushing + punching - assists with upward rotation of scapula by pulling inferior angle laterally
37
long thoracic nerve
formed from spinal nerve roots C5-7 passes inferiorly over the lateral surface of serratus anterior innervates serratus anterior nerve protected when limbs at side, but is vulnerable when limbs elevated
38
long thoracic nerve palsy
caused by injuries to the long thoracic nerve trauma, heavy weightlifting repeated throwing causes paralysis of serratus anterior - lack of protraction scapular cannot be held firmly against the posterior aspect of the thoracic cage winging of the scapula ''C5, 6, 7 spread your wings and go to heaven''
39
muscles that stabilise and/or move the glenohumeral joint and arm
1. pectoralis major 2. latissimus dorsi
40
pectoralis major; origin
large muscle on anterior chest wall - it has 2 heads origin: clavicular head: medial 1/2 clavicle sternocostal head: sternum, upper 6 costal cartilages, aponeurosis of external oblique
41
pectoralis major; insertion
lateral lip of bicipital groove
42
pectoralis major; innervation
medial pectoral nerve [C8-T1] lateral pectoral nerve [C5-7]
43
pectoralis major; actions
- flexes shoulder from the extended position - adducts and internally rotates humerus
44
medial pectoral nerve
arises from medial cord of brachial plexus formed by contributions from spinal nerve roots C8-T1. passes inferiorly deep to pectoralis minor providing innervation
45
lateral pectoral nerve
arises from lateral cord of brachial plexus formed by contributions from spinal nerve roots C5-7 descends deep to pectoral muscles and innervates them from posterior
46
latissimus dorsi; origin
back muscle, very well developed in rowers origin: - spinous process of T6-L5 & S1-2 - thoracolumbar fossa - inferior ribs - posterior iliac crest of pelvis - inferior angle of scapula
47
latissimus dorsi; insertion
floor of bicipital groove
48
latissimus dorsi; innervation
thoracodorsal nerve C6-8
49
latissimus dorsi; actions
- extends, adducts, medially rotates humerus - downward rotation of scapula
50
thoraco-dorsal nerve (C6-8)
arises from posterior cord of the brachial plexus formed by contributions of spinal nerves C6-8 passes inferiorly, between scapula and thorax to reach and innervate latissimus dorsi upon reaching latissimus dorsi, runs obliquely [inferomedially] along L. Dorsi innervating the whole muscle
51
arterial blood supply to upper limb
the axillary artery has 3 parts: 1. proximal to pectoralis minor 2. deep to pectoralis minor 3. distal to pectoralis minor there are 6 branches of the axillary artery: 1st part: 1 branch 2nd part: 2 branches 3rd part: 3 branches once the axillary artery passes the inferior border of the teres major muscle, it becomes known as the brachial artery
52
axillary artery [part 1]
superior thoracic artery - passes anteriorly and inferiorly between pectoralis major and minor - supplies pectoralis major and minor
53
axillary artery [part 2]
Thoraco-acromial artery: - runs over pectoralis minor and divides into 4 branches supplying: clavicle, deltoid, acromion, pectoral muscles Lateral thoracic artery: - descends along lower border of pectoralis minor to supply: serratus anterior, both pectoral muscles, N.B. in female provides additional branches to breast
54
axillary artery [part 3]
Anterior circumflex humeral artery: - passes anteriorly around surgical neck of humerus anastomosing with posterior circumflex humeral artery Posterior circumflex humeral artery: - passes posteriorly around surgical neck of humerus anastomosing with anterior circumflex humeral artery Subscapular artery: - largest branch of axillary nerve - divides into: circumflex scapular artery & thoracodorsal artery
55
anastomosis:
Anastomosis: a cross-connection between adjacent channels, tubes, fibres, or other parts of a network
56
Arterial Supply Around the Scapula: Anastomosis
Terminal branches from Subclavian artery supply medial and superior scapula. Terminal branches from axillary artery supply inferior and lateral scapula These terminal branches anastomose together to provide complete coverage of the scapula
57
veins of pectoral and dorsal region
Axillary Vein drains venous blood proximally toward the heart. It is formed at the lower border of teres major by the union of the brachial vein and basilic vein. It runs superomedially, anteromedial to axillary artery, until it crosses the lateral border of the first rib where it becomes the subclavian vein. The axillary vein receives tributaries that correspond to branches of the axillary artery. Proximally, the axillary vein also receives the cephalic vein

Anatomy - Upper limb (10 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions