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By the end of this section, you will be able to:
  • Identify the muscles of the pectoral girdle and upper limbs
  • Identify the movement and function of the pectoral girdle and upper limbs

Muscles of the shoulder and upper limb can be divided into four groups: muscles that stabilize and position the pectoral girdle, muscles that move the arm, muscles that move the forearm, and muscles that move the wrists, hands, and fingers. The pectoral girdle    , or shoulder girdle, consists of the lateral ends of the clavicle and scapula, along with the proximal end of the humerus, and the muscles covering these three bones to stabilize the shoulder joint. The girdle creates a base from which the head of the humerus, in its ball-and-socket joint with the glenoid fossa of the scapula, can move the arm in multiple directions.

Muscles that position the pectoral girdle

Muscles that position the pectoral girdle are located either on the anterior thorax or on the posterior thorax ( [link] and [link] ). The anterior muscles include the subclavius    , pectoralis minor    , and serratus anterior    . The posterior muscles include the trapezius    , rhomboid major    , and rhomboid minor    . When the rhomboids are contracted, your scapula moves medially, which can pull the shoulder and upper limb posteriorly.

Muscles that position the pectoral girdle

The left panel shows the anterior lateral view of the pectoral girdle muscle, and the right panel shows the posterior view of the pectoral girdle muscle.
The muscles that stabilize the pectoral girdle make it a steady base on which other muscles can move the arm. Note that the pectoralis major and deltoid, which move the humerus, are cut here to show the deeper positioning muscles.
Muscles that Position the Pectoral Girdle
Position in the thorax Movement Target Target motion direction Prime mover Origin Insertion
Anterior thorax Stabilizes clavicle during movement by depressing it Clavicle Depression Subclavius First rib Inferior surface of clavicle
Anterior thorax Rotates shoulder anteriorly (throwing motion); assists with inhalation Scapula; ribs Scapula: depresses; ribs: elevates Pectoralis minor Anterior surfaces of certain ribs (2–4 or 3–5) Coracoid process of scapula
Anterior thorax Moves arm from side of body to front of body; assists with inhalation Scapula; ribs Scapula: protracts; ribs: elevates Serratus anterior Muscle slips from certain ribs (1–8 or 1–9) Anterior surface of vertebral border of scapula
Posterior thorax Elevates shoulders (shrugging); pulls shoulder blades together; tilts head backwards Scapula; cervical spine Scapula: rotests inferiorly, retracts, elevates, and depresses; spine: extends Trapezius Skull; vertebral column Acromion and spine of scapula; clavicle
Posterior thorax Stabilizes scapula during pectoral girdle movement Scapula Retracts; rotates inferiorly Rhomboid major Thoracic vertebrae (T2–T5) Medial border of scapula
Posterior thorax Stabilizes scapula during pectoral girdle movement Scapula Retracts; rotates inferiorly Rhomboid minor Cervical and thoracic vertebrae (C7 and T1) Medial border of scapula

Muscles that move the humerus

Similar to the muscles that position the pectoral girdle, muscles that cross the shoulder joint and move the humerus bone of the arm include both axial and scapular muscles ( [link] and [link] ). The two axial muscles are the pectoralis major and the latissimus dorsi. The pectoralis major    is thick and fan-shaped, covering much of the superior portion of the anterior thorax. The broad, triangular latissimus dorsi    is located on the inferior part of the back, where it inserts into a thick connective tissue shealth called an aponeurosis.

Questions & Answers

list down all the hormones secreted by adrenal gland
Odong Reply
The amount of blood pumped by the left ventricle of the heart in one contraction.
Javid Reply
how we can calculate the cardiac output
khater
and how do we calculate the strock valume
khater
stroke volume is not all the blood contained in the left ventricle; normally, only about two-thirds of the blood in the ventricle is expelled with each beat.
Javid
Cardiac output 5.5 l S. V 68.75 ml H. R 80bpm
Javid
If we consider SV 70, end systolic vol is about 15% of total(approx always) out of a total of 80-85 ml only 70ml is pumped per systole
Kartik
what is macrophages?and its function
Sajjad Reply
macrophages they are white blood cells that engulf dead cells in the body
patience
what is power stroke?
muravha
no idea
patience
what is the stroke volume of heart?
up
If an autoimmune disorder targets the alpha cells, production of which hormone would be directly affected?
Samantha Reply
what is a muscle?
Gideon Reply
A band or bundle of fibrous tissue in a human or animal body that has the ability to contract, producing movement in or maintaining the position of parts of the body
Mody
ok
Gideon
what's endolphthamities and panophthalmities?
Gideon
fluid around the brain
louise Reply
what ?
Asif
cerebro spinal fluid
Bhupender
The brain and spinal cord are surrounded by a clear fluid called cerebrospinal fluid (CSF). This fluid is produced and stored in cavities in the brain called ventricles. It circulatesaround the brain, moving from ventricle to ventricle. ... Hydrocephalus is a condition in which there is too much CSF
Archie
what is hydrocphalus
aminul Reply
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Bhupender
when cerebrospinal fluid produce în the brain, i.e. brain ventricles, is to abundent in the brain and is not trăind out of the brain. as a consequence this lichid pute mechanical pressure oñ the brain and it pushes the cerebrum tissue. as a consequence this pressure on the neuronscan cause neurologi
Centerkinet
cal disfunctions, for example clinical headache
Centerkinet
. It is posible to drainout the fluid through a device dalles shunt,as i remember.
Centerkinet
but where are also home medicinsfor decreasing the production of cerebrospin.fluid etc
Centerkinet
there are some medicines that can decrease the production of csf
Centerkinet
a neurologist advice is needed
Centerkinet
i wrote some medicines NOT home medicines. it is a serious condition and specialized medical advice is needed. of course also general medical knowledge may be helpful, but not enough, a specialist is neede
Centerkinet
if anyone help me in physiology
Radika Reply
i am BSN student of first year which book is best for physiology
Radika
i am BSN student of first year which book is best for physiology
Radika
ross and wilson anotomy and physiology
Sajjad
it's 1 book for anotomy and physiology it's best for bs nursing
Sajjad
yes Ross and wilson physiology is better for study
Nasir
I'm also the student of bs nursing
Sajjad
I study guiton and hall &ganong
Gentle
I'm also midwif help me be the best book for midwif
nimco
what ia the function of indocrine system
sheraz
salam all friend
sheraz
help me with this question; explain at least five emergency acute pain found in fundamental emergency medicine
Christon
Fascial compartment of forearm
Hidayatullah
what's a tissue?
Mwape Reply
a group of cells with the same function
Dee
tissue is a group of cells that perform the same functions.
Rashid
explain a bit about a tissue
Mwape
A tissue is made up of cells that are similar in shape and perform the same function, for instance brain cells form up a brain tissue. Whereas a group of tissues that perform the same function form an organ... so in this case the brain which is the organ is formed as a result of brain tissues.
Isaac
what is gross anatomy
Joseph
the branch of anatomy that deals with the structure of organs and tissues that are visible to the naked eye.
Archie
1.To know how the structures functions. 2.To easily identify the micro structures and the macro structures. 3.To be able to explain that anatomy is the study of the structures and physiology is the study of how the structures functions
Abban Reply
Describe the two classes of hormones (3 with subclasses) and how they affect their target cells.
Shalaeha Reply
what is control centre
Gohil Reply
Angie The larger air passage of the lung is
Angie Reply
guys help to make me understand the structure of the skin
Olokojo Reply
the skin has three layers epidermis,dermis,and subcutaneous tissue
Antony
guys what is esrf
Antony
End Stage of Renal Failure
sheraz
what's the meaning of OPD
Sintung
Out Patient Department
Shahab
the skin has the assesory structures.that is, sebaceous glands, sweat glands, hairs, nails,blood vessels and lymph vessels.
Mutebe
yh
Gideon
define cell and give it's brief description of the orgenelles
Manish Reply
a cell is a basic unit of life
emmanuella
what about philosophy
Smart
the organelle is a membrane bound structure in the cell that performs a particular function
emmanuella
Cell.Is a basic functional unit of life. it has the organelles, Golgi apparatus, smooth endoplasmic membrane, rough endoplasmic reticular,Lysosomes, mitochondrial and others.
Mutebe

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Source:  OpenStax, Anatomy & Physiology. OpenStax CNX. Feb 04, 2016 Download for free at http://legacy.cnx.org/content/col11496/1.8
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