ANAT 315 1/2 Flashcards
Axial Skeleton
Anchoring point for appendicular skeleton (bones of skull, accessory bones, vertebral column, thoracic cage)
Appendicular Skeleton
Upper limbs and pectoral girdle, lower limbs and pelvic girdle
what is the Vertebral Column made up of
Made up of 26 bones (Vertebrae: 7 cervical, 12 thoracic, 5 Lumbar & the sacrum and coccyx)
What are the functions of the vertebral column?
- column of support
-protect spinal cord, passage of nerves - attachment site for muscles
Vertebra Anatomy
-vertebral body (stacked makes vertebral column)
-Spinous process (b/w transverse processes)
-Transverse process (stick out laterally)
-pedicle (connects vertebral body and transverse process)
-vertebral foramen (hole in middle)
-lamina (connects spinous and transverse processes)
What is the term for 2 vertebrae meeting?
(Superior and Inferior) articular process + facet
What consists between vertebrae?
Intervertebral discs ( made up of Nucleus pulposus and Annulus fibrosis)
Herniated DIsc
When nucleus pulposus herniates into vertebral canal due to tear in annulus fibrosis
Cervical vs Thoracic vs Lumbar Vertebrae
Cervical - spinus process split into 2 parts (Bifid)
Thoracic - slope down, costal facets for ribs
Lumbar - much larger, kidney shaped
What are the first two vertebrae
C1 and C2 (atlas and axis), the dens (odontoid process) is a C2 projection. Ligament holds dens in place to create “no” motion of head
Functions of the Thoracic Cage
1)Encloses and protects viscera of the thoracic cavity
2) Thoracic skeleton acts as an anchor/attachment site for muscles
Parts of Thoracic cage
1)Sternum
2) 12 pairs of ribs
3)Thoracic Spine: T1-T12 vertebrae
Parts that make up the sternum
Body, Manubrium, Xiphoid Process, Sternal angle, Clavicular Notch’s
What makes up rib cage
-12 pairs, 24 total
-Costal Cartilage (articulates with sternum and contributes to elasticity of thoracic cage)
Types of RIbs
True Ribs: 1-7, articulate with sternum via costal cartilage
False Ribs: 8-10, articulate with sternum indirectly via fused costal cartilage
Floating Ribs: 11&12, no anterior articulation
Anatomy of a Rib
-Sternal end (articulates with sternum
-Head
-Tubercle
-Costal groove (runs along anterior surface, this is where Intercostal vein, artery & nerve run)
Unique feature of Thoracic Vertebrae
Contain costal facets where ribs articulate with vertebral column (some vertebrae have 2 or 1)
Articulation of rib at vertebral column
Tubercle: articulates with transverse process of thoracic vertebrae
Head: articulates with body of thoracic vertebrae via costal facet
Superficial Muscles of thoracic cage
Pectoralis Major & Minor, Subclavius, Serratus Anterior, Serratus Posterior
Pectoralis Major Origin
Origin: anterior surface of clavicle, anterior surface of sternum ], external oblique aponeurosis
**most superficial layer
Pectoralis Minor origin
ribs 3-5 on anterior surface
Subclavius Origin
1st rib
Serratus Anterior Origin
Origin: surface of ribs 1-8
**spans entire thoracic cage
Serratus Posterior Superior Origin
Origin: C7-T3 spinous processes
Serratus Posterior Inferior Origin
Origin: T11-L2 spinous processes
Which of the following does NOT originate on the ribs
a) Pec Minor
b) Subclavius
c) Serratus anterior
d) Serratus posterior superior
d) Serratus posterior superior - originates on the spinous processes
Deep Muscles of Thoracic Cage
External & Internal Intercostals, Innermost Intercostals, Transverse Thoracis, Subcostales
External Intercostals Origin
Origin: inferior border of ribs
** muscle fibres travel medially and inferiorly
**most superficial of intercostals
Internal Intercostals
Origin: inferior border of ribs
**muscle fibres travel medially, anteriorly and superiorly
Innermost Intercostals
Origin: inferior border of ribs
**deepest intercostals
**less developed and play less a role
Transversus Thoracis origin
Origin: Pleural (inside) surface of ribs 2-6 anteriorly
Subcostales Origin
Origin: Pleural (inside) surface of lower ribs (posteriorly)
Diaphragm origin
Origin: Xiphiod process of sternum, L1-L4 vertebra (anterior surface), costal arch of ribs 7-12
** main driver of breathing mechanisms
Pectoralis Minor Insertion
Coracoid process of scapula
Pec Minor Action
pulls (contracts) scapula down and anteriorly
Pec Minor Innervation
Medial pectoral nerve
Subclavius Insertion
interior surface of clavicle
Subclavius Action
Pulls down and stabilizes clavicle
Subclavius Innervation
C5-C6 cervical nerves
Pec Major Insertion
Intertubercular groove
Pec Major Action
Adducts, Flexes and Medially rotates arm
Pec Major Innervation
Medial and Lateral Pectoral Nerves
Serratus Anterior Insertion
medial border od scapula on costal surface
Serratus Anterior Action
protract scapula and elevate ribs (boxing)
Serratus Anterior Innervation
long thoracic nerve
Serratus Posterior Superior Insertion
Superior border of ribs 2-4
Serratus Posterior Superior Action
elevates upper ribs
Serratus Posterior Superior Innervation
T1-T4 ventral rami
Serratus Posterior Inferior Insertion
inferior borders of ribs 9-12
Serratus Posterior Inferior Action
depresses lower ribs (pulls lower ribs together)
Serratus Posterior Inferior Innervation
T9-T12 anterior rami
External Intercostals Insertion
Superior border of rib below
External Intercostals Action
Elevate ribs (inspiration)
External Intercostals Innervation
intercostal nerves
Internal Intercostals Insertion
Superior border of rib below
Internal Intercostals Action
lower ribs (expiration)
Internal Intercostals Innervation
intercostal nerves
Innermost Intercostals Insertion
Superior border of rib below
Innermost Intercostals Action
lower ribs (expiration)
Innermost Intercostals Innervation
intercostal nerves
Transverse Thoracis Insertion
Posterior surface of sternum, Xiphoid process
Transverse Thoracis Action
Lower ribs (expiration)
Transverse Thoracis Innervation
Intercostal nerves
Subcostals Insertion
superior border of ribs below; lower ribs
Subcostals Action
Contracts, pulls ribs down (expiration)
Subcostals Innervation
intercostal nerves
Diaphragm Insertion
central tendon of diaphragm
Diaphragm Action
contracts and compresses abdomen (inspiration); relaxes (expiration)
Diaphragm Innervation
Phrenic Nerve (C3,C4,C5 keeps the diaphragm alive)
Path of Anterior Blood Supply on the RIGHT side
- Arch of aorta
- Brachiocephalic artery
- R. Subclavian artery
- R. internal thoracic artery
- Anterior intercostal arteries
Path of Anterior Blood Supply on the LEFT side
- Arch of aorta
- L. Subclavian artery
- L. internal thoracic artery
- Anterior intercostal arteries
**no branching off aorta
Path of POSTERIOR blood supply
- Arch of aorta
- Descending thoracic aorta
- Posterior intercostal arteries
Venous Drainage in Upper Limbs
- Hemiazygos vein
- Accessory hemiazygos veins
- Azygos vein
- Superior Vena Cava
Joint (articulation)
-site where two or more bones connect
-the function and range of motion of each joint is dependent upon its anatomy
***not all joints permit movement
Purpose of joints
- Link the skeletal system
- Joins facilitate movement of the skeleton
Relationship between stability and mobility
Inverse: More mobile = less stable and vice versa
Classification of joints based on function: by increasing range of motion
Synarthrosis, Ampiarthrosis, Diarthrosis
*based on motion permitted
Classification of joints based on structure
Fibrous, Bony Fusion, Cartilaginous, Synovial
*What tissues join the articulating bones
Synarthrosis Movement
-Immobile or nearly immobile
Synarthrosis Joint anatomy
-strong union between articulating bones
Structure classification of Synarthrosis Joint
Fibrous, Bony Fusion, or cartilaginous
Amphiarthrosis Movement
Slightly Moveable
Structure classification of Amphiarthrosis
Fibrous or Cartilaginous
Cartilaginous amphiathrosis example
Bones joined by a wedge of cartilage
ex. intervertebral discs
Diarthrosis movement
wide range of movement
Structure classification of diarthrosis joint
Synovial
Bony Fusion
created when bones fuse together, boundaries separating bones disappear
ex. pelvis
Diarthrosis Joint anatomy
charcaterized by joint cavity (fluid-filled space)
Where are synovial Joints most commonly found
at ends of long bones like upper and lower limbs
Basic components of synovial joints:
- Joint capsule
- Articular cartilage
- Joint cavity filled synovial fluid
- synovial membrane
- accessory structures
*have extra tissues than other joints to allow movement
Make up of Joint capsule:
Joint capsule: encloses joint cavity
- Outer dense connective tissue layer
- Inner synovial membrane
Purpose of synovial membrane
-lines inner surface of joint cavity but DOES NOT cover articulating bone surfaces
-produces synovial fluid
Purpose of Synovial Fluid
-fills joint cavity to lubricate, absorb shock, and distribute nutrients to cells of articular cartilage
Articular Cartilage
-covers surface of articulating bones with in joint cavity
-smooth surface helps reduce friction during movement
Accessory structures of Synovial Joints
- Menisci
- Ligaments
- Bursae
- Fat Pads
*to provide support and additional stability
Menisci (Meniscus)
-fibrocartilage pads between bone
-Reduce friction disperse weight across joint, protect & cushion joint surface
Ligaments
-tissue connecting bone to bone
-support and strengthen synovial joints
-can be inside (intracapsular) or outside (extracapsular) of joint cavity
Bursa (Bursae)
-Small fluid-filled pockets in connective tissue, occur around tendons and bones
-Filled with synovial fluid lined by a synovial membrane
-reduce friction
-act as shock absorbers
Fat Pads
-around periphery of joint
-protect articular cartilages
-cushion joint as a whole
Types of Movement as Synovial Joints
Gliding, Angular, Rotational, Special Movements
Gliding (planar/linear) movement
two opposing flat surfaces sliding past eachother
Angular Movement
movement that changes the angle between articulating bones
(flexion, extension, abduction, adduction, circumduction)
Pronation
Radius rolls across anterior surface of ulna
Inversion
sole of foot twists inward
Eversion
sole of foot twists outwards
Dorsiflexion
elevate sole of foot
Plantar flexion
Elevate heel of foot
Opposition
Thumb moves across palm to touch.the tips of the fingers
Reposition
Thumb and fingers move from opposition back to anatomical position
Protraction
moving part of body anteriorly in transverse plane
Retraction
Part of bosy moves posteriorly in transverse plane
Elevation
Move in superior direction
Depression
Move in inferior direction
Lateral flexion (of Vertebral Column)
bending side to side
6 types of synovial joints
Pivot, Hinge, Ball and socket, Saddle, Gliding, Ellipsoidal (condylar)
Hinge Joint
Monoaxial; permits angular movement across one axis (flexion/extension), convex surface fits into concave surface
examples: elbow (ulna & humerus), ankle, interphalangeal
Pivot Joint
Monoaxial; permits only rotation, pointed surface of bone articulates with a ring
example: atlanto-axial joint (C1 & C2) and proximal radioulnar
Ellipsoidal (condylar) Joint
Biaxial; permits motion across 2 axes, oval face sits within depression on opposite surface
Flexion, extension, abduction, adduction and circumduction
Example: Metacarpophalangeal
Saddle Joint
Biaxial: angular movement across 2 axes, articular surface of bone fits into saddle shaped bone
example: first carop,metacarpal joint
Ball and Socket Joint
Triaxial: angular and rotational movement across 3 axes, round head fits into cup shaped
Angular motion, circumduction, rotation
Example: shoulder, hip
Components of pectoral girdle
Clavicle and scapula
3 distinct features of the scapula
spine, inferior angle and glenoid fossa
Components of clavicle
-sternal end (medial)
-acromial end (lateral)
-tubercle (inferior surface)
-Concave (1/3)
-convex (2/3)
Sternoclavicular joint
clavicular notch of sternum articulates with sternal end of clavicle to create a Saddle-synovial joint
Borders of the scapula
Medial, lateral and superior
Fossae of the scapula
Supraspinous (above scapula spine), infraspinous (below scapular spine), and subscapular (anterior side of scapula)
Features of anterior scapula
Acromion
-articulates with lateral end of clavicle
Coracoid Process
Features of Posterior scapula
Scapular spine that divides two posterior fossa
Features of Lateral Scapula
Gleniod fossa
-forms shoulder joint with humerus
Glenohumeral joint
ball and socket joint created by head of humerus and glenoid fossa articulating, protected by bursae
Acromioclavicular joint
connected by acromioclavicular ligament
Coracoacromial joint
connected by coracoacromial ligament
Components of proximal humerus (6)
Head, Greater tubercle, lesser tubercle, surgical neck, anatomical neck, and intertubercular groove
Features of distal humerus
capitulum, trochela, coronoid fossa, olecranon fossa, radial fossa, lateral epicondyle and medial epicondyle
Bone of Forearm
Radius (thumb side), Ulna (pinky side)