Anatomy: Skeletal System Overview PDF

Bone Function Support, Protection &Movement ❑ supports body’s weight ❖.protects lungs, etc ❖ bones and muscles interact when ❖ Inorganic Salt Storage ❑ limbs or body parts move calcium ❖ phosphate ❖...

Bone Function Support, Protection &Movement ❑ supports body’s weight ❖.protects lungs, etc ❖ bones and muscles interact when ❖ Inorganic Salt Storage ❑ limbs or body parts move calcium ❖ phosphate ❖ magnesium ❖ sodium ❖ Blood Cell Formation ❑ potassium ❖ red marrow ❖ ٣  Introduction Axial skeleton Appendicular Forms the long axis of Bones of upper & lower the body extremities and girdles bones in three 80 bones in three major 126 major regions regions Skull – Girdles – Vertebral column – Shoulder girdle Pelvic girdle Bony thorax – Ribs Upper extremity – Sternum Lower extremity – ٤  Skeletal Organization Axial Skeleton ❑ skull ❖ vertebral column ❖ thoracic cage ❖ Appendicular Skeleton ❑ upper limbs ❖ lower limbs ❖ pectoral girdle ❖ pelvic girdle ❖ ٥ ٦  Parts of the skeletal system Bones (skeleton) Joints Cartilages Ligaments (bone to bone) Tendon(bone to muscle) ٧ Types of Bones ٨ ٩ Cranial bones (8) (1) (2) (1) (2) (1) (1) ١٠ ١١  Bones of the Skull Cranial bones Facial bones Paired Temporal Maxillae Parietal Zygomatic bones Nasal bones Lacrimal bones Palatine bones Inferior nasal conchae Unpaired Frontal Mandible Occipital Vomer Sphenoid Ethmoid ١٢ Bones of the Skull ١٣ ١٤ ١٥  The Bony Thorax Made-up of three parts Sternum ✓ Ribs & costal ✓ cartilages Thoracic vertebrae ✓ Figure 5.19a ١٦ Ribs All ribs attach to vertebral column posteriorly True ribs (1-7) : The superior seven pairs of ribs (attach to the sternum.(the breast bone) in the front and are known as true (or sternal) ribs) False ribs (8-12): Do not directly connect to the sternum and are.(known as false ribs The upper three false ribs connect to the costal cartilages of the ribs.just above them The last two false ribs (11–12), however, usually have no ventral attachment (no anchor at all in front) and are called floating,.fluctuating or vertebral ribs ١٧  Vertebral Column: General Characteristics Formed from 26 irregular bones in adult It provide axial support for the trunk Transmits weight of trunk to lower limbs Protects spinal cord Attachment site for ribs and muscles Separated by intervertebral discs There are 24 vertebrae, a sacrum (5 fused) and a coccyx (4 fused) ١٨ Regional Characteristics Cervical C1-C7 Neck / movable – Thoracic T1-T12 Rib cage / limited – movement Lumbar L1-L5 Low back / movable – Sacral 5 fused Joins the pelvis – Coccyx 4 fused Terminus – ١٩ Normal Curvatures Cervical and lumbar are concave Thoracic and are sacral are convex Primary curvatures Thoracic and sacral – Secondary curvatures Cervical and lumbar – ٢٠ ٢١  Structure of a Vertebrae Vertebral Body Vertebral Arch Vertebral Arch Is formed of the following parts Spinous processes Transverse processes Pedicles Lamina Articular processes ٢٢  Difference between vertebra Cervical (3-7) Thoracic Lumber Body Small, wide side to Larger than cervical, heart kidney shaped side shapes, has two costal demifacets Spinous Short bifid, projects Long sharp, projects inferiorly Short, blunt, projects process directly posteriorly directly posteriorly Vertebral Triangular circular triangular foramen Transverse Contain foramina Bear facets for ribs (except Thin and tapered process T11-T12) ٢٣ ٢٤ ٢٥ ٢٦ Atlas – C1 ٢٧ Axis – C2 ٢٨ ٢٩ Bones of the Shoulder Girdle ٣٠ ٣١  Bones of the Upper Limb The arm is formed by a single bone Humerus ٣٢  Bones of the Upper Limb The forearm has two bones Ulna Radius ٣٣ ٣٤ Pronation and Supination Supination: Palm facing upwards Pronation: Palm facing downwards Involved joints Proximal radioulnar joint Proximal radioulnar joint ٣٥  Bones of the Upper Limb The hand Carpals – wrist Metacarpals – palm Phalanges – fingers ٣٦  The Pelvis &pelvic girdle Structure of the Pelvic Girdle The bony pelvis consists of the Two hip bones (pelvic bones) the sacrum.the coccyx :There are four articulations within the pelvis Sacroiliac joints – between the ilium of the hip bones, and the sacrum.Sacrococcygeal symphysis – between the sacrum and the coccyx.Pubic symphysis – between the pubis bodies of the two hip bones ٣٧  The Pelvis &pelvic girdle Hip bones (pelvic bones) ٣٨ The Pelvis &pelvic girdle ٣٩ Bones of the Lower Limbs The thigh has one bone Femur – thigh bone ٤٠ Bones of the Lower Limbs The leg has two bones Tibia Fibula ٤١ Bones of the Lower Limbs Ankle The foot Tarsus – ankle Sole Metatarsals – Toes sole Phalanges – toes ٤٢ ٤٣ ٤٤  MUSCULAR SYSTEM Muscles are tissues that can contract, enabling.movement.Muscle cells are called myocytes Functions of muscular system.Attach to bones of the skeletal system -.Moves food through digestive system -.Passes blood through circulatory system -.Expels fluids through excretory system - ٤٦ ٤٧  Skeletal Muscle (A).Produce the movements of skeleton.Voluntary muscles.Made of striped ms. fibers & Has 2 attachments at least; origin.insertion.Fleshy part of muscle called belly : The ends of ms. are attached to.bone, cartilage or ligaments ٤٨ The attachment of ms. to bone may : take one of following shapes.Tendon: a cord of fibrous T.1 Aponeurosis:Strong sheet of fibrous.2.T ٤٩ Raphe: interdigitation of tendinous ends.3.of fibers of flat muscles ٥٠  Classification of skeletal muscles (according to direction of ms. fibers) Parallel : ms. fibers are parallel to the (A) long axis of muscle: one of two types Strap like: e.g. sartorius Fusiform: e.g. Biceps brachii, Digastric Quadrilateral: Quadratus lumborum ٥١ ٥٢ :Circular (B) The muscle fibers surround a circular orifice Convergent: ( C) Muscle fibers converge near the point of insertion...e.g. Pectoralis major.Oblique: muscle fibers run obliquely (D) pennate (means “feather shape”) MUSCLES: :three types.Unipennate; looks like half a feather Bipennate: are fascicles that insert into the tendon.from both sides; they are stronger than unipennate Multipennate: are the strongest (biceps femoris). The fascicles are in multiple bundles inserting on one tendon ٥٣ Anatomical Terms of Movement Flexion and Extension -1 Flexion and extension are movements that occur in the sagittal plane. They refer to increasing and decreasing the angle :between two body parts Flexion refers to a movement that decreases the.angle between two body parts Extension refers to a movement that increases the.angle between two body parts of Movement ٥٤  Anatomical Terms of Movement Abduction and Adduction -2 Abduction and adduction are two terms that are used to describe movements towards or away from the midline of the.body Abduction is a movement away from the midline. abduction of the shoulder raises the arms out to.the sides of the body Adduction is a movement towards the.midline. Adduction of the hip squeezes the legs together ٥٥  Anatomical Terms of Movement Medial and Lateral Rotation-3 Medial and lateral rotation describe movement of the limbs around their long axis Medial rotation is a rotating movement towards the midline Lateral rotation is a rotating movement away from the.midline ٥٦  Skeletal Muscle Action Prime mover : chief ms. or.1 member of a chief group of ms. responsible for a particular movement; as Quadriceps.femoris ms. in extending knee Antagonist : any ms..2 opposing action of prime mover. Before prime mover can contract, antagonist ms..must be relaxed ٥٧ Synergist : when prime.3 mover ms. crosses several joints before reaching the joint at which its main action takes place, groups of synergists contract to stabilize intermediate joints & prevent.unwanted movements ٥٨  Nerve Supply of Skeletal Muscle :Nerve trunk to a muscle : is a mixed nerve containing.motor fibers (60%).1.sensory fibers (40%).2.some sympathetic fibers.3 Motor point : is located where the motor nerve enters the muscle. It is where the muscle is most electrically excitable. This usually lies at the junction of the upper and middle..one third of the fleshy belly of the muscle ٥٩ Naming of skeletal ms. : Is according to: shape, size, heads, position, depth, attachments or actions. Muscle Tone: A slight unconscious continuous contraction in the skeletal.muscle ٦٠  Smooth Muscles (B).These muscles are involuntary ✓ found in the GIT ,blood and lymph ✓ vessels walls,, and in various hollow organs stomach ٦١  Cardiac Muscles (C).These muscles are attached to the heart ✓ They are responsible for ✓ moving the blood through the heart's chambers and pumping it to all parts of.the body These muscles are ✓.involuntary ٦٢