Transcript
Structural KinesiologyKIN172
Functional Anatomy
• The study of muscles, bones, and joints involved in movement
How many bones in the body? - More than ½ in the hands and feet
How many muscles in the body?
Skeletal systems• 206 bones make up the skeletal system, which
provides:
• Bone: matrix of inorganic salts and collagen• Osteocytes: bone cells
– Osteoblasts: cells that create bone
- Osteoclasts: cells that resorb bone
Functions of the Skeleton• Leverage• Support• Protection (brain, internal organs)• Storage (fat and minerals)• Blood cell formation (hematopoiesis)*Critically important for movement
Skeleton may be divided into:
- The Axial skeleton - The Appendicular skeleton
Axial Skeleton
• Forms the axis of the body and supports/ protects the organs of the head, neck, and trunk
Skull Vertebral column Ribs Sternum Auditory ossicles ‘ear bones’
Appendicular Skeleton• Composed of the bones of the upper and lower
extremities and the bony girdles that anchor the joints of the axial skeleton.
• Shoulder and pelvic girdles
Reference Positions
Anatomical Position- All directional terms that describe the relationship of one
body part to another assume the body
is in the anatomical position
Subject standing with upright posture,
feet parallel and close,
palms facing forward Most commonly used
Directional Terminology
• Anterior In front, or front part Ex: The quadriceps is located at the anterior aspect of the thigh
• Posterior Behind, or back part Ex: The triceps are located
at the posterior aspect of the arm
Directional Terminology
• Proximal Nearest the trunk or midline Ex: The elbow is proximal to the wrist
• Distal Further away from the trunk or midline Ex: The distal aspect of the tibia is near
the ankle
Directional Terminology
• Superior Above, higher Ex: The head is superior to the shoulders
• Inferior Below, lower Ex: The shoulders are inferior to the head
Directional Terminology
• Lateral Farther from, outside Ex: The fibula is lateral to the tibia
• Medial Closer to the midline, inside The hip adductors are located medially
Planes of the Human Body
• Sagittal or Anterioposterior Plane Divides the body into left and right halves
• Frontal or Lateral Plane Divides the body into front and
back halves
• Transverse/horizontal plane
Divides the body into top and bottom halves
General Movements
• Abduction- lateral movement away from the midline of the trunk in the frontal plane.
• Adduction- movement medially toward the midline of the trunk in the frontal plane.
• Flexion- bending movement that results in a decrease in joint angle by bring bones together.
• Extension- Straightening movement that results in an increase of the joint angle by moving bones apart.
Movement of the ankle and foot
• Eversion- Turning the sole of the foot outward or laterally in the frontal plane; abduction.
• Inversion- Turning the sole of the foot inward or medially in the frontal plane; adduction.
• Dorsiflexion- Flexion movement of the ankle that results in the top of the foot moving toward the anterior tibia bone in the sagittal plane.
• Plantar flexion- Extension movement of the ankle that results in the foot and/or toes moving away from the body in the sagittal plane.
Types of Bones
• Long Bones- Long cylindrical shaft, which functions as levers
- Phalanges: bones of the toes and fingers- Metatarsals: arch of the foot- Metacarpals: fingers- Tibia and fibula: leg- Femur: thigh- Radius, ulna, humerus: upper arm and forearm
Types of Bones
• Flat Bones- Broad surface for muscle attachments or
protection of underlying organs- Ilium: “hip region”- Ribs, sternum, chest area- Clavicle: shoulder girdle, scapula- Cranial bones: head
Types of Bones
• Short bones- small, transfers forces and absorbs shock
carpals: wrist
tarsals: foot/ankle
• Irregular bones- many physical features for muscle attachments
vertebrae (24), sacrum, spine,
maxilla: facial bones
Muscles
Characteristics of Muscle• Irritability - Ability to respond to stimulation• Contractility - Ability to shorten when it receives
sufficient stimulation
• Extensibility- Ability to stretch/lengthen beyond resting length (protective mechanism)
• Elasticity– Ability to return to resting length after being stretched (protective mechanism)
Functions of Muscle
• Produce movement• Maintain postures and positions• Stabilize joints• Other functions
– Support and protect visceral organs
– Alter and control cavity pressure
– Maintain body temperature
– Control entrances/exits to the body
Gross structure of Muscle
• Epimysium – sheath covering the entire muscle
• Perimysium – sheath covering bundles of muscle fibers
• Endomysium - sheath covering individual fibers
• Myofibrils - strands of contractile filaments within muscle fibers
* Actin (thin filaments) and Myosin (thick filaments)
• Sarcoplasm- Cytoplasm of muscle cell
• Sarcoplasmic reticulum (within the sarcoplasm)
- Specialized endoplasmic reticulum of muscle cells
- Storage site for calcium
Fiber Type• Type I (Slow twitch)
- oxidative
- red (because of high myoglobin content)* myoglobin transfers O2- carried in the blood to mitochondria and act as O2 store in muscles
- fatigue resistant, contract slowly
- endurance athletes
• Type IIa (Fast twitch) - similar to Type 1, - high mitochondria content
- fatigue resistant, increased capacity to produce ATP
- distance runners, and endurance athletes
• Type IIb (Fast twitch)- white, low myoglobin, low mitochondrial content,
- high force production over short period
- high intensity events – weight lifting, sprinters, jumpers
Roles of Muscle
• Agonist: (prime mover) functions to cause a movement
• Antagonist: functions to resist movement
• Stabilizer: functions to fixate an area so another movement can occur
• Synergist: assist another muscle
• Neutralizer: functions to prevent undesired movement
Muscle Contraction
• Isometric: no change in muscle length during contraction
ex. Holding arms out to sides/ pushing against a wall
• Isotonic exercise (change in length )• Concentric: muscle length shortens during contraction
ex. Up phase of a sit-up
• Eccentric: muscle length increases during contraction
ex. Lowering phase of squat
• Isokinetic: speed constant during a movement/contraction
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