Anatomy

• We take a systemic approach to learning the body, meaning we study the body by system
• Positive feedback increases the bodily response until an end point is reached

  • Example: childbirth
• Serous membranes cover the organs of trunk cavities and line the cavity to protect and reduce friction. They can be found:

  • Pericardium surrounds the heart
  • Pleura surrounds the lungs and lines the thoracic cavity
  • Peritoneum surrounds many abdominal organs and lines the abdominopelvic cavity
• The functions of the skeletal system are support, protection, movement, storage, and blood cell production
• There are three types of cartilage:

  1. Hyaline cartilage is the most common and is found in between the ribs and sternum and at articular surfaces
  2. Fibrocartilage is the most dense and is found in the intervertebral discs and meniscus
  3. Elastic cartilage provides support, is the most flexible, and is found in the outer ear
• Chondroblasts are the basic building block of cartilage
• Bone ossifies through either intramembranous ossification or endochondral ossification
• When a bone does not have enough collagen it becomes brittle
• Epiphyseal lines are only found in long bone and is made of hyaline cartilage to help the bone grow in length
• The medullary cavity contains red bone marrow in children and yellow marrow in adults
• Osteogenesis is the formation of bone and is aided by:

  1. Osteoblasts to help build bone
  2. Osteoclasts to break down bone
  3. Osteocytes which are mature bone cells
• The trabeculae are interconnected rods of bone that become oriented along lines of stress
• There are three main types of bone shapes that include:

  1. Long bones have a periosteum and endosteum and include the femur
  2. Flat bones are a sandwich of compact bone that surrounds spongy bone and include the parietal bones
  3. Short and irregular bones have a similar structure the epiphysis of long bones and include the vertebrae
• Parathyroid hormone activates osteoclasts and prevents bone formation
• Reproductive hormones are responsible for the growth of epiphyseal plates
• There are 7 types of fractures including transverse, linear, oblique, greenstick, spiral, comminuted, and impacted
• The process of bone repair is as follows

  1. Hematoma formation -> callus -> callus ossification -> bone remodeling
• Cartilage is made of mostly II collagen, proteoglycans, and elastin
• Joints can be classified based on structure or function
• Joints can be classified by function based on their range of motion and include:

  1. Synarthrosis are non-moveable
  2. Amphiarthrosis are slightly moveable
  3. Diarthrosis are freely moveable
• Joints can be classified by structure based on the connective tissue within the joint and include:

  1. Fibrous joints have no joint cavities and little movement. Ex: sutures, syndesmoses, and gomphoses
  2. Cartilaginous joints are two bones united by pad of cartilage
  3. Synchondroses which contain hyaline cartilage and include sternocostal joints and
  4. Symphyses which contain fibrocartilage and include the pubic symphysis and SI joint
  5. Synovial joints contain large amounts of movement and are typically a complex joint
• Synovial fluid contains a mixture of polysaccharides, proteins, fats, and cells which provide nutrients
• There are 6 classifications of synovial joints

  1. Plane joint is uniaxial and include the acromioclavicular joint
  2. Saddle joint is biaxial and includes the sternoclavicular joint
  3. Hinge joint is uniaxial and includes the elbow joint
  4. Pivot joint is uniaxial and includes the atlantoaxial joint
  5. Ball-and-socket joint is multiaxial and includes the hip joint
  6. Ellipsoid in biaxial and includes the atlantooccipital joint
• Active range of motion is accomplished by muscle contraction
• Active assisted range of motion is accomplished by both passive and active means
• Passive range of motion is accomplished by an external force
• The temporomandibular joint includes special movements of lateral excursion
• The shoulder joint is deepened by the glenoid labrum
• The elbow contains three joints include the humeroulnar, radioulnar, and proximal radioulnar
• The round ligament of the femur contains the blood supply for the head of the femur
• The knee contains fibrocartilage discs known as meniscus
• The anterior cruciate ligament runs from lateral to medial and prevents anterior translation of the tibia
• There are three types of muscle tissue:

  1. Skeletal muscle is voluntary and controls locomotion, posture, and facial expressions
  2. Smooth muscle is involuntarily controlled by the endocrine and autonomic nervous system and lines the walls of hollow organs, glands, and skin
  3. Cardiac muscle is autorhythmic and controls the flow of blood through the heart
• Functions of the muscular system include movement of the body, posture, respiration, heat production, communication, constriction of organs and vessels, and contraction of the heart
• Contractility is the ability for muscle to shorten with force
• Excitability describes that a muscle can respond to a stimulus
• Extensibility is the ability for a muscle to contract beyond it's resting length
• Elasticity is the ability of a muscle to recoil after being stretched
• Motor neurons stimulate cardiac and smooth muscle
• The layering of skeletal muscle tissue is as follows:

  1. Epimysium surrounds the entire muscle and merges with muscular fascia
  2. Perimysium surrounds a group a fascicles
  3. Endomysium surrounds individual muscle fibers