Structure

• A cell is the smallest structural unit of the body
• there are 4 basic cell types:

  muscle

  nerve

  epithelial

  connective tissue
• tissues are groups of similar cells which all share the same function
• organs are groups of different tissues that work together to perform a specific function
• organ systems are groups of organs that work together to perform a specific function
• organisms are the final level of structural classification
• there are three types of epithelial cell

  sqaumous

  cubodial

  columnar

  they can be simple or stratified
• functions of epithelial cells:

  protect body from environment

  secretory

  separate body compartments

  absorptive
• skin is an example of stratified squamous epithelial tissue
• examples of connective tissue:

  adipose, areolar, bone, blood, cartilage, tendons

  adipose proves insulation and protection

  tendons transfer the force of muscle contraction
• Types of muscle tissue:

  skeletal - for movement

  cardiac - in the heart

  smooth - arterial walls

  skeletal and cardiac muscle are striated due to sarcomeres
• Two types of nervous cells

  neurones - transmit electrical stimuli throughout the body

  glial cells - support cells and insulate neurones from each other
• histology is the study of the microscopic anatomy of cells and tissues
• organ systems

  control: endocrine, nervous

  maintenance: cardiovascular, renal, reproductive

  support: musculoskeletal

  defense: integumentary (skin), lymphatic
• the axial skeleton forms a line from head, spine, ribs and sacrum
• the appendicular skeloton makes up the limbs, scapula and pelvis
• splanchnic bones are found in soft organs

  os penis - penis bone in cats and dogs

  ossa cordis - in the heart
• bone classification

  long = limbs

  short = carpus/tarsus

  flat = skull for protection

  irregular = midline of body, vertebrae

  sesamoid = patella, reduces friction

  pneumatic = sinuses to reduce weight, skull - birds have lots of these bones to decrease weight for flight

  splanchnic = soft organs
• vertebrae

  cervical

  thoracic

  lumbar

  coccygeal
• the cartilage and bone in ribs is joined at costochondral junction
• muscle groups

  epaxial = on or above axis

  hypaxial = below axis, form muscles of body wall, head and neck, appendicular skeleton
• muscle terminology

  origin = muscle end attached to more stationary part, commonly the proximal end

  insertion = muscle end attached to the bone with the greatest movement

  belly = largest portion of muscle between origin and insertion

  extrinsic = originates outside of limb, but inserts on limb

  intrinisic = contained within one limb
• body cavities

  dorsal = cranial and vertebral

  ventral = thoracic and abdominopelvic
• serous membranes

  line body cavities and organs within them. they secrete serous fluid which stops organs sticking together.

  basement membrane and simple squamous epithelium

  thorax = pleura

  heart = pericardium

  pelvis = peritoneum