Digestive system

• Anatomy


  The study of form and structure
• Gross anatomy


  The study of structures that can be seen with the naked eye
• Microscopic anatomy


  The study of structures that require a microscope to be seen
• Physiology


  The study of the functions of the body and all its parts, including cells, tissues and organs
• Organ systems


  • Integumentary system (skin)
  • Skeletal system (bones)
  • Muscular system (muscles)
  • Circulatory system (heart & blood vessels)
  • Digestive system (stomach & intestines)
  • Nervous system (nerves)
  • Respiratory system (lungs & passageways)
  • Urinary system (kidneys & bladder)
  • Endocrine system (glands & hormones)
  • Reproductive system (organs involved in producing offspring)
• Integumentary system


  • Regulating body temperature
  • Balancing water
  • Protecting internal organs
• Components of the integumentary system

  • Skin
  • Hair
  • Nails
  • Horns
  • Sebaceous glands
  • Sweat glands
• Epidermis


  The outer layer of the skin, containing no blood cells
• Dermis


  The inner layer of the skin, containing blood vessels, lymph vessels, nerves, glands, hair follicles, and muscle fibers
• Skin appendages


  • Hair
  • Scales
  • Hoofs
  • Feathers
  • Claws
  • Horns
  • Nails
• Coat coverings differ between animal species
• Hair, wool and feather are all comprised of protein and are essential for regulating body temperature
• Arrector pili muscles


  Small bundle of smooth muscle fibers that can contract to pull the hair perpendicular to the skin surface
• Sweat glands


  Release water to cool the body
• Sebaceous glands


  Secrete oil substances to lubricate the skin and hair
• Sensory receptors in the dermis

  • Merkel cells
  • Meissner's corpuscles
  • Paccinian corpuscles
  • Free nerve endings
• Merkel cells


  Respond to very light pressure
• Meissner's corpuscles


  Sensitive to touch, found in delicate areas like lips and fingertips
• Paccinian corpuscles


  Detect pressure
• Free nerve endings


  Sense heat, cold and touch
• Skeletal system


  • Framework of the body
  • Provides structural support for all other organ systems
  • Protects the organs of the body
• Components of the skeletal system

  • Axial skeleton (skull, vertebrae, ribs, sternum)
  • Appendicular skeleton (forelegs, hindlegs, pelvic region)
• Classes of bones


  • Long bones
  • Flat bones
  • Short bones
  • Irregular bones
• Long bones


  Found in the limbs, supporting columns and levers for the skeletal system and body
• Flat bones


  Protect the body's organs and serve as an area of muscle attachment
• Short bones


  Diffuse concussion, diminish friction, and change the direction of tendons
• Irregular bones


  Found in the vertebral column
• Organic matter in bone

  Mostly collagen, gives bone flexibility and resilience
• Inorganic matter in bone

  Mostly tricalcium phosphate, gives bone rigidity and hardness
• Yellow marrow


  Soft tissue in the inner core of bone, consisting of yellow fat
• Red marrow


  Soft tissue in the outer portion of bone marrow, responsible for blood cell and platelet formation
• Endochondral ossification


  The process of bone formation from cartilage when the animal is an embryo
• Osteoblasts


  Bone forming cells
• Osteocytes


  Mature bone cells
• Primary ossification


  Occurs at the metaphyseal growth plate
• Secondary ossification


  Occurs at the epiphyseal growth plate, in the center of the epiphysis
• Ligaments


  Connect bone to bone
• Tendons


  Attach muscle to bone
• Types of cartilage


  • Hyaline cartilage
  • Elastic cartilage
  • Fibrocartilage
• Hyaline cartilage


  Found on the ends of bones, acts as cushioning in joints