Biology 2 Pre Finals

• Skeletal system


  Includes bones and tissues that are important for protecting, supporting and moving the body
• Three basic types of skeleton in the animal kingdom

  • Hydrostatic skeleton (e.g. earthworm)
  • Exoskeletons (e.g. corals, crabs, mollusks)
  • Endoskeletons (e.g. humans, animals, fishes)
• Hydrostatic skeleton


  • Supported by liquid in their bodies for locomotion, support and protection. Present in lower invertebrates.
• Exoskeletons


  • External hard part or covering, provides protection and framework.
• Endoskeletons


  • Serves as internal framework, provides leverage in locomotion as well as for blood production (in humans).
• Human skeletal system


  Collection of bones that hold the rest of the body, provide shape, support, protection, attachment of muscles, produce blood cells, storage of calcium and phosphorous compounds and other minerals
• The body consists of 350 bones when born but as the human developed it comprises of 206 bones
• Bone


  A type of hard connective tissue that is constantly being formed and replaced. Each bone is a living organ made up of different tissues.

  
• Two types of bones as to its origin

  • Membrane bone
  • Cartilage bone

  
• Membrane bone


  Any bone that develops within membranous tissue, such as the clavicle and bones of the skull, without cartilage formation. It gives support to the tendons that secure the muscle to the bone and also serves as a protective sheath.

  
• Cartilage bone


  Bones which develop from the hardening of cartilage cells (chondrocytes) known as chondrification then bone ossification.

  
• Cartilage is a type of connective tissue found in the body. When an embryo is developing, cartilage is the precursor to bone. Some cartilage remains and is dispersed throughout the body, especially to cover the joints.

  
• Four types of bone

  • Long bone (arms, legs, hands, feet, phalanges)
  • Short bones (hands, feet)
  • Flat bones (skull, shoulder blade, sternum, ribs, pelvis, clavicle)
  • Irregular bones (vertebrae, knee, jaw bone, cheek bone)

  
• Two types of bones as to its location in the human body

  • Axial (skull, breastbone, vertebral column)
  • Appendicular (shoulder, arms, hips, legs)
• Types of bone cells

  • Osteoblasts
  • Osteoclasts
  • Osteocytes
• Bone development and growth

  1. Ossification

  2. Remodeling

  3. Repair

  
• Types of joints

  • Synarthrosis (immovable)
  • Amphiarthrosis (slightly moveable)
  • Diarthrosis (freely moveable)
• Immovable joints


  The two or more bones are in close contact, but no movement can occur - e.g. the bones of the skull (sutures)

  
• Slightly movable joints


  Bones are connected by hyaline cartilage or fibrocartilage - e.g. joints between vertebrae and intervertebral disks

  
• Ball-and-socket joint


  A joint in which the rounded surface of a bone moves within a depression on another bone, allowing greater freedom of movement than any other kind of joint - e.g. shoulder and upper arm/femur and pelvic bone

  
• Saddle joint


  The bone forming one part of the joint is concave at one end and looks like a saddle. The other bone's end is convex, and looks like a rider in a saddle - e.g. carpometacarpal joint of the thumb, sternoclavicular joint of the thorax, incudomalleolar joint of the middle ear, calcaneocuboid joint of the heel
• Hinge joint


  A type of synovial joint that exists in the body and serves to allow motion primarily in one plane - e.g. elbow, knee, interphalangeal joints of the hand and foot, tibiotalar joint of the ankle
• Pivot joint


  Consists of the rounded end of one bone fitting into a ring formed by the other bone - e.g. joint of the first and second vertebrae of the neck
• Condyloid joint


  Occurs where an egg-shaped surface of a bone fits into a concavity in another bone - e.g. wrist joint, temporomandibular joint

  
• Gliding joint


  A synovial joint in which only a slight, sliding or gliding motion is allowed in the plane of articular surfaces - e.g. intermetacarpal joints, acromioclavicular joint
• Muscular system


  Together with the skeletal system, gives the body the structure and support for movement
• Muscle


  A group of muscle tissues which contract together to produce a force. A muscle consists of fibers of muscle cells surrounded by protective tissue, bundled together many more fibers, all surrounded in a thick protective tissue.

  
• Three types of muscle in humans

  • Skeletal muscle
  • Cardiac muscle
  • Smooth muscle

  
• Skeletal muscle


  Characteristics: multinucleated, striated, voluntary, covers bony skeleton, motor fibers

  
• Smooth muscle


  • Found in coelenterates, annelids, mollusks, brachiopods and echinoderms, but lacking in arthropods
• Types of muscle in humans

  • Skeletal muscle

  
• Fascicle


  A bundle of structures, such as nerve or muscle fibers or conducting vessels in plants
• Perimysium


  The sheath of connective tissue surrounding a bundle of muscle fibers

  
• Epimysium


  The dense connective tissue that surrounds the entire muscle tissue

  
• Endomysium


  A delicate network of connective tissue, which surrounds individual muscle fibres and contains the vessels and nerves

  
• Sliding filament theory


  1. Calcium ions released from sarcoplasmic reticulum

  2. Calcium ions bind to troponin

  3. Cross bridges (on myosin) pull on actin (power stroke)

  4. Cross bridge detaches from actin

  5. Muscle fiber lengthens & relaxes

  6. Calcium ions pumped back into sarcoplasmic reticulum
• Respiratory system


  Biological system consisting of specific organs and structures used for gas exchange in animals and plants
• Functions of the respiratory system

  • Gas Exchange – oxygen and carbon dioxide
  • Breathing – movement of air
  • Sound Production
  • Olfactory Assistance – sense of smell
  • Protection – from dust and microbes entering body through mucus production, cilia, and coughing

  
• Parts of the respiratory tract

  • Upper respiratory tract (nose, nasal cavity, pharynx)
  • Lower respiratory tract (larynx, trachea, bronchi, lungs)

  
• Major parts of the respiratory system

  • Airway
  • Lungs
  • Muscles of the respiratory system