Support And Movement In Animals Flashcards
What is a hydrostatic skeleton
Skeleton that consists of water filled cavities surrounded by muscle
How does a hydrostatic skeleton work
Fluid exerts pressure that provides support and allows animal to change shape for movement
What are examples of animals with a hydrostatic skeleton
Earthworms
Sea anemones
Jellyfish
What are disadvantages of hydrostatic skeletons
Allow slow movement
Limit size of animal
No protection
What is an exoskeleton and in which animals does it occur
Skeleton made from chitin that occurs outside of the animals body
Occurs in arthropods
What are the advantages of exoskeletons
Protect underlying tissue
Protect from desiccation
Allows for movement
Allows for attachment of muscle = quick movement
Can form wings in some insects which enable flight
What are the disadvantages of exoskeletons
Weight is exoskeleton limits size of animal
Skeleton is impermeable to gas = need special respiratory system
Exoskeleton cannot grow = animals moult and shed old skeleton to get new skeleton = no proper protection so vulnerable to predators
What are the advantages of an endoskeleton
Living tissue = grows with organism
Provides structural support and shape to body
Place of attachment of muscles
Protects internal organs
What are the disadvantages of an endoskeleton
Does not offer protection against desiccation
What are the functions of the human skeleton
Movement - anchor for muscles
Protection - e.g ribs protect lungs and heart and skull protects brain
Support - provides structural support and gives shape
Mineral storage - calcium and phosphates stored in bone
Blood cell formation - red and white blood cells formed in red bone marrow
Hearing - 3 ear ossicles transmit and amplify sound to enable hearing
What do the appendicular and axial skeleton consist of
Appendicular:
Limbs
Pelvic girdle
Pectoral girdle
Axial:
Skull
Spine
Rib cage
What does the skull consist of
Flat bones fused by sutures
Opening through which spinal cord enters skull = foramen magnum
What are frontanelles and why are they important
Filled spaces that exist between cranium bones
Important to aid in neutral birth and allow for growth of baby’s brain before sutures start growing
What is the function of the vertebral column
Supports skull
Surrounds and protects spinal cord
Place of attachment of ribs and pelvic and pectoral girdle
S shape curvature provides flexibility and absorb shock
What is the structure of the vertebral column
Comprised of 33 bones
Bones joined by cartilage discs which allow some flexibility
Cervical vertebrae = 7; atlas is the first and allows for nodding, axis is the second and allows to move side to side
Thoracic vertebrae = 12; place of attachment of ribs
Lumbar vertebrae = 5; form lower back
Sacrum = 5 fused vertebrae that are place of attachment for pelvic girdle
Coccyx = 4 fused vertebrae, our tail bone
What does the ribcage consist of
12 pairs of ribs
7 pairs true ribs - directly connect to the sternum
3 pairs false ribs - connect indirectly to sternum (connects to cartilage of rib above)
2 pairs floating ribs - connect to thoracic vertebrae only
What are the functions of the ribcage
Protects heart and lungs
Plays a role in breathing - movement of ribcage changes thoracic pressure during breathing
Which bones make up the pectoral girdle and what is its functions
Clavicle and scapula
Attaches upper limbs to the axial skeleton
Allows for movement of upper limbs
What are the three types of joints and what is an example of each
Immovable joints / fibrous joint - sutures between cranium bones
Semi-moveable / cartilaginous joint - joints between vertebrae and pubic symphysis
Synovial joints - (allow free movement) shoulder and elbow joints
What are the different types of synovial joints, how much movement does each allow and what are examples of each
Ball and socket - movement in any direction, e.g: shoulder and hip
Hinge - movement in one plane, e.g: elbow and knee
Gliding/plane joint - limited movement in any direction, e.g: wrist and ankle
Pivot - allow head to turn side to side e.g: atlas on axis and joint between radius and ulna
What causes a joint injury
Torn/stretched ligament and tendon
Sprain or strain
Dislocation
How do antagonistic pairs work
Muscle pairs with opposite functions, as one contracts another relaxes
Contract = flex; extend = relax
What is rickets
Deficiency disease where bones weaken and bend as they grow caused by lack of vitamin D or calcium
What is osteoporosis
Disease of the bones that causes loss in bone density
Caused by shortage of calcium
Bones weaken and fracture easily
Most common in older women
