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SI Worksheet
Skeletal System
- Name the functions of the skeletal system.
- Support/Rigidity
- Muscle attachment
- Protection of body organs
- Bone surrounds organs
- The skeletal system is composed of ______and ______
- Bone and cartilage
- Cartilage consists of ______and surrounded by a gel-like
material made of ______and ______
- Chondrocytes
- Protein and fiber
- Bone is a ______material and contains nerves and blood vessels. The
hardness comes from ______
- Living
- Calcium carbonate
- Types of bone include ______and ______. Describe them.
- Endochondral and Membranous
- Endochondral bones:
- Bones replace cartilage in skeleton
- Cartilage is ossified into bone
- Most common type of bone
- Cartilage inside
- Membranous bones:
- From membranes
- Forms with no cartilage precursor
e.g., facial bones, most of the cranium
- Compare and contrast Exoskeletons and Endoskeletons
- Exoskeleton
- Hard outer layer
- Found on many invertebrates
- Has growth limitations
- Skeleton must be shed to facilitate growth
- Vulnerable during shedding process
- Endoskeleton
- Found in vertebrates
- Most bones internally located
- Can grow and function without shedding
- Some vertebrates mimic having an exoskeleton
- Pseudo exoskeleton (e.g., turtles), armor of primitive fish, armadillo
- Give one example of a pseudo exoskeleton in vertebrates.
- Turtles, armadillo, primitive fish armor
- The ______skeleton includes the vertebrae, cranium, ribs, and
sternum. The ______skeleton includes girdles and limbs.
- Axial and Appendicular
- True / False Fish vertebrae do not interlock
- True
- True / False Amphibians display increased ossification, but less specialization of the vertebral column compared to fish
- False (both more ossified and more specialized)
- ______have the most cranial bones, which allows for greater cranial
______
- Fish
- kinesis
- Reptile vertebrae display more ______for support out of
______
- interlocking, water
- Bird skulls are similar to ______, but are ______fragile.
- Diapsid reptiles
- more
- What is the beak?
- Beak is primarily elongated premaxilla and dentary bones
- Fish have upaired medial fins for ______
- stabilization
- Describe the girdles found in fish
- Girdles poorly developed, provide fin support, generally not connected to vertebral column
- Small pelvic girdle with fins for limbs
- Better developed pectoral girdle with fins for limbs
- Describe the girdles found in tetrapods
- Pelvic girdle firmly connected to vertebral column (especially in birds where bones fuse)
- Pectoral girdle becomes well developed, but does not become fused to vertebral column
- The basic pattern of vertebrae is ______digits, though many amphibians have ______
- 5 and 4
- True / False Climbers generally have longer bones.
- False
- Name the two main innovations in the skeleton for locomotion, (i.e. such as going from _____ to _____)
- Swimming to walking – new niches be invaded
- Sprawling limbs to limbs under the body – more efficient and rapid movement.
- ______of fish jaws allow for tremendous movement and diversification
- Multiple articulation points
- Evolution of ______articulation from articular-
quadrate allowed other jaw bones to be used for ______
- squamosal-dentary
- sensing vibrations
- What is unique about the snake jaw?
- Much of jaw unfused, allowing snakes to disconnect (unhinge) jaw bones and ingest prey larger than their head!