exam 3 Flashcards
what are skeletal systems?
mostly what animals use for a rigid support structure to attach muscles to and move
what is cartilage?
adds flexibility to skeleton
how many bones does a human have?
over 200
what organisms have hydrostatic skeletons?
soft bodied invertebrates
what organisms have exoskeletons?
arthropods and insects
what organisms have endoskeletons?
humans and dogs
what is a hydrostatic skeleton?
a volume of fluid enclosed inside a body cavity surrounded by muscle
what structure helps organisms with hydrostatic skeletons anchor to the ground to prevent backward sliding?
setae (bristles)
what kind of skeletal system does a grasshopper have?
exoskeletal
what is an exoskeleton?
a rigid structure on the outer surface for muscle attachment
how do organisms with exoskeletons move?
muscle contractions
what is a cuticle in exoskeletons?
a type of exoskeleton that covers the outer surface of the arthropod
what is the exoskeleton made of?
chiton- nitrogen containing a polysaccharide
what is an endoskeleton?
an internal skeleton covered by other soft body tissues
what is the endoskeleton for in vertebrates?
internal scaffolding for muscles to attach to and pull against
how are bones connected to one another?
joints
what are types of connective tissues?
cartilage and bone
what are cartilage cells made of?
a matrix of tough and rubbery mix of polysaccharides and collagen proteins
what does cartilage allow for?
flexibility
where is cartilage often located?
where stiffness and resilience are needed (ie: joints) and stiff and flexible structures (ie: nose and voice box)
what makes bone harder than cartilage?
calcium phosphate
what are the 3 living cells of bone?
osteoblasts, osteocytes, osteoclasts
osteoblasts
build new matrix material on bone surfaces
osteocytes
former osteoblasts that are now located in inside cavities of bone
osteoclasts
break down old bone that release calcium from bone into extracellular fluid
what are osteoclasts derived from?
the same cell lineage as white blood cells
what are the 2 types of bone?
membranous bone and cartilage bone
what is membranous bone?
forms on a scaffold of connective tissue membrane
what is cartilage bone?
first forms as cartilage-structure that looks like the future mature bone, then slowly ossifies/hardens into bone
chondroblasts
make cartilage and become chondrocytes
what makes collagen?
fibroblasts
how do bones grow?
the ossification process- start as cartilage, then ossification happens in the center of the long bones first, then outwards at the ends
what are epiphyseal plates?
places where cartilage that forms between ossification centers
what happens when long bones are under significant stress?
the force can bend the bone
