Ch 38 pt 1

Question 1

Types of Skeletons

Answer 1

Hydrostatic
Exoskeleton
Endoskeleton

Question 2

Hydrostatic

Answer 2

Soft-bodied, fluid filled cavity
Ex: earthworms, jellyfish
Advantage: Flexible
Disadvantage: drying/squishy

Question 3

Exoskeleton

Answer 3

Rigid hard case
Muscle attached internally
Ex: Arthropods
Advantage: Resist desiccation and protection
Disadvantage: Must molt to grow (vulnerable to predation) and weighs more

Question 4

Endoskeleton

Answer 4

Echinoderms and Vertebrates
Cartilage - joint movement
Ligaments - joint stability
Tendon - muscle attachment

Advantage: Project internal organs, calcium and phosphorus reserve
Disadvantage: susceptible to disease and no external protection

Question 5

Human Axial Skeleton

Answer 5

Bones of central axis - skull, sternum, rib cage

Vertebral column - cervical, thoracic, lumbar, sacral, Coccyx

• Fused

Question 6

Human Appendicular Skeleton

Answer 6

Bones of limbs - Pectoral girdle (forelimb), Pelvic girdle (hindlimb)

Question 7

Pectoral girdle

Answer 7

[Forelimb]
Scapula - shoulder
Clavicle - collar bone
Humerus - upper arm
Ulna & Radius - forearm
Carpels & Metacarpals - wrist/hand
Phalanges - fingers

Question 8

Pelvic Girdle

Answer 8

Illium
Ischium
Pubis

Question 9

Hindlimb (Pelvic Girdle)

Answer 9

Femur - upper leg
Patella - knee cap
Tibia and Fibula - lower leg
Tarsals & Metatarsals - ankle/foot
Phalanges - toes

Question 10

Structure of Bone

Answer 10

Long
Short
Flat
Irregular
Sesamoid
Sutural

Question 11

Long bones

Answer 11

Length > width
Diaphysis (shaft)
Epiphyses (ends, growth plates)
EX: Femur and Humerus

Question 12

Short Bone

Answer 12

Cuboidal
Length = Width
EX: Carpels and Tarsals

Question 13

Flat Bones

Answer 13

Thin and broad
Organ protection
EX: Sternum and Ribs

Question 14

Irregular Bones

Answer 14

Complex shapes
EX: Vertebrae and hip

Question 15

Sesamoid Bones

Answer 15

Small and flat
EX: Patellae

Question 16

Sutural Bones

Answer 16

Small and Flat, irregular
EX: Skull Bone

Question 17

Bone Tissue

Answer 17

Bones = organs
Collection of tissue

Compact Bone vs Spongy Bone

Question 18

Compact Bone

Answer 18

Cortical bone
Hard, external all bones
Protection and strength

Question 19

Spongy Bone

Answer 19

Cancellous bone
Inner layer, no osteons
Trabecular and Bone marrow (red and yellow marrow)
Forms blood cells

Question 20

Bone Cells and Function

Answer 20

Mesenchyme
Osteoblasts
Osteoclasts

Question 21

Mesenchyme

Answer 21

Loosely organized embryonic mesoderm [Undifferentiated stem cells]
Ex: Connective and skeletal tissues

Question 22

Osteoblasts

Answer 22

Cells that secrete the matrix for bone formation

Question 23

Osteoclasts

Answer 23

Multinucleate cells
Derived white blood cells that break down bone matrix
Homeostasis control

Question 23

Osteocytes

Answer 23

Trapped osteoblasts
Living bone cells

Question 24

Lacunae

Answer 24

Tight spaces that house osteoblasts

Question 25

Canaliculi

Answer 25

Canals connecting lacunae that allows osteocytes to communicate

Question 26

Haversian canal

Answer 26

Central canal that contains blood vessels for osteon

Question 27

Ossification

Answer 27

Osteogenesis - Bone formation (but not calcification)

Question 27

Intramembranous

Answer 27

Fibrous membranes
Start - mesenchymal cells
End - flat bones, mandible

Question 28

Endochondral

Answer 28

Hyaline cartilage is deposited by chondrocytes

Start - chondrocytes
End - all other bones

Question 29

Growth plate

Answer 29

Epiphyseal plate
Ossifies - growth stops
Based on age

Question 30

Bone remodeling

Answer 30

Repeated stress can cause bone to thicken in response
Prevents fractures, but may fracture near site

Question 31

Chronic low calcium

Answer 31

Low bone mass
Constant remodeling
Weakens bones and increase risks of fractures