Chapter 7 Book Notes
7.1 Introduction to the Skeletal System
Cartilage - semi-rigid connective tissue that is more flexible than the bone. Mature cartilage is avascular. Two
cartilage that’s associated with the skeletal system:
1. Hyaline cartilage
a. attaches ribs to the sternum (costal cartilage)
b. covers the ends of some bones (articular cartilage)
c. cartilage within growth plates (epiphyseal plates)
d. provides a model during development for the formation of the fetal skeleton
2. Fibrocartilage
a. weight-bearing cartilage that withstands compression
b. forms the intervertebral discs, the pubic symphysis (cartilage between bones of the pelvis), and
the cartilage pads of the knee joints (menisci)
3. Ligaments - dense regular connective tissue that anchors bone to bone
4. Tendons - dense regular connective tissue that connects muscle to bone
7.2 Bone: The Major Organ of the Skeletal System
❖ Living bone may be yellowish in color
7.2a General Functions
Several basic functions ❖ Support and protection
❖ Levers for movement
❖ Hematopoiesis
❖ Storage of mineral and energy reserves
Support and Protection ❖ Provides structural support and serve as a framework for the
entire body
❖ Protect many delicate tissues and organs from injury and trauma
Levers for Movement ❖ Serves as attachment sites for skeletal muscles, other soft tissues,
and some organs
❖ Bones of the skeleton can alter the direction and magnitude of the
forces generated by the skeletal muscles
1
, Chapter 7 Book Notes
Hematopoiesis ❖ process of blood cell production
❖ occurs in red bone marrow connective tissue
Storage of Mineral and Energy ❖ Most of the body’s reserves of minerals calcium and phosphate are
Reserves stored within and then released from the bone
➢ Calcium - an essential material for body functions such as
muscle contraction, blood clotting, and release of
neurotransmitters from nerve cells
➢ Phosphate - structural component of ATP, other
nucleotides, and phospholipids; and is an important
component of the plasma membrane
7.2B Classification of Bones
Four classes of bones as determined by shapes:
Long Bones ❖ Greater in LENGTH than in width.
❖ Elongated, cylindrical shaft (diaphysis)
❖ Most common bone shape
❖ Found in upper limbs(arms, forearm, palms, and fingers) and lower limbs
(thigh, leg, sole and toes).
❖ Examples:
➢ Small bones in the fingers and toes
➢ Femur
➢ Tibia
➢ fibula of the lower limb
Short Bones ❖ Length nearly equal to their width
❖ Examples:
➢ Carpals (wrist bones)
➢ Tarsals (bones of the foot)
➢ Sesamoid bones (kneecap/patella - largest sesamoid bones)
Flat Bones ❖ Flat, thin surface that may be slightly curved
❖ Provide extensive surface areas for muscle attachment and protect
underlying soft tissues
❖ Examples:
2
, Chapter 7 Book Notes
➢ Roof of the skull
➢ Scapulae / shoulder blades
➢ Sternum / breastbone
➢ ribs
Irregular Bones ❖ Elaborate, sometimes complex shapes and do not fit into any of the
preceding categories
❖ Examples:
➢ Vertebrae
➢ Ossa Coxae (hip bones)
➢ Several bones in the skull (ethmoid, sphenoid, and maxilla)
3
7.1 Introduction to the Skeletal System
Cartilage - semi-rigid connective tissue that is more flexible than the bone. Mature cartilage is avascular. Two
cartilage that’s associated with the skeletal system:
1. Hyaline cartilage
a. attaches ribs to the sternum (costal cartilage)
b. covers the ends of some bones (articular cartilage)
c. cartilage within growth plates (epiphyseal plates)
d. provides a model during development for the formation of the fetal skeleton
2. Fibrocartilage
a. weight-bearing cartilage that withstands compression
b. forms the intervertebral discs, the pubic symphysis (cartilage between bones of the pelvis), and
the cartilage pads of the knee joints (menisci)
3. Ligaments - dense regular connective tissue that anchors bone to bone
4. Tendons - dense regular connective tissue that connects muscle to bone
7.2 Bone: The Major Organ of the Skeletal System
❖ Living bone may be yellowish in color
7.2a General Functions
Several basic functions ❖ Support and protection
❖ Levers for movement
❖ Hematopoiesis
❖ Storage of mineral and energy reserves
Support and Protection ❖ Provides structural support and serve as a framework for the
entire body
❖ Protect many delicate tissues and organs from injury and trauma
Levers for Movement ❖ Serves as attachment sites for skeletal muscles, other soft tissues,
and some organs
❖ Bones of the skeleton can alter the direction and magnitude of the
forces generated by the skeletal muscles
1
, Chapter 7 Book Notes
Hematopoiesis ❖ process of blood cell production
❖ occurs in red bone marrow connective tissue
Storage of Mineral and Energy ❖ Most of the body’s reserves of minerals calcium and phosphate are
Reserves stored within and then released from the bone
➢ Calcium - an essential material for body functions such as
muscle contraction, blood clotting, and release of
neurotransmitters from nerve cells
➢ Phosphate - structural component of ATP, other
nucleotides, and phospholipids; and is an important
component of the plasma membrane
7.2B Classification of Bones
Four classes of bones as determined by shapes:
Long Bones ❖ Greater in LENGTH than in width.
❖ Elongated, cylindrical shaft (diaphysis)
❖ Most common bone shape
❖ Found in upper limbs(arms, forearm, palms, and fingers) and lower limbs
(thigh, leg, sole and toes).
❖ Examples:
➢ Small bones in the fingers and toes
➢ Femur
➢ Tibia
➢ fibula of the lower limb
Short Bones ❖ Length nearly equal to their width
❖ Examples:
➢ Carpals (wrist bones)
➢ Tarsals (bones of the foot)
➢ Sesamoid bones (kneecap/patella - largest sesamoid bones)
Flat Bones ❖ Flat, thin surface that may be slightly curved
❖ Provide extensive surface areas for muscle attachment and protect
underlying soft tissues
❖ Examples:
2
, Chapter 7 Book Notes
➢ Roof of the skull
➢ Scapulae / shoulder blades
➢ Sternum / breastbone
➢ ribs
Irregular Bones ❖ Elaborate, sometimes complex shapes and do not fit into any of the
preceding categories
❖ Examples:
➢ Vertebrae
➢ Ossa Coxae (hip bones)
➢ Several bones in the skull (ethmoid, sphenoid, and maxilla)
3
