CHAPTER 7 SKELETAL SYSTEM

Explain how the structures of cervical, thoracic, and lumbar vertebrae differ.

Cervical (7) compromise the bony axis of the neck. Thoracic (12) is larger than the cervical vertebra. Lumbar consist of 5 that are in the small in the back (loin).

Medullary Cavity

Compact Bone in Diaphysis of a long bone forms a semi rigid tube, which is a hollow chamber

How do compact and spongy bone differ in structure?

Compact and spongy bone differ in structure because the compact bone is tightly packed and has extracellular matrix with no spaces and the spongy bone has holes in there to take the weight away.

Short Bone

Cubelike, lengths & widths that are equal (wrists & ankles)

Osteoblasts

Progenitor cells enlarge & further differentiate into bone-forming cells

Distinguish between the functions of red marrow and yellow marrow.

Red marrow functions in the formation of red blood cells, white blood cells(WBC) and blood platelets. As for yellow marrow which stores fat; it is not active in blood cellproduction.

Diaphysis

Shaft of bone; between epiphysis

Marrow

Soft Connective Tissue

21.What are the differences among true, false, and floating ribs?

True ribs are the first 7 rib pairs, they join the sternum directly by their costal cartilages. False ribs are the remaining 5 pairs, because their cartilages don't reach the sternum directly . The last 2 or 3 ribs are called the floating ribs, they have no cartilaginous attachments to the sternum.

Irregular Bone

Variety of shapes and are usually connected to several other bones (vertebrae compromise back & facial bones)

how are bones are classified

according to their shapes- long, short, flat, irregular, or sesamoid (round)

Describe a typical vertebra.

A typical vertebra has a drum-shaped body which forms the thick, anterior portion of the bone.

Explain how an adult skull differs from that of an infant.

An infant skull is compressible and can change shape.

five major parts of a long bone

Diaphysis, Epiphysis, Articular cartilage, Medullary cavity, and periosteum

Describe the development of an intramembranous bone

During the development, membranelike layers of unspecialized, or relatively undifferentiated, connective tissues appear at the sites of the future bones.

Locate and name each of the bones of the cranium

Each bone in the cranium is called frontal, parietal, occipital, temporal, sphenoid, ethmoid.

Locate and name each of the facial bones.

Each bone of the facial are called Maxilla, Zygomatic, Palatine, Inferior Nasal Concha, Mandible, Lacrimal, Nasal, Vomer.

Epiphysis

Each end of bone is an extended portion

Explain how an endochondral bone develops.

Endochondral bone develops in the fetus from masses of hyaline cartilage shaped like future bony structures

Spongy Bone

Epiphysis in contrast, or composed largely of SB or Cancellous Bone, w/ thin layers of compact bone on surfaces

Long Bone

Long longitude axes & expanded ends (forearm/ thigh bones)

Explain how osteoclasts and osteoblasts remodel bone

Osteoclasts break down calcium. Osteoblasts replaces with the new bone.

Flat Bone

Platelike structure w/ broad surfaces (ex: ribs, scapulae & some bones of the skull)

Name the 3 parts of the sternum

The 3 parts of the sternum are the upper Manubrium, a middle body, and a lower xiphoid process that projects downward.

Distinguish between the axial and appendicular skeleton

The axial consists of the skull, Hyoid Bone, Vertebral Column and the Thoracic Cage. The Appendicular Skeleton consists of the Pectoral Girdle, Upper Limbs, Pelvic Girdle and the Lower Limbs.

List the bones of the axial skeleton and of the appendicular skeleton.

The bones of the axial skeleton are Cranial Bones and Facial Bones (22), Middle Ear Bones (6), Hyoid (1), Vertebral Column (26), and the Thoracic Cage (25)

Which bones compose the thoracic cage?

The thoracic cage compose of the ribs, the thoracic vertebra, sternum, and costal cartilages.

Name the major functions of bones.

The major functions of bones are support, protection, body movement and blood cell formation.

Describe the microscopic structure of compact bone

The microscopic structure of the compact bone has bone cells called Osteocytes that has many layers of extracellular matrix that are clustered around the central canal (osteons)

List the substances normally stored in bone tissue

The substances normally stored in bone tissue are calcium phosphate, magnesium, sodium, potassium, and carbonate ions. Bones also store certain harmful metallic elements such as lead, radium, or strontium.

Describe the structure of the vertebral column.

The vertebral column extends from the skull to the pelvis and forms the vertical axis of the skeleton. It is composed of many body parts (vertebrae) that are separated by masses of fibrocartilage called intervertebral disks.

Endosteum

Thin layers of cells

Compact Bone/ Cortical Bone

Tightly packed tissue