Skeletal System & Bone Tissues Study Guide - fill in the blanks flashcards

The two major divisions of the Skeletal System are __________ and __________.

Axial Skeleton and Appendicular Skeleton. The Axial Skeleton consists of the skull, vertebral column, and thoracic cage, providing the main support for the body and protecting vital organs like the brain and heart. The Appendicular Skeleton includes the bones of the limbs and girdles, crucial for locomotion and manipulation of the environment.

The Axial Skeleton is composed of __________ bones, including the skull, vertebral column, and thoracic cage.

80

The Appendicular Skeleton is composed of __________ bones, including the limbs and girdles.

126

One important function of bones is to provide __________, acting as a framework for the body.

Support

Bones also provide __________, which shields vital organs like the brain.

Protection

Bones act as __________ for muscles, facilitating movement of the body.

Levers

Another function of bones is __________, which involves storing minerals like calcium and phosphorus.

Mineral Storage & Hematopoiesis

Compact bone is dense and arranged in __________, found in the diaphysis of long bones.

Osteons

The porous type of bone that contains trabeculae is known as __________ bone.

Spongy

The __________ of long bones is the shaft of the bone.

Diaphysis

The ends of long bones are known as __________.

Epiphysis

The region between the diaphysis and epiphysis is called the __________.

Metaphysis

The network found in spongy bone is referred to as __________.

Trabeculae

The outer fibrous layer surrounding bones is called __________.

Periosteum

The inner lining of bone cavities is known as __________.

Endosteum

The hollow space inside bones is called the __________ __________.

Medullary Cavity

In children, the growth plate is referred to as the __________ __________, which becomes the line in adults.

Epiphyseal Plate

The central canal of compact bone contains __________ and __________.

blood vessels and nerves.

Small cavities housing osteocytes in compact bone are called __________.

Lacunae

The channels connecting lacunae in bone are known as __________.

Canaliculi

The layers of bone matrix in compact bone are called __________.

Lamellae

____________ lamellae surround the entire bone.

Circumferential

____________ lamellae are found between osteons in compact bone.

Interstitial

____________ lamellae surround the central canal in osteons.

Concentric

____________ canals connect blood supply between osteons in bone.

Perforating

The structural unit of compact bone is called an __________.

Osteon

Osteogenic cells differentiate into __________, which are found in the periosteum and endosteum.

Osteoblasts

__________ are cells that form new bone and are derived from osteogenic cells.

Osteoblasts

____________ maintain the bone matrix and are derived from osteoblasts.

Osteocytes

__________ are multinucleated cells that resorb bone.

Osteoclasts

The enzyme secreted by osteoblasts to facilitate hydroxyapatite deposition is called __________ __________.

Alkaline Phosphatase

The organic composition of bone matrix includes __________ __________, which provides flexibility.

Collagen fibers

The inorganic composition of bone matrix includes __________, which provides strength.

Hydroxyapatite

____________ ossification involves direct bone formation, as seen in the skull.

Intramembranous

____________ ossification occurs when bone replaces cartilage, such as in long bones.

Endochondral

Bone lengthening occurs at the __________ __________.

Epiphyseal plate

The five zones of the epiphyseal growth plate include: Resting Zone, Proliferation Zone, __________ Zone, Calcification Zone, and Ossification Zone.

Hypertrophic

New bone is added to the periosteum through __________ growth.

Appositional

The parathyroid hormone (PTH) increases __________ activity to raise calcium levels in the body.

Osteoclast

____________ inhibits osteoclasts to lower calcium levels in the body.

Calcitonin

__________ indicates low calcium levels, which can lead to muscle spasms.

Hypocalcemia

__________ indicates high calcium levels, potentially causing weak muscles.

Hypercalcemia

Hormones like __________ and __________ stimulate bone growth but later close growth plates.

Estrogen and Testosterone

The hormone that promotes bone lengthening is called __________ __________.

Growth Hormone

____________ (Vitamin D) helps with calcium absorption in the body.

Calcitriol

A __________ (open) fracture is when a bone breaks through the skin.

Compound

A __________ (closed) fracture is when a bone does not break the skin's surface.

Simple

A __________ fracture is when the bone is fully broken.

Complete

An __________ fracture is a partial break of the bone.

Incomplete

A __________ fracture is when the bone is misaligned after breaking.

Displaced

A __________ fracture is when the bone remains aligned after a break.

Non-displaced

Bone __________ is the continuous process of bone replacement.

Remodeling

The first step in bone repair is __________ formation, where a blood clot forms at the fracture site.

Hematoma

The second step in bone repair is the formation of the __________ __________, which serves as a temporary cartilage bridge.

Fibrocartilaginous Callus

The third step in bone repair is __________ __________ formation, where spongy bone replaces cartilage.

Bony Callus

The final step in bone repair is __________ __________, where compact bone replaces spongy bone.

Bone Remodeling

Calcium __________ can lead to various health issues related to bone density and function.

Imbalance