Human Anatomy and Physiology: The Skeletal System

Practice flashcards covering key concepts and information from the Human Anatomy and Physiology lecture on the Skeletal System.

What is the skeletal system composed of?

The skeletal system includes bones, cartilages, joints, and ligaments.

What are the primary roles of the skeletal system?

The skeletal system provides structure, protects organs, produces blood cells, stores minerals, and anchors skeletal muscles.

What is Dual-energy x-ray absorptiometry (DEXA)?

DEXA is the most common test for measuring bone mineral density (BMD) at various fracture-prone sites.

What distinguishes the axial skeleton from the appendicular skeleton?

The axial skeleton consists of 80 bones in the vertical axis, including the skull, spine, and rib cage; the appendicular skeleton includes bones of the limbs and shoulders.

What is osteoporosis?

Osteoporosis is a bone disease characterized by low bone mass and structural deterioration, leading to increased fracture risk.

What types of tissues are found in the human skeletal system?

The human skeletal system consists of bones, cartilage, ligaments, and tendons.

What are the two types of bone formation processes?

Intramembranous ossification and endochondral ossification.

What is the role of osteoblasts in bone tissue?

Osteoblasts build the matrix of bone and initiate calcification.

What is the significance of red bone marrow?

Red bone marrow is the site for the formation of red blood cells, white blood cells, and platelets.

Define trabecular bone.

Trabecular bone, also known as cancellous or spongy bone, is light, porous, and less dense than compact bone.

What is a common cause of osteoarthritis?

Osteoarthritis is a chronic degenerative joint disease, often related to aging and the wear and tear of joints.

What are the two classifications of osteoporosis?

Primary Osteoporosis (Type I - Postmenopausal) and Type II (Age-Related Osteoporosis).

What is the anatomical term for a hole in a bone?

Foramen (plural: foramina) is a passageway for a nerve or blood vessel in a bone.

What are Haversian canals?

Haversian canals are microscopic tubes in the outermost region of cortical bone that allow blood vessels and nerves to travel through.

What is the function of osteoclasts?

Osteoclasts resorb or break down bone tissue.

What is the compressive strength of bone related to?

The compressive strength of bone is directly proportional to its density.

What is the role of cartilage in the skeletal system?

Cartilage is strong, flexible connective tissue that protects joints and bones.

Describe one consequence of osteoporosis.

Osteoporosis can lead to fragile bones and an increased risk of fractures.

What is the purpose of the periosteum?

The periosteum is a tough sheath of dense connective tissue that covers areas of bone not covered by articular cartilage.

What are ligaments?

Ligaments are strong bands of connective tissue that connect bones to other bones at joints, providing stability and support.

What are tendons?

Tendons are fibrous connective tissues that attach muscles to bones, enabling movement by transmitting the force generated by muscle contractions.

What is cartilage?

Cartilage is a flexible connective tissue found in various parts of the body, providing support and cushioning between bones at joints. It also plays a crucial role in the growth and development of bones.

What is compressive strength of bone directly proportional to?

The density of the bone

What conditions affect the axial skeleton?

Fractures, fibrous dysplasia, ankylosing spondylitis

What is a depression in bone?

A fossa

What is a lump on a bone called?

A tuberosity or a tubercle.

What is a projection from a bone called?

A process or an apophysis.

What is diaphysis?

Bone shaft or body

What is epiphyses?

Distal and proximal ends of bone

What are metaphyses?

Regions between the diaphysis and epiphyses of a long bone, where growth occurs.

Where would you find articular cartilage?

At the ends of bones, covering the epiphyses.

What is the periosteum?

The periosteum is a dense layer of vascular connective tissue that surrounds the outer surface of bones, providing attachment for muscles and serving as a conduit for blood vessels and nerves.

What is the medullary cavity?

The medullary cavity is a central cavity within long bones that stores yellow bone marrow, which is responsible for the production of blood cells.

What is the endosteum?

The endosteum is a thin membrane that lines the medullary cavity and covers the trabecular surfaces of spongy bone, playing a role in bone growth, repair, and remodeling.

What are hematopoietic stem cells?

Hematopoietic stem cells are multipotent cells found primarily in the bone marrow that give rise to all blood cell types, including red blood cells, white blood cells, and platelets.

What are osteogenics?

Osteogenics are precursor cells in the bone that differentiate into osteoblasts, which are responsible for bone formation and remodeling.

What are osteocytes?

Osteocytes are mature bone cells derived from osteoblasts, embedded in the bone matrix, and play a crucial role in maintaining bone tissue and regulating mineral content.

Where would you find trabecular bone?

Found in most areas of bone not subject to great mechanical stress

What are lacunae?

Lacunae are small cavities in the bone matrix that house osteocytes, allowing them to communicate and maintain bone integrity.

What type of bone contains red bone marrow?

Red marrow is found in trabecular (spongy) bone, primarily in the epiphyses of long bones and in flat bones.

How much of the human skeleton is made up of spongy bone?

About 20% of the human skeleton is made up of spongy bone, which provides structural support and houses bone marrow.

What is cortical bone?

Cortical bone, also known as compact bone, forms the outer layer of bones and provides strength and support, making up approximately 80% of the human skeleton.

What does cortical bone contain?

Closely packed osteons or Haversian systems

What are Haversian canals?

Haversian canals are microscopic channels in cortical bone that contain blood vessels and nerves, facilitating the supply of nutrients and communication within the bone tissue.

What is the difference between red and yellow bone marrow?

Red bone marrow produces blood cells, while yellow bone marrow stores fat.

What is the blood supply of bones?

The blood supply of bones consists of periosteal arteries and periosteal veins that penetrate the bone tissue, mainly through the nutrient arteries, which branch into smaller vessels forming an extensive network that supports bone health and function.

When does ossification occur in embryos?

Ossification begins during the embryonic stage, typically around the sixth to seventh week of gestation, as the skeleton starts to form and develop from cartilage and fibrous tissue into bone.

What are intramembranous bones?

Intramembranous bones are bones that develop directly from mesenchymal tissue through a process called intramembranous ossification, which does not involve a cartilage precursor. Examples include the flat bones of the skull and the clavicles.

What is endochondral ossification?

Endochondral ossification is the process by which bone forms by converting hyaline cartilage into bone tissue, primarily occurring in long bones and during fetal development.

What is bone remodelling?

Bone remodeling is the process by which bone tissue is continuously renewed and repaired throughout life, involving the resorption of old bone by osteoclasts and the formation of new bone by osteoblasts. This process helps maintain bone strength and mineral balance in the body.

What are the 3 types of joints?

The three types of joints are fibrous, cartilaginous, and synovial joints, each categorized based on their structure and the degree of movement they allow.