Chapter 11-14 Skeletal Tissues, System, and Articulation Flashcards
What are the two types of bone?
Compact bone- Dense and solid
Cancellous (spongy)- branched
What are the 4 parts of long bones?
Diaphysis- main shaft of bone. Hollow, cylindrical shape and thick outer shell(compact bone)
Epiphyses- bulbous end of bone. Made of cancellous bone and filled with marrow
Articular cartilage- layer of hyaline cartilage that covers Articular surface of epiphyses
Medullary cavity- hollow space in diaphysis filled with connective tissue rich in fat (yellow marrow)
What are the 5 functions of bone?
Support- framework of body for shape, alignment, and positioning. Ligaments help hold bones together
Protection- skull, rib cage
Movement- joints make levers
Mineral storage- Ca+, phosphorus and other minerals
Hematopoiesis- blood cell production
What are the 5 parts of compact bone structure?
Periosteum- outer shell
Osteons/ Haversian Canal- cylindrical units. Contain arteries and veins
Blood vessels/nerve fibres
Blood supply
Volkmann canals- canals containing nerves, blood, and lymph nodes. Joins Haversian canals together
What are the components of an osteon?
Lamellae- concentric rings around Haversian canal
Lacunae- small spaces in lamellae where osteocytes sit
Central Canal (Haversian Canals)- extends lengthwise through each osteon
Structural framework of compact bone
Sire of blood vessels and lymphatic vessels
What are the different types of bone cells?
Osteoblasts- bone forming cells
Osteoclasts- bone destroying cells. Break down bone for remodelling and calcium release
Osteocytes- mature bone cells. Non dividing. Surrounded by matrix and lying in lacunae
What are the traits of cancellous bone?
High surface area
Trabeculae framework (instead of osteons) -softer, weaker, more flexible, site of metabolic activity
Located at end of long bones
Extremely vascular
Red bone marrow
What are the two types of bone marrow (myeloid tissue)?
Red marrow- produce red blood cells, found in medullary cavity of long bones and spaces of spongy bones
Yellow marrow- marrow cells that become saturated in fat cells. No longer active in blood cell production
Replaces red marrow during aging process
What are the main adult bones that still contain red marrow and what are some conditions that may affect red marrow levels?
Ribs, bodies of vertebrae, humerus, pelvis, and femur
Yellow marrow may change to red marrow in times of decreased blood supply (anemia, exposure to radiation, etc)
Describe the calcium homeostatic process
Blood calcium level increases
Thyroid secretes calcitonin
Ca++ level decreases as osteoblasts remove calcium from blood by forming bone
Regular blood Ca++ level
OR
Blood calcium level decreases
Thyroid secretes hormone
Ca++ levels increase as osteoclasts release calcium into flood by breaking down bone
Why is homeostasis of calcium ion level so important?
Calcium homeostasis is essential for:
Bone formation
Blood clotting
Transmission nerve impulses
Maintenance of skeletal and cardiac muscle contraction
What is osteogenesis?
Development of bow from cartilage or membrane into adult bone using osteoblasts(building) and osteoclasts (destroying)
What is endochondral ossification?
One type of bone formation- growing in length.
Bones form from centre out
What is the process of fracture healing?
Fractures destroy the blood vessels that carry nutrients to osteocytes
Osteoblasts form callus tissue that binds broken ends together
Fracture hematoma happens immediately after fracture
Hematoma eventually turns into bony callus
Does bone remodelling stop after bones have calcified and stopped growing?
Bone formation (ossification) and bone destruction (reabsorbtion) happen concurrently throughout an organisms life.
At what age is the skeleton fully ossified?
Mid 20s
Changes may occur under specific conditions (nutritional deficiencies , illness)
What is osteoporosis?
Metabolic bone disease.
Increased bone porosity
reduced mineral density and mass
Fracture easily
What are the characteristics of cartilage?
A vascular
Flexible
No canal system/blood vessels, so chondrocytes receive oxygen and nutrients by diffusion
What are the different types of cartilage?
Hyaline- Articular surfaces
Elastic- external ear, epiglottis
Fibrocartilage- intervertebral disks, pubic symphysis
What are the characteristics of hyaline cartilage?
Most common type
Forms tracheal rings, bronchi, tip of the nose, Articular surfaces of bones, and costal cartilage
Made up of collagen
Clear glassy, bluish colour
What are some traits of elastic cartilage?
Forms external ear, epiglottis, and Eustachian tubes
Flexible and bendable support
Made of elastic fibres that confer elasticity and resiliency
What are characteristics of fibrocartilage?
Found in pubic symphysis, and intervertebral discs
Strong, rigid, and compressible
Small quantities of matrix
What are the main functions of cartilage?
Serve as a shock absorber
Strong yet pliable support structure
Permits growth of long bones
What are the three types of joints?
Fibrous joints
Cartilaginous joints
Synovial joints
What are fibrous joints and where are they found?
Immovable joints united by fibrous tissue
The sutures of the skull are fibrous joints
Also syndesmoses- long fingers found between tibia and fibula
What are cartilaginous joints and where are they found?
Joints connected by cartilage (hyaline and fibrocartilage)
Pubic symphysis, intervertebral joints
What are synovial joints and where are they found? What are their components?
Freely movable joints (most numerous)
Found in appendicular skeleton
Joint capture- extension of periosteum
Synovial membrane- secreted synovial fluid
Articular cartilage- hyaline. Covered ends of bone
Joint cavity- space between bones
Ligaments- sense fibrous tissue physically connecting bones
Bursae- cushion filled with synovial fluid
