A&P1 Chapter 7 Lecture 3 Flashcards
Lamellae
Layers of the matrix, arranged in a concentric manner, surrounding a central Haversian canal
Haversian canal
Central hole within osteon, contains blood vessels and nerves
What is each lamella connected to others through
Canaliculi
Osteon
Structural unit of bone, contains lamellae, Central canal, lacunae, canaliculi, perforating canals, osteocytes
How are collagen fibeers arranged within lamellae
Corkscrew down the lamellae, like a helix, one direction in one lamella, opposite in the next
What is the function of collagen fibers in lamellae
Structural support
Lacunae
Small cavities, contain osteocytes
What are the canals that bring vessels and nerves of the periosteum to the central canals and deeper into the bone tissue
Perforating/Volkmann’s canals
How are volkmann’s canals oriented in relation to central canals
Right angles
What is the beginning of perforating canals
Foramina
What are central and perforating canals lined by
Endosteum
What part of compact bone is not arranged in osteons
Inner and outer boundaries
How do lamellae run in the outer and inner parts of the bone
Parallel to the bone surface
What are lamellae not in osteons called
Circumferential lamellae
What do circumferential lamellae surround
Compact and spongy bone
What part of the bone (lamellae, osteons, etc) does growth happen
Circumferential lamellae
What lamellae exist between osteons
Interstitial Lamellae
Interstitial lamellae
Remains of old osteons that have broken down as the bone has grown, then remodeled, irregular shape
What is spongy bone arranged in
trabeculae
Are there osteons in spongy bone
No
What does the matrix of spongy bone contain
Irregularly arranged lamellae, osteocytes, and canaliculi
What supplies nutrients to spongy bone
Capillaries in endosteum
Trabeculae
Little columns with spaces in between them
Why is a central canal not needed in spongy bone
Marrow between trabeculae, each osteocyte is not very far from blood
How do trabeculae align
Along lines of mechanical stress or pull of muscle
Why do trabeculae align along lines of stress
Adds strength without weight
Bone marrow
Soft tissue that occupies bone cavities
Types of bone marrow
Red and yellow
What is another name for red marrow
Myeloid Tissue
What type of marrow is in all cavities in infants
Red marrow
What is the term for a tissue that produces blood cells (like red marrow)
Hemopoietic tissue
What happens in terms of bone marrow in adults
Most red marrow is replaced by yellow marrow (fatty type), red marrow remains in small locations
Yellow marrow
Fatty type, mainly consisting of fat cells, isn’t able to produce fat
Where is red marrow found in adults
Spongy areas of head of femur and humerus, flat bones
