Bone shapes Flashcards
What are the characteristics of the Zone of Calcified Cartilage?
- consists of dead cells located in a calcified matrix
- This calcified matrix is destroyed by osteoclasts and is then invaded by osteoblasts and capillaries from the diaphysis.
What are the parts of a long bone?
The Diaphysis, epiphysis, periosteum, articular cartilage, compact bone, spongy bone, endosteum, medullary cavity, and yellow and red bone marrow
What are the characteristics of the zone of hypertrophic cartilage?
- Extremely large chondrocytes that are arranged in columns.
- The growth of these cells also leads to an increase in the length of the bone.
- Osteoblasts begin laying down bone salts causing the chondrocytes to die.
The appendicular skeleton consits of which bones?
includes the limbs of the upper and lower extremities,
and the bones that attach those limbs to
the trunk (pectoral and pelvic girdles)
What are the components of an osteon?
Osteocytes, concentric lamella, and central canals
The medial malleolus of the tibia articulates with the?
talus
What are the microscopic parts of bone?
Spongy bone, compact bone, osteon, osteocyte, canaliculi, central canal, perforating canal, lacuna, lamella, trabeculae, sharpy’s fibers, periosteum
What are the origins of endochondral ossification
and intramembranous ossification?
Endochondral ossification: Fromed from a hyaline cartilage model
Intramembranous ossification: Fromed within a fibrous connective tissue membrane
What are the characteristics of the proliferating cartilage?
- Chondrocytes divide (mitosis) increasing the number of cells
- As the number of cells increase, the plate becomes thicker.
The metatarsals consists of how many bones?
5
How does parathyroid horomone increase the blood calcium concentration?
- Stimulates osteoclast activity.
- Stimulates kidney tubules to reabsorb Ca++
- Stimulates intestinal mucosa to reabsorb Ca++.
What are Osteoclasts?
Bone cells that secrete lysosomal enzymes that digest inorganic bone matrix.
Where do each of the two ossification centers for endochondral ossification take place?
Primary ossification center: The diaphysis.
Secondary Ossification centers: The epiphyses.
Where is parathyroid hormone found and why is it released?
Found: The parathyroid
Released: In response to decreased blood calcium concentrations.
Where is calcitonin found and why is it released?
Found: Thyroid gland
Released: in response to increased blood calcium concentrations
The medial and lateral condyles of the femur articulate with the?
Medial and lateral condyles of the tibia
What are Perforating canals?
They are canals that connect adjacent central canals
What are the 4 zones of the epiphyseal plate?
- Zone of resting cartilage
- Zone of proliferating cartilage
- Zone of Hypertrophic cartilage
- Zone of calcified cartilage
How many tarsal bones are in the foot?
7
How many bones are in the carpals?
8
What happens during each of the two ossification centers for endochondral ossification?
Primary ossification center:
- Bone replaces hyaline cartilage
Secondary ossification center:
- Eventually bone replaces hyaline cartilage.
What is the endosteum?
Vascular membrane that lines the inside of bones
The Medial end of the clavicle articulates with the?
manubrium of the sternum
The Head of the humerus articulates with the?
glenoid cavity of the scapula
What is the location, function, and composition of articular cartilage?
Location: Covers the outside of the epiphysis Function: Serves as shock absorbers Composition: Hyaline cartilage
What is the location, function, and composition of the periosteum?
Location: Fibrous outer covering of the diaphysis Function: site of attachment for tendons and ligaments Composition: Richly supplied with blood, lymph vessels, and nerves
How does calcitonin decrease the blood calcium concentration?
- Inhibits osteoclast activity.
- Stimulates kidney tubules to secrete Ca++
- Stimulates intestinal mucosa to secrete Ca++.
What is the location, function, and composition of the epiphysis?
Location: Enlarged end regions Function: Site of articulation with other bones Composition: Compose predominantly of spongy bone
What are the characteristics flat bones and give an example
Characteristics: Thin, flat, curved bones Example: Skull bones, ribs, scapula
What are Canaliculi?
They are are connecting canals that connect the lacunae of the osteocytes
The trochlea of the humerus articulates with the
trochlear notch of the ulna
What are the characteristics long bones and give an example
Characteristics: Contain a thin central region and two enlarged ends Example: Femur, Humorous, tibia
What are the three regoins for the vertebrae and how many vertebrae are in each?
Cervical (7), Thoracic (12), Lumbar (5)
The lateral malleolus of the fibula articulates with the?
talus
How many ribs are there in the human body?
24
What is the location, function, and composition of the diaphysis?
Location: thin central region of bone Function: contains the medullary cavity which is filled with yellow and red bone marrow Composition: composed primarily of compact bone
The metacarpals consists of how many bones?
5
What factors affect the rate of bone growth?
- Human Growth Hormone (HGH) produced by the pituitary gland.
- Sex hormones produced from the gonads.
What are the characteristics sesamoid bones and give an example
Characteristics: located within connective tissue Example: Patella, hyoid bone
How many phalanges are in the fingers?
14
What are the characteristics short bones and give an example
Characteristics: They are cube shaped bones Example: Carpals, Tarsals
What is trabeculae and what is found here?
They are the bone fragements within spongy bone and they contain red bone marrow
The Head of the femur articulates with the?
Acetabulum of the coxa
What are the characteristics of the Zone of Resting Cartilage?
- Small, scattered chondrocytes
- Anchor plate of epiphysis
What is an osteon?
Layers of extracellular matrix concentrically clustered around a central canal
What is the location, function, and composition of the epiphyseal line?
Location: Between diaphysis and epiphysis Function: Growth plate Composition: Calcified cartilage
What are the characteristics irregular bones and give an example
No true structural characteristics Example: auditory ossicles, vertebrae
The axial skeleton consists of which bones?
It includes bones of the skull, hyoid bone, vertebral column and thoracic cage.
How many cranium bones and facial bones are there?
Cranial bones: 8
Facial bones: 14
What is the primary inorganic substance in bone?
Hydroxyapatite
What are the two hormones involved with calcium homeostasis?
- Parathyroid hormone (PTH)
- Calcitonin
What are lamella?
Lamella are concentric layers around the central canal
