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50 Cards in this Set
- Front
- Back
____________ - blood cell production
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hematopoiesis (or hemopoiesis)
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2 types of bone structures
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compact (lamellar) bone
spongy (cancellous) bone |
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What does lamellar mean?
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consisting of thin concentric layers
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___________ - the structural element of spongy bone, resembling a small arch
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trabeculae
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The joint surface on the epiphysis of a long bone is covered with __________.
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hyaline cartilage (or articular cartilage)
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Why do long bones enlarge at the epiphyses?
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1. to strengthen and stabilize the joint
2. to provide added surface area for the attachment of tendons and ligaments |
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___________ - double-layered outer membrane fused to the surface of bones
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periosteum
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The periosteum has an inner osteogenic layer. What does this mean?
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It is capable of forming bone.
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What type of tissue makes up the outer layer of the periosteum?
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dense irregular connective tissue proper
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The periosteum is secured to underlying bone by collagenous fibers called _____________.
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Sharpey's fibers
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_____________ - delicate membrane covering internal surfaces of bone
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endosteum
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What 2 cell types are found in the inner osteogenic layer of the periosteum?
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osteoclasts
osteoblasts |
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Tendons and ligaments attach to the ______________ of bone.
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periosteum
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What is the basic structure of short, irregular, and flat bones?
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thin plates of compact bone on the outside with spongy bone sandwiched between
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In the cranium, spongy bone is called _________.
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diploë
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What type of bone marrow produces the formed elements of blood?
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red bone marrow
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What type of bone marrow consists primarily of hematopoietic cells within a reticular connective tissue proper?
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red bone marrow
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Yellow bone marrow is primarily...
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adipose tissue (fat)
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Where is red bone marrow found in the newborn baby?
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At birth, all bone marrow is red marrow.
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Where is red bone marrow found in the adult?
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the spongy bone of the skull, ribs, sternum, vertebrae, and most of the pelvis and within the proximal epiphyses of the femur and humerus
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Why do children have a greater proportion of red bone marrow?
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As a child grows in stature, the blood volume must also grow.
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__________ - bone-forming cells
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osteoblasts
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__________ - cells that resorb the bone matrix
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osteoclasts
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__________ - unmineralized bone matrix
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osteoid
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What is osteoid is composed of?
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proteoglycans and collagen
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What cells secrete osteoid?
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osteoblasts
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What important property does osteoid impart to bone?
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Osteoid imparts a degree of flexibility to the bone, making the bone less brittle.
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What are the primary mineral salts in bone?
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calcium phosphate
calcium hydroxide |
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________ – the structural unit of compact bone
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osteon
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_________ – the process of bone tissue formation
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osteogenesis (or ossification)
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All of the bones of the skeleton below the base of the skull (except the clavicles) are formed by __________.
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endochondral ossification
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The flat bones of the skull, the mandible, and the clavicles are formed by ____________.
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intramembranous ossification
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In the process of _____________, bone forms by replacing a hyaline cartilage model.
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endochondral ossification
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Postnatal longitudinal bone growth occurs from the ____________.
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epiphyseal plates
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Bones can continue to increase in thickness or diameter throughout life by ______________.
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appositional growth
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What process of bone growth involves the osteogenic layer of the periosteum?
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appositional bone growth
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During infancy and childhood, epiphyseal plate activity is stimulated by __________.
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growth hormone
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___________ – an active process in which bone is resorbed and deposited
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bone remodeling
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Bone remodeling is necessary to...
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1. repair microfractures
2. reshapes bones in response to use and disuse 3. maintain Ca2+ and phosphate homeostasis |
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State Wolff’s law.
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A bone grows or remodels in response to the forces or demands placed upon it.
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____________ – a deficiency in blood Ca2+
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hypocalcemia
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____________ - an excess of blood Ca2+
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hypercalcemia
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Under conditions of ______________, the parathyroid gland secretes parathyroid hormone (PTH).
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hypocalcemia
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What effects does PTH have on the kidneys?
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1. PTH stimulates Ca2+ reabsorption in the kidneys, decreasing the loss of Ca2+ in the urine.
2. PTH stimulates the kidneys to release the active form of vitamin D. |
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__________ - the active form of vitamin D
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calcitrol
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What effect does PTH have on bone?
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PTH increases numbers and activity of osteoclasts, stimulating Ca2+ release from the bones.
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How does calcitrol help to increase the plasma Ca2+ concentration?
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Calcitrol increases the absorption of Ca2+ from the diet.
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Under conditions of ___________, the thyroid gland secretes the hormone calcitonin.
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hypercalcemia
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What effect does calcitonin have on bone?
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Calcitonin inhibits osteooclasts and increases the number and activity of osteoblasts.
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What effect does calcitonin have on the kidneys?
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Calcitonin inhibits Ca2+ reabsorption in the kidneys, increasing Ca2+ excretion into the urine.
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