Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
76 Cards in this Set
- Front
- Back
Bone Tissue is...
|
- aka osseous tissue
- connective tissue - continuously growing, remodeling, & repairing itself - 18% of the body weight |
|
How does bone tissue contribute to homeostasis of the body?
|
- provides support, protection, production of blood cells, & storage of minerals & triglycerides
|
|
Skeletal Cartilages (Definition)
|
- form of connective tissue
- chondrocytes in lacunae - surrounded by ECM (holds H20 = spongy & resilient) |
|
General Properties of Cartilage (3)
|
- lacks nerve fibers
- avascular - perichondrium (dense irregular tissue; surrounds cartilage & provides nutrients) |
|
What are the 3 types of cartilage?
|
- hyaline cartilage
- elastic cartilage - fibrocartilage |
|
Hyaline Cartilage
|
- looks shiny/glossy on slide
- fibers are made of COLLAGEN only - function = flexible and supportive - where = costal, articular, respiratory, nasal |
|
Elastic Cartilage
|
- fibers are collagen & abundant amounts of ELASTIC fibers
- function = more flexible than hyaline cartilage - where = pinna of the ear & epiglottis |
|
Fibrocartilage
|
- fibers are THICK COLLAGEN fibers
- function = most compressible & yet resistant - where = pubic symphysis & intervertebral discs |
|
How does cartilage grow? (2 ways)
|
- appositional growth (along the periphery)
- interstitial growth (from within) |
|
List the functions of the skeletal system (6)
|
1. support
2. protection 3. assistance in movement by providing levers 4. mineral homeostasis 5. blood cell production 6. triglyceride storage |
|
How does the skeletal system provide... support?
|
- structural framework for "soft tissues"
- point of attachment for tendons of skeletal muscles |
|
How does the skeletal system provide... protection?
|
- protects the most important internal organs from injury
|
|
How does the skeletal system provide... assistance with movement by providing levers?
|
- skeletal muscles attach to bones
- when they contract, they pull on the bone to produce movement |
|
How does the skeletal system provide... mineral homeostasis?
|
- bone tissue stores several minerals
- most important: calcium and phosphorus (heart needs Ca +2) |
|
How does the skeletal system provide... blood cell production?
|
- w/in certain bones, the RED BONE MARROW produces blood (WBC, RBC, & platelets)
- this process is called HEMO-PO-IE-SIS (hemopoiesis) |
|
How does the skeletal system provide... triglyceride storage?
|
- in certain other adult bones, the YELLOW BONE MARROW (mostly adipose) stores triglycerides.
|
|
What are the 4 types of bone?
|
- long bone
- short bone - flat bone - irregular bone |
|
What are the 7 parts of a long bone?
|
- diaphysis
- epiphyses - metaphyses - articular cartilage - periosteum - medullary cavity - endosteum |
|
Diaphysis
|
- shaft or body of the bone
|
|
Epiphyses
|
- distal & proximal ends of the long bone
|
|
Metaphyses
|
- region where diaphysis joins epiphysis
- growing bones include an epiphyseal plate |
|
Articular Cartilage
|
- thin layer of hyaline cartilage on epiphysis
- forms a protective layer where bone meets bone in an articulation |
|
Periosteum
|
- tough sheath
- dense irregular tissue - surrounds bone surface - attached to bone via Sharpey's fibers (perforating fibers) |
|
Medullary Cavity (aka marrow cavity)
|
- space w/in diaphysis
- contains the bone marrow - red marrow is usually a young bone, yellow marrow is usually an adult bone |
|
Endosteum
|
- thin membrane
- lines medullary cavity |
|
What is the composition of the ECM of osseous tissue?
|
- 25% water
- 25% collagen fibers - 50% crystallized mineral salts |
|
What is the most abundant mineral salt in osseous tissue?
|
- calcium phosphate
- combines w/ calcium hydroxide to form hydroxyapatite (HYDR-OXY-APA-TITE) |
|
1. Bones hardness depends on _______ _______ _______ _______.
2. Bones flexibility depends on _______ _______. |
1. crystallized inorganic mineral salts
2. collagen fibers |
|
What are the 4 cell types present in bone?
|
1. osteogenic cells
2. osteoblasts 3. osteocytes 4. osteoclasts |
|
Osteogenic Cells
|
- unspecialized stem cells
- derived from mesenchyme (MES-EN-CHYME) = tissue from which all connective tissues forms - ** only bone cells that undergo cell division |
|
Osteoblasts
|
- bone-building cells
- synthesize and secrete organic compounds & collagen fibers to build ECM - initiate calcification |
|
Osteocytes
|
- mature bone cells
- main cells in bone tissue - maintain daily metabolism - e.g exchange of nutrients & wastes w/ blood |
|
Osteoclasts
|
- huge cells
- derived from the fusion of as many as 50 monocytes - release powerful lysosomal enzymes & acids - digest protein & mineral components of the underlying bone matrix (resportion) |
|
About ____% of the skeleton is compact bone.
|
18%
|
|
Compact Bone
|
- contains few spaces
- strongest form of bone - found beneath periosteum of all bones - makes up bulk of of the diaphysis of long bones |
|
1. What 3 things penetrate compact bone via the periosteum?
2. How so? 3. What do they connect w/? |
1. blood vessels, lymphatic vessels, & nerves
2. perforating Volkmann's canals 3. medullary cavity & Haversian canals |
|
Haversian Canal of Compact Bone
|
- aka central canal
- runs longitudinally through the bone |
|
Concentric Lamella of Compact Bone
|
- rings of calcified ECM (rings of a tree trunk)
- surrounds Haversian canal |
|
Lacunae of Compact Bone
|
- spaces that contain the osteocytes
|
|
Radiating Canaliculi of Compact Bone
|
- tiny canals filled w/ fluid which connect the lacuna
|
|
Osteons (aka haverian sytems)
|
- components of compact bone arranged in repeating units
- components include: 1. central canal 2. concentrically arranged lamellae 3. lacuna 4. osteocytes 5. canaliculi |
|
Osteons of compact bones and trabuculae of spongy bones tend to be aligned in the same direction as ______ __ _______.
|
- lines of stress
|
|
Spongy Bone does not contain _________.
|
- osteons
|
|
Spongy Bone Composition
|
- consists of lamallae arrange in an irregular lattice
- creates thin columns called trabeculae - spaces b/w trabeculae make bones lighter & can be filled w/ marrow - canaliculi radiate ouwtard from lacunae |
|
Osteocytes of spongy bone receive nourishment from the _______ circulating through the _________ ________.
|
- directly from the blood
- medullary cavities |
|
Spongy bone makes up most of the bone tissue of what 3 types of bone?
|
1. short
2. flat 3. irregular |
|
Where can you find spongy bone on long bones?
|
- forms epiphyses
- narrow rim around the medullary cavity of the diaphysis |
|
Ossification aka Osteogenesis
|
- the process by which bone forms
- 2 methods: intramembraneous & endochondrial |
|
Intramembraneous Ossification (IO)
|
- occurs when bone forms directly w/in mesenchyme
- arranged in sheet-like layers that resemble membranes |
|
Endochondrial Ossification (EO)
|
- occurs when bone forms w/in hyaline cartilage that develops from mesenchyme
|
|
Appositional growth
|
- during childhood
- bones throughout the body grow in thickness 1. bones in the periosteum differentiate into osteoblasts 2. osteoblasts secrete ECM 3. osteoclasts in the endosteum destroy the bone tissue lining the medullary cavity, so it can grow as well. |
|
Interstitial Growth
|
- during childhood
- long bones lengthen - addition of bone material on diaphyseal side of epiphyseal plate |
|
Epiphyseal Plate
|
- part of metaphysis
- layer of hyaline cartilage (4 zones) of a growing bone Zone of ________ cartilage 1. resting 2. proliferating 3. hypertrophic 4. calcified 5. zone of ossification. |
|
Bone Remodeling
|
- ongoing replacement of old tissue by new bone tissue
- involves bone resorption (removal of minerals & collagen fibers by osteoclasts) - bone deposition (by osteoblasts) |
|
Factors For Normal Bone Metabolism
|
1. adequate dietary intake of minerals & vitamins
2. sufficient levels of certain hormones |
|
What minerals are essential for normal bone metabolism?
|
- calcium & phosphorus
|
|
Bone metabolism:
Vitamin C |
- needed to synthesize collagen
|
|
Bone metabolism:
Vitamin K & B |
- needed for proteins synthesis
|
|
Bone metabolism:
Vitamin A |
- stimulates osteoclasts
|
|
Bone metabolism:
Insulin-Like Growth Factors (IGF's) |
1. stimulate osteoblasts
2. promote cell division -> in the epiphyseal plate & periosteum 3. enhance protein synthesis |
|
IGF's are produced in response to secretion of _________, which is produced by the _________ ___________.
|
- hGH (human growth hormone)
- pituitary gland |
|
How does the thyroid hormone promote growth?
|
- stiumlates osteoblasts
|
|
How do sex hormones promote growth?
|
- at puberty, secrtion of sex hormones contributes greatly to osteoblast activity causing a growth spurt
|
|
Fracture
|
- any break in a bone
|
|
Fracture Repair
|
1. fracture hematoma
2. fibrocartilage callus 3. bony callus 4. bone remodelling |
|
What are the types of fractures? (8)
|
1. close (simple)
2. open (compound) 3. comminuted 4. spiral 5. depressed 6. compression 7. epiphyseal 8. greenstick |
|
How does bone play a role in calcium homeostasis?
|
- a major reservoir for calcium in the body
- parathyroid hormone is secreted by the parathyroid gland in response to low blood calcium levels (resorption of bone & release of Ca+2) |
|
Calcitonin
|
- produced by the thyroid gland
- stiumlates bone formation w/ the storage of calcium in the bone matrix |
|
Vitamin D (calcium homeostasis)
|
- enhances bone resportion
- raises the calcium level of the blood |
|
Imbalances b/w bone ___________ and ____________ underlie all skeletal disorders.
|
- formation
- resorption |
|
Osteomalcia & Rickets
|
- occur when bone is inadequately mineralized
- bones become soft & deformed - most frequent cause is inadequate vitamin D |
|
Osteoporosis
|
- any condition in which bone breakdown outpaces bone formation
- causes bone to become weak & porous - postmenopausal women are particularly susceptible |
|
Paget's disease
|
- characterized by excessive & abnormal bone remodeling
|
|
Osteogenesis is ___________ and ________ timed.
|
- predictably
- precisely |
|
When does longitudinal bone growth stop?
|
- end of adolescence
- skeletal mass increases dramatically during pubery when formation exceeds resportion |
|
Bone mass is _________ _______ during young adulthood, but beginning in the 40's bone ___________ exceeds _________.
|
- fairly constant
- resportion - formation |