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A&P I Test 3
Bone Tissue and Joints
Question | Answer |
---|---|
What are the fxns of the skeletal system? | Support – Protection – Movement – provide levers for muscles Mineral storage – reservoir for minerals, especially calcium and phosphorus Blood cell formation – hematopoiesis occurs within the red bone marrow Triglyceride storage: in yellow bone ma |
Study the structure of a typical long bone: epiphysis, metaphysic, diaphysis, articular cartilage, bone marrow (yellow and red). | |
epiphysis(epiphyses) | Tubular shaft that forms the axis of long bones Composed of compact bone that surrounds the medullary cavity Yellow bone marrow (fat) is contained in the medullary cavity |
metaphysic(metaphyses) | In a mature bone- the regions where the diaphysis joins the epiphyses In a growing bone – include the epiphyseal plate which is a layer of hyaline cartilage that allows the Diaphysis of the bone to grow in length, but not in width; |
metaphysic(metaphyses) | Epiphyseal line: bone growth in length stops |
diaphysis | Expanded ends of long bones Exterior is compact bone, and the interior is spongy bone Joint surface is covered with articular (hyaline) cartilage Epiphyseal line separates the diaphysis from the epiphyses |
Articular cartilage | made of Hyaline cartilage; reduces friction and absorbs shock at freely movable joint; lacks a perichondrium, repair of damage is limited. |
Medullary (marrow) cavity = bone marrow (yellow and red) | contains fatty yellow bone marrow in adults. spongy bone= contains RED BONE MARROW. Contains red bone marrow, which produces blood cells. Contains yellow bone marrow, which stores triglycerides (fats), a potential chemical energy reserve. |
The region of a long bone where the epiphysis and diaphysis join is called the _____. | metaphyses |
What are the two layers of the periosteum? | Outer fibrous layer & Inner osteogenic layer |
Outer fibrous layer | IS dense irregular connective tissue |
Inner osteogenic layer | consists of cells. is composed of osteoblasts and osteoclasts Richly supplied with nerve fibers, blood, and lymphatic vessels, which enter the bone via nutrient foramina Secured to underlying bone by perforating (Sharpey’s) fibers |
What are functions of the periosteum? | 1.osteogenic= bone formation 2. protection- fiber layers 3.serve as attachment for muscle 4.assist in the bone repairing . if fracture bone= periosteum has lots of blood supply |
Periosteum: Does it cover articular cartilage? | NO |
Periosteum | is a tough connective tissue sheath and its associated blood supply that surrounds the bone surface wherever it is not covered by articular cartilage. |
Periosteum | Some of the cells enable bone to grow in thickness, but not in length. The periosteum also protects the bone, assists in fracture repair, helps nourish bone tissue, and serves as an attachment point for ligaments and tendons. |
Periosteum | The periosteum is attached to the underlying bone by perforating (Sharpey’s) fibers, thick bundles of collagen that extend from the periosteum into the bone extracellular matrix. |
What are characteristics and functions of osteocytes, osteoblasts, and osteoclasts? | |
1. Osteogenic cells: | unspecialized stem cells; the only bone cells to undergo cell division; develops into osteoblasts. |
2. Osteocytes: | derived from osteoblasts; are mature bone cells; maintains bone tissue. |
3. Osteoblasts | bone-building cells; form bone matrix. |
4. Osteoclasts: | derived from the fusion of many Monocytes, functions in resorption, the destruction of bone matrix. |
A structural unit of compact bone is an _________. | osteon (harvesian systems) |
The central canal of an osteon contains ________. | central canal= haversian canal; blood vessels n nerves n lymphatic vessels the bone's nerve and blood supplies |
Study the structure of an osteon: central canal, lamellae (interstitial, circumferential, concentric), perforating canal, canalicullae, lacunae) | |
Compact bone tissue | is composed of repeating structural units called osteons, or haversian systems |
Each osteon consists of concentric lamellae arranged around a______? | central(haversian) canal |
central canal | run longitudinally through the bone |
Around the canals are ? Resembling the growth rings of a tree,____? | concentric lamellae |
Between the concentric lamellae are small spaces called? | lacunae that contain osteocytes. (la-KOO-ne=little lakes; singular is lacuna |
Radiating in all directions from the lacunae are tiny_____? | canaliculi (kan-a-LIK-u-lı= small channels), which are filled with extracellular fluid. Inside the canaliculi are slender fingerlike processes of osteocytes |
The areas between neighboring osteons contain lamellae called_____ | interstitial lamellae, which also have lacunae with osteocytes and canaliculi. Interstitial lamellae are fragments of older osteons that have been partially destroyed during bone rebuilding or growth |
Blood vessels, lymphatic vessels, and nerves from the periosteum penetrate the compact bone through____? | transverse perforating canals or Volkmann’s canals.The vessels and nerves of the perforating canals connect with those of the medullary cavity, periosteum, and central canals. |
Arranged around the entire outer and inner circumference of the shaft of a long bone are lamellae called___? | circumferential lamellae. They develop during initial bone formation. |
The circumferential lamellae directly deep to the periosteum are called___? | outer circumferential lamellae (just beneath the periosteum). They are connected to the periosteum by perforating (Sharpey’s) fibers. |
The circumferential lamellae that line the medullary cavity are called | inner circumferential lamellae encircle the medullary cavity. |
What is characteristic of spongy bone tissue, but not of compact bone tissue? | Osteons (haversian systems) in compact bone and trabeculae in spongy bone. spongy bone=trabeculae, red bone marrow, medullary cavity. NO osteons. compact bone=osteon,central canal, concetric lamellae,lacunae,canaliculi,osteocytes,NO red bone marrow.. |
Compact Bone Tissue | forms the external layer of all bones; provides protection and support and helps bones resist stress -Arranged in units called Osteons (Haversian systems). |
Compact Bone Tissue | -Central canal run longitudinally through the bone. Around the canals are concentric lamellae. Between the lamellae are small spaces called lacunae that contain osteocytes. |
Compact Bone Tissue | Canaliculi: filled with extracellular fluid, fingerlike processes of osteocytes. - Blood vessels, lymphatic vessels, and nerves from the Periosteum penetrate the compact bone through transverse perforating (Volkmann’s) canals. |
Compact Bone Tissue | -The areas between osteons contain interstitial lamellae; outer circumferential lamellae just beneath the Periosteum; inner circumferential lamellae encircle the medullary cavity |
Spongy Bone Tissue | -Consists of lamellae that are arranged in an irregular lattice of thin columns of bone called trabeculae. -In short, flat, and irregularly shaped bones; most of the epiphyses; a narrow rim around the medullary cavity. |
Spongy Bone Tissue | -contains spaces that are sometimes filled with red bone marrow |
What is the intramembranous ossification? What bones does it produce? | - Bone forms directly within Mesenchyme arranged in sheet-like layers that resemble membranes. - The flat bones of the skull and mandible |
What is endochondral ossification? | -The formation of bone within hyaline cartilage that develops from mesenchyme. Long bones |
What are the major steps in this process:endochondral ossification? | Development of the cartilage model. Growth of the cartilage model. Development of the primary ossification center. Development of secondary ossification centers. Formation of articular cartilage and epiphyseal plate. |
Development of the cartilage model.p.161 | Mesenchymal cells crowd together-> chondroblasts that produce a cartilage matrix -> a hyaline cartilage model is formed. - Perichondrium develops. |
Growth of the cartilage model. | -Chondroblasts->chondrocytes: cell division, further secretion of matrix. -Calcification of chondrocytes in the midregion of the model; mainly due to the burst of chondrocytes (hypertrophy) that release their contents and increase the pH of the matrix. |
Development of the primary ossification center. | -Occurs in the shaft or diaphysis of the long bone, prior to birth. -A nutrient artery penetrates the perichondrium, stimulating osteogenic cells to differentiate into osteoblasts, and then a bony collar around the shaft is formed. |
Development of the primary ossification center. | -The perichondrium around the diaphysis converted to a Periosteum -Medullary cavity. |
Development of secondary ossification centers. | -In the epiphyses, around the time of birth. -No medullary cavity is formed; spongy bone remains. |
Formation of articular cartilage and epiphyseal plate. | both structures consist of hyaline cartilage. |
What does the presence of an epiphyseal line indicates? | epiphyseal line= no more bone growth occurs, happens after puberty,The epiphyseal plate fades, leaving a bony structure called the epiphyseal line. With the appearance of the epiphyseal line, bone growth in length stops completely. |
Normal bone growth and replacement on the presence of ____, ____, _____. | i.several minerals (e.g., calcium, phosphorus, etc.) ii.several vitamins (e.g., C, A, and D) iii.weight-bearing exercise iv.several hormones (e.g., human growth hormone, sex hormones, etc.) |
Study the types of the fracture. p.166 What is a Colles' fracture? | -Colles’ fracture: Fracture of the distal end of radius. Occurs often in winter, in children |
-Pott’s fracture: | Fracture of the distal end of fibula |
-Impacted fracture: | One end of fractured bone is force-fully driven into the interior of the other |
- Greenstick: | incomplete fracture where one side of the bone breaks and the other side bends; occurs only in children |
- Comminuted: | bone fragments into three or more pieces; common in the elderly |
- Open (compound) fracture | The broken ends of the bone protrude through the skin. open muscle, skin more chance of infection |
closed (simple) | Conversely, a closed (simple) fracture does not break the skin. |
What type joint contains a joint cavity? Fibrous, cartilaginous, or synovial? | synovial joints |
Based on structures: 1. Fibrous: | the bones are held together by fibrous CT; no synovial cavity. |
2. Cartilaginous: | held together by cartilage, no synovial cavity. |
3. Synovial: | united by the dense irregular CT of an articular capsule; has a synovial cavity. |
Which type of joint has the most movement? Synarthrosis, diarthrosis, or amphiarthrosis? | diarthrosis |
Based on the degree of movement: Synarthrosis | an immovable joint |
Amphiarthrosis: | a slightly movable joint. |
diarthrosis | a freely movable joint. All diarthroses are synovial joints. |
3. What are the dense irregular or regular connective tissue structures that bind one bone to another bone? | Ligaments are dense irregular or dense regular connective tissue structures that bind one bone to another bone. |
What structures are the most responsible for holding bones together at a synovial joint? | ligaments |
What secretes the synovial fluid? | secreted by the synovial membrane |
What are the functions of the synovial fluid? | functions are: lubrication, supply nutrients and remove wastes for cartilages, phagocytic cells remove microbes and the debris. |
Can ligaments be extracapsular or intracapsular? | Both. Extracapsular (ex.colateral ligament) n Intracapsular (ex.anterior clusor) ligaments hold ur bones together |
gliding movement | One flat bone surface glides or slips over another similar surface Examples – intercarpal and intertarsal joints, and between the flat articular processes of the vertebrae |
each angular movement: Flexion | Flexion — bending movement that decreases the angle of the joint |
Extension | Extension — reverse of flexion; joint angle is increased |
Dorsiflexion and plantar flexion(ex.ballerina) | up and down movement of the foot |
Abduction | movement away from the midline |
Adduction | movement toward the midline |
Circumduction | movement describes a cone in space |
Rotation | The turning of a bone around its own long axis; examples: Between first two vertebrae |
Supination and pronation | turn palm up; turn palm down |
What are the types of fibrous joints? And the examples? | 1. Suture-ex. frontal suture 2. Syndesmosis- ex.Distal tibiofibular 3. Interosseous membrane- ex.B/w tibia and fibula, b/w ulna and radius |
What are the types of cartilaginous joints? And the examples? | 1. synchondrosis-ex epiphyseal plate=growth plate 2.symphysis- ex pubic symphysis, intervetebral disk |
Do all symphyses occur in the midline of the body? | Yes, All symphyses occur in the midline of the body: intervertebral joints, pubic symphysis. |
What are the types of synovial joints? And the examples? In addition, their movement | All synovial joints are diarthrosis. Planar hinge Pivot Condyloid Saddle Ball-and socket |
Planar | Functional classification: Many biaxial (ex. intercarpal, intertarsal side to side, gliding (ex. sternocostal) |
Hinge | Monaxial (ex. elbow, knee flexion-extention (ex interphalangeal) |
Pivot | monaxial, rotation (ex. atlantoaxial, b/w 1st and 2nd vertabrae.radioulnar joints |
condyloid | biaxial ( ex radiocarpal) flexion-extention (ex metacarpophalangeal (2nd to 5th) Abduction-adduction (ex wrist, joints |
saddle | triaxial, (Carpometarcarpal joint b/w trapezium and 1st metacarpal)(only thumb) flexion-extention Abduction-adduction rotation |
ball-and socket | Triaxial (ex. shoulder and hip joints) flexion-extention Abduction-adduction, circumduction, rotation |