A & P chapter 6 Bones

How does cartilage grow?

2 ways: Appositional and interstitial Appositional: Chondroblasts in the perichondrium add new cartilage to the outside edge of the existing cartilage. -The chondroblasts lay down new matrix and add new chondrocytes to the outside of the tissue Interstitial growth: Chondrocytes within the tissue divide and add more matrix between the cells

Test

5,6,7,8 and up to here on 9-action potential and neurontransmitters

Angular movements: abduction and adduction

Abduction is movement away from the midline Adduction is movement towards the midline Bending at the waist to one side is usually called lateral flexion of the vertebral column rather than abduction

Range of Motion

Amount of mobility demonstrated at a given joint Types: Active- amount of movement accomplished by muscle contraction Passive- amount of movement accomplished by some outside force like a physical therapist Dislocation: bones are moved out of proper alignment Sprain: stretched or completely torn ligaments

Outer surfaces of compact bone

Are formed by circumferential lamellae, which are thin plates that extend around the bone Between the osteons are interstitial lamellae, which are remnants of concentric or circumferential lamellae that were partially removed during bone remodeling

Special movements

Are those movements that are unique to only one or two joints and do not fit neatly into any other category Elevation and depression Protraction and retraction Excursion Opposition and reposition Inversion and eversion

Articulations

Articulations or joints, are named according tot the bones or portions of bones that join together; for example, the temporomadibular joint is between the temporal bone and the mandible Joints are classified structurally as fibrous, cartilaginous, or synovial, according to the major connective tissue type that binds the bones together and whether a fluid filled joint capsule is present

Axial skeleton

Axial skeleton Skull (22 separate bones + 6 auditory ossicles) Hyoid bone Vertebral column Thoracic (rib) cage

Shoulder joint (glenohumeral)

Ball and socket joint that has less stability but more mobility than the other ball and socket joint, the hip Flexion/extension, abduction/adduction, rotation, and circumduction all occur in the shoulder joint The rim of the glenoid cavity is built up slightly by a fibrocartilage ring, the glenoid labrum, to which the joint capsule is attached A subscapular opens into the joint cavity A subacromial bursa is located near the joint cavity but separated from the cavity by the joint capsule

More accessory structures of Synovial joints

Bursae: pockets of synovial membrane and fluid that extend from the joint. Found in areas of friction -bursitis Ligaments and tendons: stabilization Menisci: fibrocartilaginous pads in the knee Tendon sheaths: synovial sacs that surround tendons as they pass near or over bone

Periosteum

Double layered connective tissue membrane covering the outer surface of bone except where articular cartilage is present Outer is fibrous Inner is single layer of bone cells including osteoblasts, osteoclasts, and osteochondral progenitor cells Ligaments and tendons attach to bone through the periosteum Blood vessels and nerves from the periosteum supply the bone The periosteum is where bone grows in diameter

Special movements: Elevation and depression

Elevation moves a structure superiorly Depression moves it inferiorly Shrugging the shoulders is scapular elevation Depression of the mandible opens the mouth and elevation closes it

Synovial joint: Ellipsoid

Modified ball and socket, articular surfaces are ellipsoid Biaxial Example: Atlantooccipital

Bones of Nasal Cavity

Nasal cavity. Pear-shaped, open anteriorly Nasal septum divides nasal cavity into right and left halves -Bony part is vomer and perpendicular plate of the ethmoid -Hyaline cartilage anterior part Nasal conchae: form lateral walls, bony shelves -Inferior: separate bones -Middle and superior: projections of the ethmoid -Increase surface of nasal cavity

Posterior view of Skill

Occipital condyle -Articulates with C1 (atlas vertebrae) "yes" joint External occipital protuberance -Ligamentum nuchae: Helps keep head erect

Action potentials

Phases: -Depolarization: Inside of plasma membrane becomes less negative. If change reaches threshold, depolarization occurs -Repolarization: return of resting membrane potential. Note that during repolarization, the membrane potential drops lower than its original resting potential, then rebounds. This is because Na+ plus K+ together are higher, but then Na/K+ pump restores the resting potential All-or-none principle: like camera flash system Propagate: Spread from one location to another. Action potential does not move along the membrane: new action potential at each successive location. Frequency: number of action potential produced per unit of time

Circular movements

Rotation, pronation and supination, and circumduction Involve rotating a structure around an axis or moving the structure in an arc

What are the three types of fibrous joints?

Sutures, syndesmoses, and gomphoses

Mechanical stress and bone strength

Stress causes bone remodeling to: Increase bone mass (density) and align trabeculae with stress Changes causes by: Osteoblast activity.- increases with stress.

What are the 5 functions of the skeletal system?

Support, Protect, Movement Storage, and Blood cell production

What are two effects of aging on skeletal system?

1. Bone matrix decreases causing the bone to be more brittle due to lack of collagen 2. Bone mass decreases and increased bone fractures

What is the process of calcium homeostasis?

1. Decreased blood Ca2+ stimulates Parathyroid hormone secretion from parathyroid glands. 2. PTH stimulates osteoclasts to break down bone and release Ca2+ into the blood 3. In the kidneys, PTH increases Ca2+ reabsorption from the urine. PTH also stimulates active Vitamin D formation 4. Vitamin D promotes ca+2 absorption from the small intestine into the blood 5. Increased blood calcium stimulates calcitonin secretion from the thyroid gland 6.Calcitonin inhibits osteoclasts, which allows for osteoblast uptake of calcium from the blood to deposit into bone This is NEGATIVE feedback. If it were positive, you would decrease calcium and still decrease it.

Active and passive influences (7)

1. Shape of articular surfaces forming joint 2. Amount and shape of cartilage covering surfaces 3. strength and location of ligaments and tendons 4. Location of muscles associated with joint 5. Amount of fluid in and around joint 6. Amount of pain in and around joint 7. Amount of use/disuse of joint

Essay over Intramembranous ossification

5th week of development in embryo, embryonic mesenchyme forms a collagen membrane containing osteochondral progenitor cells Begins at the 8th week of embryonic development and is completed by 2 years of age Forms many skull bones, part of mandible, diaphyses of clavicles The locations in the membrane where ossification begins are called centers of ossification Steps of intramembranous ossification: 1. Mesenchymal cells become osteochondral progenitor cells, which specialize to become osteoblasts. The osteoblasts produce bone matrix that surrounds collagen fibers and the osteoblasts become osteocytes. As a result, many trabeculae of woven bone develop 2. Additional osteoblasts gather on the surfaces of the trabeculae and produce more bone. Spongy bone forms as the trabeculae join together resulting in an interconnected network separated by spaces 3. Cells within the spongy bone specialize to form red bone marrow. Cells surrounding the developing bone form periosteum. Osteoblasts lay down bone matrix to form an outer surface of compact bone

Syndesmoses (fibrous joint)

A syndesmoses is a fibrous joint in which the bones are farther apart than in a suture and are joined by ligaments Some movement may occur at syndesmoses because the ligaments are flexible This occurs in the radioulnar syndesmosis, for example, which binds the radius and ulna together

Skeletal system function: Storage

Calcium and phosphorus are stored then released as needed. Adipose tissue is stored in marrow cavities and released when needed

Paranasal Sinuses

Associated with the bones of the nasal cavity Functions: -Decrease skull weight -Resonating chambers Named for bones in which they are found: -Frontal -Maxillary -Ethmoidal -Sphenoidal

Chapter 7: gross anatomy

Be prepared to identify every bone on a lab exam

Spongy/cancellous bone

Can be woven or lamellar and is classified by the amount of bone matrix relative to the amount of space within the bone Appears porous, has less bone matrix and more space than compact bone Consists of interconnecting rods or plates of bone called trabeculae. Between the trabeculae are spaces that are filled with bone marrow and blood vessels Trabeculae consist of several lamellae with osteocytes located in lacunae between the lamellae. Each osteocytes is associated with other osteocytes. Covered with endosteum Oriented along stress lines

Bone Histology

Bone Matrix and Bone cells Connective tissue Bone cells produce the matrix, become entrapped within it, and break it down so that new matrix can replace the old matrix

How is bone different from cartilage?

Bone differs from cartilage in that the processes of bone cells are in contact with one another through the canaliculi. Instead of diffusing through the mineralized matrix, nutrients and gases can pass through the small amount of liquid surrounding the cells in the lacunae or pass from cell to cell through the gap junctions connecting the cell processes

What are Osteoblasts and its function?

Bone forming cells Have an extensive endoplasmic reticulum and numerous ribosomes Produce collagen and proteoglycans, which are packaged into vesicle by the golgi and released by exocytosis. Also release matrix vesicles- membrane bound sacs formed when the plasma membrane buds Precursors of hydroxyapatite stored in vesicles, then released, which stimulate further hydroxyapatite formation and mineralization of the matrix Communicate through gap juctions

What is Calcium Homeostasis?

Bone is a major storage site for calcium The level of calcium in the blood depends upon movement of calcium into or out of bone -Calcium enters bone when osteoblasts create new bone; calcium leaves bone when osteoclasts break down bone -Two hormones control blood calcium levels- parathyroid hormone and calcitonin

Skeletal system function: Protection

Bone is hard and protects the organs it surrounds Example: Skull encloses and protects the brain Rib cage protects the heart and lungs and other organs

Skeletal system function: Support

Bone is rigid and strong- suited for bearing weight and is the major supporting tissue of the body Cartilage provides a firm and flexible support- nose, ear, thoracic cage, and trachea Ligaments are strong bands of fibrous connective tissue that attach to bones and hold them together

Hyaline cartilage

Bone lengthening and bone repair often involve the production of hyaline cartilage followed by its replacement with bone Hyaline cartilage consists of specialized cells called Chondroblasts that produce a matrix surrounding themselves Chondrocytes are surrounded by matrix and occupies a space called lacuna within the matrix -The matrix contains collagen, which provides strength and proteoglycans, which make cartilage resilient by trapping water

Endochondral Ossificiation

Bones of the base of the skull, part of the mandible, epiphyses of the clavicles, and most of remaining bones of skeletal system Steps: 1.Chondroblasts produce a hyaline cartilage model that is surrounded by perichondrium. Chondroblasts become chondrocytes. 2. When blood vessels invade, osteochondral progenitor cells become osteoblasts, which produce compact bone forming a bone collar. The chondrocytes hypertrophy, and calcified cartilage forms 3. A primary ossification center forms as blood vessels and osteoblasts invade the calcified cartilage. The osteoblasts lay down bone matrix forming spongy bone 4. The process of bone collar formation, cartilage calcification, and spongy bone production continues. Calcified cartilage begins to form in the epiphyses. A medullary cavity begins to form in the center of the diaphysis. 5. Secondary ossification centers form in the epiphyses of long bones 6. The original cartilage model is almost completely ossified. Unossified cartilage becomes the epiphyseal plate and the articular cartilage. 7. In a mature bone, the epiphyseal plate has become the epiphyseal line, and all the cartilage in the epiphysis, except the articular cartilage, has become bone.

What are the four components of the skeletal system?

Bones, Cartilage, tendons, and ligaments

How is bone maintained?

By Osteocytes: mature bone cells. Osteoblasts--> Osteocytes Become relatively inactive but can produce components to maintain the bone matrix

What is woven bone and its function?

Collagen fibers are randomly oriented in many directions. Formed during fetal development or during the repair of a fracture After its formation, osteoclasts break down the woven bone and osteoblasts build new matrix Process of removing old bone and adding new bone is called Bone Remodeling. ((Ossification is formation of new bone by osteoblasts)) Woven bone is remodeled to form lamellar bone

Circular movement: circumduction

Combination of flexion, extension, abduction and adduction Occurs at freely movable joints, such as the shoulder. The arm moves so that it describes a cone, with the shoulder joint at the apex, as occurs when pitching a baseball

Combination movements

Combining movements together Example: when a person steps forward and to the side at a 45degree angle, the movement at the hip is a combination of flexion and abduction

Elbow joint

Compound hinge joint -humeroulnar joint -humeroradial joint -proximal radioulnar joint Cubital joint = humeroulnar + humeroradial joints

Synchondroses (Cartilaginous joint)

Consists of two bones joined by hyaline cartilage where little or no movement occurs Epiphyseal plates of growing bones are synchondroses -epiphyseal plates: the synchondrosis is converted to a synostosis as bone replaces the existing cartilage Other synchondroses are converted to synovial joint, whereas others persist throughout life Bones farther apart than suture and joined by ligaments

Synovial joint: plane

Consists of two flat bone surfaces of about equal size Slight gliding motion can occur Uniaxial Examples: intervertebral, carpals and metacarpals, ribs, sacrum and coxal bone, and tarsal bones and metatarsal

Synovial joint: Saddle

Consists of two saddle shaped articulating surfaces oriented at right angles to each other Biaxial Examples: thumb (carpometacarpal pollicis) intercarpal, and sternoclavicular

Synovial joints

Contain synovial fluid Allow considerable amount of movement Most joints that unite bones of appendicular skeleton reflecting greater mobility of appendicular skeleton compared to axial More complex than fibrous and cartilaginous joints

Bone remodeling

Converts woven bone into lamellar bone. Young to adult. Caused by migration of basic multicellular units, which are groups of osteoclasts and osteoblasts that remodel bones Involved in bone growth, changes in bone shape, adjustments in bone due to stress, bone repair, and Ca ion regulation Relative thickness of bone changes as bone grows. Bone constantly removed by osteoclasts and new bone formed by osteoblasts. Formation of new osteons in compact bone: Osteoclasts enter the osteon from blood in the central canal and internally remove lamellae. Osteoblasts replace bone Osteoclasts remove bone from the exterior and the bone is rebuilt

Pelvic Girdle

Coxal bones and sacrum form ring Pelvis: pelvic girdle and coccyx Coxal bones: Right and Left -Ilium -Ischium -Pubis Acetabulum: articulates with head of femur Obturator foramen Sacrum

Hip joint

Coxal joint (ball and socket) More stable but less mobile than shoulder joint Flexion/extension, abduction/adduction, rotation, and circumduction Extremely strong joint capsule reinforced by ligaments including that bears much of the body weight while standing Ligament of head of femur or ligamentum teres; does not contribute much toward strengthening the hip joint but - it carries nutrient artery to the head of the femur in 80% of population

Interior of the Cranial Cavity again

Cranial cavity: occupied by the brain Floor divided into anterior, middle, and posterior fossae Crista galli: prominent ridge in center of anterior fossa. Point of attachment for the dura mater (one of the meninges) Olfactory fossae lateral to crista galli. Olfactory bulb within -Cribriform plate of the ethmoid forms floor of olfactory fossae -Olfactory nerves pass through the foramina of the cribriform plate Sella turcica: part of sphenoid bone that houses the pituitary gland Foramen magnum: opening where brain attaches to spinal cord

Compact bone

Denser and has fewer spaces than spongy bone Has bloods vessels that enter the substance of the bone itself and the lamellae of compact bone are primarily oriented around those blood cells. Vessels that run parallel to the long axis of the bone are contained within central canals, which are line with endosteum and contain blood vessels, nerves, and loose connective tissue Concentric lamellae are circular layers of bone matrix that surround the central canal An osteon consists of a single central canal, its contents, and associated concentric lamellae and osteocytes

How does connective tissue develop?

Develops embryologically from mesenchymal cells Some mesenchymal cells become stem cells, which give rise to more specialized cell types Osteochondral progenitor cells are stem cells that can become osteoblasts (bone forming cells) or chondroblasts (cartilage forming cells) Osteochondral progenitor cells --> osteoblasts --> osteocytes

Structure of a long bone: diaphysis and epiphysis

Diaphysis: the shaft of the bone. Primarily compact bone Epiphysis: End of the bone and is primarily spongy bone. Covered with hyaline cartilage called articular cartilage Diaphysis-->ossification-->epiphysis

Growth at articular cartilage

Does not ossify and persists through life

Table 7.9 general structure of a vertebra

Dont pay much attention to this table Just know what they look like on a picture

Perichondrium

Double layered connective tissue sheath. Covers cartilage except at articulations. Inner perichondrium: More delicate, has fewer fibers, contains chondroblasts Outer perichondrium: blood vessels and nerves penetrate. No blood vessels in cartilage itself, so nutrients must diffuse through the cartilage matrix to reach the chondrocytes

Bone development

During fetal development, bone forms in two patterns: intramembranous ossification and endochondral ossification intramembranous ossification: takes place in connective tissue membranes endochondral ossification: takes place in cartilage Both methods initially produce woven bone, which is then remodeled. After remodeling, bone formed by intramembranous ossification cannot be distinguished from bone formed by endochondral ossification

Knee joint

Ellipsoid/condyloid: allowing flexion/extension, small amount of rotation Menisci: fibrocartilage articular disks that build up the margins of the tibia and deepen articular surface Cruciate ligaments: extend between intercondylar eminence of tibia and fossa of the femur -Anterior cruciate ligament (ACL) prevents anterior displacement of tibia -Posterior cruciate ligament (PCL) prevents posterior displacement of tibia Collateral and popliteal ligaments: along with tendons of thigh muscles strengthen the joint Patella: Bursae: may result in slow accumulation of fluid in the joint (water on the knee)

Epiphyseal plate and epiphyseal line

Epiphyseal plate: Growth plate Area of hyaline cartilage between the diaphysis and epiphysis; cartilage growth followed by endochondral ossification results in growth in bone length Epiphyseal line: When the bone stops growing, the epiphyseal plate becomes ossified and is called the epiphyseal line

Lateral view of skull

Features of the temporal bone -External auditory meatus -Mastoid process Maxilla Mandible. Articulates with the temporal bone. Only join in skull with movement

Symphyses (cartilaginous joint)

Fibrocartilage uniting two bones Slightly movable Examples: symphysis pubis, between the manubrium sternum and the body of the sternum, and intervertebral disks

Structure of flat, short, and irregular bones

Flat bones: No diaphyses or epiphyses. Sandwich of spongy bone between compact bone Short and irregular bone: Compact bone that surrounds spongy bone center, similar to structure of epiphyses of long bones Some flat and irregular bones of skull have sinuses (air filled space) lined by mucous membranes

Angular movements

Flexion and extension Flexion: movement of a body part anterior to the coronal plane or in the anterior direction Extension: movement of a body part posterior to the coronal plane, or in the posterior direction Movement of the foot toward the plantar surface as when standing on the toes is called plantar flexion Movement of the foot toward the shin as when walking on the heels is called dorsiflexion Hyperextension: abnormal, forced extension of a joint beyond its normal range of motion

Vertebral Column again

Four major curvatures in adults -Cervical: anterior -Thoracic: posterior -Lumbar: anterior -Sacral & Coccygeal: posterior At birth, column is C shaped -When head is raised, cervical curve appears -When sitting and walking begin, lumbar curve develops Abnormal curvatures -Lordosis. Exaggeration of lumbar -Kyphosis. Exaggeration of thoracic -Scoliosis. Lateral, often accompanied by kyphosis

Rotator cuff (shoulder joint)

Four muscles that along with 3 sets of ligaments give stability to the joint

Arches of the Foot

Function: Distribute weight of body between heel and ball of foot: weight transferred from the tibia and fibula to the talus. From there, the weight is distributed first to the calcaneus then through the arch system along the lateral side of the foot to the ball (head of the metatarsals). Footprint in wet sand: only heel, lateral margin, ball, and toes of foot imprinted. Three major arches: -Transverse arch -Longitudinal arches: Medial and lateral

Vertebral Column

Functions -Supports weight of head and trunk -Protects the spinal cord -Allows spinal nerves to exit the spinal cord -Provides site for muscle attachment -Permits movement of head and trunk Twenty-six bones in adult; 33-34 in embryo -5 fuse to form sacrum -4 or 5 coccygeal fuse to form the coccyx Regions -Cervical (7 vertebrae) -Thoracic (12 vertebrae) -Lumbar (5 vertebrae) -Sacral bone (1) -Coccygeal bone (1) Number of bones in spine will def be on test

Rib Cage

Functions: -Protects vital organs -Forms semi-rigid chamber for respiration Parts: -Thoracic vertebrae -Ribs (12 pair) --True or Vertebrosternal: superior seven. Attach directly to sternum via costal cartilages --False: inferior five Vertebrochondral (3) joined by common cartilage to sternum Floating or vertebral (2) do not attach to sternum

Growth in bone width

Long bones increase in width and other bones increase in size or thickness because of appositional bone growth beneath the periosteum Interstitial growth cannot occur because matrix is solid. Occurs on old bone and or on cartilage surface

Appendicular skeleton

Girdles: Pectoral or shoulder Pelvic Upper Limbs: Arm Forearm Wrist Hand Lower Limbs: Thigh Leg Foot

What are the types of movement?

Gliding, angular, circular, special, and combinational

Gomphoses (Fibrous joint)

Gomphoses are specialized joints consisting of pegs that fit into sockets and are held in place by bundles of regular collagenous connective tissue The only gomphoses are the joints between the teeth and the sockets (alveoli) of the mandible and maxillae. The connective tissue bundles between the teeth and their sockets are called periodontal ligaments and they allow a slight amount of give to the teeth during mastication

Growth in bone length

Growth in length occurs at the epiphyseal plate Growth at epiphyseal plate involves the formation of new cartilage by interstitial cartilage growth followed by appositional bone growth on the surface of the cartilage 1.New cartilage is produced on the epiphyseal side of the plate as the chondrocytes divide and form stacks of cells 2. Chondrocytes mature and enlarge 3. Matrix is calcified and chondrocytes die 4. The cartilage on the diaphyseal side of the plate is replaced by bone

What are the four steps to bone repair?

Hematoma formation, callus formation, callus ossification, bone remodeling 1. Hematoma formation: Blood released from damaged blood vessels forms a hematoma 2. Callus formation: The internal callus forms between the ends of the bones, and the external callus forms a collar around the break. 3. Callus ossification: Woven, spongy bone replaces the internal and external calluses 4. Bone remodeling: Compact bone replaces woven bone, and part of the internal callus is removed, restoring the medullary cavity

What are the three types of cartilage?

Hyaline cartilage, fibrocartilage, and elastic cartilage

Bone fractures cont.

Impacted fractures: one fragment is driven into the spongy portion of the other fragment Classified on basis of direction of fracture: Linear, transverse, spiral, oblique Dentate: rough, toothed, broken ends Stellate radiating out from a central point.

Arches of foot

Internal (medial) longitudinal arch, External (lateral) longitudinal arch, and transverse arch 2 major functions: hold the bones in their proper relationship as segments of the arch and to provide ties across the arch somewhat like a bowstring Stretching and recoiling of ligaments in the foot

Special movements: inversion and eversion

Inversion: turning the ankle so the plantar surface of foot faces medially Eversion: turning the ankle so the plantar surface of foot faces laterally

Features to describe bones

Involve the relationship between the bones and associated soft tissues If a bone posses a tubercle (lump) or a process (projection), most likely a ligament or tendon was attached to that tubercle or process during life. If a bone has a smooth, articular surface, that surface was part of a joint and was covered with articular cartilage. If the bone has a foramen (hole) in it, that foramen was the opening through which a nerve or blood vessel passed. Some skull bones contain mucous membrane lined air spaces called sinuses

Lamellar bone

Lamellar bone is mature bone that is organized into thin sheets or layers called lamellae Collagen fibers of one lamella lie parallel to one another, but at an angle to the collagen fibers in the adjacent lamellae Osteocytes within their lacunae (spaces occupied by the osteocyte) are arranged in layers sandwiched between lamellae

Special movements: Excursion

Lateral excursion is moving the mandible to either the right or the left of the midline -grinding the teeth or chewing Medial excursion returns the mandible to the midline position

Skull: definitely know these

Ligamentum nuchae (nuchal ligament) = elastic ligament - keeps head erect Occipital condyles - articulate with C1 (atlas) = "yes" joint External auditory meatus = external ear canal Mastoid process - contains air cells of the middle ear Maxilla = upper jaw Mandible = lower jaw (TMJ - only joint of the skull with movement)

Ligand Gated ion channel and trasmitters

Ligand-gated. Ligands are molecules that bind to receptors. Receptor: protein or glycoprotein with a receptor site Example: neurotransmitters Gate is closed until neurotransmitter attaches to receptor molecule. When Ach attaches to receptor on muscle cell, Na+ gate opens. Na+ moves into cell due to concentration gradient Voltage-gated Open and close in response to small voltage changes across plasma membrane

Bone matrix

Like reinforced concrete. Rebar is collagen fibers, cement is hydroxyapatite Organic: Collagen and proteoglycans Inorganic: Calcium phosphate crystals called hydroxyapatite Without minerals the bone is too bendable and flexible Without collagen, the bone is too brittle and breaks easily

Intervertebral Disks

Located between adjacent vertebrae Functions: -Provide support -Prevent vertebrae rubbing against each other Consist of -Annulus fibrosus: external -Nucleus pulposus: internal and gelatinous Becomes compressed with age and height decreases With age, more susceptible to herniation

Sternum

Manubrium: -Articulates with first rib and clavicle -Jugular notch superiorly -Sternal angle: point where manubrium joins body. Second rib articulates here Body: third through seventh ribs articulate -Also called gladiolus Xiphoid process: inferior tip

Skeletal system function: Blood cell produciton

Many bones contain cavities filled with red bone marrow, which gives rise to blood cells and plateletes

Synovial joint: Ball-and- socket

Multiaxial Shoulder and hip joints

Skull Continued

Nasal conchae - Increase surface area in nasal cavity: clean, warm and humidify air Paranasal cavities: decrease weight of skull, resonance chambers Cranial cavity - holds the brain; calvaria = dome of the skull -Crista galli = meninges attachment -Sella turcica (Turkish saddle): holds the pituitary gland (roof of mouth) -Foramen magnum - spinal cord attaches to brain Occipital condyles - articulate with C1 (atlas) = "yes" joint

Synaptic Vesicles

Neurotransmitter: substance released from a presynaptic membrane that diffuses across the synaptic cleft and stimulates (or inhibits) the production of an action potential in the postsynaptic membrane. -Acetylcholine Acetylcholinesterase: A degrading enzyme in synaptic cleft. Prevents accumulation of ACh

Bone Fractures

Open (compound)- bone break with open wound. Bone may be sticking out of wound. Closed (simple)- Skin not perforated. Incomplete- doesn't extend across the bone. Complete- does Greenstick: incomplete fracture that occurs on the convex side of the curve of a bone Hairline: incomplete where two sections of bone do not separate. Common in skull fractures Comminuted fractures: complete with break into more than two pieces

Special movements: opposition and reposition

Opposition is movement of the thumb and pinkie finger -occurs when these two digits are brought toward each other to touch -the thumb can also oppose the other digits, but those digits flex to touch the tip of the opposing thumb Reposition returns the thumb and pinkie finger

How does bone grow or add new bone by ossification?

Ossification is the formation of bone by osteoblasts Appositional growth on the surface of previously existing bone or cartilage Elongated cell processes from osteoblasts connect to the cell process of other osteoblasts through gap junctions. Bone matrix produced by the osteoblasts covers the older bone surface and the result is a new layer of bone.

What are the three bone cells?

Osteoblasts, osteocytes, and osteoclasts

What are Osteoclasts and its function?

Osteoclasts are bone destroying cells Perform reabsorption or breakdown of bone that mobilizes calcium and phosphate ions for use in many metabolic processes Releases enzymes that digest the bone Derived from monocytes (which are formed from stem cells in red bone marrow) Multi-nucleated and probably arise from fusion of a number of cells

What are the 6 types of synovial joints?

Plane, saddle, hinge, pivot, ball-and-socket, and ellipsoid Movements at synovial joints are described as uniaxial (around one axis), biaxial (two axes at right angles) and multiaxial (several axes)

Skull or cranium

Protects brain, supports, the organs of vision, hearing, smell, and taste; and provides a foundation for the structures that take air, food, and water into the body. Think of the skull except for the mandible as a single unit. The top of the skull or the skull cap is called the calvaria

Special movements: Protraction and retraction

Protraction is a gliding motion that moves a structure in an anterior direction Retraction moves the structure back to the anatomical position Jutting out the jaw and hunching the shoulders are examples of protraction Pulling the jaw back and pinching or pulling the scapulae back toward the vertebral column is retraction

Circular movements: Pronation and supination

Refer to the unique rotation of the forearm Pronation is rotation of the forearm so that the palm faces posteriorly in relation to the anatomical position Supination is rotation of the forearm so that the palm faces anteriorly in relation to the anatomical position.

What is the Endosteum and its function?

Similar to periosteum but more cellular Single layer of cells that Lines all internal spaces including spaces in spongy bone Includes osteoblasts, osteoclasts, and osteochondral progenitor cells

Gliding movement

Simplest of all the types Occur in plane joints between two flat or nearly flat surfaces that slide or glide over each other Slight movement as occurs between carpal bones

Factors affection bone growth

Size and shape of a bone determined genetically but can be modified and influenced by nutrition and hormones Nutrition: Lack of calcium, protein and other nutrients during growth and development can cause bones to be small. -Vitamin D: Necessary for absorption. Rickets-lack of vitamin D during childhood. Osteomalacia: lack of Vitamin D during adulthood leading to softening of bones -Vitamin C: necessary for collagen synthesis by osteoblasts. Lack of vitamin C also causes wounds not to heal, teeth to fall out Hormones: growth hormones, thyroid hormone required for growth of all tissues. Sex hormones cause growth at puberty but also cause closure of the epiphyseal plates

Skeletal system function: Movement

Skeletal muscles attach to bones by tendons, which are strong bands of connective tissue Contraction of the skeletal muscles moves the bones producing body movements Joints allow allow movement between bones Smooth cartilage covers the ends of bones within some joints allowing the bones to move freely Ligaments allow some movement between bones but prevent excessive movements

Axial skeleton bones

Skull Mandible Hyoid bone Sternum Ribs Vertebral column Sacrum Protects the brain, spinal cord, vital organs within thorax

Total amounts of bones per section

Skull: 22 Bones associated with skull: 7 Vertebral column: 26 Rib cage: 28 Total axial skeleton bones: 80 Total pectoral girdle and upper limb bones: 64 Total pelvic girdle and lower limb bones: 62 Total appendicular: 126 Total bones: 206

Sutures (Fibrous joint)

Sutures are seams between the bones of the skull Few sutures are smooth, and the opposing bones often interdigitate (have interlocking, fingerlike processes), which adds stability to sutures The tissue between the bones is dense regular collagenous connective tissue and the periosteum on the inner and outer surfaces of the adjacent bones continues over the joint The two layers of periosteum plus the dense fibrous connective tissue in between form a Sutural Ligament

What are the two types of cartilaginous joints?

Synchondroses (hyaline) and Symphyses (fibrocartilage) Cartilaginous joints unite two bones by means of either hyaline cartilage or fibrocartilage

Temporomandibular Joint

TMJ Mandible articulates with the temporal bone Is a combination plane and ellipsoid joint, with the ellipsoid portion predominating Fibrocartilage disk divides joint into superior and inferior cavities Allows depression/elevation, excursion, and protraction/retraction

Overview

Terms: Body: main part Head: enlarged end Neck: constriction between head and body Margin or border: edge Angle: bend Ramus: branch off body Condyle: smooth rounded articular surface Facet: small flattened articular surface Projections: Process: prominent projection Tubercle: small rounded bump Tuberosity: knob Trochanter: tuberosities on proximal femur Epicondyle: near or above condyle These will show up in test questions for lecture and lab. First 4 slides of ppt

Accessory structures of synovial joints

The articular surfaces of bones within synovial joints are covered with a layer of hyaline cartilage called articular cartilage, which provides a smooth surface In some, a flat plate or pad of fibrocartilage called an articular disk, lies between the articular cartilages of bones -Temprormandibular, sternoclavicular, and acromioclavicular joints A meniscus is a fibrocartilage pad found in joints such as the knee and wrist -Much like an articular disk with a hole in the center

Medullary Cavity

The diaphysis of a long bone can have a large internal space called the medullary cavity The cavities of spongy bone and the medullary cavity are filled with marrow In children, medullary cavity is red marrow. Red marrow is the site of blood cell formation -This gradually changes to yellow marrow (adipose tissue) in limb bone and skull (except for epiphyses of long bones). Rest of skeleton is red marrow

Ankle: Talocrural joint

The distal tibia and fibula form a highly modified hinge joint with the talus called the ankle joint or talocrural joint

What is the space occupied by the osteocyte called?

The spaces occupied by osteocyte cell bodies are called lacunae and the spaces occupied by the osteocyte cell processes are called canaliculi, which are canals

Circular movements: rotation

The turning of a structure around its long axis, as in rotating the head, the humerus, or the entire body

Synovial joints cont.

They are inclosed within a synovial joint cavity, which is surrounded by a joint capsule -this capsule helps hold the bones together while still allowing movement Joint capsule has two layers: outer fibrous capsule and an inner synovial membrane Ligaments and tendons may be present outside the fibrous capsule contributing to the strength and stability of the joint while limiting movement in some directions

How do osteocytes receive nutrients and eliminate waste?

They do this through the canal system within compact bone. Blood vessels from the periosteum or medullary cavity enter the bone through perforating canals, which run perpendicular to the long axis of the bone Both perforating and central canals contain blood vessel Direct flow of nutrients from vessels through cell processes of osteoblasts and from one cell to the next Nutrients and wastes travel to and from osteocytes via: -Interstitial fluid of lacunae and canaliculi -From osteocyte to osteocyte by gap junctions

Articular cartilage

Thin layer of hyaline cartilage covering a bone where it forms a joint (articulation) with another bone. Has no perichondrium, blood vessels or nerves

Synovial joint: Pivot

Uniaxial Cylindrical bony process rotating within a circle of bone and ligament Example: articulation between dens of axis and atlas (atlantoaxial), proximal radioulnar, and distal radioulnar

Synovial joint: Hinge

Uniaxial joint that restricts movement to rotation around a single axis Examples: elbow, ankle, and interphalangeal

Bone tissue is classified as what?

Woven or Lamellar. And either one can be cancellous/spongy or compact

Is the clavical apart of the spine?

might be on test

Table 6.3 skeletal system with growth and developmental disorders

whole thing will not be on test

Ossification: endochondral and intramembranous

will be on test for sure