Week 6: Bones (Tissues & Skeletal System) Flashcards
Osteology
Study of bones
Skeletal System Composition
-composed of bones, cartilages, and ligaments
a.Cartilage—forerunner of most bones
Covers many joint surfaces of mature bone
b.Ligaments—hold bones together at joints
c.Tendons—attach muscle to bone
Function of the Skeletal System
- Support
- Protection
- Movement
- Electrolyte Balance
- Acid-Base Balance
- Blood Formation
Function of the Skeletal System: Support
Support—limb bones and vertebrae support body; jaw bones support teeth; some bones support viscera
Function of the Skeletal System: Protection
Protection of brain, spinal cord, heart, lungs, and more
Function of the Skeletal System: Movement
limb movements, breathing, and other movements depend on bone
Function of the Skeletal System: Electrolyte Balance
calcium and phosphate levels
Function of the Skeletal System: Acid-Base Balance
buffers blood against large pH changes by altering phosphate and carbonate salt levels
Function of the Skeletal System: Blood Formation
red bone marrow is the chief producer of blood cells
Bone (osseous tissue)
connective tissue with the matrix hardened by calcium phosphate and other minerals
Mineralization or calcification
the hardening process of bone
Individual bones (organs)- tissue types
consist of bone tissue, bone marrow, cartilage, adipose tissue, nervous tissue, and fibrous connective tissue
Types of Bones
- Flat Bones
- Long Bones
- Short Bones
- Irregular Bones
- Sesamoid Bone
Bone General Features: Compact/ Spongy Bone
- Compact bone
- dense outer shell of bone - Spongy (cancellous) bone
- loosely organized bone tissue
- Found in center of ends and center of shafts of long bones and in middle of nearly all others
- Covered by more durable compact bone - Skeleton three-fourths compact and one-fourth spongy bone by weight
Long Bone: Features
- Epiphyses and diaphysis
- Compact and spongy bone
- Marrow cavity
- Articular cartilage (made up of hylaine cartliage)
- Periosteum
- fibrous layer (collagen/ reticular fibers)
- cellular layer (osteoblasts)
Articular cartilage
-layer of hyaline cartilage that covers joint surface; allows joint to move more freely (decreases friction of joint surfaces)
Nutrient foramina
minute holes in bone surface that allows blood vessels to penetrate
Periosteum
- External sheath covering most of bone (does not cover the epiphysis- which is covered by articular cartliage)
- Some fibers continuous with tendons
- Perforating fibers—penetrate into bone matrix
- Periosteum contains blood vessels, nerves, and lymphatic vessles.
- Important to bone growth and healing of fractures
- Outer fibrous layer of collagen
- Inner osteogenic layer of bone-forming cells
Endosteum
- Thin layer of reticular connective tissue lining/ adjacent to the medullary/ marrow cavity
- Has cells that dissolve osseous tissue and others that deposit it (grow, repair, and remodel throughout life)
- osteoclast
- osteoblast
- osteocytes
- osteogenic cells
Epiphyseal plate
- growth plate
- area of hyaline cartilage that separates epiphyses and diaphyses of children’s bones
- Enables growth in length
- Epiphyseal line: in adults, a bony scar that marks where growth plate used to be
Diaphysis, Epiphysis, Medullary Cavity
- Diaphysis—shaft that provides leverage
- Medullary cavity (marrow cavity)—space in the diaphysis of a long bone that contains bone marrow
- Epiphyses—enlarged ends of a long bone; strengthen joint and anchor ligaments and tendons
Flat Bone: Structure/ Function
- Sandwich-like construction
- Two layers of compact bone enclosing a middle layer of spongy bone
- Both surfaces covered with periosteum
- Diploe—spongy middle layer
- Absorbs shock
- Marrow spaces lined with endosteum
Bone Cell Types
- osteogenic cells
- osteoblasts
- osteocytes
- osteoclasts
Osteogenic Cells
-“Baby” Bone Cells
- Stem cells found in endosteum and inner layer of periosteum
- Arise from embryonic mesenchyme
- Multiply continuously and give rise to most other bone cell types
Osteoblasts
- Growing pre-teen bone cells
- Synthesize bone matrix (ostioid) for bone growth AND deposit calcium into matrix to harden the bone
- actively mitotic
Osteocytes
- Adult Bone Cells
- Monitors and maintains bone
- Detects and responds to increased mechanical stress/ damage on bones by communicating with osteoblasts/ osteoclasts; this allows for bones to remodel when stressed or fractured.
Osteoclasts
- Derived from the same homatopoetic stem cells as macrophages
- Help break down/ dissolve bone in bone resorption
- Breaking down bone for various reasons
- Maintain Calcium Homeostasis: can be a response to low calcium level (important to recycle for cardiac processes and neurotransmission)
- Remodels Old Bone to ensure durability and proper functioning
Lacunae
tiny cavities where osteocytes reside
Canaliculi
little channels that connect lacunae
Bone Cell Development
Bone Matrix (Don’t Study)
- Matrix of osseous tissue is, by dry weight, about one-third organic and two-thirds inorganic matter
1. Organic matter—synthesized by osteoblasts - Collagen, carbohydrate–protein complexes, such as glycosaminoglycans, proteoglycans, and glycoproteins
2. Inorganic matter - 85% hydroxyapatite (crystallized calcium phosphate salt)
- 10% calcium carbonate
- Other minerals (fluoride, sodium, potassium, magnesium)
Compact Bone Structure
- Osteon: unit of bone
- Central Canal (medullary cavity)
- opening in the center of the osteon
- carries blood vessles and nerves
3.Perforating (Volkmann’s) Canal:
- Lacunae:
- Cavities containing bone cells (osteocytes)
- Arranged in concentric rings - Lamellae
- Rings around the central canal
- Sites of lacunae - Canaliculi
- Tiny canals
- Radiate from the central canal to lacunae
- Form a transport system
Spongy Bone Structure
1.Structure:
Spongy bone consists of:
-Lattice of bone covered with endosteum (no periosteum)
-Slivers of bone called spicules
-Thin plates of bone called trabeculae
-Spaces filled with red bone marrow
-Few osteons and no central canals
-All osteocytes close to bone marrow
- Function: Provides strength with minimal weight
- Trabeculae develop along bone’s lines of stress
Bone Marrow & Types
soft tissue occupying marrow cavities of long bones and small spaces of spongy bone
- Red
- Yellow
Red Marrow
- Also called Myeloid Tissue
- Contains hemopoietic tissue—produces blood cells
- In nearly every bone in a child
- In adults, found in skull, vertebrae, ribs, sternum, part of pelvic girdle, and proximal heads of humerus and femur
Yellow Marrow
- Found in adults
- Fatty marrow that does not produce blood
- Can transform back to red marrow in the event of chronic anemia
- Function: Storage of fat and production of red blood cell in life threatening situations
Ossification/ Osteogenesis
the formation of bone
Bone Development in Infants: Two Types
1.Intramembranous ossification
- Woven bone is formed WITHOUT cartliage- derives from mesenchyme
- Produces flat bones of skull and clavicle in fetus
- Thickens long bones throughout life
2.Endochondral ossification (interstitual growth)
- Formed from cartliage matrix (made by chondrocytes)
- Leads to development of most bones in body
Intramembranous Ossification
- Deposition of osteoid tissue into embryonic messenchyme
- Calcification of osteoid tissue and entrapment of osteocytes
- Honeycomb of spongy bone with developing periosteum
- Filling of space to form compact bone
Endochondral Ossification (infancy/ childhood)
- During infancy and childhood, the epiphyses fill with spongy bone
- Cartilage limited to the articular cartilage covering each joint surface, and to the epiphyseal plate
- A thin wall of cartilage separating the primary and secondary marrow cavities
- Epiphyseal plate persists through childhood and adolescence
- Serves as a growth zone for bone elongation
Endochondral Ossification (late teens/ early 20s)
- By late teens to early 20s, all remaining cartilage in the epiphyseal plate is generally consumed
- Gap between epiphyses and diaphysis closes
- Primary and secondary marrow cavities unite into a single cavity
- Bone can no longer grow in length
Bone Growth/ Remodeling & Ossification
- Ossification continues throughout life with the growth and remodeling of bones
- Bones grow in two directions : Length & Width
Bone Elongation
- Epiphyseal plate—cartilage transitions to bone
- Functions as growth zone where bone elongates
- Has typical hyaline cartilage in the middle with transition zones on each side where cartilage is replaced by bone
- Metaphysis is zone of transition facing the marrow cavity - This is interstitial growth—growth from within
- Bone elongation is a result of cartilage growth within the epiphyseal plate
- Epiphyses close when cartilage is gone—epiphyseal line of spongy bone marks site of former epiphyseal plate
- Lengthwise growth is finished
- Occurs at different ages in different bones
Dwarfism: two types
- Achondroplastic dwarfism
- Pituitary dwarfism
Achondroplastic dwarfism
-Long bones stop growing in childhood
Normal torso, short limbs
-Failure of cartilage growth in metaphysis
-Spontaneous mutation produces mutant dominant allele
Pituitary dwarfism
- Lack of growth hormone
- Normal proportions with short stature
Appositional growth
-Bone Widening & Thickening
—occurs at bone surface (within the periosteum)
-Continual growth in diameter and thickness
-Intramembranous ossification
-Osteoblasts of inner periosteum deposit osteoid tissue
-Become trapped as tissue calcifies
-Lay down matrix in layers parallel to surface
-Forms circumferential lamellae
-Osteoclasts of endosteum enlarge marrow cavity
Bone Remodeling
- Bone remodeling (absorption and deposition) occurs throughout life—10% of skeleton per year
- Repairs microfractures, releases minerals into blood, reshapes bones in response to use and disuse
- Wolff’s law of bone: architecture of bone determined by mechanical stresses placed on it
- Remodeling is a collaborative and precise action of osteoblasts and osteoclasts
- Bony processes grow larger in response to mechanical stress
Wolff’s law of bone
architecture of bone determined by mechanical stresses placed on it
Stress Fracture
- Small crack in the bone
- Break caused by abnormal trauma to a bone (example: in a fall)
- Commonly seen in athletes
Pathological Fracture
—break in a bone weakened by disease (such as bone cancer or osteoporosis)
-Usually caused by a stress that would not break a healthy bone
Fractures classified by what structural characteristics
1.Direction of fracture line
2.Break in the skin
3.Multiple pieces
Example: comminuted—three or more pieces
Common Types of Cone Fractures
Bone Fractures: 2 Main Types
- Closed (simple) Fracture: break that doesn’t penetrate the skin
- Open (compound) Fracture: broken bone penetrates through the skin
Bone Fractures
A break in the bone
Bone Fracture Treatment
- reduction and immobilization
- realignment of the bone
Bone Fracture Healing
- Hematoma Formation (blood-filled swelling):
- the hematoma is converted by granulation tissue by invasion of cells and blood capillaries - Soft Callus Formation:
- Break is splinted (immobilized) by fibrocartilage to form a callus - Hard Callus Formation (Fibrocartilage callus is replaced by a bony callus)
- osteoblasts deposit a temporary bony collar around the fracture to unite the broken pieces while ossification occurs. - Bone Remodeling (Bony callus is remodeled to form a permanent patch)
- Small Bone Fragments are removed by osteoclasts, while osteoblasts deposit spongy bone and then convert it to compact bone.
Flat Bones
- Thin, curved plates
- Protect soft organs
- Made up of marrow (diploe) sandwiched between two layers compact bones
- Example: Skull (Frontal, Parietal, Occipital), Sternum, Scapula, Ribs etc.
Long Bones
- Longer than wide
- Rigid levers acted upon by muscles; crucial for movement
- Typically found in the extremities
- Example:Femur, Humerus, Radius, Ulna,etc.
Short Bones
-Approximately equal in length and width
- Cube like in appearance
- Glide across one another in multiple directions
- Example: Carpals & Tarsal Bones
Irregular Bones
- Elaborate shapes that do not fit into other categories
- Example: Face Bones, Vertebrae, & Hip Bones
Sesamoid Bones
- Mostly Rounded in Shape
- Typically embedded within certain tendons
- Related to the surface of joints
- Examples: Patella, Metocarpoophangeal joint, Metotarsalphalangeal joint
Where do coastal cartilages join mostly ? where do they attach ?
- Coastal Cartliage are bars of hyaline cartliage connecting bony ribs to sternum or bony rib to costal arch or just lining the end of the ribs
Name each part
- A = Articular Cartliage
- B = Spongy Bone
- C = Epiphyseal Line
- D = Red Bone Marrow
- E = Endosteum
- F = Compact Bone
- G = Medullary Cavity
- H = Yellow Bone Marrow
- I= Periosteum
- J = Nutrient Cavity/ Blood Vesseles
- K= Articular Cartliage
- L = Promixal Epiphysis
- M = Metaphysis
- N = Diaphysis
- O = Distal Epiphysis
Vertebral Column Labeling
- A = Cervical Vertebrae (7)
- B = Thoracic Vertaebae (12)
- C = Lumbar Vertebrae (5)
- D = Saccrum (5)
- E = Coccyx (1)
- F = Cervical Curve
- G = Thoracic Curve
- H = Lumbar Curve
- I = Sacral Curve
- J = Intervetrebral Disc
- K= Intervertebral Foramen
- L = Saccrum
- M = Coccyx
In anatomical position, what bone is lateral to the radius ?
-The Phalanges
Gender Differences of the Pelvis
Male:
- Not as wide or broad
- Pelvic cavity is funnel-shaped
- Bones are heavier & larger
- Pubic arch more narrow
Female:
- Wider pelvis & broader hips
- Pelvic cavity is shallow
- Bones are lighter & thinner
- Pubic arch is wider
Lordosis: Symptoms & Treatment
- Anterior concavity of the curvature of the lumber and cervical spine
- Also known as “swayback”
- Causes: From pregnancy or Obesisity
- Symptoms: lower back pain & physical deformity
- Treatment: chiropractic treatment, back brace, physical exercise
Kyphosis: Symptoms & Treatment
- Extreme outward curvature of the upper thoracic vertebrae
- Also known as “hunchback”
- Causes: osteoporosis, also osteomalacia or spinal tuberculosis, wrestling or weight lifting in young boys
- Treatment: pain killer, back brace, spinal surgery, and physical therapy
Scoliosis: Location, Cause, & Treatment
- A side to side curvature of the spine
- Location: usually in the thoracic spine
- Most common; Particurlary of adolescent girls
- Causes: Developmental abnomrality in which the body and arch fail to develop on one side of the vertebrae
- Symptoms: leaning to one side, muscle spasms, uneven waist, physical deformity
- Treatment: can not be cured but; treatments include stretching, bone grafting, spinal fusion.
Osteoporosis
Brittle/ Weak Bones
Mechanism:
- Estrogen maintains bone density in both sexes; inhibits resorption by osteoclasts
- Osteoporosis is a lack of function of osteoclasts and thus, no resorption/ bone remodeling
- Bones lose mass and become brittle due to loss of organic matrix and minerals
- Affects spongy bone the most since it is the most metabolically active
- Subject to pathological fractures of hip, wrist, and vertebral column
- Kyphosis (widow’s hump)—deformity of spine due to vertebral bone loss
- Complications of loss of mobility are pneumonia and thrombosis
General Facts/ Risk Factors:
- Most common bone disease
- 1 in 5 women in USA over 50 have osteoporosis;
- Postmenopausal white women at greatest risk
- Ovaries cease to secrete estrogen
- White women begin to lose bone mass as early as age 35 (By age 70, average loss is 30% of bone mass)
- Osteoporosis also seen in young female athletes with low body fat causing them to stop ovulating and decrease estrogen secretion
- Other Risk Factors: Men over 70, race, age, gender, smoking, diabetes mellitus, diets poor which are poor in: calcium, protein, vitamins C and D
Treatment:
- Estrogen replacement therapy (ERT) slows bone resorption, but increases risk of breast cancer, stroke, and heart disease
- Drugs Fosamax, Actonel destroy osteoclasts
- PTH slows bone loss if given as daily injection
- Forteo (PTH derivative) increases density by 10% in 1 year
- May promote bone cancer so use is limited to 2 years
- Best treatment is prevention: exercise and a good bone-building diet between ages 25 and 40
Name Process & Label Structures
- A1=perichondrium
- A2=periosteum
- B=Bony Collar
- C=Hyaline Cartliage
- D=Enlarging Chondrocytes
- E=Primary Ossification Center
- F=Primary Marrow Cavity
- G=Secondary Ossification Center
- H=Blood Vessel
- I=Secondary Marrow Cavity
- J=Epiphysis
- K=Diaphysis
- L=Epiphyseal Plate
- M=Nutrient Foramen
- N=Metaphysis
- O=Cartliage
- P= epiphyseal line
- Q=Articular Cartliage
- R= Spongy Bone
- S=Compact Bone
- T =Marrow Cavity
- 1=embryonic phase
- 2=at birth
- 3=child
- 4=adult
Foramen
- Structure: An opening through a bone, usually round
- Function: Serves as a passageway for blood vessels, nerves, or ligaments
- Example: foramen magnum of the occipital bone
Facet
- Structure: A smooth, flat, slightly concave or convex articular surface that forms a joint/ articulates with another flat bone or another facet, together creating a gliding joint.
- Function: to guide and limit movement of the spinal motion segment. In the lumbar spine, for example, the facet joints function to protect the motion segment from anterior shear forces, excessive rotation and flexion.
- Example: Facet of thoracic vertebrae
Trochanter
- Structure:A large prominence on the side of the bone. Some of the largest muscle groups and most dense connective tissues attach to the trochanter.
- Function:Important muscle attachment site
- Example: greater trochanter of the femur (unique to the femur)
Ramus
- Structure: The curved part of a bone that gives structural support to the rest of the bone.
- Function: Gives strucutral support to rest of bone
- Example: superior/inferior pubic ramus and ramus of the mandible.
Spine
- Structure: a sharp, slender, or narrow process
- Function: ?
- Example: Mental spines of the mandible or Scapula Spine
Name this bone
Temporal Bone
Name this bone
Lacrimal Bone
Name this bone
Sphenoid Bone
Name this bone
Maxillae
Name this bone
Humerus
Name this bone
Phalanges
Name this bone
Radius
Name these bones
A=Cervical Vertebrae
B=Thoracic Vertebrae
C=Lumbar Vertaebrae
Name this bone
Sacrum
Name this structure
Intervertebral Disc
Name this bone
Coccyx
Name this bone
Atlas (C1)
Name these structures on the cranium
A=Frontal Bone
B=Parietal Bone
C=Coronal Suture
D=Saggital Suture
E=Lambdoid Suture
F=Squaemous Suture
Name these bones on the anterior view of skull
- A= Frontal Bone
- B= Parietal Bone
- C=Coronal Suture
- D=Sphenoid Bone
- E=Squamous Suture
- F=Temporal Bone
- G=Ethnoid Bone
- H=Lacrimal Bone
- I= Nasal Septum (Perpendicular Plate of Ethmoid Bone)
- J=Inferior Nasal Conchae
- K=Maxilla
- L=Avelor Process of Maxilla AND Aveolor Process of Mandible
- M=Nasal Bone
- N=Sphenoid Bone
- O=Zygomatic Bone
- P=Vomer Bone
- Q=Mandible
Name these bones on the lateral/ inferior view of skull
- A=Coronal Suture
- B=Parietal Bone
- C=Temporal Bone
- D=Lambdoid Suture
- E=Squamous Suture
- F=Occipital Lobe
- G=Zygomatic Process
- H=External Acoustic Meatus
- I=Mastoid Process
- J=Styloid Process
- K=Mandibular Process
- L=Mental Foramen
- M=Mandible
- N=Avelor Margins (Inferior/ Superior Avelor)
- O=Maxilla
- P=Zygomatic Bone
- Q=Lacrimal Bone
- KK=Nasal Bone
- R=Ethmoid Bone
- S=Sphenoid Bone
- T=Frontal Bone
- U=Maxilla
- V=Palantine Bone
- W=Zygomatic Arch (above is the Zygomatic Bone)
- X=Vomer
- Y=Mandibular Fossa (on the Mandible)
- Z=Styolid Process
- AA=Mastoid Process
- BB=Temporal Bone
- CC=Parietal Bone
- DD=Maxilla
- EE=Spehnoid Bone
- FF=Foramen Ovale
- GG=Carotid Canal (on the Temporal Bone)
- HH=Jugular Foramen (on the occipital bone)
- II=Occipital Condyle (on the occipital bone)
- JJ= Foramen Magnum (on the occipital bone)
Name these bones on the lower limb
- A=Coxal Bone
- B= Saccral Bone
- C=Pubic Symphysis
- D=Femur
- E=Patella
- F=Lower Leg
- G=Tibia
- H=Fibula
- I=Tarsal
- J=Metatarsal
- K=Phalanges
- a.=7 Tarsals
- b.=5 Metatarsals
- c=14 phalanges (toe bones- 4 distal, middle, proximal and 1 distal/proximal)
Name these bones on the tarsals
- A=Talus
- B=Navicular
- C=Intermediate Cuneiform
- D=Medial Cuneiform
- J=Lateral Cuneiform
- D Above=Phalanges
- E=Distal Phalanges
- F=Medial Phalanges
- G=Proximal Phalanges
- H=Metatarsal
- I=Tarsals
- K=cuboid
- L=Calcaneus
How to label/ number phalanges ?
- Big phalanges in both toes and fingers are assigned I… Numbers increase in medial direction on fingers AND increase in lateral direction on toes
Name the bones on the hands
- A=Phalanges
- B=Distal
- C=Middle
- D=Proximal
- E=Metacarpals
- a.=5
- b.=4
- c.=3
- d.=2
- e.=1
- F=Carpals
- G=Hamate
- H=Pisiform
- I=Triquetral
- J=Lunate
- K=Ulna
- L=Trapezium
- M=Trapezoid
- N=Scaphoid
- O=Capitate
- P=Radius
Name the bones on the bronchial
- A=Ulna
- B=Radius
- C=Carpal
- D=Metacarpal
- E=Phalanges
- F=Scapula
- G=Clavivcle
- H=Humerus
Name the bones on the rib cage
- A=True Ribs
- B=False Ribs
- C=Floating Ribs
- a.=1-7
- b.=8-12
- c.=11,12
- D=Vertebra, L1
- E=Vertebra, T1
- F=Jugular Notch
- G=Clavicular Notch
- H=Sternum
- I=Manubria
- J=Sternal Angle
- K=Body
- L=Xiphoidsternal Joint
- M=Xiphoid Process
- N=Coastal Cartliage
- O=Intercoastal Space
Paranasal Sinus Structure/ Function
- Four skull bones (maxillary, sphenoid, frontal, and ethmoid) contain air-filled cavitities lined with the mucous membrane that lead to the nasal pasages
- Para=near
Function:
- Lighten the facial bones
- Help produce sound by acting as a resonance chamber to the voice
- Provide mucus to provide lubrication for the tissues of the nasal
