Skeletal System Flashcards
Skeletal System: Function
- Supports the body
- Protects soft body parts
- Produces blood cells
- Stores minerals and fat
- Permits flexible body movement
Skeletal System: Tissue
Connective:
- Bone
- Cartilage
- Ligaments (connect bone –> bone
Bone Anatomy: Diaphysis
- Shaft of bone
- medullary cavity
- contains yellow marrow
- walls = compact bone
- lined with endosteum- a thin, vascular
membrane
Bone Anatomy: Periosteum
Fibrous connective tissue that covers a long bone
- Contains blood vessels, lymphatic vessels, and nerves
Bone Anatomy: epiphysis
- Composed mainly of spongy bone
- red marrow
- Coated in hyaline cartilage (articular cartilage)
Compact bone: Osteons
Tubular units in bone
Compact bone: lacunae
- Tiny chambers arranged in concentric circles around a central canal
- Matrix fills space in between lacunae
Bone cells: Osteocytes
Mature bone cells that lie in lacunae
Compact bone: canaliculus
Tiny canals that run through the matrix in bone
Spongy bone: trabeculae
thin plates that are unorganized throughout spongy bone
Spongy bone
- Unorganized appearance
- Designed for strength
- Lighter than compact bone
Cartilage
- Weaker than bone
- More flexible than bone
- Gel-like matrix
- Contains collagenous and elastic fibers
- No nerves
- No blood vessels
- Slow to heal
Cartilage: chondrocytes
Cells that lie within lacunae that are irregularly grouped
Cartilage: Type #1
- Hyaline –> firm, glassy appearance, many collagen fibers
* Found at end of long bones, in the nose, ends of the ribs, larynx, and trachea
Cartilage: Type #2
- Fibrocartilate –> stronger than hyaline
- matrix has wide rows of thick, collagenous fibers
- able to withstand tension and pressure
- found where support = #1
- Found in the disks between vertebrae & cartilage of the knee
Cartilage: Type #3
- Elastic –> more flexible
- matrix contains more elastin fibers
- found in ear flaps and epiglottis
Fibrous Connective Tissue
- Makes up ligaments and tendons
- Contains rows of fibroblast cells separated by bundles of collagenous fibers
of Bones in the Body
206
Axial Skeleton
- Midline of the body:
- Skull
- Hyoid bone
- Vertebral column
- Rib cage
Major Cranial Bones (& Location)
- Frontal bone (forehead)
- Parietal bone (top/base of the head)
- Temporal bone (sides/temples)
- Occipital bone (lower back of the head)
Skull: Foramen Magnum
Large opening through which the spinal cord passes
Skull: Sphenoid bone
- Bat shaped
- extends across the floor of the cranium
- all other bones articulate with it
SkSkull: Sinuses
Air spaces lined by mucus membrane
- reduce the weight of the skull
- give a resonant sound to the voice
Facial Bones
- Mandible (lower jaw)
- Maxillae (upper jaw)
- Zygomatic bones (cheekbones)
- Nasal bone (bridge of nose)
Hyoid Bone:
- Only bone not articulated with another bone
- Anchors the tongue
- Site for attachment of muscles used for swallowing
- Fractured hyoid bone –> suspicious death
Vertebral Column
- 33 vertebrae
- 4 curvatures
- Intervertebral foramina: spinal nerves branch from spinal column and travel through these holes
- Processes: MA that move the vertebral column
Cervical Vertebrae
- Located in the neck
- # 1 = Atlas (yes)
- # 2 = Axis (no)
Thoracic Vertebrae
- Long, thin spinous processes
- Articular facets for rib attachment
Lumbar Vertebrae
- Large bodies
- Thick processes
Sacrum
5 sacral vertebrae that are fused together
Coccyx
Tailbone:
- usually 4 fused vertebrae
Intervertebral Disks
- Composed of fibrocartilage
- act as padding: prevent ginding & absorb
shock
- act as padding: prevent ginding & absorb
- Allow vertebrae to move as we bend, flex, etc.
- May become weak, herniate, rupture and/or slip
Rib cage/ribs
- AKA thoracic cage
- Rib = flattened bone
- 12 pairs
- 1-7 = true
- 8-12= false (do not directly connect to sternum)
- 11-12 = floating (no connection to sternum)
Sternum
- Flat bone
1. Manubrium (handle)- articulates with clavicles
- costal cartilages form ribs #1
- Body (blade)
- Xiphoid process (point)
- attachment site for the diaphram (separates the thoracic cavity from abdominal cavity)
Appendicular Skeleton
- Pectoral girdles and their attached limbs
2. Pelvic girdle and their attached limbs
Clavicle
- Extends across thorax
- Articulates with
- sternum
- acromion process of scapula
Scapula
- Muscle attachment
- corocoid process
Glenoid caity
- Articulates with head of humerus
- small
Rotator cuff
- Tendons that connect 4 small muscles to the scapula
- Vigorous circular movement here can damage rotator cuff
Olcranon Process
- Bump at the back of the elbow
- Ulna
Humerus
- Head (top)
- Torchlea (AW ulna)
- Capitulum (AW radius)
Hand
- 8 Carpal bones (wrist - small pebbles)
- 5 Metacarpals (hand bones)
- Phalanges
Pelvic
Pelvis: 1. Pelvic girdle - Coxal bones (2) - 3 parts: ilium (largest), ischium (sitting portion), pubis (anterior) * Meet at hip socket: acetabulum 2. Sacrum 3. Coccyx
Femur
- Longest and Strongest bone in our body
- Short neck betters the position for walking
- 2 large processes: MA
- greater trochanter (anterior)
- lesser trochanter (posterior)
- Distal end: 2 condyles: AW tibia
- medial condyle
- lateral condyle
Patella
- Kneecap
- Held together by quadriceps tendon (butcher’s
tendon –> AW tibia tuberosity)
Tibia
- Larger of the two lower leg bones
- Medial malleolus –> inner bulge of the ankle
Fibula
- Smaller/Slender bone of lower leg
- Distal lateral malleolus –> outer bulge of ankle
Foot bones
- 7 tarsal bones (ankle)
- talus can move freely - AW tibia & fibula
- calcaneus (heel)
- talus + calcaneus = support weight of body
- 5 metatarsal bones (instep)
- distal end = ball of the foot
- flat feet –> weakened ligaments here
- phalanges (toes)
- short and sturdy
Joints
- synovial
- Freely moveable
- fibrous
- sutures between cranial bones
- cartilaginous
- hyaline cartilage
- intervertebral disks
Bursa (e)
Fluid-filled sacs that ease friction between bare areas of bone and overlapping muscle (or between skin and tendons)
Flexion
Joint angle decreases
Extension
Joint angle increases
Adduction
Body part moves towards midline
Abduction
Body part moves away from midline
Supination
Hand faces anterior/downward
Pronation
Hand faces posterior/downward
Circumduction
Body part moves so that a cone shape is outlined
Inversion
Sole of foot turns inward
Eversion
Sole of foot turns outward
Skeleton starts forming in ___ embryonic development
6 weeks
Osteoblasts
Bone-forming cells
- When surrounded by calcified matrix, they
become osteocytes within lacunae
Osteoclasts
Bone absorbing cells
Osteocytes
Mature bone cells derived from osteoblasts
Formation of bone is called
Ossification
Intramembranous ossification
Bones develop between sheets of fibrous connective tissue