Final Exam Flashcards
Name the three major layers of the skin from the outer surface going inward.
- Epidermis
- Dermis
- Hypodermis
Name and major function of the specialized cells of the epidermis.
- Keratinocytes
- Melanocytes
- Dendritic (Langerhans) cells
- Tactile (Merkel) cells
Starting at the basement membrane list and give a brief description of the layers of the epidermis.
- Stratum basale
- Stratum spinosum
- Stratum granulosum
- Stratum lucidum
- Stratum corneum
What are the functions of bone?
- Support
- Protection
- Movement
- Mineral and growth factor storage
- Blood cell formation
- Triglyceride (fat) storage
- Hormone production
Structure of long bone.
- Articular cartilage
- Proximal epiphysis
- Spongy bone
- Epiphyseal line
- Diaphysis
- Compact bone
- Medullary cavity (endosteum)
- Periosteum
- Distal epiphysis
Describe the cells of osseous tissue. i.e., What do osteoblasts do? Osteoclasts, etc?
- Osteogenic cell: stem cell, mitotically active
- Osteoblast: bone forming cell
- Osteocyte: monitors and maintains mineralized bone matrix
- Osteoclast: bone resorbing cell
Describe the histology of compact bone. What is the structural unit of compact bone?
- Histology: Central canal (artery, vein, nerve fiber), lamellae (concentric rings), and collagen fibers
- Structural unit: osteon
Structure and function of spongy bone.
- Trabeculae
- No osteons
- Irregular lamellae and and osteocytes connected by canaliculi
- Capillaries in endosteum provide nutrients
- Align along lines of stress to help resist it
Negative feedback hormonal loop for blood Ca2+ homeostasis.
- Stimulus: Falling Ca2+ blood levels
- Triggers parathyroid glads to release parathyroid hormone (PTH)
- Osteoclasts degrade bone matrix and release Ca2+ into blood
Bone homeostasis response to mechanical stress (e.g., Wolf’s Law)
- Bones grow and remodel based on the stress put on them
- Hormonal controls determine whether and when remodeling occurs
- Mechanical stress determines where remodeling occurs
What are the three regions of the axial skeleton?
- Skull
- Vertebral column
- Thoracic cage
List the sections of the vertebral column and know how many bones each has.
- Cervical vertebrae (7)
- Thoracic vertebrae (12)
- Lumbar vertebrae (5)
- Sacrum
- Coccyx
Compare and contrast cervical vertebrae, thoracic vertebrae and lumbar vertebrae. Which receives the most stress because it bears the most weight?
- Cervical: C1=axis, C2=atlas, C3-C7=oval body, short spinous process, large vertebral foramen, transverse foramen
- Thoracic: circular vertebral foramen, long spinous process that points downward
- Lumbar: massive bodies, receives most stress
Describe the ribs and their attachments.
- 12 pairs
- Attach posteriorly to thoracic vertebrae
- Pairs 1-7: True ribs, attach directly to sternum
- Pairs 8-12: False ribs
How are joints classified -structural, functional?
- Structural: fibrous, cartilaginous, synovial
- Functional: synarthrosis, amphiarthroses, diarthroses
Describe the three classes of fibrous joints and the two types of cartilaginous joints, where each type is found (Figs 8.1, 8.2).
- Three classes of fibrous joints: suture (skull), syndesmosis (fibula and tibia), gomphosis (teeth)
- Two classes of cartilaginous joints: synchondrosis (first rib and sternum), symphyses (between vertebrae)
Explain the characteristics of synovial joints.
- Articular cartilage
- Joint (Synovial) cavity
- Articular capsule
- Synovial fluid
- Reinforcing ligaments
Describe the structure of synovial joints. Function of bursae membranous sacs.
- Ligament
- Joint cavity with synovial fluid
- Articular cartilage
- Articular capsule (fibrous capsule and synovial membrane)
- Bursae: reduce friction
Describe the four types of movement based on planes.
- Nonaxial
- Uniaxial
- Biaxial
- Multiaxial
Describe the types of synovial joints.
- Plane
- Hinge
- Pivot
- Condyloid
- Saddle
- Ball and socket
Describe the three types of muscle.
- Skeletal
- Cardiac
- Smooth
Describe the structure of a sarcomere (the functional unit of skeletal muscle).
- Thick filaments (myosin)
- Thin filaments (actin)
- Z disc
- H zone
- M line
Describe the events of the sliding filament model of muscle contraction, include the actions of the SR, calcium, troponin, tropomyosin, myosin head, actin fiber, etc. What do the myosin heads attach to? Compare these to the events in smooth muscle.
- Motor neuron stimulates muscle fiber
- AP, ACh, ion permeability of sarcolemma changes, depolariation, end-plate potential
- Excitation-contraction coupling occurs
- AP across sarcolemma and T tubules, SR releases Ca2+, Ca2+ binds to troponin, myosin binding sites on actin exposed, myosin heads bind to actin
What causes muscles to relax?
- Ca2+ released from troponin
- Resorption of Ca2+ into SR
Describe the neuromuscular junction and the events that occur there, compare to varicosities in smooth muscle.
- AP arrives at axon terminal of motor neuron
- Ca2+ channels open and Ca2+ enters the axon terminal
- Ca2+ entry causes synaptic vessels to release ACh
- ACh diffuses across the synaptic cleft and binds to receptors in the sarcolemma