Advanced Anatomy Unit 2 Exam Flashcards
Functions of connective tissue
protection, lubrication, filtration
Hyaline cartilage
- Found at the end of long bones, ribs, trachea, bronchi, nose, and embryotic skeleton
- Type 2 collagen
- Provides smooth surfaces for joints and support
Fibrocartilage
- Found at the pubic symphysis, intervertebral discs, and menisci
- Type 1 and type 2 collagen
- Provides support
Elastic cartilage
- Found in the epiglottis, external ear, and auditory tube
- Type 2 collagen
- Provides support through flexibility
Classification of bone shapes: long bones
- bones that are longer than wide (bones of the limbs)
Classification of bone shapes: short bones
Short cube bones (bones of the wrists and ankles)
Classification of bone shapes: flat bones
Sternum, ribs, some bones of the skull
Classification of bone shapes: irregular bones
All other bones (vertebrae, hip bones)
Classification of bone locations: sutural
Located within the sutures of the skull (not always present)
Classification of bone locations: sesamoid bones
- Shaped like a sesame seed and is surrounded by a tendon
- Knee: patella
- Hands: first and second metacarpal
- Feet: first metatarsal
- Wrist: pisiform bone
- Neck: hyoid bone
- Ear: the lenticular process of the incus
Structure of a long bone
Diaphysis, epiphyses, epiphyseal lines, periosteum, and endosteum
Diaphysis
The shaft of a long bone that contains a yellow marrow cavity
Epiphyses
- Ends of long bones (joint surfaces)
- Spongy bone
- Covered with articular cartilage (hyaline cartilage)
Epiphyseal lines
- Between epiphyses and diaphysis
- Former growth plates or epiphyseal plates
Periosteum
Connective tissue membrane which surrounds the external surface of the diaphysis
Endosteum
Connective tissue membrane which surrounds the internal surfaces of the bone
Bone histology: osteoblasts
- Makes bone and secretes osteoid
- Turns into osteocytes
Bone histology: osteocytes
- Mature bone cells
- cell bodies sit in a space called lacunae
- cell processes of osteocytes sit in spaces called canaliculi
Bone histology: osteoclasts
Breaks down bone tissue
Extracellular bone matrix: osteoid
- secreted by osteoblasts
- accounts for bones strength
Extracellular bone matrix: hydroxyapatites
Accounts for bone hardness
Compact bone
outer bone comprised of osteons
Osteon
- tube of bone matrix formed by rings called concentric lamellae
- central canals connected by perforating canals
Spongey bone
- surrounded by compact bone
- no osteons
- composed of plates of bone called trabeculae
Intramembranous ossification
- bone originates from connective tissue membranes
- Mesenchyme
- flat bones of skull and clavicle
Endochondral ossification
- bone originates from hyaline cartilage
- most bones
Wolf’s law of bone architecture
- stress correlates with density
- action of osteoclasts and osteoblasts
Bone hormonal control: PTH
- released when Ca level in blood is too low
- PTH stimulates osteoclasts to breakdown bone
Bone hormonal control: calcitonin
- released when Ca level in blood is too high
- calcitonin inhibits osteoclasts
Osteomalacia (rickets)
- osteoid produced but hydroxyapatites are not deposited
- results in soft bones, bones might bend (bow legged)
- caused by Vitamin D deficiency or lack of Ca in diet
Osteoporosis
More bone is broken down than formed
Skeletal muscle
- attached to mainly bone
- striated
- cells are long and like cylinders
- Voluntary movement
Cardiac muscle tissue
- Striated and involuntary
- cells are shorter than skeletal muscle and the fibers are branched
- gap junctions
Smooth muscle tissue
- in the walls of hollow organs and skin
- nonstriated and involuntary
Functions of muscle tissue
Movement, support, generates heat
Skeletal muscle structure: epimysium
Layer of connective tissue that covers the entirety of the external surface of the muscle
Skeletal muscle structure: perimysium
Layer of connective tissue that surrounds each fascicle
Skeletal muscle structure: endomysium
Layer of connective tissue that covers each fiber
Skeletal muscle fiber anatomy: sarcolemma
Specialized plasma membrane
Skeletal muscle fiber anatomy: sarcoplasm
- Specialized cytoplasm
- Contains glycogen and myoglobin
- Contains myofibrils
Skeletal muscle fiber anatomy: thick myofilaments (myosin)
- Composed of myosin proteins
- Each protein has a tail and two heads
Skeletal muscle fiber anatomy: thin myofilaments (actin)
Composed of the proteins actin, tropomyosin, and troponin
Actin proteins
Each actin protein has a myosin binding site that form cross bridges during muscle contraction
Tropomyosin proteins
- String like
- Covers myosin binding sites when the muscle is at rest
Troponin proteins
- Sectioned into sarcomeres
- Z disc to z disc and contains the A band, I band, H zone, and M line regions
A band of troponin proteins
Contains both thick and thin myofiliments
I band of troponin proteins
Contains thin myofiliments
H zone of troponin proteins
- Contains thick myofilaments
- Covers the largest area of the sacromeres
M line of troponin proteins
Middle of the H zone and contains proteins that connect thick myofiliments
Sarcoplasmic reticulum (SR)
- SER of skeletal muscle cells
- Stores Ca
- Dilated ends are called terminal cisternae and are located in the T tubule
Neuromuscular junctions
A specialized synapse between a motor neuron and the sarcolemma of the skeletal muscle cell
Neuromuscular junctions: synaptic cleft
The space between the neuron and the sarcolemma
Neuromuscular junctions: presynaptic terminal
- Terminal portion of the motor neuron
- Releases neurotransmitters
Neuromuscular junctions: postsynaptic membrane
Region located at the neuromuscular junction
Sliding filament model
Skeletal muscle movement occurs because thick and thin myofilaments slide across each other, shortening the sarcomeres to shorten
Rigor mortis
- When we die, cells undergo autolysis
- Ca leaks from SR
- The Ca binds to troponin and triggers the binding of the myosin heads to actin
- There are no APs, so myosin cannot be released from actin
Functional classification of joints: synarthrosis
Nonmovable (tooth to jaw, costochondral joints, sutures, epiphyseal joints)
Functional classification of joints: amphiarthrosis
Slightly movable (radius to ulna, tibia to fibula, pubic symphyses, invertebral disc articulations)
Structural classification of joints: fibrous joints
Joints held together by collagen fibers (sutures of the skull, tooth in jaw, syndesmosis)
Structural classification of joints: Cartilaginous joints
Joints held together by a disc of cartilage (pubic symphysis, vertebral discs, ribs)
Structural classification of joints: synovial joints
Bones are separated by a fluid filled joint cavity, very movable
Associations with synovial joints: articular cartilage
- Hyaline cartilage found at the ends of long bones
- Provides a smooth surface, absorbs shock, and reduces friction
Associations with synovial joints: joint cavity
- Space filled with synovial fluid that surrounds the joint
- Synovial fluid nourishes the cartilage and reduces friction
Associations with synovial joints: joint capsule
Surrounds the joint, with a fibrous capsule outer layer and a synovial membrane inner layer
Associations with synovial joints: bursa sacs
Sacs filled with synovial fluid that reduce friction
Associations with synovial joints: tendon sheaths
Elongated bursae that wraps around the tendon and reduces friction
Temporomandibular joint (TMJ)
Synovial joint formed by the mandibular condyles of the mandible and the mandibular fossae of the temporal bones
Shoulder (Glenohumeral) Joint
- Most movable joint
- Head of the humerus and glenoid fossa of scapula
- Glenoid labrum, ligaments of the shoulder, and the four rotator cuff muscles
Ligaments of the shoulder
Glenohumeral, acromioclavicular, coracoacromial, and the coracoclavicular ligaments
Rotator cuff muscles of the shoulder
Supraspinatus, infraspinatus, teres minor, and subscapularis
Hip (coxal) joint
- Strongest joint
- “Ball in socket”
- acetabular labrum and ligaments
Hip: Acetabular labrum
Circular rim of fibrocartilage that helps deepen joint cavity
Ligaments of the hip
- Semicircular placement so they can assist with range of motion; function of the normal movement of the joint
- Ligamentum teres is an internal ligament that does not help with structure, but protects an artery
Knee joint
- Most complex joint
- Formed be the medial and lateral condyles of the femur and the medial and lateral condyle of the patella
Major ligaments of the knee: Patellar ligament
- continuation of patellar tendon and attaches to the tibial tuberosity
- Knee jerk reflex
Major ligaments of the knee: medial collateral ligament
- attached to the epicondyle of the femur and the medial tibia
- Strengthens medially
Major ligaments of the knee: lateral collateral ligament
- Attached to the lateral epicondyle of the femur and the head of the fibula
- Strengthens laterally
Major ligaments of the knee: anterior cruciate ligament
- Attached to the medial surface of the lateral condyle of the femur and the anterior portion of the intercondylar eminence
- Prevents anterior sliding of the tibia on the femur and hyperextension of the knee
Major ligaments of the knee: posterior cruciate ligament
- attached to the lateral portion of the medial condyle of the femur and the posterior portion of the intercondylar eminence
- Prevents hyperextension and posterior sliding of the tibia on the femur
