Exam 3 Flashcards
Sarcoplasmic reticulum:
Holds onto calcium ions
Troponin:
Binds to tropomyosin; removes blockage of tropomyosin
Tropomyosin:
Binds to actin to prevent it from binding to myosin
ATP:
Allows cross bridges between actin and myosin to release
What is pulled closer together when smooth muscle contracts?
Dense bodies
Excitation-Contracting Coupling:
- Action potential reaches T-tubules
- Calcium released into sacroplasm
- Calcium binds to troponin
- Exposes active site of actin (thin) filament as troponin binds to tropomyosin
What comes after Excitation-Contracting Coupling?
Cross-Bridge Movement
Synostosis/Bony joint:
A bony joint that forms when the gap between two bones ossify (fibrous or cartilaginous joints) and become a single bone. This an immoble joint.
Examples of a synostosis:
Mandible; ilium, ischium, and pubis.
Synarthrosis/Fibrous joint:
Adjacent bones are bound by collagen fibers. There are 3 different kinds of fibrous joints.
What are the 3 types of synarthrosis/fibrous joints?
- Suture- Mostly immobile; found in the bones of the skull. (Serrate, lap, and plane sutures)
- Gomphoses- Like a nail embedded in wood; tooth in its socket.
- Syndesmoses- The collagen fibers are relatively long, so this is the most mobile kind of fibrous joint. Can be found between the shafts of the radius and ulna.
Amphiarthrosis/Cartilaginous joint:
Two bones are linked by cartilage. There are 2 types.
What are the 2 types of amphiarthrosis/cartilaginous joints?
- Synchondroses- Bones are joined by hyaline cartilage. Epiphyseal plate of a growing child, and the first ribs attachment to the sternum.
- Symphyses- Two bones are joined by fibrocartilage; can be found in pubic symphysis, and intervertebral discs.
What is articular cartilage made up of?
Hyaline cartilage
Synovial fluid:
Nourishes the articular cartilage, removes waste, and lubricates the joint.
Joint (Articular) capsule:
Encloses the joint cavity and retains synovial fluid. It has an outer fibrous capsule and an inner synovial membrane.
Examples of synovial joints:
Knee, both ends of the clavicle,
Tendon:
Muscle to bone.
Ligament:
Bone to bone
Bursa:
A firbrous sac of synovial fluid located between adjacent muscles, where a tendon passes over bone. Helps tendons slide more easily over joints.
Tendon (Synovial) sheaths:
Elongated cylindrical bursae wrapped around a tendon.
Shoulder joint:
Glenohumeral joint; spherical head of the humerus articulates with the glenoid cavity of the scapula.
Glenoid labrum:
A ring of fibrocartilage that deepens the joint cavity.
What 4 muscles stabilize the shoulder joint?
Subscapularis, infraspinatus, supraspinatus, and teres minor. Their tendons form the rotator cuff.
What are the 3 principal ligaments that support the shoulder joint?
Glenohumeral, coracohumeral, and transverse humeral ligaments.
Elbow joint:
Composed of the humeroulnar (trochlea of humerus to trochlear notch of ulna) and humeroradial joint (capitulum of humerus to head of the radius).
Side to side motions are restricted in the elbow joint by what 2 ligaments?
- Radial (lateral) collateral ligament
- Ulnar (medial) collateral ligament
Hip joint:
Head of femur inserts in to acetabulum of the hip bone.
What ligaments support the coxal (hip) joint?
-Iliofemoral and pubofemoral ligaments on the anterior side
-Ischiofemoral on the posterior side
Tibiofemoral (knee) joint:
The knee is mainly stabilized by the quadriceps tendon in front and the tendon of the semimembranous muscle in the back.
What 2 ligaments prevent the knee from rotating when the joint is extended?
- Fibular (lateral) collateral ligament
- Tibial (medial) collateral ligament
ACL:
Anterior cruciate ligament; prevent hyperextension.
PCL:
Posterior cruciate ligament; prevents the femur from sliding off the from the tibia.
Endomysium
Loose connective tissue that wraps around each muscle fiber.
Perimysium:
Thicker connective tissue sheath; wraps around fascicles.
Epimysium:
Fibrous sheath that wraps around the entire muscle.
Fascia:
Separates neighboring muscles from one another.
Excitation:
- Arrival of the nerve signal and causes the release of calcium.
- Calcium causes the release of acetylcholine.
- Acetylcholine (ACh) binds to receptors in sacrolemma.
- Ligand-gated ion channels (Na come in, K comes out) create an end-plate potential.
- Voltage-regulated ion gates create action potential.
Unhappy triad:
ACL, Medial meniscus, and tibial collateral ligament