Structure And Function Of Body System Flashcards
The ________________ of the human body consists of bones, joints, muscles, and tendons configured to allow the great variety f movements characteristic of human activity.
Musculoskeletal System
Muscle can on _______________: but through the system of bony levers, muscle pulling forces can be manifested as either pulling or pushing forces against external Objects.
Pull, not push
The _________ consisted of the skull(cranium), vetebral column(C1 through the coccyx), ribs and sternum.
Axial Skeleton
The _______Includes the shoulder (or pectoral) girdle (left and right scapula and clavicle; bone of the arms, wrists, and hands (left and right humeru, radius, ulna, carpals, metacarpals, and phalanges); the pelvic girdle(left and right coral or innominate bones); and the bones of the legs, ankles and feet
Appendicular Skeleton
Junctions of the bones are called ____________
Joints
___________allow virtually no movement
___________ allow limited movement (intervebral discs)
___________ allow considerable movement (elbow and Knee)
Fibrous joints
Cartilaginous joints
Synovial joints
Articulating bone ends are covered with smooth ___________, and the entire joint is enclosed in a capsule filled with ____________.
Hyaline cartilage
Synovial Fluid
____________, such as the elbow, operate as hinges, essentially rotating about only one axis.
Uniaxial Joints
_________, such as the angle and wrist, allow movement about two perpendicular axes.
Biaxial joints
____________, including the shoulder and hip ball-and-socket joints, allow movement about all three perpendicular axes that define space.
Multiaxial Joints
the _____________ is made up of bones separated by flexible disks that allow movement to occur.
Vertebral column
__ cervical vertebrae
__thoracic Vertebrae
__ Lumbar vertebrae
__ sacral Vertebrae
7
12
5
5
Fibrous connective tissue, or ______________, covers the body’s more than 430 skeletal muscles
Epimysium
The ______ is attached to the bone periosteum, a specialized connective tissue covering all bones, any contraction of the muscle pulls on the tendon and, in turn, the bones.
Tendon
Limb muscles have two attachment to bone: ___________(closer to the trunk) and ___________ (further from the trunk)
Proximal
Distal
The two attachments of trunk muscles are termed ____________ (closer to the head) and ___________ (Closer to the feet)
Superior
Inferior
Muscle cells, often called ______________, are long (sometimes running the entire length of a muscle), cylindrical cells 50 to 100um in diameter (about the diameter of a human hair.
Muscle Fibers
Under the _____________ the muscle fibers are grouped in bundles (fasciculi) that consist of up to 150 fibers.
Epimysuim
The bundles of fasciculi are surrounded by connective tissue called _____________
Perimysium
Each muscle fiber is surrounded by connective tissue called _________
Endomysium
Endomysium is encircled by and is contiguous with the fibers membrane, or ______________
Saroclemma
A nerve cell is a what ?
Motor Neuron
The junction between a motor neuron and the muscle fibers it innervates is call the motor end plate, or, more often, the ______________
Neuromuscular Junction
A mother neuron and the muscle fibers it innervates are called _________________
Motor unit
The ____________, which is the cytoplasm of a muscle fibers contains contractile components consisting of protein filaments, other proteins, stored glycogen and fat particles, enzymes, and specialized organelles such as mitochondria and the sarcoplasmic reticulum.
Sarcoplasm
Hundreds of _____________ (each about 1 um in diameter, 1/100 the diameter of a hair) dominate the sarcoplasm.)
- contain the apparatus that contracts the muscle cell.
Myofibrils
Myfibrils contain the apparatus that contracts the muscle cell, which consists primarily of two types of _______________________.
Myofilament: myosin & Actin
The globular heads protude away from the myosin filament at regular intervals, and a pair of myosin filament forms a ________________
Cross-bridge
Myosin and actin filaments are organized longitudinally in the smallest contractile unit of skeletal muscle, the ______________.
Sarcomere
____ actin filaments surround each myosin filament, and each actin filament is surrounded by ____ myosin filament.
- 6
- 3
The dark _______ corresponds with the alignment of the myosin filament, whereas the light _________ corresponds with the areas in two adjacent sarcomeres that contain actin filaments.
A-band
I-band
The ________ is in the middle of the I-band and appears as thin, dark line running longitudinally through the I-ban.
Z-line
The ________ is the area in the center of the sarcomere where only myosin filaments are present.
- During muscle contraction, _______ decreases as the actin slides over the myosin toward the center of the sarcomere.
H-zone
Parallel to an surrounding each myofibril is an intricate system of tubules called the _______________________ which terminates as vesicles in the vicinity of the Z-lines.
Sarcoplasmic Reticulum
____________, or ____________, run perpendicular to the sacoplasmic reticulum and terminate in the vicinity of Z-line between two vesicles.
T-Tubules or Transverse Tubules
An Electrical Nerve Impulse is a ?
Action Potential
____________ states that the actin filaments at each end of the sarcomere slide inward on myosin filaments, pulling the Z-lines toward the center of the sarcomere and thus shortening the muscle fiber.
Sliding -Filament Theory
____________ - little calcium is present in the myofibril (most of its is stored in the sarcoplasmic Reticulum), so very few of the myosin crossbridges are bound to the actin.
Resting Phase of Sliding Filament Theory
