Upgrade to remove ads
Musculoskeletal System (Anatomy)
Terms in this set (57)
Individual bones are the organs of the skeletal system. Bones contain active tissue.
Bones are classified according to their shapes -
Long, short, flat or irregular
Parts of a Long Bone (Holes 144)
Epiphyses at each end are covered with articular cartilage and articulate with other bones.
The shaft of the bone is called the diaphysis.
Except for the articular cartilage, a bone is covered by periosteum.
Compact bone has a continuous extracellular matrix with no gaps.
Spongy bone has irregular interconnecting spaces between bony plates, trabeculae, that reduce the weight of bone.
Both compact and spongy bone are strong and resist bending.
The diaphysis contains a medullary cavity filled with marrow.
Compact bone contains osteons cemented together.
central canals contain blood vessels that nourish the cells of osteons.
Diffusion from the surface of the thin, bony plates nourishes the cells of spongy bone.
Intramembraous bones (Holes 146)
Develop from sheetlike layers of unspecialized connective tissues. Osteoblasts within the membranous layers form bone tissue. Mature bone cells are called osteoclasts.
Develop as hyaline cartilage that is later replaced by bone tissue. The primary ossification centers appear in the diaphysis, whereas the secondary centers appear in the epiphyses. The epiphyseal plates are responsible for lengthening. Long bones continue to lengthen until the epiphseal plates are ossified. Growth in thicknes is due to ossification beneath the periosteum.
Bone Function (Holes 148)
1. Shape and form body structures. Support and protect softer underlying tissues.
2. Bones and muscles function together as levers. A lever consists of a bar, a pivot (fulcrum), a resistance, and a force that supplies energy.
3. Blood cell formation -- at different ages, hematopiesis occurs in the yolk sac, liver and spleen, and red bone marrow. Red marrow houses developing red blood cells, white blood cells, and blood platelets. Yellow marrow stores fat.
4. Storage of inorganic salts - bones store calcium i the extracellular matrix of bone tissue, containing large quantities of calcium phosphate. When blood calcium is low, osteoclasts break down bone, releasing calcium salts. When blood calcium is too high, osteoblasts from bone tissue and store calcium salts. Bone stores small amounts of magnesium, sodium, potassium, and carbonate ions.
Axial Skeleton (Holes 153)
Consists of the skull, hyoid bone, vertebral column and thoracic cage
Consists of pectoral girdle, upper limbs, pelvic girdle and lower limbs
Skull (Holes 155)
Consists of 22 bones, 8 cranial and 14 facial
Cranium encloses and protects the brain, contains air filled paranasal sinuses, cranial bones include frontal, parietal, occipital, temporal, sphenoid, and ethmoid bones.
Facial bones form the basic shape of the face and provide attachment for muscles. Inclue the maxillae, palatine, zygomatic, lacrimal, nasal, vomer, inferior nasal conchae, and mandible.
Infantile skull - fontanels connect incompletely developed bones. Proportions of the infant skull differ from those of the adult skull.
Extends from the skull to the pelvis and protects the spinal cord.
Cervical Vertebrae (C1-C7)
The atlas (first vertebra) supports and and balances the head. The dens of the axis (2nd vertebra) provides a pivot for the atlas when the head is turned from side to side.
Thoracic Vertebrae (T1-T12)
Are larger than cervical vertebrae. Facets on the sides articulate with the ribs.
Lumbar Vertebrae (L1-L5)
The vertebral bodies are large and strong. They support more body weight than other vertebrae.
The sacrum is a triangular structure formed of five fused vertebrae. Vertabral formina form the sacral canal.
The coccyx composed of four fused vertebrae forms the lowest part of the vertebral column. It acts as a shock absorber when a person sits.
Thoracic Cage (Holes 164)
Includes the ribs, thoracic vertabrae, sternum, and costal cartilages. Supports the pectoral girdle and upper limbs, protects viscera, and functions in breathing.
Twelve pairs of curved bones that form the chest wall. True ribs are the first 7 pairs; false ribs are pairs 8 to 10; floating ribs are pairs 11 and 12. A typical rib has a shaft, a head and a tubercles that articulates with the vertebrae. Costal cartilage join the true rib to the sternum directly, whereas false ribs join it indirectly or not at all.
Consists of a manubrium, body and xiphoid process. It articulates with the clavicles.
Pectoral girdle (Holes 164)
Composed of two clavicles and two scapulae. It forms an incomplete ring that supports the upper limbs and provides attachments for muscles that move the upper limbs.
Rodlike bones located between the sternum and the scapulae. They hold the shoulders in place and provide attachments for muscles.
Broad, triangular bones (shoulder blades), they articulate with the humerus of each upper arm and provide attachments for muscles of the upper limbs and chest.
Humerus (Holes 166)
Extends from the scapula to the elbow and articulates with the radius and ulna at the elbow.
The radius is located on the thumb side of the forearm between the elbow and wrist. It articulates with the humerus, ulna and wrist.
The ulna is longer than the radius and overlaps the humerus posteriorly. It articulates with the radius laterally and with a disc of fibrocartilage inferiorly.
The wrist is composed of eight carpal bones that form carpus. The palm (or the metacarpus) includes five metacarpal bones and 14 phalanges compose the fingers.
Pelvic Girdle (Holes 168)
Two hip bones that articulate with each other anteriorly and with the sacrum posteriorly.
The sacrum, coccyx and pelvic girdle form the pelvis.
Each hip bone consists of an illium, ischium, and pubis which are fused in the region of the acetabulum.
The largest portion of the hip bone it joins the sacrum at the sacroiliac joint
Lowest portion of the hip bone, it supports the body weight when sitting.
Anterior portion of the hip bone, they are joined anteriorly at the pubic symphysis.
Fermur (Holes 172)
The femur extends from the hip to the knee. Teh patella articulates with the femur anterior surface.
The tibia is located on the medial side of the leg and articulates proximally with the femur and distally with the talus of the ankle.
Located on the lateral side of the tibia. It articulates proximally with the tibia and distally with the ankle. It does not bear body weight.
The ankle consists of the tarsus formed by the talus and six other tarsals. The instep of metatarsus includes five metatarsals and fourteen phalanges compose the toes.
Joints (Holes 174)
Classified according to degree of movement as well as according to type of tissue that bines the bones together.
Bones at fibrous joints are tightly joined by a layer of dense connective tissue. Limited movement or no movement occurs at a fibrous joint. (sutures between skull bones or roots of human teeth in upper and lower jaw bones)
A layer of cartilage joins the bones of the cartilaginous joints, and allow limited movement. (examples are intervertebral discs or at the pubic symphysis)
The bones of the synovial joints are covered with hyaline cartilage and held together by a fibrous joint capsule. The joint capusle consists of an outer layer of ligaments and an inner lining of synovial membrate. Pads of fibrocartilage, menisci, act as shock absorbers in synovial joints. Bursae are located between tendons and underly bony prominences. Synovial joints that allow free movement include ball and socket, condylar, plane, hinge, pivet and saddle.
Include flexion, extension, dorsiflexion, plantar flexion, hyperextension, abduction, adduction, rotation, circumduction, pronation, supination, eversion, inversion, retraction, protraction, elevation and depression.
Muscular System (Holes 189)
Skeletal muscle tissues, nervous tissue, blood and connective tissue.
Connective tissue covering
Fascia covers the skeletal muscles. Other connective tissues attache muscles to bones or to other muscles. A network of connective tissue extends throughout the muscular system.
Skeletal muscle fibers
Each muscle fiber is multi-nucleated.
Each muscle fiber has many cylindrically-shaped myofibrils. The organization of actin and myosin filaments produces striations. Transverse tubules extend inward from the cell membrane and associate with the sarcoplasmic reticulum.
Motor neurons stimulate muscle fibers to contract. In response to an impulse, the end of a motor neuron axon secretes a neurotransmitter, which stimulates the muscle fiber to contract.
Skeletal muscle contraction (Holes 193)
Muscle fiber contraction results form a sliding movement of actin and myosin filaments.
Myosin and Actin
Heads of myosin filaments form cross-bridge linkages with actin filaments. The reaction between actin and myosin filaments generates the force of contraction.
Stimulus for Contraction
Nerve impulse causes release of ACh from synaptic vesicles
ACh binds to ACh receptors on motor end plate
Generates a muscle impulse
Muscle impulse eventually reaches the SR and the cisternae
Energy sources for muscle contraction
Stored ATP and phosphocreatine
Muscle glycogen breakdown (glycogenolysis)
Oxygen Supply and Cellular Respiration
Occurs in cytoplasm
Produces little ATP
Citric acid cycle
Electron transport system
Occurs in the mitochondria
Produces most ATP
Myoglobin stores extra oxygen
During rest or moderate exercise, muslces receive enough oxygen to respire aerobically. During strenuous exercise, oxygen deficiency may cause lactic acid to be produced. Lactic acid dissociates to from lactate. Oxygen Debt is the amount of oxygen required after physical exercise to convert accumulated lactic acid to glucose and restore supplies of ATP and creatine phosphate.
Loses its ability to contract. Muscle fatigue may be due in part to increased production of lactic acid.
More than half of the energy released in cellular respiration is lost as heat. Muscle action is an important source of body heat.
The minimal stimulus required to elicit a muscular contraction
A contractile mechanism of smooth muscle is similar to that of skeletal muscle. Contains filaments of actin and myosin, tyhpes include multiunit smooth muscle and visceral smooth muscle.
Visceral smooth muscle displays rhythmicity and is self exciting.
Smooth Muscle Contraction
Two neruotransmitters, acetylcholine and norepinephrine and hormones affect smooth muscle function.
Smooth muscle can maintain a contraction longer with a given amount of energy than an skeletal muscle. Smooth muscles can change length without changing tension.
Cardiac Muscles (Holes 201)
Like skeletal muscle cells, cardiac muscle cells have actin and myosin filaments that are well orangized and striated.
Cardiac muscle twitches last longer than skeletal muscle twitches.
Intercalated discs connect cardiac muscle cells.
A network of fibers contacts as a unit
Cardiac muscle is self exciting and rhythmic.
Skeletal Muscle Actions
Skeletal muscles generate a great variety of body movements.
The action of each muscle mostly depends upon the kind of joint it is associated with and the way the muscle is attached on either side of that joint.
Origin and Insertion
The relatively immovable end of a skeletal muscle is its origin, and the relative moveable end is the insertion. Some muscles have more than one origin
Interaction of Skeletal Muscles
Skeletal muscles function in groups. An agonist causes a movement.
Antagonist are muscles that oppose a movement.
Muscles that work together to assist a moevement are synergists.
An agonist doing most of the work to cause a movement is a prime mover.
Smooth movements result from agonists and antagonists working together.
Sets with similar terms
Biology: Muscoskeletal System
Skeleton, Muscle, Skin
Chapters 5 & 6
Anatomy Unit 3
Other sets by this creator
Bronchitis and Pneumonia
Other Quizlet sets
gly1102 topic 21-37
FS 301 Final Review
Computer midterm study guide
Econ Chapter 4 Flashcard Review Liz