Muscular and Skeletal Systems Flashcards
(44 cards)
The musculoskeletal system forms the basic __ __ of the vertebrate body. Muscles and bones work in close coordination to produce ___ __. In addition, they perform a number of other ____ functions. Physical support and ___ are the function are the functions of the animal skeletal system, while the muscular system generates ____
internal framework, voluntary movement, independent, locomotion, force
An ____ serves as a framework in all vertebrate organisms. Muscles are attached to the bones, permitting _____. The endoskeleton also provides ___ by surrounding delicate ___ __ with bone. The ___ ___ protects the thoratic organs like the ___ and lungs. The ___ and the ___ __ protect the brain and spinal cord. The two major components of the skeleton are ___ and ____
endoskeleton, movement, protection, internal organs, rib cage, heart, skull, vertebrate column, cartilage, bone
Cartilage is a type of connective tissue that is ___ and more ___ than bone. Cartilage is retained in adults where ____ and ____ are needed. In humans, the ___ ___, nose, walls of the ____ and ____, and ___ ___ contain cartilage.
softer, flexible, firmness, flexibility, external ear, larynx, trachea, skeletal joints
Cells responsible for synthesizing cartilage
chrondrocytes
Bone is a specialized type of ______ connective tissue that has the ability to withstand ___ ____. Ideally adapted for ___ ___, bone tissue is hard and ___, while at the same time somewhat ___ and lightweight. There are two basic types of bone, ____ bone and ____ bone
mineralized, physical stress, physical support, strong, elastic, compact, spongy
Compact bone is a ___ bone that does not appear to have any ____ when observed with the naked eye. The bone matrix is deposited in structural units called _____ (____ systems). Each one consists of a central microscopic channel called a ___ ___, surrounded by a number of concentric circles of bony matrix (____ ___) called ____.
dense, cavities, osteons, haversian systems, haversian canal, calcium phosphate, lamellae
Spongy bone is much less dense and consists of an ____ ___ of bony ____ (_____). The cavities between them are filled with ___ or ___ bone marrow. The former is ____ and infiltrated by __ ___, which the latter is involved in ___ __ formation
interconnecting lattice, spicules, trabeculae, yellow, red, inactive, adipose tissue, blood cell
Two types of cells found in bone tissue are ___ and ____.
Osteoblasts, osteoclasts
Osteoblasts synthesize and secrete the _____ constituents of the ___ ___. Once they have become surrounded by their matrix, they mature into _____
organic, bone matrix, osteocytes
Osteoclasts are large, ______ cells involved in bone _____, wherein bone is ___ ___ and_____ are released into the blood
multinucleated, reasborption, broken down, minerals
Bone formation occurs by either ___ ___ or by ___ _____. In the former, existing ___ is replaced by bone. This is how __ ___ primarily arise. In the latter, _____ (embryonic or undifferentiated) connective tissue is transformed into and replaced by bone
endochondral ossification, intramembranous ossification, cartilage, longbones, mesenchymal
The ____ skeleton is the basic framework of the body, consisting of the ____, __ __ and the __ ___. It is the point of attachment of the ______ _____, which includes the bones of the ___ and the pectoral and ___ girdles
axial, skull, vertebrate column, rib cage, appendicular skeleton, appendages, pelvic
___ or ____ joints, hold the bones of the skull together. Bones that move relative to one another are held together by movable ___ and are additionally supported and strengthened by ____. These serve as _____ connectors. ___ attach skeletal ___ to bones and bend the skeleton at movable joints
sutures, immovable, joints, ligaments, bone-to-bone, tendons, muscle
The point of attachment of a muscle to a stationary bone (_____ end in ___ muscles) is called the ____. The point of attachment of a muscle to a bone that moves (___ end in limb muscles) is called the ____.
proximal, limb, origin, distal, insertion
___ indicates the straightening of a joint, whereas ____ refers to a bending of a joint
extension, flexion
Muscle tissue consists of bundles of specialized ____ ___ held together by connective tissue. There are three morphologically and functionally distinct types of muscle in mammals: _____ muscle, ___ muscle, and ___ muscle
contractile fibers, skeletal, smooth, contractile
Nervous control of the muscular system involves the axons of the ___ __ of the __ ___ which descend from the brain to synapse on lower motor neurons in the ___ __ and __ ___. Because there are no intervening synapses, the __ ___ is able to provide rapid commands to the skeletal muscles and various other organs. Several other centers can issue somatic motor commands as a result of processing performed at the ___, ___ level. These centers and their associated tracts comprise the _____ _____. The ___ __ located in the mesencephalon, is the component of the extrapyramidal system primarily in control of skeletal __ ____
pyramidal cells, motor cortex, brain stem, spinal cord, pyramidal system, unconscious, involuntary, extrapyramidal system, red nucleus, muscle tone
Skeletal muscle is responsible for voluntary movements and is innervated by the __ _____ ___. Each fibre is a ___ cell created by the fusion of several ___ ___ cells. Embedded in the fibres are filaments called ____, which are further divided into contractile units called ____.
somatic nervous system, multinucleated, mononucleated embryonic, myofibrils, sacromeres
The myofibrils are enveloped by a modified endoplasmic reticulum that stores ___ ___ and is called the ___ ____. The cytoplasm of the muscle fiber is called the _______, and the cell membrane is called the _____.
calcium ions, sarcoplasmic reticulum, sarcoplasm, sarcolemma
The sacrolemma is capable of propagating an __ __ and is connected to a system of __ ____ (T system) oriented ______ to the myofibrils. The T system provides ____ for ___ __ throughout the muscle fibers and can also propagate an AP.
action potential, transverse tubules, perpendicularly, channel ion flow,
Because of the high-energy requirements of ____, ___ are very abundant in muscle cells and are distributed along the ____.
contraction, mitochondria, myofibrils
Skeletal muscle has striations of __ and ___ bands and is therefore also referred to as ___ ___
light, dark, striated muscle
The sarcomere is composed of ___ and ___ filaments. The former are chains of ____ molecules. The latter are composed of organized bundles of ___ molecules
thin, thick, actin, myosin
Electron microscopy reveals that the sarcomere is organized as follows: ____ ___ define the boundaries of a single sarcomere, and anchor the ___ ___. The ___ __ runs down the center of the sarcomere, The ___ __ is the region containing thin filaments only. The ___ ___ is the region containing thick filaments only. The ___ ___ spans the entire length of the thick filaments and any overlapping portions of thin filaments. When the muscles contract, the __ ___ move toward each other. Note that during contraction, the ___ ___ is not reduced in size, whereas the ___ zone and __ band are.
z lines, thin filaments, m line, I band, H zone, A band, z lines, a band, h, i
