BasicPhysiology Flashcards
Muscle Tissue
Made up of contractile fibers that are under neural control
3 types of muscle
SmoothCardiacStriated
Smooth
Usually formed in sheets surrounding hollow viscera- digestive tract- respiratory tract- blood vessels, uterine walls etc.INVOLUNTARY as it is innervated by the autonomic nervous systemCan be partially contracted for long periods of timeCells interlocked and regional contraction occurs instead of single fiber contractions
Cardiac
Only found in walls of the heart and base of the great vessels adjacent to itINVOLUNTARYCells are branched
Striated
AKA skeletal or VOLUNTARY muscleusually attached to the skeleton and can move parts of it43% of adult body weight is composed of skeletal musclesEach fiber is made up of longitudinally arranged MYOFIBRILSFibers are not branched, but packaged in parallel bundles
Skin is made up of 2 layers
Epidermis and Dermis
Epidermis
Squamous and stratified in organizationTissue is not vascularized
Functions of the skeletal system
1) Support - provide rigid framework for body2) Mechanical basis of movement- providing attachments for muscles, levers for them to act on3) Protection - rigid walls or cages that house vital organs4) Source of blood cells: RBCs, lymphoctes, WBCs, platelets5) Storage of salts - mineral resevoir for calcium, phosphorus, and magnesium
Types of Bones
Compact (Cortical)CancellousBone Marrow
Compact (cortical) bone
Dense outer shell around cancellous boneHarder stronger stiffer than cancellous boneSupports weight of the body, made up of calcium and mineralsPrimary anatomical and functional unit is called an osteon
Cancellous (trabecular/spongy) bone
Consists of slender, irregular bars (trabeculae) of compact bone forming a matrixHighly vascularInterconnecting spaces are filled with bone marrow, production of blood cells occursPrimary functional unit of cancellous bone is trabecula
Bone Marrow
Red bone marrow is active blood formationYellow bone marrow which is mainly inert and fatty
Classification by Shape (5)
1) Long2) Short3) Flat4) Irregular5) Sesamoid
Long Bones
Designed for leverage and weight bearingGreater in length than width, can be curvedTubular, consisting of a shaft (diaphysis) and two ends (epiphysis)Ends form articulations and are covered with hyaline cartilageExample: Femur
Short bones
Cuboidal in shapeOnly found in wrist and handSix surfaces : four or less for articulation, rest for attachment of tendons and ligaments or entry of blood vesselsExample: Carpals
Flat Bones
Designed for protection and muscle attachmentConsists of two plates of cortical bone with spongy bone and marrow betweenExamples: vertebrae, some of the facial bones
Irregular Bones
Complex design and shapeHave some or all of characteristics of long, short, flat bonesExamples: Vertebrae
Sesamoid Bones
Round or oval nodules of bone that develop in tendons that pass over certain articulationsArticular side is covered in cartilage, other side is buried in the tendonfunction is to protect tendon from wear and improve mechanical advantage of tendon acting on a jointExamples: Patella, Pisiform, and Sesamoids of 1st ray in LE
Classification of Bone by Region
AxialAppendicular
Axial Skeleton
Includes the skull vertebrae, ribs, and sternum
Appendicular
Bones associated with and including the upper and lower limbs
Classification of Joints
FibrousCartilaginousSynovial
Fibrous Joint
Little or no movementNo joint cavityArticulating bones are bound tightly with fibrous connective tissueExamples: Suture joint between cranial bones, tibiofibular jointException: interosseus membrane uniting the radius and ulna, which allows pronation/supination
Cartilaginous Joint
Little or no movementNo joint cavityArticulating bones bound tightly with cartilageExample: Sacro-coccygeal
2 types of Cartilaginous Joint
Hyaline Ex. 1st sternocostal joint, epiphyseal plates in growing bonesFibrocartilagenousEx. Intervertebral discs and symphysis pubis
Synovial Joints
Most common and important functional typeProvide large ranges of motion, and greater degrees of freedom than other jointsDistinguished by- presence of joint cavity- lubricated articular cartilage- joint capsule of fibrous tissue- synovial membrane lines joint capsule- bones of articulation are held together by accessory ligaments, which are usually thickenings of the fibrous capsule (intra or extra capsular)
Synovial fluid
Secreted by cells of the synovial membraneActs as a viscous lubricant, aiding cartilage in providing near frictionless motionAlso provides nourishment to the articular cartilage within the joint capsule
Importance of Accessory Ligaments and Joint Capsule
Important in maintaining a normal relationship between the two bonesLimits ranges of motion and the planes in which motion can occur
Articular Cartilage
Usually hyaline in typeCollagenous matrix of fibersNo nerve supplyAvascularReceives nourishment from synovial fluid
Sub Classifications of Synovial Joints
UniaxialBi-axialTri-axial
Uni-axial
Uniaxial- permits motion in one plane about one axisHinge- One surface is concave, the other is convex- Examples: Elbow, Ankle, Interphalangeal jointsPivot- Rounded process of bone rotates about its longitudinal axis within a sleeve or ring composed of a bony fossa- Examples: proximal Radioulnar joint and Atlanto axial joint
Bi-axial
Permits motion in 2 planes about 2 axes that are at right angles to each otherCondyloid- CIRCULAR rounded process of bone that can flex/extend and ab/adduct or circumduct within socket of adjacent boneEx. MCP jointsEllipsoid- OVAL rounded process of bone that can flex/extend and ab/adduct or circumduct within socket of the adjacent boneEx. Radiocarpal (wrist) joint
Tri-axial
Permits motion in all three planes about all three axes that are at right angles to each otherPlane- bony surfaces are more or less flat- allows limited gliding and rotational motion about the longitudinal axis- Ex. Acromioclavicular joint, carpal and tarsal joints of the hands and feet respectivelySaddle- bony surfaces are reciprocally shaped like a saddle- contains a concave and convex portion- Ex. Carpometacarpal joint of the thumbBall and Socket- Spherical surface of one bone moves within a socket of the other- Highly movable allowing flex/extension, ab/adduction, in/external rotation, and circumduction- Ex: Shoulder and Hip
Nerve
Nerve fibers (axons) are arranged in bundles (fasicles)CNS is composed of the brain and spinal cordPNS is everything outside of the CNS (cranial and spinal nerves)
Dermis
dense collagenous tissue that is firmly adhered to deep side of the epidermis
