Basic Physiology Flashcards
Muscle Tissue
Made up of contractile fibers that are under neural control
3 types of muscle
Smooth
Cardiac
Striated
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 system
Can be partially contracted for long periods of time
Cells 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 it
INVOLUNTARY
Cells are branched
Striated
AKA skeletal or VOLUNTARY muscle
usually attached to the skeleton and can move parts of it
43% of adult body weight is composed of skeletal muscles
Each fiber is made up of longitudinally arranged MYOFIBRILS
Fibers are not branched, but packaged in parallel bundles
Skin is made up of 2 layers
Epidermis and Dermis
Epidermis
Squamous and stratified in organization
Tissue is not vascularized
Functions of the skeletal system
1) Support - provide rigid framework for body
2) Mechanical basis of movement- providing attachments for muscles, levers for them to act on
3) Protection - rigid walls or cages that house vital organs
4) Source of blood cells: RBCs, lymphoctes, WBCs, platelets
5) Storage of salts - mineral resevoir for calcium, phosphorus, and magnesium
Types of Bones
Compact (Cortical)
Cancellous
Bone Marrow
Compact (cortical) bone
Dense outer shell around cancellous bone
Harder stronger stiffer than cancellous bone
Supports weight of the body, made up of calcium and minerals
Primary anatomical and functional unit is called an osteon
Cancellous (trabecular/spongy) bone
Consists of slender, irregular bars (trabeculae) of compact bone forming a matrix
Highly vascular
Interconnecting spaces are filled with bone marrow, production of blood cells occurs
Primary functional unit of cancellous bone is trabecula
Bone Marrow
Red bone marrow is active blood formation
Yellow bone marrow which is mainly inert and fatty
Classification by Shape (5)
1) Long
2) Short
3) Flat
4) Irregular
5) Sesamoid
Long Bones
Designed for leverage and weight bearing
Greater in length than width, can be curved
Tubular, consisting of a shaft (diaphysis) and two ends (epiphysis)
Ends form articulations and are covered with hyaline cartilage
Example: Femur
Short bones
Cuboidal in shape
Only found in wrist and hand
Six surfaces : four or less for articulation, rest for attachment of tendons and ligaments or entry of blood vessels
Example: Carpals
Flat Bones
Designed for protection and muscle attachment
Consists of two plates of cortical bone with spongy bone and marrow between
Examples: vertebrae, some of the facial bones
Irregular Bones
Complex design and shape
Have some or all of characteristics of long, short, flat bones
Examples: Vertebrae
Sesamoid Bones
Round or oval nodules of bone that develop in tendons that pass over certain articulations
Articular side is covered in cartilage, other side is buried in the tendon
function is to protect tendon from wear and improve mechanical advantage of tendon acting on a joint
Examples: Patella, Pisiform, and Sesamoids of 1st ray in LE
Classification of Bone by Region
Axial
Appendicular
Axial Skeleton
Includes the skull vertebrae, ribs, and sternum
Appendicular
Bones associated with and including the upper and lower limbs
Classification of Joints
Fibrous
Cartilaginous
Synovial
Fibrous Joint
Little or no movement
No joint cavity
Articulating bones are bound tightly with fibrous connective tissue
Examples: Suture joint between cranial bones, tibiofibular joint
Exception: interosseus membrane uniting the radius and ulna, which allows pronation/supination
Cartilaginous Joint
Little or no movement
No joint cavity
Articulating bones bound tightly with cartilage
Example: Sacro-coccygeal
2 types of Cartilaginous Joint
Hyaline
Ex. 1st sternocostal joint, epiphyseal plates in growing bones
Fibrocartilagenous
Ex. Intervertebral discs and symphysis pubis
Synovial Joints
Most common and important functional type
Provide large ranges of motion, and greater degrees of freedom than other joints
Distinguished 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 membrane
Acts as a viscous lubricant, aiding cartilage in providing near frictionless motion
Also 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 bones
Limits ranges of motion and the planes in which motion can occur
Articular Cartilage
Usually hyaline in type
Collagenous matrix of fibers
No nerve supply
Avascular
Receives nourishment from synovial fluid
Sub Classifications of Synovial Joints
Uniaxial
Bi-axial
Tri-axial
Uni-axial
Uniaxial- permits motion in one plane about one axis
Hinge
- One surface is concave, the other is convex
- Examples: Elbow, Ankle, Interphalangeal joints
Pivot
- 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 other
Condyloid
- CIRCULAR rounded process of bone that can flex/extend and ab/adduct or circumduct within socket of adjacent bone
Ex. MCP joints
Ellipsoid
- OVAL rounded process of bone that can flex/extend and ab/adduct or circumduct within socket of the adjacent bone
Ex. Radiocarpal (wrist) joint
Tri-axial
Permits motion in all three planes about all three axes that are at right angles to each other
Plane
- 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 respectively
Saddle
- bony surfaces are reciprocally shaped like a saddle
- contains a concave and convex portion
- Ex. Carpometacarpal joint of the thumb
Ball 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 cord
PNS is everything outside of the CNS (cranial and spinal nerves)
Dermis
dense collagenous tissue that is firmly adhered to deep side of the epidermis
