BIOL2140 Exam 3 Study Guide

articulations

aka joints; where two or more bones meet

hold bones together and allow for mobility

functions of joints

functional and structural

two classifications of joints

fibrous joints

bones united by dense fibrous connective tissue; all synarthrotic; no joint cavity

suture

joins cranial bones

syndesmoses

fibrous joint; slightly more movement than sutures but still largely immobile; ex: distal end of tibia and fibula

gomphosis

tooth held in socket by peridontal ligament; type of fibrous joint

cartilaginous joints

bones connected by cartilage; no joint cavity

synchondrosis

made of hyaline cartilage; immovable; ex: first rib and sternum and epiphyseal plate

symphysis

made of fibrocartilage; amphiarthrotic; ex: pubic symphysis, intervertebral joints

synovial joints

articulating bones separated by a joint cavity containing fluid; include all limb joints and most joints of the body; diarthrotic

articular cartilage, synovial cavity, articular capsule, synovial fluid, reinforcing ligaments, nerves and blood vessels

six distinguishing features of synovial joints

plasma and hyaluronic acid

what is synovial fluid made of?

lubricates and nourishes articular cartilage

function of synovial fluid

capsular ligament

thickened part of outer fibrous layer of joint capsule

extracapsular ligament

ligament outside joint capsule

intracapsular ligament

ligament deep to joint capsule and covered by synovial membrane

articular capsule

distinguishing feature of synovial joints; made of two layers: external fibrous layer made of dense irregular connective tissue and an inner synovial membrane made of loose connective tissue that secretes synovial fluid

articular cartilage

prevents crushing of bone ends in joints

fatty pads, bursae, articular discs, tendon sheaths

four other features of some synovial joints

bursae

sacs lined with synovial membrane that contain synovial fluid; reduce friction where ligaments, muscles, skin, tendons, or bones rub together

tendon sheaths

elongated bursa wrapped completely around tendon subjected to friction

shapes of articular surfaces, ligament number and location, muscle tendons that cross joint

three stabilizing factors for synovial joints

knee joint

largest, most complex joint of body; actually 3 joints surrounded by a single joint cavity

femoropatellar joint

plane joint that allows gliding motion during knee flexion

lateral and medial tibiofemoral joints

femoral condyles with lateral and medial menisci of tibia that allow flexion, extension, and some rotation when knee is partly flexed

medial and lateral patellar retinacula, patellar ligament

anteriorly, the quadriceps tendon gives rise to what three broad ligaments?

fibular and tibial collateral ligaments, oblique popliteal ligament, arcuate popliteal ligament

extracapsular ligaments of the knee; help prevent hyperextension

anterior cruciate ligament, posterior cruciate ligament

intracapsular ligaments of knee that prevent anterior-posterior displacement

collateral ligaments, cruciate ligaments, cartilages

What are the “Three C’s” of extended knee injuries?

coracohumeral ligament

reinforcing ligament that helps helps support weight of upper limb in the shoulder

glenohumeral ligaments

reinforcing ligaments of the shoulder that are weak and sometimes absent

subscapularis, supraspinatus, infraspinatus, teres minor

four rotator cuff tendons encircling the shoulder joint

elbow joint

articulation of radius and ulna with humerus; hinge joint

anular ligament

ligament surrounding head of the radius; hinge type

ulnar and radial collateral ligaments

two capsular ligaments restricting side-to-side movement in the forearm

hip (coxal) joint

ball and socket type joint; head of the femur articulates with the acetabulum; good range of motion but limited by the deep socket

acetabular labrum

fibrocartilage rim in the coxal joint that enhances the depth of the socket to prevent dislocation

iliofemoral ligament, pubofemoral ligament, ischiofemoral ligament, ligamentum teres

reinforcing ligaments of the hip joint

temporomandibular joint

mandibular condyle articulates with temporal bone; allows for hinge and gliding; most easily dislocated joint in the body

origin

attachment to immovable bone

insertion

attachement to movable bone

nonaxial

slipping movements only

uniaxial

movement in one plane

biaxial 

movement in two planes

multiaxial

movement in or around all three planes

gliding

one flat bone surface glides or slips over another

cartilage tears, sprains, dislocations

common types of joint injuries

bursitis, tendonitis, lyme disease

inflammatory injuries to joints

bursitis

inflammation of a bursa, caused by a blow to joint or friction; treated with anti-inflammatories

tendonitis

inflammation of the tendon sheath usually from over-use; treat with anti-inflammatories

lyme disease

caused by bacteria transmitted by tick bite; can cause joint pain and arthritis; treat with long term antibiotics

osteoarthritis, rheumatoid arthritis, gouty arthritis

three types of arthritis

osteoarthritis

most common chronic arthritis; related to wear and tear from aging

rheumatoid arthritis

autoimmune type of arthritis that can lead to deformities; symptoms begin with bilateral inflammation 

gouty arthritis

inflammation of joints caused by deposition of uric acid crystals from blood; more common in men; can usually be controlled by diet

movement, posture, stabilizing joints, heat generation

four important functions of muscle tissue

excitability, contractility, extensibility, elasticity

special characteristics of muscle tissue

excitability

ability to receive and respond to stimuli

contractility

ability to shorten forcibly when stimulated

extensibility

ability to be stretched 

elasticity

ability to recoil to resting length

endomysium

areolar connective tissue enclosing a single muscle fiber

perimysium

fibrous connective tissue wrapping around a fascicle of muscle fibers

epimysium

dense irregular connective tissue covering the entire skeletal muscle

tendons

cordlike structures made of collagen fibers; connect muscle directly to bone

aponeuroses

sheetlike structures that attach muscles indirectly to bones, cartilages, or connective tissue coverings

skeletal muscle

muscle tissue containing all three types of connective tissue coverings

cardiac and smooth muscle

muscle tissue type containing only endomysium connective tissue covering

sarcolemma

specialized plasma membrane of a muscle fiber

myofibrils

long organelles inside muscle fibers; contain thin and thick microfilaments which organize to create characteristic striation

I band

light band; contains only thin filaments (actin); Z disc is a midline interruption where thin filaments are anchored

A band

dark band; contains entire length of thick filaments; H zone is a lighter central area that lacks thin filaments at rest; M line is in center of H zone

sarcomere

contractile unit of a muscle fiber; extends from the middle of one Z disc to another

cross bridges

when myosin heads link thin and thick filaments during contraction

sarcoplasmic reticulum

specialized smooth endoplasmic reticulum; joins with the sarcolemma, stores and releases calcium, and surrounds the myofibril

action potential

stimulus that prompts a contraction in a muscle fiber

motor unit

one motor neuron and all the skeletal muscles stimulated by that neuron

neuromuscular junction

association site of axon terminal of the motor neuron and sarcolemma of a muscle fiber

neurotransmitter

chemical released by nerve upon arrival of a nerve impulse in the axon terminal

acetylcholene

neurotransmitter that stimulates skeletal muscle to contract

synaptic cleft

gap between nerve and muscle; nerve and muscle do not make contact; filled with interstitial fluid

rigor mortis

in the absence of ATP after death, myosin heads will not detach

graded response

different degrees of skeletal muscle shortening

number of fibers, size, stimulation, stretch

muscle force depends on

tetanus (normal)

rapid continued muscle stimuli resulting in complete smooth sustained contraction

tetanus (lockjaw)

uncontrolled muscle spasms caused by a toxin produced by a bacteria

isotonic contractions

type of muscle contraction in which tension in muscle increases, muscle shortens, and movement occurs; ex: bending knee

isometric contractions

tension in the muscle increases, but muscle is unable to shorten or produce movement; ex: pushing against a wall with bent elbows

muscle tone

________ keeps muscles healthy and ready to react; result of a staggered series of nerve impulses delivered to different cells within the muscle

direct phosphorylation, aerobic respiration, anaerobic glycolysis and lactic acid formation

three ways to generate ATP

longitudinal layer and circular layer

two layers of smooth muscle tissue

longitudinal layer of smooth muscle

fibers parallel to long axis of organ; during contraction, it dilates and shortens

circular layer of smooth muscle

fibers in circumference of organ; during contraction, constricts lumen and elongates organ

peristalsis

alternating contractions and relaxations of smooth muscle layers that mix and squeeze substances through lumen of hollow organs

calveolae

pouchlike infoldings of smooth muscle sarcolemma that sequester calcium ions

autonomic nerve fibers

Smooth muscle is innervated by

varicosities

bulbous swellings of nerve fibers that store and release neurotransmitters into diffuse junctions

calmodulin

protein in smooth muscle that binds calcium

dense bodies

proteins that anchor noncontractile intermediate filaments to sarcolemma and contractile myofilaments at regular intervals; correspond to Z discs of skeletal muscle