Lab 2 Flashcards
Define joint
A point where two bones meet, Does not imply mobility. also be called Articulations
joint stability
Increase in stability means decrease in mobility
Joint Mobility
Increase in Mobility means decrease in stability
Structural (anatomy)
Surfaces of the bones of the joint.
Based upon whether the bones are directly connected via connective tissue or if there is a joint cavity.
Fibrous Joints (structural Classification)
Bones are connected by fibrous connective tissue
Cartilaginous Joints (structural Classification)
Bones are connected by cartilage (hyaline or fibrocartilage)
Synovial Joints (structural Classification)
Articulation surfaces not directly connected but come into contact with one another in a joint cavity.
Define functional classifications of joints
Based upon amount of mobility between adjacent bones
synarthroses
Immobile or nearly immobile.
Very Strong - High stability, little or no mobility.
examples of synarthroses
Edges of bones may touch or interlock
May be fibrous or cartilaginous
Sutures in the skull
amphiarthroses
more movable than synarthrosis
Strong than a diarthrosis
may be fibrous or cartilaginous
Syndesmosis (Amphiarthroses Type)
bones connected by a ligament
Symphysis (Amphiarthroses Type)
bones connected by fibrocartilage
examples of amphiarthroses
intervertebral discs
uniaxial joint
Motion in a single plane
elbow - extension
biaxial joint
Motion within two planes
knuckle joint - move knuckles side to side. bend fingers apart or flex them
triaxial (multiaxial) joint
Motion within three planes
ball and docket joints - Shoulder and hip joint
sutures (skull)
between the bones of the skull
The temporomandibular joint is a synovial joint
fontanelles
found in newborn and infants
bones are further apart
Discuss the purpose of fontanelles
They provide flexibility during birth and for a rapid growth of the skull and brain
synostosis
location where bone is fused to bone and no more connective tissue is present.
synostosis example
synostosis is a metopic suture of the frontal bone
syndesmosis
syndesmosis is when two parallel bones are joined by fibrous connective tissue
syndesmosis example
Interosseous membrane - Broad sheet of connective tissue
gomphosis
Joint that is not between two bones. Anchors root of tooth into its boney socket of the mandible.
Periodontal ligaments
fibers that go in between tooth root and socket
synchondrosis
is when bones are joined by hyaline cartilage
synchondrosis temporary and permanent example
Epiphyseal plate is a joint that is temporary. It turns into epiphyseal line
First sternocostal joint (first rib and the manubrium) is a permanent synchondrosis
symphysis
is when bones are joined by fibrocartilage
symphysis Example
Pubic symphysis (where right and left hip bones come together)
Intervertebral discs
Describe the structure of a synovial joint
diarthroses - freely mobile joints
Surrounded by joint capsule
synovial membrane produces synovial fluid
Articular cartilage
a hyaline cartilage that covers the articulating surfaces of the bones. prevents bone on bone contact
Discuss the functions of synovial fluid
Thick, Slimy Fluid produced by the synovial membrane
Lubricates joint to reduce friction
Nourishes articular cartilage
Removes waste from articular cartilage
Extrinsic Ligaments
outside the joint capsule
Intrinsic Ligaments
fused to or incorporated in the joint capsule
intracapsular ligaments
found within the joint capsule
tendons
muscle is bound to the bone
Articular Discs
Fibrocartilage pads between articulating bones
Typically small and ovoid
Menisci
Fibrocartilage pads between articulating bones
Typically larger and C-Shaped
Describe function of articular discs and menisci
Both unite bones of the joint, provide shock absorption, and smooth movements between articulating bones
Bursae
Thin connective tissue sac filled with synovial fluid
Prevents friction between bones and overlying tendons or skin
Subcutaneous bursa
between skin and underlying bone - Patella bursa
Submuscular Bursa
between a muscle and underlying bone - trochanteric Bursa
Subtendinous Bursa
between tendon and underlying bone - Suprapatellar bursa
Tendon Sheath
not a bursa but similar concept - kind of like a bursa but smaller. surrounds a muscle tendon where the tendon crosses a joint. carpal tunnel
Pivot Joint
rounded portion of a bone enclosed within a ring
Uniaxial - rotation is around a single axis
Pivot Joint Examples
Atlantoaxial joint - between c1 and c2 allows you to shake your head.
Proximal Radioulnar joint - allows for supination and pronation
Hinge Joint
convex end of one bone articulate with concave end of adjoining bone.
Uniaxial - rotation is around a single axis
Hinge Joint Example
knee, ankle, elbow, interphalangeal joints
Condyloid joint
Shallow depression at the end of one bone articulates with a rounded structure from the articulating bone
Biaxial - Motion within two planes
Condyloid joint example
metacarpophalangeal (knuckle) joints
radiocarpal joint - between radius and carpal bones
Saddle Joint
Both articulating surfaces have a saddle shape (concave in one direction and convex in the other
Biaxial
Saddle Joint Example
First carpometacarpal (trapeziometacarpal) Joint - thumb opposable and reposition.
Sternoclavicular joint
Plane Joint
articulating surfaces are flat or slightly curves and similar size
Plane Joint Example
Intercarpal joints
intertarsal joints
ball-and-socket joint
rounded head of one bone fits into concave articulation of other bone
ball-and-socket joint Examlpe
Hip - shoulder
Shoulder least stable joint in the body
Flexion and Extension
Movements in the anterior-posterior plane (sagittal plane)
Flexion
decreases angle between articulating bones
Extension
increases angle between articulating bones
Hyperextension
extension past anatomical position
Putting your hand out to say stop, hyperextension of the wrist.
Abduction and Adduction
Movements in the frontal plane - medial lateral movements.
Abduction
Movement away from longitudinal axis (mid line)
Adduction
Movement towards longitudinal axis (mid line)
Circumduction
A complete circular movement without rotation
when you draw a large circle in front of you your shoulder
Rotational Movement
Rotation in reference to anatomical position
left or right rotation of the head
Limb rotation is relative to longitudinal axis of body
Medial Rotation (internal rotation toward long axis)
Lateral Rotation (external rotation away from body)
Pronation
Rotates forearm so that radius rolls across ulna
Results in palm facing posteriorly
Supination
Turns palm anteriorly
Forearm is supinated in anatomical position
Inversion
Twists sole of foot medially
Eversion
Twists sole of foot laterally
Dorsiflexion
Flexion at ankle (lifting toes)
Plantar Flexion
Extension at ankle (pointing toes)
Protraction
Anterior movement in horizontal plane (forward scapula or mandible)
Retraction
opposition of protraction (pulling back scapula or mandible)
Depression
Moving a structure inferiorly (down scapula or mandible)
Elevation
Moving a structure superior (up scapula or mandible)
Lateral Excursion
Movement of mandible away from midline
Medial excursion
Movement of mandible back to resting position on midline
Opposition
Movement of thumb toward palm or other fingers
Reposition
Opposite of Opposition
General function and common properties of all muscle types
Cells are specialized for contraction
Common properties include: Excitability, Contractility, Extensibility, Elasticity
functions of skeletal muscles
Move the body by pulling on bones
Maintaining posture and body position
Supporting Soft tissues
Guarding Body entrances and exits
Maintaining body temperature
True of False Skeletal Muscle is non-striated and involuntary.
False: Skeletal muscle is Striated and Voluntary
True or False Cardiac Muscle is Striated and Involuntary
True: Cardiac muscle is striated and involuntary
True or False Smooth Muscle is Striated and voluntary
False: Smooth Muscle is non-striated and involuntary
Describe the Structure of Empimyisum
Epi = On top of My= Muscle
Epimysium is a layer of collagen fibers that surronds the muscle. Connected to deep fascia.
Describe the function of Epimysium
Separates the muscle from surrounding tissues.
Describe the structure of Perimysium
Peri = Around Suronds muscle fiber(myocyte) and Bundles (fascicles)
Describe the function of Perimysium
Contains collagen fibers, elastic fibers, blood vessels, and nerves
Describe the structure of Endomysium
Surrounds individual muscle cells (muscle fibers or myocytes)
Describe the function of Endomysium
Contains capillary networks, myosatellite cells that repair damage, and nerve fibers
Describe the structure of Tendons
Bundles of collagen fibers of the connective tissue and attaches skeletal muscles to bones
Describe the structure of Aponeuroses
Sheets of collagen fibers of the connective tissue come together in sheets to attach skeletal muscles to bones
Myofiber Structure
Enormous compared to other cells, contains hundreds of nuclei, also known as striated muscles cells.
Myofiber Formation
Myofiber are developed by fusion of embryonic cells
Describe the properties of the sarcolemma
plasma membrane of a muscle fiber, surrounds the sarcoplasm, is integral to muscle contractions
Describe the function of Transverse Tubules
Transverse Tubules or T-Tubules extend from the surface of muscle fibers deep into sarcoplasm. Transmit action potentials from sarcolemma to cell interior.
Sarcoplasmic Reticulum
Sarcoplasmic Reticulum or SR is a tubular network surrounding each myofibril. Specialized to store and release calcium ions.
Myofibrils
Lengthwise subdivisions within a muscle fiber. Made of bundles of protein filaments
Myofilaments (thin)
The Two Types of thin myofilaments are Actin and troponin
Myofilaments (thick)
The two types of thick myofilaments Myosin
Sacromeres
Functional unit of skeletal muscles, interaction between filaments produce contractions
Thin filaments composition
Filamentous Actin, Tropomyosin, and Troponin
Filamentous Actin
Twisted strand composed of two rows of globular G-actin molecules
Tropomyosin
Covers the active sites on actin
Troponin
Calcium sensor bound to tropomyosin and g actin
Thick Filaments
Made up of myosin molecules
Myosin Molecules Structure and Their Functions
Tail - binds to other myosin molecules. Head - projects toward nearest thin filament in the presence of ATP.
Neuromuscular Junction
Synapse between the motor neuron terminal and muscle fiber.
Excitation
Is when a microfiber is stimulated by the action potential from a motor neuron.
What happens after the microfiber is stimulated?
Calcium enters and activates the exocytosis of neurotransmitters.
Excitation-Contraction coupling
Action potential arrives from t tubules, calcium binds to troponin and changes its shape, toponin complex changes position contraction is intitated
Contraction Cycle
The contraction cycle begins when calcium causes the troponin to change position. This exposes the Actin’s active sites. Myson binds to the now exposed acting causing a cross-bridge formation. Myosin head pivots (power stroke) which causes the actin to slide. Cross bridge is detached.
Relaxtion occures when
Motor neuron stops releasing Acetylcholine, runs out of ATP or Calcium
What happens when relaxation occurs.
ACh degraded by acetylcholinesterase in synaptic cleft. Muscle fiber repolarizes, no more calcium release from Sarcoplasmic reticulum. SR refills with calcium. Troponin returns to its original shape. Tropomyosin covers actin
Glycolysis
Glucose from blood and muscle produces ATP.
Aerobic Respiration
After glycolysis occurs if there is enough oxygen present at the site aerobic respiration will begin. Aerobic respiration converts the byproducts of glycolysis into ATP Carbon Dioxide and water.
Muscle Strenght
related to number of myofibrils and sacromeres within each fiber
Hypertrophy
when myofibers get larger
Muscle Tension
the force generated by contraction
Isotonic Contractions
Muscle changes length to move a load
Isotonic Concentric Contraction
Muscle shortens - Lifting a weight up increasing tenstion
Isotonic Eccentric Contraction
Muscle Lengthens - Moving the weight down extends the muscle releasing tension
Isometric Contractions
Muscle produces tension does not move a load Plank exercise
Motor unit
A motor neuron an all of the muscle fiber it controls
Length-Tension Relationship
Tension is produced by a muscle fiber in relation to how far it is being made to extend the sarcomeres.
Hypotonia
Adsence or reduced amount of muscle tone
Hypertonia
Excessive muscle tone
Slow Oxidative
Slow to contract slow to fatigue. Contracts slowly and uses aerobic resperation for ATP production
Fast Glycolytic Fibers
Fast to Contract and fast to fatigue. Contracts quickly and uses glycolysis and fermentation for ATP production
Endurance Exercise
Cardio running a marathon. utilizies slow oxidative fibers. Does not Stimulate muscle hypertrophy,
Resistance Training
Fast glycolytic fibers, short powerful non-repetitive movements. Stimulate hypertrophy. lifting weights.
Describe overall characteristics of cardiac muscles
Found only in the heart, Excitable membranes, striated like skeletal muscles and involuntary.
Autorhythmicity
pacemaker cells that set your heart rate and can do this regardless of nervous system input
Intercalated Discs
Junctions between cardiac myocytes. Gap junctions which allow for direct ion movement between adjacent cells. keeps heart beating rhythmically.
Describe the structural characteristics of smooth muscle
Long, Slender, Spindle-shaped cells with a single central nucleus.
