Anatomy Exam 3 Flashcards
- Where two bones meet
- Where body movement occurs
Joints
What are the 4 structural classifications?
- Fibrous
- Cartilaginous
- Bony
- Synovial
Immovable Joint; strong; edges may touch or interlock
Synarthrosis
Slightly moveable joint
Amphiarthrosis
Freely moveable joint
Diarthrosis
What are the 4 types of Synarthrosis joints?
- Suture
- Gomphosis
- Synchondrosis
- Synostosis
- Found only between bones of skull
- Edges of bones interlock
- Bound by dense fibrous connective tissue
Suture
- Binds teeth to bony sockets
- Fibrous connection (periodontal ligament)
Gomphosis
- Rigid cartilaginous bridge between two bones
- Found between vertebrosternal ribs and sternum
- Also, epiphyseal cartilage of growing long bones
Synchondrosis
- Created when two bones fuse
- Example: metopic suture of frontal bone
- And epiphyseal lines of mature long bones
Synostosis
What are the 2 types of Amphiarthrosis joints?
Syndesmosis and Symphysis
Bones connected by a ligament
Syndesmosis
Bones connected by fibrocartilage
Symphysis
- Freely movable joints
- At ends of long bones
- Surrounded by joint capsule
Synovial joints
- Covers articulating surfaces
- Prevents direct contact between bones
Articular cartilage
- Has the consistency of egg yolk
- Primary functions include
- -Lubrication
- -Nutrient distribution
- -Shock absorption
Synovial fluid
What joint is stabilized by accessory structures
- Cartilages and fat pads
- Ligaments
- Tendons
Synovial
Fibrocartilage pad between opposing bones
Meniscus
- Adipose tissue covered by synovial membrane
- Protect articular cartilages
Fat Pads
Support and strengthen joints
Ligaments
Ligament with torn collagen fibers
Sprain
Attach to muscles around joint
Tendons
- Small pockets of synovial fluid
- Cushion areas where tendons or ligaments rub against other tissues
Bursae
How are movements described?
In terms that reflect the
- Plane or direction of movement
- Relationship between structures
Monaxial
1 Plane
Biaxial
2 Planes
Triaxial
3 Planes
-When two flat surfaces slide past each other
Example: between carpal bones
Gliding Movement
Movement away from longitudinal axis
Abduction
Movement toward longitudinal axis
Adduction
-Flattened or slightly curved surfaces
-Limited motion (nonaxial)
Ex- Manubrium and Clavical
Plane Joint (Gliding)
Angular motion in a single plane (monaxial)
Ex- Elbow, knee, and ankle joint
Hinge Joint
-Oval articular face within a depression
-Motion in two planes (biaxial)
Ex-
Condylar Joint (Ellipsoid)
-Articular faces fit together like a rider in a saddle
-Biaxial
Ex- Metacarpal bone of thumb and trapezium
Saddle Joint
-Rotation only
-Monaxial
Ex- Axis and Atlas vertebrae
Pivot Joint
-Round head in a cup-shaped depression
-Triaxial
Ex- Shoulder and hip joint
Ball and Socket Joint
Separates vertebral bodies
Intervertebral disc
- Tough outer layer of fibrocartilage
- Attaches disc to vertebrae
Anulus fibrosus
- Elastic, gelatinous core
- Absorbs shocks
Nucleus pulposus
-Cover superior and inferior surfaces of disc
Vertebral end plates of cartilage
Connect laminae of adjacent vertebrae
Ligamenta flava
- Bind vertebrae together
- Stabilize the vertebral column
Intervertebral ligaments
What are the 4 movements vertebrae are capable of?
- Flexion
- Extension
- Lateral flexion
- Rotation
- Largest, strongest joint at elbow
- Between trochlea of humerus and trochlear notch of ulna
- Limited movement
Humero-ulnar joint
- Smaller joint
- Articulation between capitulum of humerus and head of radius
Humeroradial joint
- Between head of humerus and glenoid cavity of scapula
- Greatest range of motion of any joint
- Most frequently dislocated joint
Shoulder Joint
Between head of femur and acetabulum of hip bone
Hip joint
Pain and stiffness in musculoskeletal system
Rheumatism
All rheumatic diseases that affect synovial joints
Arthritis (joint inflammation)
- Caused by wear and tear of joint surfaces, or genetic factors affecting collagen formation
- Generally affects people over age 60
Osteoarthritis
Crystals of uric acid form within synovial fluid
Gouty arthritis
Bone formation
Osteoblasts
Bone recycling
Osteoclasts
___ and ____ muscles control movements inside the body
Cardiac and Smooth
___ muscles moves the body by pulling on bones
Skeletal
What are the 4 common properties of muscle tissue?
- Excitability (responsiveness)
- Contractility (ability of cells to shorten)
- Extensibility (stretching)
- Elasticity (recoil)
Skeletal muscles have three layers of connective tissue which are…
- Epimysium
- Perimysium
- Endomysium
- Layer of collagen fibers that surrounds the muscle
- Connected to deep fascia
- Separates muscle from surrounding tissues
Epimysium
Surrounds muscle fiber bundles (fascicles) Contains -Collagen fibers -Elastic fibers -Blood vessels -Nerves
Perimysium
Surrounds individual muscle cells (muscle fibers)
Contains
-Capillary networks
-Myosatellite cells (stem cells) that repair damage
-Nerve fibers
Endomysium
Are skeletal muscles voluntary or involuntary?
Voluntary
True or False: Skeletal muscles are striated muscle
True
How are skeletal muscle fibers developed?
Fusion of embryonic cells
Plasma membrane of a muscle fiber
Sarcolemma
___ surrounds the sarcoplasm
Sarcolemma
- Tubes that extend from surface of muscle fiber deep into sarcoplasm
- Transmit action potentials from sarcolemma into cell interior
Transverse tubules (T tubules)
- A tubular network surrounding each myofibril
- Similar to smooth endoplasmic reticulum
- Forms chambers
Sarcoplasmic reticulum (SR)
Responsible for muscle contraction
Myofibrils
Composed primarily of actin
Thin filaments
Composed primarily of myosin
Thick filaments
Smallest functional units of a muscle fiber
Sarcomeres
Dark bands of sarcomeres
A bands
Light bands of sarcomeres
I bands
What does the A band consist of?
M line, H band, and Zone of overlap
- In center of A band
- Proteins stabilize positions of thick filaments
M Line
- On either side of M line
- Has thick filaments but no thin filaments
H Band
- Dark region
- Where thick and thin filaments overlap
Zone of Overlap
- Elastic protein
- Extends from tips of thick filaments to the Z line
- Keeps filaments in proper alignment
- Aids in restoring resting sarcomere length
Titin
Contain F-actin, nebulin, tropomyosin, and troponin proteins
Thin Filaments
- Twisted strand composed of two rows of globular G-actin molecules
- Active sites on G-actin bind to myosin
Filamentous actin (F-actin)
Holds F-actin strand together
Nebulin
Covers active sites on G-actin
Prevents actin–myosin interaction
Tropomyosin
A globular protein
Binds tropomyosin, G-actin, and Ca2+
Troponin
A graph showing tension development in muscle fibers
Myogram
- Action potential moves across sarcolemma
- SR releases Ca2+
Latent period
- Calcium ions bind to troponin and cross-bridges form
- Tension builds to a peak
Contraction phase
- Ca2+ levels in cytosol fall
- Cross-bridges detach and tension decreases
Relaxation phase
- Caused by repeated stimulations immediately after relaxation phase
- Produces a series of contractions with increasing tension
Treppe
- Increasing tension due to summation of twitches
- Caused by repeated stimulations before the end of relaxation phase
Wave summation
- Muscle produces near-maximum tension
- Caused by rapid cycles of contraction and relaxation
Incomplete Tetanus
- Higher stimulation frequency eliminates relaxation phase
- Muscle is in continuous contraction
- All potential cross-bridges form
Complete Tetanus
A motor neuron and all of the muscle fibers it controls
Motor Unit
Characteristics of Motor Units
- May contain a few muscle fibers or thousands
- All fibers in a motor unit contract at the same time
- Involuntary “muscle twitch”
- Involves more than one muscle fiber
Fasciculation
The normal tension and firmness of a muscle at rest
Muscle Tone
- Skeletal muscle changes length
- Resulting in motion
Isotonic contractions
- Muscle tension > load (resistance)
- Muscle shortens
Isotonic concentric contraction
- Muscle tension < load
- Muscle elongates
Isotonic eccentric contraction
- Skeletal muscle develops tension that never exceeds the load
- Muscle does not change length
Isometric contractions
The ____ the load, the longer it takes for movement to begin.
Heavier
How ATP relates to muscles
- Contracting muscles use a lot of ATP
- Muscles store a lot of ATP so they can start up a contraction
- More ATP must be generated to sustain a contraction
- Anaerobic process
- Breaks down glucose from glycogen stored in skeletal muscles
- Produces two ATP per molecule of glucose
Glycolysis
- Primary energy source of resting muscles
- Breaks down fatty acids
Aerobic metabolism
The time required after exertion for muscles to return to normal
Recovery Period
What hormones increase metabolic activities in skeletal muscles?
- Growth hormone
- Testosterone
- Thyroid hormones
- Epinephrine
The maximum amount of tension produced
Force
The amount of time an activity can be sustained
Endurance
What are the 3 types of skeletal muscle fibers?
- Fast
- Slow
- Intermediate
- Majority of skeletal muscle fibers
- Contract very quickly
- Produce strong contractions, but fatigue quickly
Fast Fibers
- Slow to contract and slow to fatigue
- Contain myoglobin (red pigment that binds oxygen)
Slow Fibers
- Are mid-sized
- Little myoglobin
- Slower to fatigue than fast fibers
Intermediate Fibers
Muscle growth from heavy training
Muscle Hypertrophy
Reduction of muscle size, tone, and power due to lack of activity
Muscle Atrophy
When muscles can no longer perform at a required level
Muscle Fatigue
Fast/quick activities are known as ___ endurance
Anaerobic
Prolonged activities is known as ___ endurance
Aerobic
Join sarcolemmas of adjacent cardiac muscle cells by gap junctions and desmosomes
Intercalated discs
- Contraction without neural stimulation
- Controlled by pacemaker cells
Automaticity
Structural characteristics of smooth muscle
- Long, slender, spindle-shaped cells
- Single, central nucleus
- No T tubules, myofibrils, or sarcomeres
True or false: smooth muscle is nonstriated muscle
True
The ability to function over a wide range of lengths
Plasticity
Skeletal muscle fibers form bundles called…
Fascicles
- Muscle fibers spread out like a fan and converge on an attachment site
- Fibers pull in different directions, depending on activity
Convergent muscles
Slender band of collagen fibers
Raphe
- Muscle fibers pull at an angle relative to tendon
- Do not move their tendons as far
- Contain more myofibrils
- Develop more tension
Pennate muscles
All fascicles on same side of tendon
Unipennate
Fascicles on both sides of a central tendon
Bipennate
Tendon branches within muscle
Multipennate
- Act as valves in digestive and urinary tracts
- Surround body openings and hollow organs
Circular muscles (sphincters)
Almost all skeletal muscles attach to ___
Bones
Site of connection to a bone affects ___, ___, and ___
Force, speed, and range of motion
Moves on a fixed point
Fulcrum
Fulcrum lies between applied force and load
First-class lever
Load lies between applied force and fulcrum
Second-class lever
Applied force is between load and fulcrum
Third-class lever
Fixed point of attachment of a muscle to bone is the…
origin
Movable point of attachment is the..
insertion
Mostly responsible for producing a particular movement
Agonist
Opposes movement of a particular agonist
Antagonist
A smaller muscle that assists a larger agonist
Synergist
A synergist that assists an agonist by preventing movement at another joint
Fixator
The body has approx. ___ skeletal muscles
700
Muscles visible at body surface
Externus (superficialis)
Deeper muscles
Internus (profundus
Position or stabilize an organ
Extrinsic muscles
Located entirely within an organ
Intrinsic muscles
Run across the long axis of the body
Transversus muscles
Run at a slant to long axis
Oblique muscles
Run along the long axis
Rectus (straight) muscles
Deltoid
Triangle
Orbicularis
Circle
Pectinate
Comblike
Piriformis
Pear Shaped
Platysma
Flat Plate
Pyramidal
Pyramid
Rhomboid
Parallelogram
Serratus
Serrated
Splenius
Bandage
Teres
Round and long
Trapezius
Trapezoid
Alba
White
Brevis
Short
Gracilis
Slender
Latae
Wide
Latissimus
Widest
Longissimus
Longest
Longus
Long
Magnus
Large
Major
Larger
Maximus
Largest
Minimus
Smallest
Minor
Smaller
Vastus
Great
Buccinator
Trumpeter
Risorius
Laugher
Sartorius
Like a tailor
Constricts the mouth opening
Orbicularis oris
- Moves food across the teeth
- In infants, provides suction for nursing
Buccinator
- Elevate, depress, and protract mandible
- Slide mandible from side to side (lateral excursion)
Pterygoid muscles
Helps elevate the mandible
Temporalis
Strongest jaw muscle
Masseter
Move food into esophagus
Pharyngeal constrictor muscles
- Elevate the soft palate and adjacent portions
- Pull open entrance to auditory tube
Palatal muscles
Raise the larynx
Laryngeal elevators
- Controls position of larynx
- Extends from chin to hyoid bone
- And from hyoid to mastoid portion of temporal bone
Digastric
- Elevates floor of the mouth
- Depresses jaw
Mylohyoid
Extends between hyoid bone and chin
Geniohyoid
Between hyoid bone and styloid process of skull
Stylohyoid
- Extends from clavicle and sternum to mastoid
- Turns head obliquely to opposite side
Sternocleidomastoid
Attaches scapula, clavicle, first rib, and hyoid
Omohyoid
Rotate and flex the neck
Longus capitis and longus colli
Flexes vertebral column and depresses ribs
Quadratus lumborum
- Between xiphoid process and pubic symphysis
- Divided longitudinally by linea alba
- Divided transversely by tendinous inscriptions
Rectus abdominis
- Position and stabilize pectoral and pelvic girdles
- Move upper and lower limbs
Appendicular Muscles
- Large and superficial
- Covers back and portions of the neck
- Extends to base of skull
- Originates on midline of neck and back
- Inserts on clavicles and scapular spines
Trapezius
- Fan-shaped muscle on chest
- Originates along ribs
- Inserts on anterior margin of scapula
Serratus anterior
Produce medial rotation at shoulder
Subscapularis and teres major
Produce lateral rotation at shoulder
Infraspinatus and teres minor
Produces flexion and adduction at shoulder
Coracobrachialis
- Between thoracic vertebrae and humerus
- Produces extension at shoulder joint
Latissimus dorsi
Mainly on posterior and lateral surfaces of arm
Extensors
Mainly on anterior and medial surfaces
Flexors
- Flexes elbow and supinates forearm
- Stabilizes shoulder joint
- Originates on scapula
- Inserts on radial tuberosity of radius
Biceps brachii
Flex the elbow
Brachialis and brachioradialis
- Originate on humerus and ulna
- Rotate radius
Supinator and pronator teres
- Originates on ulna
- Assists pronator teres in opposing actions of supinator or biceps brachii
Pronator quadratus
- Wide band of connective tissue
- Posterior surface of wrist
- Stabilizes tendons of extensor muscles
Extensor retinaculum
- Anterior surface of wrist
- Stabilizes tendons of flexor muscles
Flexor retinaculum
