BSC2085 L 7

A joint that holds bones together and allows skeletal system flexibility.

Articulation

Joints joined by fibrous tissue, mostly synarthrotic (no movements). Types include sutures and syndesmoses.

Fibrous Joints

Type of fibrous joint that interlocks bones, primarily found in the skull.

Sutures

Type of fibrous joint where articulating bones are connected by short ligaments, such as the tibia and fibula.

Syndesmoses

Joints where articulating bones are connected by cartilage, mostly amphiarthrotic (slight movements). Types include symphyses and synchondroses.

Cartilaginous Joints

Type of cartilaginous joint where bones are connected by broad fibrocartilage discs (e.g., intervertebral discs).

Symphyses

Type of cartilaginous joint where bony portions are united by hyaline cartilage (e.g., 1st rib/sternum).

Synchondroses

Joints that allow free movement, with articulating bone ends separated by a joint cavity filled with synovial fluid.

Synovial Joints

 enclose joint surface;

 reinforced by ligaments; may contain bursae (fluid sacs); may contain fibrocartilage pads (articular discs)

Articular Capsule

Inner layer of smooth connective tissue that produces synovial fluid.

Synovial Membrane

A motor neuron and the muscle fibers it innervates.

Motor Unit

The area where a neuron's axon interacts with muscle cells.

Neuromuscular Junction

A neurotransmitter released at the neuromuscular junction that signals muscle contraction.

Acetylcholine (ACh)

The process where muscle fibers generate tension and shorten in response to stimulation.

Muscle Contraction

A type of muscle contraction where muscle length does not change while force is applied.

Isometric Contraction

A type of muscle contraction where muscle length changes, but the force remains the same.

Isotonic Contraction

Types of synovial joints:

plane 

hinge 

pivot 

condyloid/ellipoidal

saddle

ball and socket

flat surface (intercarpal/tarsal joints & vertebrocostal joints of ribs 2-7)

plane

round end to concave surface

      (elbow & interphalangeal joints)

hinge

round/conical bone to shallow

      depression/foramen (atlas & axis)

Pivot

oval condyle to

      ellipsoidal depression (radiocarpal joint &

      metacarpophalangeal joints)

Condyloid/Ellipsoidal

saddle shaped, one convex, one

      concave (metacarpal & trapezium of wrist)

 Saddle

ball-shaped head fits into

        cuplike depression

Ball and socket

decrease joint angle

Flexion

increase joint angle

 Extension

increase joint angle over 180°

Hyperextension

limb away from midline

Abduction

limb towards midline

Adduction:

movement around longitudinal axis

Rotation

distal end moves in circle

Circumduction

palm from anterior to posterior

 Pronation

palm from posterior to anterior

Supination

medial turn of sole

Inversion

lateral turn of sole

Eversion

ankle joint dorsal movement

Dorsiflexion:

ankle joint flex downward

Plantar flexion:

forms the thin filaments, anchored by

      the Z disc

Actin

forms the thick filaments, anchored

      by the M line

myosin

smallest functional contractile unit

      of muscle.  From Z disc of an I band to next Z disc

Sarcomere:

indention of the

         sarcolemma (plasma membrane) forms a tubule

         at A/I band junction

Transverse (T) tubule

•region of sarcomere containing thick filaments

A band

region of sarcomere containing only thin filaments

I band

muscle cell’s smooth

        endoplasmic reticulum, used to store calcium

        (Ca²⁺) ions         

Sarcoplasmic reticulum

structure consisting of two terminal cisterns

         of the sarcoplasmic reticulum and a transverse

         tubule between them

Triad

1?

joint cavity

2

articular cartilage 

3

fibrous layer

4

synovial membrane

5

articular capsule

identify 

plane joint 

identify

hinge joint

identify

pivot joint

identify

condylar joint 

identify 

saddle joint 

identify 

ball and socket joint 

1

hyperextension

2

extension

3

flexion 

1

hyperextension

2

flexion

1

flexion 

2

flexion

1

extension

1

hyperextension 

2

extension

1

abduction

2

adduction 

3

circumduction

1

rotation

2

lateral rotation 

3

medial rotation

1

pronation

2

supination 

1

dorsiflexion

2

plantar flexion

1

inversion 

2

eversion

1

sarcolemma

2

mitochondrion 

3

myofibril

4

nucleus

5

light I band

6

Dark A band 

1

thin (actin) filament

2

thick (myosin) filament

3

Z disc

4

H zone

5 

Z disc 

6

M line

7

I band

8

A band 

9

I band

1

myofibril 

2

sarcolemma

3

triad

4

t tubule 

5

terminal cisterns of the SR (2)

6

tubules of the SR

7 

myofibrils 

1

tendon