Joints and Muscles -
Transcript of Joints and Muscles -
Joints and Muscles
Classification of Joints by Movement• Synarthroses (synarthrotic joints) – non movable
most fibrous joints
e.g. sutures
• Amphiarthroses (amphiarthrotic joints) – semimovable
mostly cartilaginous
e.g. intervertebral disks
• Diarthroses (diarthrotic joints) – movable joints
synovial joints
Classification of Joints by Structure
Fibrous joints – composed of fibrous (inelastic) connective tissue.
sutures – between cranial bones
syndesmoses – e.g. tibia-fibular joint, sternum-clavicle and acromion-clavicle.
Synovial Joints
• movable joints
• contain a joint capsule of synovial membrane
Structure of a SynovialJoint
periosteum
Extracapsular ligament
Fibrous capsule
Synovial membrane
Articular cartilage
Articularcapsule}
Joint cavity
Figure 8.3
Plane or Gliding Joint
Gliding or planar joints – bones slide against one another.
e.g. between carpals or tarsals
Gliding Movement is Non-axial
e.g. elbow, knee.
Hinge Joints
Movements at Uniaxial Joints:
Flexion – decreasing the angle between two bones or parts.
180o
•Begin at anatomical position
•Reduce angle from 180o
Extension– increasing the angle between two bones or parts.
Increase angle back to anatomical position
Return to anatomical
position
Beyond anatomical position is hyperextension
Flexion and Extension of
the VerterbralColumnFlexion
Extension
Hyperextension
When extension proceeds beyond anatomical position it is called hyperextension.
When extension proceeds beyond anatomical position it is called hyperextension.
Flexion and Extension of the Head
FlexionExtension
HyperextensionFlexion
Pivot Joints
e.g. radius with ulna and humerus,
atlas-axis
Rotation of the Head and
Thigh
Rotation of the Radius
Supination – to move palm up
Pronation – to move palm down
Condyloid Joint
Phalange-metacarpal, Carpal-metacarpal,
occipito-atlas and tibia-talus joints.
Saddle Joint
Additional Movements at Biaxial
Joints
Abduction –to move away from the midline or apart.
Adduction –to move toward the midline or together.
Circumduction – a sequence of movements in which one end inscribes a circle.
Ball-and-Socket Joints
Shoulder and hip joint
Movements of the Foot
plantarflexion: point toes down
dorsiflexion: point toes up
Inversion and Eversion
Left foot
Inversion, incorrectly called
supination
Eversion, incorrectly called
pronation
The Elbow Joint
trochlea
Trochlear notch
synovial cavity
Tendon of biceps b.
Tendon of triceps b.
Figure 8.10 a
Articularcartilage
Figure 8.10 b
Annular ligament
Radial (lateral) collateral ligament
Articularcapsule
Figure 8.10 d
Annular ligament
Ulnar (medial) collateral ligament
Elbow radiograph, lateral view
Trochlear notch
Trochlea
Elbow radiograph, dorsal view
Olecranon process
Head of the radius
Sagittal Section of The Right Knee
Articular capsule
Anterior cruciateligament
Posterior cruciateligament
Tibia
Femur Patella
Figure 8.11 a
Patellar ligament
Quadriceps tendon
Anterior View of the Right KneeFigure 8.11 b
Tibia
Fibula
Patellar ligament
Patella
Quadriceps tendon
Medial condyleLateral condyle
Tibial (medial) collateral ligament
Fibular (lateral) collateral ligament
Posterior cruciateligament
Anterior cruciateligament
Lateral meniscus Medial meniscus
Patella
Femur
Tibia Fibula
Condyles
Knee Radiograph
3 Types of Muscle TissueA Comparison
Skeletal Attached to the bones for movement
Muscle TypeLocation Characteristics Control
Long, cynlindricalcells;
multinucleated, striated
Voluntary
Cardiac Muscle of the HeartShort, branching cells, mononucleated, faintly
striated. Forms functional syncytia.
Involuntary
myogenic
Smooth Muscle
Single Unit: GI, Respiratory, &
Genitourinary tract mucous membranes.
Multi-unit: smooth muscle in blood vessel
walls.
Small oblong cells, mononucleated, also may
form a functional syncytium.
Involuntary
myogenic
Skeletal MuscleCharacteristics
Skeletal muscle cells are long multi-nucleated cylinders, separated by connective tissue.
nuclei
Connective endomysiumseparates cells.
Striations are the dark bands Myofibrils fill
cell interiorperpendicular to cell length
Skeletal Muscle photomicrographs
Striations reflect the arrangement of protein myofilaments within the cell. The dark bands are called A-bands, the light areas between are the I-bands.
Z lines run through the middle of each I-band. The unit from one Z line to the next is a sarcomere.Z-line
The sarcolemma is the cell membrane
Structure of a
Skeletal Muscle
Cardiac MuscleCharacteristics
Cardiac muscle cells are faintly striated, branching cells, which connect by means of intercalated disks to form a functional network.
Intercalated disks
nucleus
The action potential travels through all cells connected together in the syncytium causing them to function as a unit.
Cardiac cells are branched, mono-nucleated cells
Smooth Muscle Characteristics
A small spindle-shaped mononucleated smooth muscle cell.
Smooth muscle cells connect to form single-unit syncytiasimilar to cardiac muscle. But impulses and contractions occur much more slowly in smooth than in cardiac muscle.
nucleus
Smooth Muscle Arrangement
In the intestine smooth muscle forms two distinct layers, one running along, the other running around the organ. Together these layers cause wave-like peristalsis which propels the contents.
The longitudinal layer runs along the intestine; it causes wave-like contractions.
The circular layer runs around the intestine and its contraction causessegmentation
Lab Protocol
I. Arthrology
1. Describe and give examples for joint types: synarthroses, amphiarthroses and diarthroses.
2. Relate the types of joints to their structure: fibrous, cartilaginous and synovial.
3. Identify the types of synovial joints with examples and movements. Discuss how these movements can supplement (synergists), oppose (antagonists) or stabilize (fixators) one another.
4. Use cadavers to identify the major structural aspects of selected joints.
II. Muscle Histology
1. Compare structure of skeletal, cardiac and smooth muscle.
2. Identify major anatomical features of each type and relate tofunction.
Assignment to Turn In
1) Complete Review Sheets for Exercise 13.
2) Make a labeled drawing of the three types of muscle from microscopy done in the lab, or from photos available in The Virtual Microscope