Body Movements and Muscle Histology

Lab # 7

Flexion, Extension and HyperextensionFlexion: Movement that decreases the joint angle in hinge joints Extension: Movement that straightens a joint and generally returns a body part to the zero position

Hip flexion

Knee flexion

Extension

Flexion Lateral flexion

Hyperextension: Further extension of a joint beyond the zero position. Flexion and extension occur at nearly all diarthroses, hyperextension is limited to a few joints.

Extension

Flexion

Hyperextension

Hyperextension

Abduction: Movement of a body part in the frontal plane away from the midline of the body

Adduction: Movement of a body part in the frontal plane back toward the midline

Elevation: A movement that raises a body part vertically in the frontal plane

Depression: A movement that lowers a body vertically part in the frontal plane

Protraction: The anterior movement of a body part in the transverse (horizontal) plane

Retraction: The posterior movement of a body part in the transverse (horizontal) plane

Supination: Forearm movement that turns the palm to face anteriorly or upward. The forearm is supinated in anatomical position (the radius is parallel to the ulna)

Pronation: Forearm movement that turns the palm to face posteriorly or downward. The radius spins on the capitulum of the humerus. The head spins in the radial notch of ulna and the radius crosses stationary ulna like an X

Tendons: Narrow bands of connective tissue that connect muscles to bone

TENDONS

Aponeuroses: Bands of connective tissue that attach flat muscle to another muscle or to several bones APONEUROSIS

Ligaments: Bands of connective tissue that join bone to bone

LIGAMENT

Epicraneal aponeuroses ( Galea )

Lumbar aponeuroses

Abdominal aponeuroses

Muscle Tissue

MARTINI page 133

1- Skeletal muscle2- Cardiac muscle3- Smooth muscle

DIFFERENT TYPES OF MUSCLE

MUSCLE HISTOLOGY(pages 36-39 and 77-80)

Types of muscle:

1- Skeletal

2- Cardiac

3- Smooth

Long,

Short,

Short,

Cylindrical,

Branched,

Spindle,

Striated,

Striated,

Non-striated,

Multinuclear

Single nucleusSingle nucleus

C e l l c h a r a c t e r i s t i c s

Muscle fiber (cell)

Fascicle

Skeletal Muscle

Endomysium

Perimysium

Epimysium

MUSCLE FIBER (cell)

Capillary

Sarcolemma

Endomysium

Axon

Sarcoplasm

NucleusMitochondria

Myofibrils

They are involved in the repair of damaged muscle

Myosatellite cell

They consist of bundles of myofilaments (thin filaments and thick filaments)

Motor Unit (page 79)

Motor neuron Axon terminal

Muscle cell or fiber

Neuromuscular junction

Axon of motor neuron

SarcolemmaMyofibril

Myofilaments

Nucleus

It releases the neurotransmitter

It carries the nerve impulse

(They are organized in sarcomeres)

Thin filament

Terminal cisterna

Sarcolemma

Structure of the Skeletal Muscle Fiber

Sarcoplasm

They conduct the nerve impulse from the sarcolemma to the interior of the cell

Sarcoplasmic reticulum

T tubulesIt stores calcium for muscle contraction

Triad

MitochondriaThey produce the chemical energy (ATP) for muscle contraction

Thick filamentMyofibril

Neuromuscular Junction and Muscle Cell or Fiber

Superior view

Myofibrils

It carries the nerve impulse

They release the neurotransmitter

Neuromuscular junction

Axon of the motor neuron

Axon terminal

Endomysium

Sarcomeres

Sarcolemma

Nuclei

Sarcoplasm

They consist of proteins called actinins, which interconnect thin filaments of adjacent sarcomeres

They are the smallest functional units of the muscle fiber

Sarcomere

A band

H band

M line

M line: It consists of proteins that connect the each filament with its neighbors

H band: It is a lighter region on either side of the M line, which contains only thick filaments

Zone of overlap: It is the region where the thin filaments are situated between the thick filaments

Zone of overlap

Zone of overlap

A band: Its length is equal to the length of the thick filaments. It contains both thin and thick filaments

I band (It contains thin filaments but not

thick filaments

Z lineI band

Zone of overlap

H band M line

Actin (thin filaments)

Myosin (thick filaments)

Z line Z lineTitin (elastic protein

that attaches the thick filaments to

the Z discs)

I band I band

A band

H band

Zone of overlap

Zone of overlap

M lineZ line Z line

When a skeletal muscle fiber contracts:

1- The H bands and I bands get smaller

2- The zone of overlap get larger

3- The Z lines move closer together

4- The width of the A band remain constant

Z line Z line

Sarcomere

A band

H zone

Zone of overlap

I band

Thin filament M line Thick filament

Sarcomere Structure