Body Movements and Muscle Histology

Lab # 7

2- List the three types of muscle tissue and function of each.

3- Describe the histological appearance of each type.

4- Describe the organization of the skeletal muscle.

5- Describe the microanatomy of a muscle fiber.

6- Understand the rules that determine the name of some muscles.

1- Describe and demonstrate the different types of body movements.

OBJECTIVES

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 toward the midline of the body.

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

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

Skeletal muscle

Cardiac muscle

Smooth muscle

Long, cylindrical, unbranched striated , multinuclear

Short, branched, striated , single nucleus, intercalated discs

Short, spindle-shaped, non-striated , single nucleus

Cell characteristics

Nerve ending

Nuclei

Striations Intercalated disk

Nucleus

Nucleus

Types of Muscle Tissue

Muscle fiber (cell)

Fascicle

Skeletal Muscle

Endomysium

Perimysium

Epimysium

Organization of the Skeletal Muscles (Unit 13, page 173)

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)

SKELETAL MUSCLEContains: Surrounded by:

MUSCLE FASCICLEContains: Surrounded by:

MUSCLE FIBER (CELL)Contains: Surrounded by:

Muscle fascicles Epimysium

Muscle fibers (cells) Perimysium

Myofibrils Endomysium

MYOFIBRILContains:Myofilaments

They are organized in sarcomeres

Sarcomere

MYOFILAMENTSThick filaments: myosinThin filaments: actin

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

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 thick 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

Myosin (thick filaments)

Z line Z line

Actin (thin filaments)

MYOFIBRIL

Sarcomere Structure

Z line Z line

Sarcomere

A band

H zone

Zone of overlap

I band

Thin filament M line Thick filament

Sarcomere Structure

The Neuromuscular Junction

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)

It is the point where the motor neuron and the muscle fiber meet.

Mitochondrion

Synaptic vesiclesThey contain the neurotransmitter

Synaptic vesicles releasing the neurotransmitter

Axon Terminal or Synaptic Knob

They produce the ATP for active transport of ions

Smooth E.R.

Neuromuscular Junction and Muscle Cell or Fiber

It carries the nerve impulse

Axon of the motor neuron

Myelin sheath

Sarcolemma

Sarcolemma

Endomysium

Endomysium

Terminal (T) tubulesSarcoplasmic reticulum

Terminal cisternae

Triad

They store calcium for muscle contraction

They carry the nerve impulse inside the muscle cell

It stores calcium for muscle contraction

Two terminal cisternae and one T tubule

Mitochondria

Myofibril

Myofilaments Sarcoplasm

They provide the energy (ATP) for muscle contraction

Synaptic vesicles

They contain the neurotransmitter

Motor end plate

Junctional folds

Synaptic cleft

Neuromuscular Junction and Muscle Cell or Fiber

It carries the nerve impulse

Axon of the motor neuron

Myelin sheath

Sarcolemma

Endomysium

Transverse (T) tubules

Sarcoplasmic reticulum

Terminal cisternae

Triad

They carry the nerve impulse inside the muscle cell

It stores calcium for muscle contraction

Two terminal cisternae and one T tubule

MitochondriaThey provide the energy (ATP) for

muscle contraction

Synaptic vesiclesThey contain the neurotransmitter

Junctional folds

Synaptic cleft

Myofilaments

AXON TERMINAL

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

Two terminal cisternae and one T tubule

T tubule

Terminal cisterna

They provide the energy (ATP) for muscle contraction

It stores calcium for muscle contraction

Sarcoplasmic reticulum Mitochondrion

They carry the nerve impulse inside the

muscle cell

They store calcium for muscle contraction

Triad

Thin myofilaments (Actin)

Thick myofilaments (Myosin)

Microstructure of the Muscle Fiber