Muscular Anatomy Flashcards
(48 cards)
What are the different kinds of muscle tissues?
- Skeletal
- Cardiac
- Smooth
What are the types, locations, cell shape, contraction of regulation of skeletal tissues?
Body Location: attached to the bones (or some facial tissues) to skin
Cell Shape: Single, very long, cylindrical, multinucleate, obvious striation
Regulation of contraction: Voluntary via axon terminals of somatic nervous system
What are the types, locations, cell shape, contraction of regulation of cardiac tissues?
Body Location: walls of heart
Cell Shape: Branching, uni or binucleate, striations
Regulation of contraction: Involuntary, intrinsic system regulation, ANS, hormones, stretch
What are the types, locations, cell shape, contraction of regulation of smooth tissues?
Body Location: present in visceral layer of hollow organs (other than heart) -> longitudinal and circular layer (eg: blood vessels, urinary bladder, uterus, stomach, small intestine)
Cell Shape: Single, fusiform, uninucleate, no striations
Regulation of contraction: Involuntary, autonomic nerves, hormones, local chemicals, stretch
What are the characteristics of muscle tissues?
- Excitability (responsiveness when receive stimulus of chemical or neuro)
- Contractility (how it shortens forcefully when adequately stimulated)
- Extensible (can stretch without tearing, when contracted and relaxed)
- Elasticity (recoil strength)
What are the similarities and differences of muscles?
Other names:
- Skeletal = Somatic
- Cardiac = Myocardial
- Smooth = Visceral
Striation:
- Skeletal: Yes
- Cardiac: Yes
- Smooth: No
Quick Contraction:
- Skeletal: Yes
- Cardiac: Yes
- Smooth: No
Voluntary
- Skeletal: Yes
- Cardiac: No
- Smooth: No
Subject to fatigue
- Skeletal: Yes
- Cardiac: No
- Smooth: No
What are the functions of the muscular system?
- Movement
o Helps pump blood
o Propels substances throughout hollow organs - Maintains posture
o Adjusting the position of the body with respect to gravity - Stabilizes joints
o By exerting tension around the joint - Generates heat
o Through cellular metabolic processes
What is the gross anatomy of the skeletal muscle?
- Know the
o Origins of the tendon
o Insertional end of tendon
- eg: biceps branchii o origin: scapula bone o running down on humerus bone o insert: radius bone o connected to bones via tendons o action of elbow joint: flexion -> bring forearm nearer to arm
What are the levels of skeletal muscle organization?
- Complex -> smallest
o Muscle -> bundles of muscle fibers (fascicle) -> muscle fiber (muscle cells) -> myofibril (bundle of myofilaments) -> myofilament (stands of contractile proteins) -> contractile proteins (actin, myosin)
What are the structure and organization of skeletal muscle?
- Muscle:
o Consists of hundreds to thousands of muscle cells + connective tissue wrappings
o Connective tissue wrappings -> covered externally by epimysium
- Fascicle:
o Bundle of muscle cells -> separated by muscle sheath
o Connective tissue wrappings -> surrounded by perimysium
- Muscle fiber:
o Elongated multinucleate cells
o Striated appearance
o Connective tissue wrappings -> surrounded by endomysium
What are the different coverings?
- Epimysium: covers the muscle
- Perimysium: covers the fascicle (a bunch of myofibril)
- Endomysium: covers the myofibrils
Describe the microscopy of skeletal muscle fibre?
- Myofibrils
o Have striations - Sarcolemma
o Cell membrane/plasma membrane - Sarcoplasm
o Cytoplasm of muscle tissue, underneath the endomysium - Sarcoplasmic reticulum
o Smooth and rough endoplasmic reticulum
o Production of fat
o Production of protein - T tubules
o Inbound folding of the plasma membrane
o Where Ca2+ and Na+ channels -> activate the neuromuscular for movements - Mitochondria
o Powerhouse of energy in periphery of sarcomere
What are myofibrils?
- Bundle of myofilaments
- Rod-like contractile elements -> occupy most of muscle cell volume
- Composed of sarcomeres -> end to end -> appear like bands
- Between 2 Z discs
- M line: presence of myosin, not actin
- Titin: spring-like protein, elastic filament
- A band: overlap of myosin and actin -> appears dark
- I band: presence of actin filament only
What are sarcomeres?
- Contractile unit of muscles
- Composed of myofilaments made up of contractile myoproteins
- Contractile myofilaments o Myosin (thick) o Actin (thin)
What are myofilament or filament?
- Thick filament (bundle of myosin molecules)
o Produce a dark colour band - Thin filament (bundle of actin molecules)
o Produce a light colour band - Myofibrils are banded (thick and thick filaments)
- Sliding of thin filaments past the thick filaments -> produce muscle shortening
- Elastic filaments -> provide elastic recoil -> when muscle contraction ends
What are the nerve supply of a skeletal muscle?
- By motor neuron
- Skeletal muscle fibre -> supplied by nerve ending -> which controls the activity
- Motor end plate -> is a large terminal formation -> where axon of motor neuron contacts with striated muscle fiber
- Each muscle fiber -> forms one motor endplate
o Can fire activities of movement due to multiple supply of neurons - Muscles have rich blood supply
What are the characteristics for naming muscles?
- Location:
o Temporalis: near the skull temple, temporal lobe (skull)
o Tibialis anterior, posterior: tibial (leg bone)
o Popliteus, occipitofrontalis
- Size:
o Gluteus maximus: biggest
~ Gluteus: butt
o Pectoralis
minor/minimus: smaller
~ Pectoralis: near nipple
- Shape:
o Serratus anterior:
~ Serratus: seriated edges
o Trapezius: diamond shape
o Deltoid: triangle
- Direction:
o External oblique: outward
o Orbicularis oris
~ Oris: circular = around eye
- Number of heads:
o Biceps branchii
~ Bi = 2 heads
o Quadriceps femoris
~ Quad = 4 heads
- Action:
o Flexor digitorum
~ Flexor: bring it nearer
~ Digitorum: fingers
o Extensor digitorum
~ Extensor: bring it back to original
o Adductor longus
~ Adductor: bring together
What are the superficial muscles?
Sternocleidomastoid: Muscle of the neck -> help to rotate neck
Deltoid:
Upper arm, triangular shape, intravascular injection
Pectoralis Major:
Area near nipple, chest
Serratus anterior:
Lateral of chest, saw-like
Intercoastals:
Between ribs
Quadriceps femoris:
4 muscles on thigh
What are the muscles of the upper limb (pectoral region)?
-o Pectoralis major
o Pectoralis minor
o Serratus anterior
o Subclavius
What are the muscles of the upper limb (forearm posterior)?
o Extensors, wrists, digits
- brachioradialis
- extensor carpi
- extensor digitorum
- extensor digit minimi
- extensor carpi ulnaris
- anconeus
What are the muscles of the upper limb (forearm anterior)?
o Flexors
- biceps branchii
- brachialis
- branchioradialis
- flexor carpi radialis
- flexor carpi ulnaris
- flexor digitorum superficialis
What are the muscles of the upper limb (shoulder)?
o Extrinsic: muscles originate from torso, attached to clavicle, scapula, humerus
Trapezius
Latissimus dorsi
o Intrinsic: muscles originate from scapula or clavicle, attached to humerus Deltoid Teres major Rotator cuff muscles • Supraspinatus • Infraspinatus • Subscapularis • Teres minor
What are the muscles of the upper limb (upper arm)?
o Anterior
Biceps branchii
Brachialis
o Posterior
Triceps branchii
What are the muscles of the upper limb (hand)?
o Intrinsic muscles -> creates finer movements of the hands Thenar Hypothenar Interossei Lumbrical
