Week 4 // Muscular Tissue AND Muscular System Flashcards
What are the 3 types of muscular tissue?
Skeletal muscle
Cardiac muscle
Smooth muscle
What is the function and location of skeletal muscles?
Skeletal, function is to move bones.
What is the function and location of cardiac muscles?
In heart, function is to pump blood.
What is the function and location of visceral (smooth) muscles?
various organs, various functions (ex. paristalsis)
What is the appearance of skeletal, cardiac and smooth muscle tissue?
skeletal: multi-nucleated and striated
cardiac: one nucleus, striated, intercalated disks
What are the functions of muscular tissue?
- Generating heat
- Producing body movements
- Stabilizing body positions
- Storing and mobilizing substances within the body
(In a less known but critically important role, muscle influences energy and protein metabolism throughout the body. Muscle is a primary site for glucose uptake and storage, and it is also a reservoir of amino acids stored as protein.)
Properties of muscular tissue?
- Electrical excitability
- Contractility
- Extensibility
- Elasticity
How are muscles formed?
Myoblasts
How do skeletal muscles produce movements?
Skeletal muscles produce movements by exerting force on tendons
Tendons attach to and pull on bones, and movement occurs
Origin and Insertion
When a muscle contracts, it draws one articulating bone toward the other
Origin – the attachment to the stationary bone
Insertion – the attachment to the moveable bone
Lever Systems and Leverage
Levers are acted upon by ____ and ________
The lever is acted on by:
Load (Resistance)
Effort
Bones serve as levers and joints serve as
________
fulcrums
What is a lever?
Lever is a rigid structure that can move around a fixed point called a fulcrum
First Class Lever
Load and effort on opposite sides of fulcrum.
![](https://s3.amazonaws.com/brainscape-prod/system/cm/358/537/217/a_image_thumb.jpg?1634338620)
Second Class Lever
Load and Effort on same sides as fulcrum, the effort is farthest away from fulcrum.
(wheelbarrel)
![](https://s3.amazonaws.com/brainscape-prod/system/cm/358/537/218/a_image_thumb.jpg?1634338650)
Third Class Lever
Load and Effort on same sides as fulcrum.
Load is farthest away from fulcrum.
(Picking something up, biceps)
![](https://s3.amazonaws.com/brainscape-prod/system/cm/358/537/219/a_image_thumb.jpg?1634338688)
How are most skeletal muscles arranged?
most skeletal muscles are arranged in opposing pairs at joints
Agonist/prime mover
biceps brachii (add from text)
Antagonist
Triceps brachii muscle must relax to allow biceps to move
Synergist
During forearm flexion, for example lifting a cup, a muscle called the biceps brachii is the prime mover. Because it can be assisted by the brachialis, the brachialis is called a synergist in this action
(Smaller muscles that help Agonist and Antagonist muscles to finish movements)
How are muscles named?
A muscle may be named based on:
Location
Size
Number of origins
Appearance
Direction of fibres
Origin and insertion
Muscle action
Rectus
Parallel to midline
Transverse
Perpendicular to midline
Oblique
Diagonal to midline
Meaning of Maximus (Gluteus Maximus)
Maximus = Largest
Meaning of Minimus (Gluteus Minimus)
Minimus = Smallest
Meaning of Longus (Adductor longus)
Longus = Long
Meaning of Brevis (Adductor brevis)
Brevis = Short
Meaning of Latissimus (Latissimus dorsi) and where is it?
Latissimus = Widest
![](https://s3.amazonaws.com/brainscape-prod/system/cm/358/537/233/a_image_thumb.png?1634339210)
Meanings of muscle names
(naming muscles by size)
Magnus, Major, Minor, Vastus
Magnus= Large
(ex. Adductor magnus)
Major = Larger
(Pectoralis major)
Minor = Smaller
(Pectoralis minor)
Vastus = Huge
(Vastus lateralis)
Meaning of Muscie names
(naming muscles by action)
Flexor, Extensor, Abductor, Adductor, Levator, Depressor, Supinator, Pronator, Sphincter, Tensor, Rotator
Flexor = Decreases joint angle
(Flexor carpi radialis)
Extensor = Increases joint angle
(Extensor carpi ulnaris)
Abductor = Moves bone away from midline
(Abductor pollicis longus)
Adductor = Moves bone closer to midline
(Adductor longus)
Levator = Raises or elevates body part
(Levator scapulae)
Depressor = Lowers or depresses body part
(Depressor labii inferioris)
Supinator = Turns palm anteriorly
(Supinator)
Pronator = Turns palm posteriorly
(Pronator teres)
Sphincter = Decreases size of an opening
(External anal sphincter)
Tensor = Makes body part rigid
(Tensor fasciae latae)
Rotator = Rotates bone around longitudinal axis
(Rotatore)
Meaning of Muscie names
(naming muscles by shape)
Deltoid, Trapezoid, Serratus, Rhomboid, Orbicularis, Pectinate, Piriformis, Platys, Quadratus, Gracilis
deltoid = triangle, trapezoid = trapezius, Serratus = Saw-toothed, Rhomboid = Diamond-shaped, Orbicularis = Circular, Pectinate = Comb-like, Piriformis= Pear-shaped,
Platys, Flat, Quadratus= Square, four-sided, Gracilis=
Slender
Muscles of facial expression lie within this layer
the subcutaneous layer, originating on the fascia or bones of the skull and inserting into the skin
Occipalfrontalis *
Front of forehead - wrinkles forehead, raises eyebrows
Consists of two parts:
- *Frontal belly** (frontalis) at forehead
- Origin: Epicranial aponeurosis.*
- Insertion: Skin of eyebrow, muscles of forehead*
Occipital belly (near occiptal bone)
Origin: Occipital bone and mastoid process of temporal bone.
Insertion:Epicranial aponeurosis.
![](https://s3.amazonaws.com/brainscape-prod/system/cm/358/537/237/a_image_thumb.png?1634342005)
When muscles of facial expression contract, they move this instead of a joint
they move the skin rather than a joint
Frontal belly
Origin: Epicranial aponeurosis.
Insertion: Skin superior to supraorbital margin.
![](https://s3.amazonaws.com/brainscape-prod/system/cm/358/537/239/a_image_thumb.png?1634342049)
Zygomaticus major
origin: zygomatic bone.
insertion: sides of mouth
Draws angle of mouth superiorly and laterally, as in smiling.
Zygomaticus minor
origin= zygomatic bone. Raises upper lip, shows teeth
Levator labii superioris
Raises upper lip.
Temporalis *
Elevates and retracts mandible.
Original temporal bone, insert, coronoid process and ramus of mandible
Platysma *
Large muscle front of neck,
origin: Fascia over deltoid and pectoralis major muscles.
Draws outer part of lower lip inferiorly and posteriorly as in pouting; depresses mandible
![](https://s3.amazonaws.com/brainscape-prod/system/cm/358/537/245/a_image_thumb.png?1634589302)
Masseter *
Elevates mandible, as in closing mouth.
Medial pterygoid *
Elevates and protracts (protrudes) mandible and moves mandible from side to side.
Origin: Medial surface of lateral portion of pterygoid process of sphenoid bone; maxilla.
Insertion: Angle and ramus of mandible.
Medial pterygoid *
Protracts mandible, depresses mandible as in opening mouth, and moves mandible from side to side.
Origin: Greater wing and lateral surface of lateral portion of pterygoid process of sphenoid bone.
Insertion: Condyle of mandible; temporomandibular joint (TMJ).
Sternocleidomastoid *
Action: Acting together (bilaterally), flex cervical portion of vertebral column, extend head at atlanto-occipital joints; acting singly (unilaterally), laterally flex neck and head to same side and rotate head to side opposite contracting muscle. Laterally rotate and flex head to opposite side of contracting muscle. Posterior fibers of muscle can assist in extension of head. RMA: Elevate sternum during forced inhalation.
Origin: Sternal head: manubrium of sternum; clavicular head: medial third of clavicle.
Insertion: Mastoid process of temporal bone and lateral half of superior nuchal line of occipital bone.
The anterolateral abdominal wall is composed skin, fascia, and four pairs of muscles: (4 names)
rectus abdominus, external abdominal oblique, internal abdominal oblique, transverse abdominus
Linea Alba
white line in centre of abdomen separating muscles
Rectus Abdominus
Flexes vertebral column, especially lumbar portion, and compresses abdomen to aid in defecation, urination, forced exhalation, and childbirth. RMA: Flexes pelvis on the vertebral column.
Origin: Pubic crest and pubic symphysis.
Insertion: Cartilage of ribs 5–7 and xiphoid process.
Rectus Abdominus*
Flexes vertebral column, especially lumbar portion, and compresses abdomen to aid in defecation, urination, forced exhalation, and childbirth. RMA: Flexes pelvis on the vertebral column.
Origin: Pubic crest and pubic symphysis.
Insertion: Cartilage of ribs 5–7 and xiphoid process. (crunches abdomen and flexes pelvis) normally, insertion portion moves. In this case * insertion area does no move, and the origin portion moves! * REVERSED
Rectus Abdominus*
Flexes vertebral column, especially lumbar portion, and compresses abdomen to aid in defecation, urination, forced exhalation, and childbirth. RMA: Flexes pelvis on the vertebral column.
Origin: Pubic crest and pubic symphysis.
Insertion: Cartilage of ribs 5–7 and xiphoid process. (crunches abdomen and flexes pelvis) normally, insertion portion moves. In this case * insertion area does no move, and the origin portion moves! * REVERSED
Internal abdominal oblique *
Acting together, compress abdomen and flex vertebral column; acting singly, laterally flex vertebral column, especially lumbar portion, and rotate vertebral column.
Origin:: Iliac crest, inguinal ligament, and linea alba.
Insertion: Cartilage of ribs 7–10 and thoracolumbar fascia.
Transversus abdominis*
Compresses abdomen.
Origin: Iliac crest, inguinal ligament, lumbar fascia, and cartilages of ribs 5–10.
Insertion: Xiphoid process, linea alba, and pubis.
Quadratus lumborum
Acting together, pull 12th ribs inferiorly during forced exhalation, fix 12th ribs to prevent their elevation during deep inhalation, and help extend lumbar portion of vertebral column; acting singly, laterally flex vertebral column, especially lumbar portion. RMA: Elevates hip bone, commonly on one side.
Origin: Iliac crest and iliolumbar ligament.
Insertion: Inferior border of rib 12 and L1–L4.
The muscles of which area allow breathing?
The muscles of the thorax alter the size of the thoracic cavity so that breathing can occur
What are the muscles of the thorax?
Diaphragm, Internal intercostals, External intercostals
Diaphragm
Action: Contraction of diaphragm causes it to flatten and increases vertical dimension of thoracic cavity, resulting in inhalation; relaxation of diaphragm causes it to move superiorly and decreases vertical dimension of thoracic cavity, resulting in exhalation. (Major muscle to assist breathing)
Origin: Xiphoid process of sternum, costal cartilages and adjacent portions of ribs 7–12, lumbar vertebrae and their intervertebral discs. Insertion: Central tendon.
External intercostals
Action: Contraction elevates ribs and increases anteroposterior and lateral dimensions of thoracic cavity, resulting in inhalation; relaxation depresses ribs and decreases anteroposterior and lateral dimensions of thoracic cavity, resulting in exhalation.
Origin: Inferior border of rib above.
Superior: Superior border of rib below.
*OPPOSITE TO INTERNAL INTERCOSTAL*
Internal intercostals *
Action: Contraction draws adjacent ribs together to further decrease anteroposterior and lateral dimensions of thoracic cavity during forced exhalation. *OPPOSITE to EXTERNAL INTERCOSTAL*
Origin: Superior border of rib below.
Insertion: Inferior border of rib above.
(Origin of internal is the insertion of the external, and vice versa. They work together.)
How are the internal / external intercostal muscles opposite? *
The insertion of one is the origin of the other and vice versa
Muscles of the Thorax that move the pectoral girdle
Anterior: Subclavicus, Pectoralis minor
Serratus anterior
Posterior: Levator scapulae, trapezius, Rhomboid major , Rhomboid minor
,
Muscles of the Thorax and Shoulder that Move the Humerus
AXIAL:
Pectoralis major, Latissimus dorsi
SCAPULAR: Deltoid, Subscapularis , Supraspinatus, Infraspinatus, Teres major, Coracobrachialis,
Triceps Bracchii* What are the heads?
Has three heads:
Long head
Lateral head
Medial Head
Biceps Bracchi* What are the heads?
2 heads:
Long head
Short head