HBS Subunit 2

Subunit 2

Types of Muscle tissues

Skeletal, smooth, cardiac

Striated

Sarcomere, functional units, are repeating in a muscle tissue

Voluntary

Controlled consciously, intentional movements are allowed

Is skeletal striated and is it voluntary?

Yes, yes

Is smooth striated and is it voluntary?

No, no

Is cardiac striated and is it voluntary?

Yes, no

Location of skeletal

Between bones

Tendons attach these muscles to bones

Examples of skeletal

Tongue, hamstring, muscle, finger muscles

Location of smooth

Walls of hollow organs and blood vessels

Examples of smooth

Stomach, uterus, intestines, blood vessels, etc.

Location of cardiac

The heart

Function of skeletal muscle

Voluntary movement; locomotion; manipulation of the environment; facial expression

Function of smooth muscle

It closes and opens airways

Maintains blood pressure

Involuntary movement controller

Collects nutrients

Function of cardiac muscle

As it contracts, it propels blood into the circulation; involuntary control

What is a tendon

They are a fibrous connective tissue that attach muscles to bones.

What is a ligament

It attaches bone to bone as it is a fibrous connective tissue.

Compare and contrast the three types of muscles

There are in striations in smooth muscle unlike cardiac and skeletal muscle. Cardiac muscle contains intercalated discs compared to skeletal and smooth muscle tissues which have none.

Contraction

Muscles shortening

What is ATP?

Almost all physiological process in the body are powered by ATP, an energy molecule. To produce ATP, oxygen reacts with carbohydrate glucose in the cell.

What is ATP's function?

An energy molecule for cells

Contraction % Formula

Original length-final length/original length X 100

What role does calcium play in muscle contraction?

It exposes myosin binding sites by causing a change in the troponin complex's position on actin filaments.

How does calcium trigger muscle contraction?

It reacts with regulatory proteins.

Sarcomere

Striated muscle fibers repeating. It is the smallest muscle unit

What is sarcomere made of?

It is made up of 2 proteins: actin and myosin

Actin

Thin filaments

Myosin

Thick filaments

Actin and myosin do not shorten, but slide

True

Troponin

It is a type of proteins of muscle that forms a regulatory protein complex with tropomyosin to control actin and myosin's interactions which allow muscular contraction when combined with calcium ions.

Tropomyosin

A protein of muscle that forms a complex with troponin regulating the interaction of actin and myosin in muscular contraction. It's main function is to stop the muscle from contracting at the incorrect time.

Acetylcholine

A neurotransmitter that enables learning and memory and also triggers muscle contraction

What is a physiatrist

A physician who specializes in rehab medicine

Remember

Muscles don't work alone. An abundant supply of blood vessels brings nutrients and oxygen to muscles while also removing wastes. Nerves control when muscles contract and how strong those contractions are.

Muscle Rule 1

Muscles have at least two attachments and cross at least one joint

Muscle Rule 2

Muscles always pull and get shorter

Muscle Rule 3

The attachment that moves is known as the insertion of a muscle and the attachment that remains stationary is known as the origin.

Origin is usually

Proximal (It pulls the other attachment towards it)

Insertion is usually

Distal

Muscle Rule 4

Muscles that decrease the angle between ventral surfaces of the body are known as flexors. Muscles that increase the angle between ventral surfaces of the body are known as extensors

Extensor

Muscle that increases the angles of two joints

Flexor

Muscle that decreases the angle of two joints

Example of Muscle Rule 4

The insertion is the proximal ulna. The action is to flex or bend at the elbow.

Example of Muscle Rule 2

Ulnar attachment is being pulled forward while the humerus attachment is staying stationary.

Muscle Rule 5

Muscles work in opposing pairs

Antagonist Pair

Muscles that act on opposite sides of a joint

Antagonist

Muscle that relaxs

Agonist

Muscle that contracts

Muscle Rule 6

Muscle striations point to the attachments and show the direction of the pull

Trapezius and Rhomboid Minor

Trapezius is either one of two large superficial muscles that extend longitudinally from the occipital bone to the lower thoracic vertebrae. Rhomboid minor is a small skeletal muscle on the back that connects the scapula with the vertebrae of the spinal column.

Reason for Trapezius and Rhomboid Minor name

Trapezius is shaped like trapezoid. Rhomboid is shaped like a rhombus.

Where does the gluteus maximus arise from?

The posterior gluteal line of the inner upper ilium.

What is the shape of the gluteus minimus?

Fan-shaped.

Where does the gluteus minimus arise from?

The outer surface of the ilium.

Gluteus Maximus and Gluteus Minimus Classification

They are divided into two groups: Extenders and superficial abductors

Reason for Gluteus Maximus and Gluteus Minimus

"Maximus" means greatest, "minimus" means smallest and "gluteus" means buttocks.

Frontalis and Temporalis

Classified by location in the body

Reason for Frontalis and Temporalis name

On top of the frontal bone, the Frontalis is located there. The temporal fossa is the origin of the Temporalis location.

Orbicular Oculi and Transverse Abdominis

The fiber direction

Reason for Orbicular Oculi and Transverse Abdominis name

Fibers in orbicularis oculi form a circle. Fibers in transverse abdominis "traverse" or go across the abdomen.

Flexor Carpi Ulnaris and Extensor Digitorum Longus

Classified by action. The flexor carpi ulnaris muscle is a muscle of the human forearm that acts to flex and adduct the hand. The extensor digitorum longus is a pennate muscle, situated at the lateral part of the front of the leg.

What does 'carpus' mean?

Wrist

What is the function of the Flexor Carpi Ulnaris?

It flexes and abducts the wrist.

What does the Extensor Digitorum Longus do?

It extends the four medial fingers at the distal and proximal interphalangeal joints and metacarpophalangeal joints.

Sterno Cleidomastoid and Brachioradialis

Classified by origin and insertion

Reason for Sterno Cleidomastoid and Brachioradialis name

Sterno cleidomastoid is named after its origin of the sternum's manubrium. Brachioradialis is named after its origin of the humerous's distal part. The distal radius is the insertion.

Biceps Brachii and Triceps Brachii

Triceps Brachii is thick, large, and fusiform. Function: The elbow joint is where the extension of the triceps occurs

Reason for Biceps Brachii and Triceps Brachii name

Triceps brachii ha three heads-long, lateral, and medial.

The biceps brachii has two heads at the proximal attachment

Pectoralis minor origin

Anterior surface of ribs 3-5

Pectoralis minor insertion

Coracoid process of scapula

Pectoralis minor action

Rotates the shoulder forward

Abdominal Head of Pectoralis Major origin

Coastal cartilage ribs 5-7, (fascia of the abdominal muscles)

Abdominal Head of Pectoralis Major insertion

Lateral edge of the most proximal part of the humerus

Abdominal Head of Pectoralis Major action

Extension and adduction of the humerus at the shoulder joint, pulls the arm down; is used during a volleyball spike

Sternal head of pectoralis major origin

Ribs 1-5 on lateral edge of sternum

Sternal head of pectoralis major insertion

Lateral edge of humerus

Sternal head of pectoralis major action

Abducts the arm across the chest; is used during a sidearm pitch in baseball

Clavicular head of the pectoralis major origin

Medial half of the inferior edge of the clavicle

Clavicular head of the pectoralis major insertion

Lateral edge of the proximal humerus

Clavicular head of the pectoralis major action

Allows underhand motions; is used in bowling

Your friend comes back from the doctor and says they have pulled their tibialis anterior. What can you deduce about this muscle?

It means that the muscle was stretched too far. This causes part of the muscle to tear. They tore a tendon from a muscle near the shin.

Fibrous Joint: Immoveable

It is a fixed joint that connects bones. It is mostly made of collagen.

Cartilaginous joints: Slightly moveable

Allow only slight movement and consist of bones connected entirely by cartilage. In the space between articulating bones, there is hyaline cartilage present to connect the bones.

Synovial joint: Freely moveable

A fully moveable joint in which the synovial (joint) cavity is present between the two articulating bones

What is the most common joint?

Synovial joint which provides cushion for the joint's bones. To reduce friction, synovial fluid is found in the space around this joint.

1. Pivot Joint

A joint where the rounded portion of a bone is enclosed within a ring formed partially by the articulation with another bone and partially by a ligament.

Which vertebrae are an example of a pivot joint?

C1 and C2 vertebrae.

2. Hinge Joint

-Type of joint found between the trough shape of one bone and the rounded shape of another bone. The bones articulate similar to a hinge

-allows only for bending and straightening motions along a single axis

3. Saddle Joint

A joint between two bones that have a saddle shape. Concave (ex.inside of a shape) articular surfaces are what each bone has in 1 direction and convex (ex: out of joint) in other direction. A huge range of motion in 2 different axes is what this type of joint allows.

4. Plane (Planar) Joint

A type of joint found between 2 or more bones' flat surfaces.

How do bones move in a Plane Joint?

The bones glide against each other instead of articulating around each other.

What is another name for a Plane Joint?

Glide joint.

What limits the range of movement in a Plane Joint?

Strong ligaments surrounding the joint.

5. Condyle Joint (Ellipsoid Joint)

Between the shallow oral depression of one bone and the rounded oval surface of another bone. The joint is provided with a wide range of motion including flexion & extension, adduction & abduction, and a degree of circumlocution due to oral surfaces. Movements are limited by surrounding ligaments & the articular surfaces.

6. Ball & Socket Joint (Spheroidal Joint)

Joint in which the cup-like or socket-shaped surface of one bone articulates with the spherical head of another bone. Widest range of motion. Along multiple axial planes, the bone with the spherical end articulates. It allows for adduction & abduction, internal & external rotation, extension & flexion, and circumduction.

Ball and Socket Joint is found where?

It is only found in the hip and shoulder joints.

Rotation

Towards or away from the midline of the body. The limb moves around a fixed joint in a circular movement. At a pivot joint, the only motion allowed is rotation. This means that a bone moves in relation to another bone.

External Rotation

A joint rotating away from the midline.

Internal

A joint rotating towards the midline.

Where does rotation occur?

Occurs at a pivot joint, inside vertebral column, and ball-and-socket joint

Circumduction

It is the movement of an extremity or limb with the distal end moving in a circle while the proximal end remains stationary.