Anatomy of Compartment Syndromes

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Questions and Answers

What condition results from elevated tissue pressure within a closed muscle compartment?

Ruptured calcaneal tendon

Avulsion fracture

Foot drop

Anterior Compartment Syndrome (correct)

Which of the following is NOT a typical cause of Anterior Compartment Syndrome?

Trauma

Cumulative nerve damage (correct)

Prolonged limb compression

Exertion

What is the primary action associated with the muscles found in the lateral compartment of the leg?

Dorsiflexion of the foot

Extension of the knee

Flexion of the toes

Eversion of the ankle (correct)

Which demographic is more commonly affected by a ruptured calcaneal tendon?

Men ages 30-40 Signup and view all the answers

What characterizes foot drop?

Inability to dorsiflex the foot Signup and view all the answers

What is the primary function of skeletal muscles in relation to movement?

Producing movement and maintaining posture Signup and view all the answers

Which fiber arrangement is characteristic of a muscle designed for powerful contractions?

Pennate Signup and view all the answers

Which of the following muscle names indicates a muscle that assists in the movement?

Synergist Signup and view all the answers

What distinguishes a bipennate muscle from a unipennate muscle?

Number of tendons Signup and view all the answers

Which of the following muscles is primarily responsible for facial expressions?

Orbicularis Oculi Signup and view all the answers

What does the term 'agonist' refer to in muscle functional groups?

Muscle that performs the primary action Signup and view all the answers

Which of the following muscles is categorized as a muscle of mastication?

Masseter Signup and view all the answers

Which muscle action is associated with the term 'elevation'?

Lifting a body part upwards Signup and view all the answers

What action does the sternocleidomastoid perform?

Flexion and rotation of the head Signup and view all the answers

Which muscles are responsible for extending the head and back?

Erector spinae Signup and view all the answers

What is the primary action of the latissimus dorsi muscle?

Adducts and rotates the humerus medially Signup and view all the answers

What is the consequence of weakness in the trapezius muscle?

Drooping of the shoulders Signup and view all the answers

What is the origin of the serratus anterior muscle?

External surfaces of the lateral parts of the 1-8th rib Signup and view all the answers

Which muscle initiates the first 15° of abduction of the humerus?

Supraspinatus Signup and view all the answers

What action is primarily attributed to the external abdominal oblique muscle?

Flexes and laterally bends the trunk Signup and view all the answers

What movement does the subscapularis muscle primarily perform?

Medially rotates the humerus Signup and view all the answers

Which of the following muscles is NOT considered part of the rotator cuff?

Latissimus dorsi Signup and view all the answers

What is a common cause of rotator cuff injuries?

Repetitive use of the upper limb above horizontal Signup and view all the answers

Which muscle originates from the coracoid process?

Biceps brachii - short head Signup and view all the answers

What is the primary action of the gluteus maximus muscle?

Extending the thigh Signup and view all the answers

What is the primary action of the triceps brachii?

Extension at the elbow Signup and view all the answers

Which muscle primarily assists with medial rotation at the thigh?

Gluteus Minimus Signup and view all the answers

Which part of the biceps brachii is more commonly involved in a rupture?

Long head Signup and view all the answers

Which nerve innervates the muscles of the anterior thigh compartment?

Femoral nerve Signup and view all the answers

What is the consequence of a proximal biceps tear?

Significant loss of forearm supination Signup and view all the answers

Which muscle acts as a weak flexor of the forearm when the forearm is in a neutral position?

Brachioradialis Signup and view all the answers

What is the main action of the iliopsoas muscle group?

Flexion of the thigh at the hip Signup and view all the answers

Which of the following muscles is NOT part of the posterior thigh compartment?

Gracilis Signup and view all the answers

What bones are involved in the anatomical snuffbox?

Scaphoid and trapezium Signup and view all the answers

Which action is associated with the muscles of the lateral compartment of the leg?

Eversion of the ankle Signup and view all the answers

Which muscle is primarily responsible for the extension of the leg at the knee?

Rectus femoris Signup and view all the answers

Which action do the muscles of the medial thigh compartment primarily perform?

Adduction of the thigh Signup and view all the answers

Study Notes

The Muscular System

The muscular system is responsible for movement, posture, and various other functions.
Muscles are categorized in different types: skeletal, smooth, and cardiac.
Skeletal muscles are responsible for voluntary movements.
Smooth muscles are responsible for involuntary movements, like digestion.
Cardiac muscles are responsible for the heartbeat.

Muscle Types

Skeletal muscles are responsible for voluntary movements, like walking or lifting.
Smooth muscles are responsible for involuntary movements, such as the movement of food in the digestive tract.
Cardiac muscles form the heart muscle and are responsible for the pumping action of the heart.

Functions of Skeletal Muscles

Movement (articulation): Skeletal muscles enable movement of bones at joints, including walking.
Stop movement: Muscles work in opposing pairs to enable controlled stopping of movement.
Posture: Maintaining body position.
Stabilizing Joints: Muscles help in stabilization of joints.
Facial Expression: Muscles control expressions of the face.
Controlling Substances: Muscles control the movement of materials within the body (e.g. sphincters during urination).
Respiration: Muscles responsible for breathing. The diaphragm is a key muscle in respiration.
Protection: Muscles provide protection to organs beneath them.
Homeostasis: Helps regulate body temperature (heat production).

Structure of Skeletal Muscles

Anatomy:
- Muscle fiber: The individual muscle cell.
- Endomysium: Connective tissue surrounding individual muscle fibers.
- Fascicle/fasciculus: Bundle of muscle fibers.
- Perimysium: Connective tissue surrounding fascicles/fasciculus.
- Epimysium: Connective tissue surrounding the entire muscle.
- aa., vv., nn.: Arteries, veins, and nerves of the muscle.

Fascicle Arrangement/Shapes

Parallel: Fibers run parallel to the muscle's long axis (e.g., sartorius).
Convergent: Fibers converge towards a single tendon (e.g., pectoralis major).
Pennate: Fibers are organized at an angle to the tendon, increasing powerful muscle contractions (e.g., deltoid).
- Unipennate: Fibers run diagonally to a central tendon (e.g., extensor pollicis longus).
- Bipennate: Fibers run diagonally to each side of a central tendon (e.g., rectus femoris).
- Multipennate: A combination of fibers on multiple sides and angles to the central tendon.
Sphincters, Spiral and Fusiform: Muscles organized in different structural arrangements.

Naming of Muscles

Shape: Describing the shape of the muscle (e.g., trapezius, deltoid).
Size: Different sizes, such as maximus, medius, minimus.
Length: Using terms like "brevis" (short) and "longus" (long).
Position Relative to midline (lateralis, medialis): Terms describing location relative to the body's midline.
Direction: Describing the orientation of muscle fibers (rectus, oblique).
Location: Describing the location of the muscle in the body.
Attachments to skeleton: Describing where the muscle attaches to the skeleton (e.g., sternocleidomastoid).
Number of origins and insertion: The number of places the muscle attaches.
Actions: Describes the function of the muscle (flexor, extensor, abductor, adductor, etc.).

Functional Groups

Agonist: Prime mover muscle
Antagonist: Opposing muscle group
Synergist: Muscles working together to help the agonist.
Fixator: Stabilizing muscles.

Origins and Insertions

Origin: Fixed point of attachment of a muscle that remains stationary during contraction.
Insertion: Movable point of attachment of a muscle that moves during contraction.

Muscles of Facial Expression

Facial expressions are conveyed through specific facial muscles.
These muscles originate from bone or flat tendons and insert onto the hypodermis of the skin.
The facial nerve (CN VII) controls these muscles.

Platysma

Platysma is a neck muscle that tenses the skin of the neck and depresses the lower lip.

Orbicularis Oris

Purs and compresses the lips, and helps with speech articulation and mastication.

Buccinator

This muscle pushes food against the teeth.
It is also involved in whistling and sucking actions, and keeping cheek taut.

Orbicularis Oculi

Orbital and Palpebral regions are controlled by a specific set of muscles. The lacrimal region is controlled by different muscles.

Facial Paralysis

Facial paralysis can lead to asymmetry in facial expressions.

Muscles of Mastication

Temporalis and Masseter muscles are responsible for chewing. Temporalis muscle is involved in protrusion, retraction, and elevation, while Masseter assists in elevation and retraction of the mandible.

Sternocleidomastoid

The sternocleidomastoid assists in head movement – flexion and rotation.

Torticollis

Torticollis is a condition that can lead to a twisted neck.

Muscles of the Abdominal Wall

Abdominal muscles are responsible for movements related to posture and stability.

Anterolateral Abdominal Wall Muscles

External abdominal oblique, internal abdominal oblique, and transversus abdominis muscles control movements of the trunk and abdomen.

Median Incisions

Medial incisions involve surgical approaches to the abdominal muscles.

Erector Spinae m.

The erector spinae muscles extend the head and back, laterally flex the head and vertebral column, and rotate the head.

Latissimus Dorsi

The latissimus dorsi muscles extend, adduct, and medially rotate the humerus.

Serratus Anterior

The serratus anterior muscle protracts and stabilizes the scapula.

Winged Scapula

Winged scapula is a condition of scapular protrusion.

Trapezius

The trapezius muscle elevates, retracts, and depresses the scapula, and assists in controlling the shoulder.

Deltoid

The deltoid muscle is involved in abduction, flexion, medial rotation, and lateral rotation of the humerus.

Intramuscular Injection

Guidelines for correct intramuscular injections, particularly in the deltoid muscles.

Rotator Cuff Muscles

Supraspinatus, infraspinatus, teres minor, and subscapularis are the key rotator cuff muscles. Their roles include abduction and rotation of the humerus.

Supraspinatus, Infraspinatus & Teres Minor mm.

These muscles are part of the rotator cuff complex. They initiate abduction and assist the deltoid muscle in the movement, as well as facilitate lateral and medial rotations.

Subscapularis m.

The subscapularis is one of the rotator cuff muscles that rotates the humerus medially and adducts the arm.

Rotator Cuff Injuries

Rotator cuff injuries commonly occur from repetitive actions, or rapid abduction followed by rotation.

Biceps brachii m.

The biceps brachii muscle is involved in flexion at the elbow and shoulder, and supination.

Rupture of Biceps

Rupture of the biceps can be caused by injury or degeneration.

Brachioradialis m.

The brachioradialis muscle is a weak flexor of the forearm, and it strengthens flexion when in a neutral or mid-pronated position.

Triceps Brachii m.

The triceps brachii muscle is involved in extension of the elbow, and at the shoulder.

Anatomical Snuffbox

The anatomical snuffbox region has specific landmarks for locating important structures.

Gluteal Muscles

Gluteus maximus, medius, and minimus are important gluteal muscles. The gluteus maximus is responsible for extension and lateral rotation of the thigh. The gluteus medius and minimus are involved in abduction and medial rotation of the thigh.

Gluteus Maximus m.

Gluteus maximus is the largest gluteal muscle and it extends and laterally rotates the thigh. It's used during walking.

Gluteus Medius & Minimus mm.

Gluteus medius and minimus abduct and medially rotate the thigh, and support the pelvis while standing or walking.

Intramuscular Gluteal Injections

Guidelines for safe and effective intramuscular injections in gluteal areas.

Positive Trendelenburg

Diagnosis to asses the health of the gluteus medius.

Anterior (Thigh) Compartment

The anterior compartment of the thigh contains various extensor muscles, including the iliopsoas, pectineus, sartorius, and quadriceps muscles.

Quadriceps Femoris m.

Quadriceps femoris is a large muscle composed of four heads; it extends the knee. The rectus femoris, vastus lateralis, vastus intermedius, and vastus medialis are its component muscles.

Iliopsoas m.

The iliopsoas muscle flexes the thigh at the hip and stabilizes the hip joint.

Medial (Thigh) Compartment

Medial thigh muscles include the adductor longus, brevis, magnus, and gracilis. They all adduct, and medially rotate the thigh.

Posterior (Thigh) Compartment

Muscles of the posterior compartment (thigh) are responsible for flexion of the leg at the knee, and extension of the thigh. The semitendinosus, semimembranosus, and biceps femoris are key examples.

Muscles of the Leg (Compartments)

The muscles of the leg have differing functions depending on their location (anterior, lateral, posterior) which include plantar/dorsi flexion, eversion/inversion, and extension of toes.

Anterior (Leg) Compartment

Tibialis anterior m., Extensor hallucis longus m., and Extensor digitorum longus m. All perform dorsiflexion and toe extension.

Anterior Compartment Syndrome

It's a medical condition when tissue pressure in a closed muscle compartment becomes high, causing nerve and muscle damage.

Foot Drop

Inability to dorsiflex the foot can be a symptom of conditions such as nerve and/or muscle damage.

Lateral (Leg) Compartment

Peroneus longus m. and Peroneus brevis m. muscles are pivotal for plantar flexion and eversion of the ankle.

Avulsion Fracture

An avulsion fracture is a type of fracture caused by a tendon or ligament pulling away from the bone. It's often associated with sudden inversion and twisting movements, affecting the 5th metatarsal tuberosity.

Posterior (Leg) Compartment

The posterior compartment of the leg contains muscles responsible for plantarflexion and flexion of toes - examples of these are Gastrocnemius m., Soleus m., and Plantaris m..

Ruptured Calcaneal Tendon

A rupture of the calcaneal tendon is a common injury, especially in middle-aged men, often associated with sports activity or sudden forceful movements.

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Description

Test your knowledge on compartment syndromes, particularly focusing on the anatomy and conditions associated with them. This quiz covers topics such as the causes, symptoms, and demographics related to compartment issues in the leg. Challenge yourself to identify key concepts related to muscle compartments and their functions.