B) Scaphoid and trapezium

Explanation: The flexor retinaculum is attached to the scaphoid and trapezium bones on the radial side of the carpal tunnel.

A) Surface of the skull at the edges of the temporal muscle

Explanation: The temporal fascia, or fascia temporalis, originates from the surface of the skull at the edges of the temporal muscle and covers it.

C) Coracobrachialis

Explanation: The coracobrachialis is one of the muscles in the anterior compartment of the arm, along with the biceps brachii and brachialis.

B) To attach muscles to bones or ligaments

Explanation: Muscle tendons are bands of connective tissue of various lengths and widths that attach the muscles to bones or ligaments, facilitating movement.

C) Biceps brachii

Explanation: The biceps brachii is part of the anterior compartment of the arm, not the shoulder girdle. The shoulder girdle muscles include the deltoid, supraspinatus, infraspinatus, teres minor, teres major, and subscapularis.

C) Striated muscle

Explanation: Striated muscles regenerate from myosatellite cells, which are specialized cells that aid in muscle repair and regeneration.

B) By contracting and generating heat

Explanation: Muscles help maintain body temperature through the process of contraction, which generates heat and helps regulate the body's internal temperature.

C) 4

Explanation: There are 4 tendons of the flexor digitorum superficialis that pass through the carpal tunnel.

C) Median nerve

Explanation: The median nerve is the nerve that passes through the carpal tunnel along with the tendons of the flexor muscles.

C) Myofibrils

Explanation: Actin and myosin are structured to form essential cell organelles known as myofibrils, which are capable of converting chemical energy into mechanical force, leading to cell contraction.

C) Parotideomasseteric fascia

Explanation: The parotideomasseteric fascia, or fascia parotideomasseterica, covers the masticatory muscle from the outside and forms the sheath of the parotid salivary gland.

C) They are spindle-shaped

Explanation: Fusiform muscles are characterized by their spindle shape, which means they are wider in the middle and taper towards both ends.

C) 60%

Explanation: Approximately 60% of the nerve fibers in muscles are motor (efferent) fibers, which are responsible for stimulating muscle contractions.

B) Short muscles

Explanation: Short muscles are described as filling the interosseous spaces, which are the spaces between bones.

D) Face muscles

Explanation: The face muscles do not have fascia, which is a distinctive feature compared to other muscle groups in the head.

C) To surround and protect long tendons from friction and injury

Explanation: Tendon synovial sheaths surround the long tendons of the forearm or calf muscles, protecting them from friction and injury.

C) Converting chemical energy into mechanical force

Explanation: Myofibrils are essential cell organelles in muscle cells that convert chemical energy into mechanical force, which is the force of cell contraction.

C) Belly

Explanation: The belly of the muscle is the contractile part located between the head and the tail of the muscle.

B) A group of muscle fibers innervated by a single motor neuron

Explanation: A motor unit consists of a group of muscle fibers that are all innervated by a single motor neuron, allowing them to contract simultaneously.

C) Muscle thickens but does not shorten during contraction

Explanation: Isometric contraction is defined by the muscle thickening while maintaining its length, meaning it does not shorten during the contraction.

B) The volume of the muscle changes

Explanation: The amount of muscle fibers does not change from birth, but the volume of the muscle changes as all contractile elements, such as the sarcolemma and myofibrils, increase.

C) Continuous and passive partial contraction of muscles

Explanation: Muscle tonus refers to the continuous and passive partial contraction of muscles, or the muscle's resistance to passive stretch during the resting state.

D) Pronator quadratus

Explanation: The pronator quadratus is responsible for pronation and is part of the deep layer of the anterior compartment of the forearm.

B) Short tendon, fixed point

Explanation: The head of a muscle is characterized by a short tendon and serves as the fixed point of the muscle.

C) Cardiac muscle

Explanation: Cardiac muscle is the type of muscle tissue found in the heart, specifically forming the myocardium, which is the muscular part of the heart wall.

B) Long tendon, mobile point

Explanation: The tail of a muscle is usually characterized by a longer tendon and serves as the mobile point of the muscle.

C) Skeletal muscle

Explanation: Skeletal muscle is striated and under voluntary control, distinguishing it from smooth and cardiac muscles.

E) Extensor carpi ulnaris

Explanation: The extensor carpi ulnaris is part of the superficial layer of the posterior compartment of the forearm, not the deep layer.

C) Triceps brachii

Explanation: The triceps brachii, located in the posterior compartment of the arm, has three heads: long, lateral, and medial.

D) Extensor pollicis longus

Explanation: The extensor pollicis longus is listed as part of the deep layer of the posterior compartment of the forearm, distinguishing it from the superficial layer muscles.

D) Motor neuron

Explanation: Proprioceptors include muscular spindles and tendon spindles, which help in sensing the position and movement of the body. Motor neurons are not proprioceptors; they are involved in stimulating muscle contractions.

C) Rectus abdominis

Explanation: The rectus abdominis is part of the anterior group of abdominal muscles, along with the rectus sheath and transverse fascia.

D) Frontal belly

Explanation: The epicranius muscle group includes the frontal belly and the occipital belly, connected by the galea aponeurotica.

B) To cover and protect muscles and their groups

Explanation: Fascia are connective tissue membranes of various thicknesses that cover each muscle and its groups, allowing a single muscle or muscle group to contract effectively.

B) Interaction between actin and myosin

Explanation: Muscle movement is determined by the interaction between two proteins, actin and myosin, which are essential for the contraction and movement of muscles.

D) Producing red blood cells

Explanation: Muscles perform various functions such as performing movements, forming body shape, stabilizing joints, and protecting internal organs. However, producing red blood cells is a function of the bone marrow, not muscles.

B) Extensor carpi radialis longus

Explanation: The extensor carpi radialis longus is listed as part of the superficial layer of the posterior compartment of the forearm, distinguishing it from the deep layer muscles.

C) Gluteal fascia

Explanation: The gluteal fascia specifically surrounds the gluteus maximus and medius muscles, providing support and structure to these muscles in the lower limb.

C) Smooth muscle

Explanation: Smooth muscle is found in the walls of internal organs and is not under voluntary control, unlike skeletal muscle.

B) Contraction, movement, work

Explanation: The primary function of skeletal muscle is to facilitate contraction, movement, and work, which are essential for various bodily activities.

C) The science of the structure of the skeletal muscle system

Explanation: Myology is defined as the science of the structure of the skeletal muscle system, also known as systema musculare.

D) A thickened lateral portion of the fascia lata

Explanation: The iliotibial tract is a thickened lateral portion of the fascia lata, running along the outside of the thigh from the hip to the knee, and plays a crucial role in stabilizing the knee.

D) Systema musculare

Explanation: The skeletal muscle system is also referred to as systema musculare.

B) Muscle shortens during contraction

Explanation: Isotonic contraction is characterized by the muscle shortening during the contraction process.

B) Weakly, with connective tissue appearing instead

Explanation: Cardiac muscle regenerates weakly, and instead of forming new muscle fibers, connective tissue appears in its place.

B) The whole thigh

Explanation: The fascia lata is a deep fascia that covers the entire thigh, providing support and compartmentalization for the muscles in this region.

C) Lumbricals and interosseous muscles

Explanation: The metacarpal region of the upper extremity contains the lumbricals and interosseous muscles, which are responsible for fine motor movements of the fingers.

E) Flexor carpi radialis

Explanation: The flexor carpi radialis is part of the superficial layer, not the deep layer. The deep layer includes extensor digitorum, flexor pollicis longus, flexor digitorum profundus, and pronator quadratus.

B) Brachial fascia

Explanation: The brachial fascia surrounds the muscles of the arm, encapsulating and supporting them.

C) Tibialis anterior

Explanation: The tibialis anterior is one of the muscles located in the anterior compartment of the leg, along with the extensor digitorum longus and extensor hallucis longus.

B) Orbicularis oris

Explanation: The orbicularis oris muscle encircles the mouth and is responsible for movements such as puckering the lips.

C) Trapezius

Explanation: The trapezius is listed as one of the appendicular back muscles, which also include the latissimus dorsi, rhomboideus major, rhomboideus minor, and levator scapula.

D) Extensor digitorum longus

Explanation: The extensor digitorum longus is part of the anterior compartment of the leg, not the deep layer of the posterior compartment, which includes the tibialis posterior, flexor digitorum longus, and flexor hallucis longus.

C) Outside the endomysium

Explanation: Lymphatic capillaries are located outside the endomysium and open into lymphatic vessels, which accompany the veins.

C) Nuchal fascia

Explanation: The nuchal fascia specifically covers the descending part of the trapezius muscle, distinguishing it from other fasciae that cover different regions or muscles.

C) Pumping blood through the heart

Explanation: Pumping blood through the heart is a function of cardiac muscle, not smooth muscle. Smooth muscles regulate blood flow, control air flow, and facilitate peristaltic movement.

B) Flexion of the knee and extension of the thigh

Explanation: The muscles in the posterior compartment of the thigh, including the biceps femoris, semitendinosus, and semimembranosus, primarily function to flex the knee and extend the thigh.

C) Intermediate fibers

Explanation: Intermediate fibers possess structural and functional characteristics of both Type I and Type II fibers, making them versatile in their function.

C) They are an active component of the locomotion system

Explanation: Striated muscles are an active component of the locomotion system, performing functions such as walking, running, and maintaining body statics like standing and sitting.

C) By providing a protective layer and absorbing impact

Explanation: Muscles protect internal organs by forming a protective layer around them and absorbing impacts that could otherwise damage these vital structures.

C) Complexed muscles

Explanation: Complexed muscles are characterized by having multiple heads, multiple bellies, or other complex structures, unlike simple muscles which have one head, one belly, and one tail.

A) Muscles that perform the same movement

Explanation: Synergists are muscles that work together to perform the same movement, enhancing the efficiency and strength of the action.

D) Somatic muscles

Explanation: Striated muscles are also referred to as somatic muscles, highlighting their role in voluntary movements and control.

B) Linea alba

Explanation: The lateral group of abdominal muscles includes the external and internal oblique, transversus muscles, and structures like the linea alba and umbilical ring.

B) Gastrocnemius and soleus

Explanation: The superficial layer of the posterior compartment of the leg includes the gastrocnemius and soleus muscles, which together form the triceps surae.

E) Buccinator

Explanation: The buccinator muscle is located in the cheek and is responsible for compressing the cheeks, as in blowing or sucking.

D) The neck organs and muscles

Explanation: The pretracheal layer, or lamina pretrachealis, covers the neck organs and muscles.

A) Sarcolemma

Explanation: The sarcolemma is the plasma membrane that encloses each muscle fiber, playing a crucial role in the transmission of action potentials.

C) 35-40 percent

Explanation: In adults, muscles make up approximately 35-40 percent of body mass, which is a significant portion of the human body.

C) In the walls of internal hollow organs

Explanation: Smooth muscles form the walls of internal hollow organs, such as the intestines, blood vessels, and the bladder, playing a crucial role in various visceral functions.

B) Obturator externus

Explanation: The obturator externus is one of the muscles listed as part of the pelvic muscles.

B) Week 4-5

Explanation: Myoblasts, which are the precursor cells to muscle tissue, form during weeks 4 to 5 of embryonic development.

C) Peroneus (fibularis) longus and peroneus (fibularis) brevis

Explanation: The lateral compartment of the leg contains the peroneus (fibularis) longus and peroneus (fibularis) brevis muscles, which are responsible for eversion and plantarflexion of the foot.

C) Flexor carpi radialis

Explanation: The flexor carpi radialis is listed as one of the muscles in the superficial layer of the anterior compartment of the forearm, along with pronator teres, palmaris longus, flexor carpi ulnaris, and flexor digitorum superficialis.

C) Deltoid muscle

Explanation: The deltoid fascia specifically covers the deltoid muscle, providing support and structure to this muscle in the upper limb.

C) Somatic nervous system

Explanation: Striated muscles are controlled by the complex somatic nervous system, which allows for voluntary control of muscle function.

C) Movement of the thumb

Explanation: The thenar muscles are a group of muscles located in the palm of the hand that are primarily responsible for the movement of the thumb.

C) They perform movements in the opposite direction

Explanation: Antagonists are muscles that perform movements in the opposite direction, allowing for controlled and coordinated motion.

C) Movement

Explanation: Movement is specifically mentioned as a sign of life, highlighting its importance in the context of the skeletal muscle system.

D) Lamina superficialis

Explanation: The lamina superficialis, or superficial layer, is responsible for covering the entire neck.

A) Myosin

Explanation: Myosin is a motor protein that interacts with actin filaments to produce muscle contraction through the sliding filament mechanism.

B) Increased risk of breast and colon cancer

Explanation: Insufficient muscle activity is linked to an increased risk of breast and colon cancer, among other health issues.

C) Serratus posterior inferior and serratus posterior superior

Explanation: The superficial layer of the back proper includes the serratus posterior inferior and serratus posterior superior muscles.

D) Enhanced muscle strength

Explanation: Insufficient muscle activity leads to negative health outcomes such as obesity, type 2 diabetes, cardiovascular diseases, and dementia, but it does not enhance muscle strength.

B) Lies at the lower back as aponeurosis

Explanation: The thoracolumbar fascia is located at the lower back and functions as an aponeurosis, providing support and structure to the lower back region.

C) By the autonomic nervous and endocrine systems

Explanation: Smooth muscles are involuntary and their function is controlled by the autonomic nervous system and the endocrine system, which regulate various involuntary bodily functions.

A) Type I (slow, red)

Explanation: Type I muscle fibers, also known as slow-twitch or red fibers, are rich in mitochondria and myoglobin, which support their endurance and oxidative metabolism.

C) 7 months

Explanation: Limb muscles develop around the 7th month of fetal development.

B) Muscles that move the little finger

Explanation: The hypothenar muscles are a group of muscles located on the ulnar side of the palm, responsible for the movement of the little finger.

B) Pectoralis major

Explanation: The pectoralis major is classified as an appendicular thorax muscle, along with the pectoralis minor and serratus anterior.

B) They branch and spread through the septum of the perimysium

Explanation: After passing through the epimysium, blood vessels branch and spread through the septum of the perimysium, eventually forming a meshwork of arterioles in the endomysium.

C) Erector spinae

Explanation: The erector spinae is part of the deep layer of the back proper, along with the musculi transversospinales.

B) Depression

Explanation: Insufficient muscle activity is associated with an increased risk of depression, highlighting the importance of physical activity for mental health.

C) Sartorius

Explanation: The sartorius muscle is part of the anterior compartment of the thigh, not the pelvic muscles.

C) Pectoral fascia

Explanation: The pectoral fascia specifically covers all pectoral muscles, distinguishing it from other fasciae that cover different regions or muscles.

C) Anterior scalene, middle scalene, posterior scalene

Explanation: The deep lateral group of the neck includes the anterior scalene, middle scalene, and posterior scalene muscles, which are involved in movements of the neck and rib elevation.

E) Sternocleidomastoid

Explanation: The sternocleidomastoid is not a masticatory muscle; it is involved in the movement of the head and neck. The masticatory muscles include the masseter, temporalis, lateral pterygoid, and medial pterygoid.

A) Masseter

Explanation: The masseter muscle is primarily responsible for elevating the mandible and closing the jaw, playing a crucial role in the process of mastication.

C) Surrounds the muscles of the forearm and forms the flexor and extensor retinaculum

Explanation: The antebrachial fascia surrounds the muscles of the forearm and forms the flexor and extensor retinaculum, providing structural support and facilitating movement.

D) Quadratus lumborum

Explanation: The quadratus lumborum muscle is part of the posterior group of abdominal muscles.

C) The large vessels and nerves of the neck

Explanation: The carotid sheath, or vagina carotica, covers the large vessels and nerves of the neck.

A) Endomysium

Explanation: The endomysium is a thin layer of connective tissue that wraps around each individual muscle fiber, providing structural support and separating the fibers.

D) 50-60 percent

Explanation: In athletes, muscles make up a higher percentage of body mass, ranging from 50-60 percent, due to their enhanced muscle development.

B) Biceps femoris, semitendinosus, semimembranosus

Explanation: The posterior compartment of the thigh includes the biceps femoris, semitendinosus, and semimembranosus muscles, which are primarily responsible for flexing the knee and extending the thigh.

C) Mesoderm

Explanation: Muscles develop from the mesoderm, which is one of the three primary germ layers in the early embryo.

C) Extensor digitorum brevis and extensor hallucis brevis

Explanation: The dorsum of the foot contains the extensor digitorum brevis and extensor hallucis brevis muscles, which are involved in extending the toes.

C) Diaphragm

Explanation: The diaphragm is a dome-shaped muscle that separates the thoracic cavity from the abdominal cavity and plays a crucial role in breathing by contracting and flattening to enlarge the thoracic cavity.

C) Through the hilum of the muscle

Explanation: Blood vessels and nerve fibers enter or leave the muscle through the hilum, which is typically located in the most immobile part of the muscle, usually near the tendon of the muscle head.

A) Lumbar, costal, and sternal parts

Explanation: The diaphragm consists of the lumbar, costal, and sternal parts, along with the central tendon.

D) Pulmonary aperture

Explanation: The diaphragm has three main apertures: the aortic, esophageal, and caval apertures. There is no pulmonary aperture.

C) About 600

Explanation: The human body contains about 600 muscles, which are essential for various movements and functions.

B) Quadriceps femoris

Explanation: The quadriceps femoris is part of the anterior compartment of the thigh, responsible for extending the knee.

C) Adductor longus, adductor magnus, gracilis, pectineus, adductor brevis

Explanation: The medial compartment of the thigh includes the adductor longus, adductor magnus, gracilis, pectineus, and adductor brevis muscles, which are primarily responsible for adducting the thigh.

B) Few mitochondria and high glycogen

Explanation: Type II muscle fibers, also known as fast-twitch or white fibers, have many evenly distributed myofibrils, few mitochondria and myoglobin, and high glycogen content, which supports their rapid contraction and anaerobic metabolism.

C) Muscles of the thumb

Explanation: The thenar muscles are a group of muscles located in the hand that are responsible for the movement of the thumb.

B) Latissimus dorsi

Explanation: The latissimus dorsi is a large, flat muscle on the back that stretches to the sides, behind the arm, and is partly covered by the trapezius on the back near the midline.

C) Platysma and sternocleidomastoideus

Explanation: The superficial layer of the neck includes the platysma and sternocleidomastoideus muscles, which are located just beneath the skin.

B) The points of action of muscles and resistance forces are on both sides of the lever

Explanation: A first-class lever, also known as a double-sided lever, has the points of action of muscles and resistance forces located on both sides of the lever, creating a balance or equilibrium.

C) Rectus abdominis

Explanation: The rectus abdominis is a long, flat muscle that extends along the front of the abdomen and is commonly referred to as the 'abs.' It is crucial for flexing the lumbar spine and maintaining posture.

A) Digastric, mylohyoid, stylohyoid, geniohyoid

Explanation: The suprahyoid muscles include the digastric, mylohyoid, stylohyoid, and geniohyoid, which are located above the hyoid bone and play a role in swallowing and tongue movements.

C) Lateral pterygoid

Explanation: The lateral pterygoid muscle is involved in the protrusion and side-to-side movement of the mandible, which is essential for grinding food during mastication.

A) Closer to the axis of the lever

Explanation: In a second-class lever, the point of resistance force is closer to the axis of the lever, which allows for greater mechanical advantage.

C) The point of action of the muscle force is closer to the axis of the lever than the resistance force

Explanation: A third-class lever is characterized by the point of action of the muscle force being closer to the axis of the lever than the resistance force, which is common in many human body movements.