unit 2-Support and Motion Honors-Concept 3: The Muscular System-Study Guide-Objectives Section

all objectives answered by Anthony Hernandez

obj 1) Defend the claim that a muscle is considered an organ

there are more than 600 skeletal muscles in the human body. Muscles are located all over the body. The main function of the muscular system is to produce movement, but muscles have to contract in in order to produce movements. Muscles always tend to pull but never push. muscles connect to the insertion (bone that does the action) and origin (immovable bone). Whatever what muscle can do, the other muscle cannot do. 

obj 2 a) List the overall functions of the muscular system. MUSCLE LOCATION

The Muscles also have different shapes and sizes to them like the deltoid muscle in the should shaped like a deltoid. 

obj 2 b) List the overall functions of the muscular system. MUSCLE SIZE 

size depends on if it is longus (long), brevis (short), maximus (largest) or minimus (smallest). Ex: Gluteus maximus and gluteus minimus are the largest and smallest gluteal muscles. 

obj 2 c) List the overall functions of the muscular system. DIRECTION OF MUSCLE FIBERS

Muscle fibers in the muscles are classified into two types of directions, Rectus: fibers run parallel to the reference point and oblique: fibers run indirectly or at a slant to the reference point, and Transversus: fibers run right at a right angle to the reference point.

obj 2 d) List the overall functions of the muscular system. NUMBER OF ORIGINS 

muscles also include numbers of origins for example the biceps have two heads that attach at different origins (basically areas in the body that don’t do anything when an action is performed). 

obj 2 e) List the overall functions of the muscular system. MUSCLE ACTION 

muscles do certain actions either involuntary or voluntary and they are named for the movement they produce. Example: the abductor longus muscle adducts the thigh 

obj 2 f) List the overall functions of the muscular system. LOCATION OF THE ATTACHMENTS 

when muscles are named based off their points of origin (always listed first in their name of location) and insertion. For example, the sternocleidomastoid is a neck muscle that originates in the sternum and clavicle and inserts into the mastoid process of the temporal bone in the head. 

obj 3) describe the functions of the muscles of the shoulder 

most of the muscles that act on the humerus actually originate in the pectoral girdle. The pectoralis major is a prime mover muscle in flexion of the arm and its antagonist is the latissimus dorsi (lower back), the prime mover in extension of the arm. The thick deltoid muscles extend over the shoulder and are also essential in movements of the humerus. 

obj 4a) explain the role of the diaphragm

the diaghphram along with external intercostals and internal intercostals are key muscles in the deepest locations in the thoraric cavity that are essential for breathing.

obj 4b) summarize how the diaphragm works to accomplish this role

-the diaphragm is the main muscle used to inhale 

-when you inhale, the diaphragm tightens and moves down, making space for your lungs to fill with air 

-the external intercostals (muscles between your ribs) help by pulling your rib cage up and out 

-the internal intercostals do the opposite

• they help you exhale (breathe out)

-the diaphragm also acts like a wall that separates your chest (thoracic) and belly (abdominopelvic) areas. 

obj 5a) describe the functions of the main upper limb muscles (biceps brachii, brachialis, brachioradialis, and triceps brachii). DESCRIBE THE OVERALL FUNCTION 

these muscles cross the elbow joint and insert on the forearm bones, all of the anterior arm muscles aid in flexing the forearm. 

obj 5b) describe the functions of the main upper limb muscles (biceps brachii, brachialis, brachioradialis, and triceps brachii). DESCRIBE THE BICEPS BRACHII AND BRACHIALIS

the biceps brachii are the muscles that bulge out when you flex and the brachialis underneath the biceps act as a bridge between the humerus and ulna. Both of these muscles contract simultaneously during flexion.

obj 5c) describe the functions of the main upper limb muscles (biceps brachii, brachialis, brachioradialis, and triceps brachii). DESCRIBE BRACHIORDIALIS

it a synergist muscle for forearm extension.

obj 5d) describe the functions of the main upper limb muscles (biceps brachii, brachialis, brachioradialis, and triceps brachii).

the main arm muscle for extension. the extensor carpi radialis longus (and brevis) muscles help abduct and extend your hand at the wrist joint. 

obj 6a) Describe the functions of the lower limb muscles (sartorius, adductors, quadriceps femoris, hamstrings, calf muscles and tibialis anterior) DESCRIBE THE OVERALL FUNCTION.

movements of the thigh occur at the hip joint and are done by muscles anchored to the pelvic girdle. movements of the leg occur at the knee joint.

obj 6b) Describe the functions of the lower limb muscles (sartorius, adductors, quadriceps femoris, hamstrings, calf muscles and tibialis anterior) DESCRIBE THE SARTORIUS

the sartorius is the longest skeletal muscle in the human body and it helps flex, abduct, and laterally rotate your thigh.

obj 6c) Describe the functions of the lower limb muscles (sartorius, adductors, quadriceps femoris, hamstrings, calf muscles and tibialis anterior) DESCRIBE THE ADDUCTORS 

these are the MAGNUS, LONGUS, and BREVIS. These adductors make up your inner thighs and can be easily felt when doing a butterfly stretch. when someone says they got a “pulled groin” they are really referring to an adductor muscle.

obj 6d) Describe the functions of the lower limb muscles (sartorius, adductors, quadriceps femoris, hamstrings, calf muscles and tibialis anterior) DESCRIBE THE QUADRICEPS FEMORIS. 

this muscle is the most powerful muscle in the body in the thigh (vastus lateralis, vastus medialis, vastus intermedius and rectus femoris). They are the major extensors of the knees, and we need them for jumping, climbing, running and standing from a seated position.

obj 6e) Describe the functions of the lower limb muscles (sartorius, adductors, quadriceps femoris, hamstrings, calf muscles and tibialis anterior) DESCRIBE THE HAMSTRINGS

The quadricep muscles are antagonized by the hamstrings (biceps femoris, semimembranosus, semitendinosus) in the posterior thigh. Your hamstrings are prime movers for thigh extension and leg flexion.

obj 6f) Describe the functions of the lower limb muscles (sartorius, adductors, quadriceps femoris, hamstrings, calf muscles and tibialis anterior) DESCRIBE THE CALF MUSCLES 

this muscle contains the gastrocnemius, soleus and plantaris). these muscles are key for movement in the ankle, foot and toes. 

obj 6g) Describe the functions of the lower limb muscles (sartorius, adductors, quadriceps femoris, hamstrings, calf muscles and tibialis anterior) DESCRIBE THE TIBIALIS ANTERIOR

this muscle makes up your shin, and it is the prime mover in dorsiflexion (allowing you to flex your ankle so that your foot moves towards your knee).

obj 7a) Describe the functions of the main posterior muscles (trapezius, latissimus dorsi, erector spinae, and all of the gluteal muscles). DESCRIBE TRAPEZIUS.

big upper back muscle that moves, rotates, and stabilizes your shoulders and helps lift your head.

obj 7b) Describe the functions of the main posterior muscles (trapezius, latissimus dorsi, erector spinae, and all of the gluteal muscles). DESCRIBE LATISSIMUS DORSI

large lower back muscle that helps move your arms. used for swimming, climbing and pull ups.

obj 7c) Describe the functions of the main posterior muscles (trapezius, latissimus dorsi, erector spinae, and all of the gluteal muscles). DESCRIBE ERECTOR SPINAE

long muscles along your spine that keep your back straight and help you stand tall or bend backward

obj 7c) Describe the functions of the main posterior muscles (trapezius, latissimus dorsi, erector spinae, and all of the gluteal muscles). DESCRIBE GLUTEUS MAXIMUS

big tooshie muscle that helps you stand, walk, run and keep good posture

obj 7d) Describe the functions of the main posterior muscles (trapezius, latissimus dorsi, erector spinae, and all of the gluteal muscles). DESCRIBE GLUTEUS MEDIUS AND MINIMUS

play a major role in movement of the hips and thighs and helps lift your leg to the side and keeps your balance when walking 

obj 8a) describe the functions of the main head and neck muscles (epicranius, masseter, temporalis, buccinators, and trapezius). DESCRIBE EPICRANIUS.

the main muscle of the scalp. frontal portion of the epicranius allows a person to raise their eyebrows and wrinkle their forehead.

obj 8b) describe the functions of the main head and neck muscles (epicranius, masseter, temporalis, buccinators, and trapezius). DESCRIBE MASSETER AND TEMPORALIS

the prime movers that allow someone’s jaw to close (so they can talk/chew their food)

obj 8c) describe the functions of the main head and neck muscles (epicranius, masseter, temporalis, buccinators, and trapezius). DESCRIBE BUCCINATORS.

they are the main muscle of the cheek. kissing muscle 

obj 8d) describe the functions of the main head and neck muscles (epicranius, masseter, temporalis, buccinators, and trapezius). DESCRIBE TRAPEZIUS.

two large triangular muscles that extend over the back of the neck and shoulders. controls movement of the head and shoulder blades.

obj 8e) include what makes this group of muscles unique from all the others.

the muscles of the face are thin and lie just beneath the skin. these muscles are inserted into the skin or other muscles rather than bones. 

obj 9) Differentiate skeletal muscle tissue from the cardiac and smooth muscle tissues

skeletal muscle tissue are striated muscles that mainly attach to bones that contract voluntarily to produce movement. every muscle is composed of its own organ that is mainly made up of skeletal tissue but also includes blood vessels, nerves and connective tissue. Cardiac muscle tissue are striated muscles of the heart that contract involuntarily to pump blood throughout the body. smooth muscle tissue is nonstriated muscles in the walls of visceral organs that contract involuntarily to propel.

obj 10) sketch and label a diagram of the structure of the skeletal muscle.

obj 11a) describe the unique structure of a muscle cell

the structure of a muscle cell contains myofibrils which are organelles which make most of the muscle cell, thin filaments called myofilaments run the length of each myofibril and they are subdivided lengthwise in sarcomeres. myofibrils are almost like tiny threads bundled together to make muscle fibers and those muscle fibers form fascicles to form a muscle organ (which are hundreds of thousands of muscle cells including connective tissues, blood vessels and nerve fibers. 

obj 11b) justify the importance of two of its most abundant components: the presence of lots of mitochondria and the presence of lots of myofibrils. 

the presence of a lot of mitochondria and myofibrils will make contractions of muscles and bone occur frequently since mitochondria is needed in order to produce atp and lots myofibrils will carry that mitochondria. Each myofibril is a chain of sarcomeres and each sarcomere is separated by z disc borders on each end of the myofibrils. They also contain thick filaments contain the contractile protein myosin and the thin filaments contain the contractile protein actin.

Obj 12a) differentiate myosin and actin, both structurally and functionally. Describe MYOSIN

Myosin are are contractile protein that are in the thick filaments of a sarcomere. The thick heads of the Myosin filaments grab onto the thin actin filaments.

Obj 12b) differentiate myosin and actin, both structurally and functionally. Describe ACTIN

Actin filaments are another contractile protein that are thin filaments. Shortens the sarcomere once the actin filaments overlap the myosin filaments.

Obj 13) summarize the process of of muscle contraction using the sliding filament model

Muscle contraction happens when myosin heads grab and pull the actin filaments, making them slide past each other. This increases their overlap and shortens the sarcomere, causing the whole muscle to contract.

obj 14) explain how energy and access are obtained in order for a muscle contraction to occur

the myosin wants to bind to the actin but cannot do that because it needs energy from atp and access. this is usually because the regulatory protein tropomyosin is blocking the actin from binding.  In order for the myosin to gain access, the neuron signals an action potential in a muscle cell that triggers Ca+2 channels in the sarcoplasmic reticulum to open/release stored Ca+2. Ca+2 gets hold of tropopin (regulatory protein) which grabs onto tropomyosin and pulls that outta the way and access is granted to the myosin. In order for a myosin to get energy from atp, it grabs an atp and rips a phosphate off and that phosphate releases the energy the myosin needs in order to bind to the actin and thus muscle contractions occur.

obj 15) summarize the importance of the nervous system in muscle contractions

muscle contractions can ONLY HAPPEN if it is activated/stimulated by the nervous system. the nervous system starts muscle contractions by sending electrical signals called action potentials through somatic motor neurons from the spinal cord to the muscles. these neurons connect to muscle fibers at a special spot called the neuromuscular junction, where the signal switches from electrical to chemical. the chemical messenger acetyoline crosses the synaptic cleft and binds to receptors on the muscle cell, triggering it to become electrically active. this electrical activity inside the muscle starts the process that makes the fibers slide and contract. basically, the nervous system is what tells muscles when and how to move. 

obj 16) draw a picture of a motor neuron and a skeletal muscle in a neuromuscular junction and label the key parts. 

Obj 17) Explain the role of acetylcholine in a muscle contraction

They are neurotransmitter motor neurons used to contract muscles.

obj 18) List how muscles can increase the force of their contraction. 

-increase the frequency of motor neuron (motor unit) stimulation

-increasing the number of motor units (muscle fibers) stimulated 

-increasing the size of muscle fibers 

the bulkier the muscle (due to regular resistance exercise) the more tension that can build up 

obj 19) explain how muscles can act with bones to form lever systems and give examples of the three types of levers. Describe FIRST-CLASS LEVER

the effort is applied at one end of the lever and the load is at the other end, with the fulcrum in between. ex: the lever system that raises your head from your chest.

obj 19) explain how muscles can act with bones to form lever systems and give examples of the three types of levers. Describe SECOND CLASS LEVER

the effort is applied at one end of the lever and the fulcrum is at the other end, the load is in between the two of them. Ex: the level system that allows you to stand on your toes

obj 19) explain how muscles can act with bones to form lever systems and give examples of the three types of levers. Describe THIRD CLASS LEVER

the effort is applied between the load and the fulcrum (like tweezers or forceps). Ex: the lever system that does a bicep curl.