Muscular System: Skeletal Muscle Tissue and Organization

Transcription

1 Muscular System: Skeletal Muscle Tissue and Organization AFTER READING THE BOOK, use the following worksheet to link concepts from previous chapters with the concepts of muscle tissue. This worksheet will facilitate your synthesis of concepts; it is not intended to be a replacement for reading the book. Without reading the book, the worksheet may confuse you more. As you go through the worksheet, fill in the blanks with terms you have learned from the course so far. So far we have learned about four types of tissue: 1. cover lumens and cavities. 2. contain cells, fibers and a fluid component called a matrix. 3. provides stimulation to surrounding tissues, particularly muscles and glands. 4. is contractile, elastic, extensible and responsive to stimulus. So far we have studied concepts regarding bone, a specialized tissue. The knowledge you have gained from previous chapters will allow you to holistically understand the role of skeletal muscles. Be sure to focus on the structural and functional relationships, and muscle compartments and groups (agonist vs ). As you progress with studies of skeletal muscles, the importance of locating bony markings will become apparent. Bones are rigid structures that act as. Knowledge of boney will be necessary when identifying the origins, insertions, and actions of skeletal muscles. However, there are a few other types of muscle tissue present in the body. The functional properties of muscle are: 1., the ability to respond to stimulation. 2., the ability to exert tension, force or pull. 3., the ability to contract multiple times over a range of lengths. 4., the ability of a muscle to return to its original shape. There are three types of muscle tissue: I. tissue Examples: deltoid, quadriceps hamstrings. II. tissue Examples: wall of the heart. III. tissue Examples: sphincters, digestive viscera, constricting/dilating components of arteries/veins. All muscle tissue is organized into three concentric functional layers covered by connective tissue when view in a cross section. Another tissue type organized in the same fashion nervous tissue. Before we review the layers of muscle tissue, it would be wise to look at the Latin roots. For instance,

2 if we know that the prefix root il means not, and that literate means the ability to read then il + literate = illiterate, or cannot read (clearly you can read- you are literate). But reading smarter not only helps with understanding anatomical definitions, but also helps with questions which appear on exams. Here are some Latin prefix, identify their meanings: Epi-, or above. Example: the epidermis is the most superficial layer of the integument. Peri- Endo- Example: the endosteum is a cellular layer located deep to the bone in the medullary cavity. Draw a cross section of a muscle belly below and label all components. Organ (muscle)--- Tissues types--- Cells Organelles. Bone Now, fill in the blanks to see if you can identify some properties of the muscle tissue layers: The deepest connective tissue layer of muscle which surrounds an individual muscle fiber is the. The most superficial connective tissue layer associated with muscle is the, which separates the muscle tissue from surrounding organs. The divides a whole muscle into fascicles (functional group), a bundle of muscle fibers.

3 Muscles can be divided into categories based on their structures and function. One particular way of naming muscles is based on their location. For instance a muscle named with abdominis is located in the abdominal region. To practice your knowledge of body regions, match the following muscles with the anatomical region or bone they are located near. You can use book to determine challenging ones: R= Region, Sh=shape, Si= size, FO=fiber orientation, RP=Relative position, OI=origin and Insertion, and NH= number of heads, A= Action/movement. MUSCLES Named by Rectus abdominis Genioglossus Iliotibial tract Orbicularis oris Orbicularis oculi Levator scapulae Temporalis Fibularis longus Biceps brachialis Flexor carpi radialis longus Levator Scapulae Pronator teres Flexor carpi ulnaris Extensor digitorum Adductor magnus Select other muscles. (Use White board) To review movements that we learned during articulations fill in the blanks: When abducting the arm the arm moves toward the aspect of the body. Adducting the arm would produce a movement in the opposite direction, toward the aspect of the body. is a movement which decreases the angle between adjacent bones. is a movement that increases the angle between adjacent bones. Elevating a body parts means moving a body part. During a body part is moved inferiorly. When the arm is the palms are in anatomical position (holding a bowl of soup ). When the radius crosses over the ulna, the arm is (the pull for a free stroke when swimming). Write one more sentence for a companion set of actions below:

4 Now that you have reviewed action terms, see if you can match the following muscles on the left hand side with the actions they perform, located on the right hand side ( add some of your own). MUSCLES Levator Scapulae Pronator teres Flexor carpi ulnaris Extensor digitorum Adductor magnus ACTION Moves the radius across the ulna Decreasing the angle of the wrist Moves a body part toward the medial aspect of the body Elevates the scapula Increasing the angle of the digits This provides a helpful way of deducing the actions of a muscle depending on its name. The actions of muscles are also interconnected with other muscles within particular regions have direct effects on other muscle groups. Fill in the blanks regarding the actions accomplished by muscle group (anterior brachium compartment): Flexion is the chief movement of the biceps brachii, therefore it is a mover for flexion. A muscle which performs the opposite movement of a muscle is considered a. A muscle which inhibits the movement of a muscle so it may perform an intended action is a. A assists the prime mover in performing a particular action. Notes:

5 Synergists, Antagonists, and Fixers To develop a holistic understanding of muscles use the knowledge you have already gained from reading about muscle groups. In medicine or sports, it is rare that an individual will ask you about a specific muscle a client may say it hurts when I move my arm inward. Organize muscles based on their particular role, some muscles will pull on the lever, while others will hold the lever in a certain position. Use these common examples to develop your knowledge. Desired movement: A person lifting a weight with their right upper appendage decreases the angle between the brachium and the antebrachium. Movement type: Flexion Lever(s): Radius, Lever class: Third class Prime mover muscle: Long head, short head of biceps brachii Actions of prime mover: Flexion Antagonist(s): Triceps Brachii Actions of antagonist(s): Extension Fixer(s): Lat. Dorsi, Pectoralis Major, etc. It is important to note that while the humerus will need to be stabilized, none of the primary movers are attached to the humerus. Making notes like this will help you to visualize compartments of the body. 1) The head is in anatomical position. Movement type: Extension of the neck. Lever(s): Cervical vertebrae, occipital bone Lever class: Primary mover: Actions of primary mover: Synergist(s): Actions of synergist(s): Antagonist(s): Actions of antagonist(s): Fixer(s):

6 2) Bringing the leg towards the midline of the body. Movement type: Lever(s): Lever class: Primary mover: Actions of primary mover: Synergist(s): Actions of synergist(s): Antagonist(s): Actions of antagonist(s): Fixer(s): 3) Moving the leg posteriorly in preparation to kick a ball. Movement type: Lever(s): Lever class: Primary mover: Actions of primary mover: Synergist(s): Actions of synergist(s): Antagonist(s): Actions of antagonist(s): Fixer(s):