Module 3 - Muscle Basics PDF

Module 3 - Muscle Basics of Muscle Section 01-Types Skeletal Muscles - help the human body more , most skeletal muscle is...

Module 3 - Muscle Basics of Muscle Section 01-Types Skeletal Muscles - help the human body more , most skeletal muscle is attached to bones via tendons Cardiac Muscles neural roundintheheart contesrhythmically,andis controlled by - anda activity a Smooth Muscle- controlled by the nervous system or hormones , may be either generally inactive and then respond to stimulation or it may be , rhythmic fusiform shaped (typers off , Characterizations of Muscle ↳ Morphological (based on form) stricted-marked by both light and dark bands (strictions) characterized by long muscle · , fibres (cells) with multiple nuclei can be found in skeletal muscles (with nuclei being located peripherally) and in · heart muscles (nuclei located centrally ↳ heart muscles also contain interculated discs which connect heart muscle cells together · Smooth-each smooth muscle Fibre (cell) contains a single centrally located nucleus , found in blood vessels the digestive system and other viscera · , , has fusiform-shaped cells (spindle-like) without strictions · ↳ Functional muscle that consciously controlled order to perform specific function voluntary is in a · - oie. Muscles that more the skeleton for ↳ Skeletal muscles are controlled walking reaching talking , , , etc voluntarily Involuntary muscle that is not consciously controlled · - · consists of smooth and cardiac muscles · ex. muscles in the small intestine and the heart Excitability - the ability of muscle tissue to receive and respond to electrical signals from nerves or stimulation from hormones Contractility - when a muscle cell in contraction is excited by a nerve or hormone it causes it to , shorten , resulting Section 02-Skeletal Muscle Functions of Skeletal Muscle ↳ they contract to more parts of the body most skeletal muscles are attached to two bones across a joint such that when contracted · , the muscle brings parts of those two bones closer to each other ↳ Maintain posture and stabilize joints ↳ control excretion and swallowing ↳ produce next ↳ support and protect internal organs Organizationof Skeletal Muscle Tissue consists of muscle tissue and connective tissue the connective tissue surrounds the muscle tissue and · attaches the ends of each muscle to bone this connective tissue is the epimysium and is continuous with the tissue that ↳ becomes the tendon ↳ the perimysium is the layer of CT that surrounds a bundle of muscle fibres (fascicles within a muscle ↳ the endomysium is the layer of CT that surrounds each individual muscle cell within a muscle bundle  Features of Muscle Cells ↳ Sacrolemma the cell membrane surrounding a muscle cell this is a different entity from - , the endomysium > Nuclei -they are multinucleated the nuclei are located towards the outside of the myofibre , Myofibrils these are the structural units of the muscle cell and contain the contractile - myofilaments contractile units of the muscle cell Myofilaments the - are organized into repeating structural units known as sacromeres · ↳ When shortened sacromeres cause contraction of the muscle ↳ each unit is made up of activ and myosin One secromere spans from one 2-line to the next ↳ Secroplasmic Reticulum-surrounds each myofibril and is where the muscle cell stores calcium ↳ Transverse Tubules extensions of the sacrolemma that surround the myofibrils and - transmit nerve stimulation to the SR within the cell MuscleContraction ↳ histologically which when muscle contracts the activ and myosin filments slide over each other, , , shortens the sacromere this increases muscle tension grossly resulting in movement of structures · , ↑ & 1/17M-line888839 gggad III 88895 82208 III 33855 E Tactin myosin Tz-line I-band A-band Section 03-Axial Muscles Muscles of Facial Expressions ↳ these muscles insert into the skin and they produce facial expressions by contracting and moving the skin ↳ Frontalis the muscle that covers the frontal bone and lifts the eyebrows/wrinkles the forehead - ↳ Orbicularis Oculi-muscle the that closes the surrounding eye when contracted forcefully eye on the frontal and maxillary bones · originates ↳ Orbicularis Oris-surrounds the mouth and enables the puckering of lips originates on the maxillary bones or mandible · ↳ zygomaticus extends from the zygomatic arch to the corners of the mouth draws the - , angle of the mouth superiorly and posteriorly causing one to smile , Muscles of Mastication (Chewing Temporalis - a fan-shaped muscle that extends from the temporal fossa of the parietal bone to the coronoid process of the mandible it elevates and pulls the mandible posteriorly (retracts) · Masseter - a powerful muscle that extends from the zygomatic arch to the angle of the mandible o it elevates and protracts (move forward) the jaw Muscles thatMore the Head ↳ Anterior Sterocleidomastoid Muscle- flexes the neck with bilateral contraction and rotates the head to · , the opposite site with unilateral contraction is attached to the sternum and clavical and superiorly inferiorly · ↳ Posterior to the mastoid process of the temporal bone Semispinalis Capitis · extends the neck with bilateral contraction and turns the face slightly to - , the side with unilateral contraction ↳ attaches to the occipital bone and lies on either side of the spine  · Splenius Capitis - extends the neck with bilateral contraction and causes flexion and lateral , rotation of the neck with unilateral contraction ↳ Attaches to the occipital bone and it looks like a bandage Muscles of the Thory ↳ did in the process of breathing ↳ External Intercostals the most superficial their fibres run anteriorly and interiorly between - , the ribs and they did in inspiration , ↳ Internal Intercostals - lie deep to the externals land more medially) , their fibres run posteriorly and inferiorly they did in expiration , Muscles of the Back ↳ Erector Spinde a group of muscles that help keep the spine erect they run down - , both sides of the spinal column Muscles of the Abdominal wall ↳ facilitate movement of the trunk and did in breathing themostsuperfici museof t webruns enteriorly inferiora ↳ External Oblique - used in forced expiration ↳ unilateral contraction · causes lateral flexion and rotation of the spine ↳ Internal Oblique deep to the external oblique and its fibres run anteriorly and superiorly - , obilaterally it flexes the spine and compresses the abdominal wall unilaterally it causes lateral flexion and rotation of the spine · Transverse Abdominis runs horizontally and deep to the internal oblique - bilaterally it flexes the spine and compresses the Abdominal wall · > used in forced expiration - lateral flexion of the spine Unilaterally it causes · ↳ Rectus Abdominis-lies on either side of the lined Alba 11 line of C down the middle of the abdomen for muscle attachment) and it separated by tendinous intersections functions to flex the trunk and in forced expiration ·