MEDS1002 Human Anatomy Muscles - Part 1 2024 Lecture Notes PDF

HELP!!! MEDS1002 How to learn Essentials ofanatomy Human Anatomy Muscles - Part Sarah 1 Croker (what they look Lecturer,like) School of Medical Sciences, University of Sydney COMMONWEALTH OF AU...

HELP!!! MEDS1002 How to learn Essentials ofanatomy Human Anatomy Muscles - Part Sarah 1 Croker (what they look Lecturer,like) School of Medical Sciences, University of Sydney COMMONWEALTH OF AUSTRALIA Copyright Regulation WARNING Sarah Croker This material has been reproduced and communicated to you by or on behalf of the University of Sydney Lecturer, School of Medical Sciences pursuant to Part VB of the Copyright Act 1968 (the TEQSA PRV12057 Act). [email protected] The material in this communication may be subject to copyright under the Act. Any further reproduction or communication of this material by you may be the subject of copyright protection under the Act. CRICOS 00026A Do not remove this notice The University of Sydney Page 2 Learning outcomes - Recall the three types of muscle and state their main characteristics. - Describe different ways in which muscles can attach to other body structures. - Differentiate between intrinsic and extrinsic muscles. - Compare different muscle shapes and give examples of each. The University of Sydney What is muscle? - Muscle is a tissue made of cells that contract (get shorter). - This is how it makes things in the body move or change shape. - Muscle also relaxes to “resting” position. - Muscle only works by contracting, not pushing apart!!! The University of Sydney Etymology of “muscle” - From Latin musculus, meaning little mouse - because the movement of some muscles was thought to be reminiscent of a mouse. - Similarly in Greek, mys means both mouse and muscle - this the stem for “myo-”, pertaining to muscle (e.g. myocardium – muscle of the heart). The University of Sydney https://en.wikipedia.org/wiki/House_mouse#/me dia/File:Mouse_white_background.jpg Three types of muscle Skeletal muscle Cardiac muscle Smooth muscle Principles and Applications, Anatomedia, McGraw-Hill, Sydney. Lower images, Seeley, R.R., Upper images: Eizenberg, N., Briggs, C, Adams, C. & Ahern, G. (2007) General Anatomy: Stephens, T.D. & Tate, P 2000 Anatomy and Physiology, 5 th Edn, McGraw Hill, Boston Where is it Around bones and joints; Walls of the heart Walls of hollow organs present? eyeballs; skin of face and neck and blood vessels; skin; eyes Nerve control Voluntary control (generally) Involuntary control Involuntary control Microscopic Striated Striated Non-striated or smooth structure The University of Sydney Skeletal muscle attachments - The contractile part of a muscle is the reddish coloured fleshy part – this can be called the belly, or a belly can be split into two or more heads. - This muscle belly needs to attach to two points; when it contracts, those two points will move closer together. - Tendons are one of the most common ways a muscle will attach to another part of the body, usually a bone. The University of Sydney Moore, KL & Dalley, AF, 2006, Moore’s Clinically Oriented Anatomy, 5 th Edn, Lippincott Williams and Wilkins Tendon vs. ligament - Tendons are dense fibrous connective tissue (mostly organized collagen bundles) and are whitish/silvery in colour. Tendons don’t contract. - Ligaments are made up of similar material. - Whereas tendons attach muscle to bone, ligaments attach bone to bone*. - “Ligament” comes from the Latin ligare, to bind. - Ligaments are therefore found very deep in the body, surrounding the bone joints. * There are a few small exceptions, as there The University of Sydney always is in anatomy. Skeletal muscles can attach….. - To bone via tendons (rounded or strap-like cords of connective tissue) - To bone via aponeuroses (thin flat sheets of connective tissue) tendons The University of Sydney aponeurosis Left forearm, anterior view. Abrahams, P. et al. Abrahams’ and McMinn’s Clinical Atlas of Human Anatomy Eighth edition 2020, Elsevier.  Skeletal muscles can attach….. - Directly to: - bone e.g. masseter in the jaw - cartilage e.g. cricothyroid around the larynx - deep fascia e.g. tensor fascia latae in the iliotibial tract of the thigh - skin, such as muscles of facial expression e.g. risorius at edge of mouth - muscle, via a raphe e.g. pharyngeal raphe posterior pharynx The University of Sydney Intrinsic vs extrinsic muscles - An intrinsic muscle is one that has both its attachment points within the one area of the body, e.g. the back, foot, hand, eye, tongue. - An extrinsic muscle is one that has one attachment within this body structure and one beyond it, i.e. it attaches to another body area. Extensor digitorum longus - E.g. extensor digitorum longus (extrinsic), extensor digitorum brevis (intrinsic) Extensor digitorum brevis The University of Sydney Foot: Moore, K.L. & Dalley, A.F. 2006, Clinically Oriented Anatomy, 5 th Edn, Lippincott Williams & Wilkins, Philadelphia. Lower limb: Thieme Teaching Assistant2, Thieme Medical Publishers  Shapes of muscles - So much variety!! The University of Sydney Moore, KL & Dalley, AF, 2014, Moore’s Clinically Oriented Anatomy, 7 th Edn, Lippincott Williams and Wilkins  Shapes of muscles - Flat muscles - Parallel fibres - May be wide, and with aponeurosis - e.g. external oblique - May be thin - e.g. sartorius The University of Sydney https://en.wikipedia.org/wiki/Avicenna Modified from Moore, KL & Dalley, AF, 2014, Moore’s Clinically Oriented Anatomy, 7 th Edn, Lippincott Williams and Wilkins Shapes of muscles - Pennate muscles - Like a feather - Unipennate – e.g. extensor https://stock.adobe.com/search?k=feather&asset_id Anatomy, 7 th Edn, Lippincott Williams and Wilkins digitorum longus =278918146. Figure: Modified from Moore, KL & Dalley, AF, 2014, Moore’s Clinically Oriented - Bipennate – e.g. rectus femoris - Multipennate – e.g deltoid - [will discuss function next lecture] Feather: The University of Sydney https://en.wikipedia.org/wiki/Avicenna  The University of Sydney thin ends) - e.g. biceps brachii - Fusiform muscles spindles these are Shapes of muscles - Spindle shaped (fat round belly, https://en.wikipedia.org/wiki/Avicenna Spindle: https://jillianeve.com/ply-historical-yarn- medieval-spindles/. Figure: Modified from Moore, KL & Dalley, AF, 2014, Moore’s Clinically Oriented Anatomy, 7 th Edn, Lippincott Williams and Wilkins  Shapes of muscles - Convergent muscles - One end has a broad attachment, narrowing to a narrow attachment at other end - e.g. pectoralis major The University of Sydney https://en.wikipedia.org/wiki/Avicenna Modified from Moore, KL & Dalley, AF, 2014, Moore’s Clinically Oriented Anatomy, 7 th Edn, Lippincott Williams and Wilkins  Shapes of muscles - Quadrate muscles - Four equal sides - e.g. rectus abdominis The University of Sydney https://en.wikipedia.org/wiki/Avicenna Diver: https://www.pride.com/sports/2021/8/07/tom-daley-tokyo-2020-olympics-individual-dive-bronze-medal-forth. Figure: Modified from Moore, KL & Dalley, AF, 2014, Moore’s Clinically Oriented Anatomy, 7 th Edn, Lippincott Williams and Wilkins  Shapes of muscles - Circular muscles - Form a sphincter, close like a purse string - e.g. orbicularis occuli (around eyes) - e.g. orbicularis oris (around mouth) The University of Sydney Trump: Win McNamee/Getty Images. https://slate.com/news-and-politics/2020/01/trump-john-bolton-executive-privilege-claim-nixon.html. Diagram: Modified from Moore, KL & Dalley, AF, 2014, Moore’s Clinically Oriented Anatomy, 7 th Edn, Lippincott Williams and Wilkins  Shapes of muscles - Multiheaded / multibellied muscles - More than one attachment at one end - e.g. biceps brachii The University of Sydney https://en.wikipedia.org/wiki/Avicenna Modified from Moore, KL & Dalley, AF, 2014, Moore’s Clinically Oriented Anatomy, 7 th Edn, Lippincott Williams and Wilkins Anatomical variations - Some people may have extra bundles of muscle fibres accompanying “typical” muscles – these are usually referred to as muscle slips. - Some people may have extra tendons – commonly seen at base of thumb. - Some people may be lacking some small muscles e.g. palmaris longus. - Look for it by tensing the tips of your fingers and thumb together – look for a long skinny tendon bulging on the anterior of your wrist. - Approximately 20% of people do not have this muscle. The University of Sydney Photo: Sarah Croker Surface anatomy The University of Sydney Any questions about the quiz or the practical next week The University of Sydney