Descriptive terms of the bones, muscles and joints.ppt
- 1. A LECTURE PRESENTATION ON DESCRIPTIVE TERMS, MUSCLES, JOINTS AND MOVEMENTS BY DR. UWEJIGHO E. RAPHAEL DEPARTMENT OF ANATOMY, UNIVERSITY OF MEDICAL SCIENCES, ONDO.
- 2. Presentation Outline Anatomical position Directional terms and relations Combined terms- describe intermediate positional arrangements Anatomical Planes Anatomical sections Overview of Muscle Tissues Types of Muscle Joints and Classification of Joints types of body movements
- 3. Learning objectives After this section, you will be able to: Demonstrate the anatomical position Describe the human body using directional and regional terms Identify the planes most commonly used in the study of anatomy Describe the different types of muscle Distinguish between the functional and structural classifications for joints Define the different types of body movements Identify the joints that allow for these motions
- 4. Anatomical position The anatomical position refers to the body position as if the person were standing upright with the: Head, gaze (eyes), and toes directed anteriorly (forward). Arms adjacent to the sides with the palms facing anteriorly. Lower limbs close together with the feet parallel.
- 5. Anatomical position cont’d A- Anterior view B- Lateral/Side view C- Posterior view Supine: recumbent, lying on the back, face upward. Prone: lying on the abdomen, face downward. A B C
- 6. TERMINOLOGY AND GENERAL PLAN OF THE BODY
- 7. TERMINOLOGY AND GENERAL PLAN OF THE BODY
- 8. Anatomical Planes Median plane Sagittal planes Frontal (coronal) planes Transverse planes
- 9. Anatomical Planes cont‘d The median plane (median sagittal plane), the vertical anteroposterior plane passing longitudinally through the midlines of the head, neck, and trunk where it intersects the surface of the body, dividing it into right and left halves. Midline is often erroneously used as a synonym for the median plane. Sagittal planes are vertical planes passing through the body parallel to the median plane. A plane parallel and near to the median plane may be referred to as a paramedian plane. Frontal (coronal) planes are vertical planes passing through the body at right angles to the median plane, dividing the body into anterior (front) and posterior (back) parts. Transverse planes are horizontal planes passing through the body at right angles to the median and frontal planes, dividing the body into superior (upper) and inferior (lower) parts. Radiologists refer to transverse planes as transaxial, which is commonly shortened to axial planes.
- 10. Combined terms Combined terms describe intermediate positional arrangements: inferomedial means nearer to the feet and median plane—for example, the anterior parts of the ribs run inferomedially; superolateral means nearer to the head and farther from the median plane.
- 11. Anatomical sections Longitudinal sections run lengthwise or parallel to the long axis of the body or of any of its parts, and the term applies regardless of the position of the body Transverse sections, or cross sections, are slices of the body or its parts that are cut at right angles to the longitudinal axis of the body or of any of its parts Oblique sections are slices of the body or any of its parts that are not cut along the previously listed anatomical planes
- 12. Muscle, Types of Muscle (Muscle Tissue) Muscle cells, often called muscle fibers because they are long and narrow when relaxed, are specialized contractile cells. They are organized into tissues that move body parts or temporarily alter the shape (reduce the circumference of all or part) of internal organs. Three types of muscle are described based on distinct characteristics relating to whether it is normally willfully controlled (voluntary vs. involuntary). whether it appears striped or unstriped when viewed under a microscope (striated vs. smooth or unstriated). whether it is located in the body wall (soma) and limbs or makes up the hollow organs (viscera, e.g., the heart) of the body cavities or blood vessels (somatic vs. visceral). There are three muscle types Skeletal muscle Cardiac muscle Smooth muscle
- 13. Types of Muscle 1. Skeletal striated muscle is voluntary somatic muscle that makes up the gross skeletal muscles that compose the muscular system, moving or stabilizing bones and other structures (e.g., the eyeballs). 2. Cardiac striated muscle is involuntary visceral muscle that forms most of the walls of the heart and adjacent parts of the great vessels, such as the aorta, and pumps blood. 3. Smooth muscle (unstriated muscle) is involuntary visceral muscle that forms part of the walls of most vessels and hollow organs (viscera), moving substances through them by coordinated sequential contractions (pulsations or peristaltic contractions).
- 14. Types of Muscle
- 15. FORM, FEATURES, AND NAMING OF MUSCLES All skeletal muscles, commonly referred to simply as “muscles,” have fleshy, reddish, contractile portions (one or more heads or bellies) composed of skeletal striated muscle. Some muscles are fleshy throughout, but most also have white noncontractile portions (tendons), composed mainly of organized collagen bundles, that provide a means of attachment. A muscle’s length is the distance between its attachments. Most skeletal muscles are attached directly or indirectly to bones, cartilages, ligaments, or fascias or to some combination of these structures. Some muscles are attached to organs (e.g., the eyeball), skin (such as facial muscles), and mucous membranes (intrinsic tongue muscles). Muscles are organs of locomotion (movement), but they also provide static support, give form to the body, and provide heat. Most muscles are named on the basis of their function or the bones to which they are attached. The abductor digiti minimi muscle, for example, abducts the little finger. Other muscles are named on the basis of their position (medial, lateral, anterior, posterior) or length (brevis, short; longus, long).
- 16. CONTRACTION OF MUSCLES Skeletal muscles function by contracting; they pull and never push. When a muscle contracts and shortens, one of its attachments usually remains fixed (Origin, proximal end of the muscle) while the other (more mobile, Insertion, distal end of the muscle) attachment is pulled toward it, often resulting in movement. Reflexive Contraction: Although skeletal muscles are also referred to as voluntary muscles, certain aspects of their activity are automatic (reflexive) and therefore not voluntarily controlled. Examples are the respiratory movements of the diaphragm, controlled most of the time by reflexes stimulated by the levels of oxygen and carbon dioxide in the blood (although we can willfully control it within limits), and the myotatic reflex, which results in movement after a muscle stretch produced by tapping a tendon with a reflex hammer.
- 17. CONTRACTION OF MUSCLES cont‘d Tonic Contraction: Even when “relaxed,” the muscles of a conscious individual are almost always slightly contracted. This slight contraction, called tonic contraction or muscle tone (tonus), does not produce movement or active resistance (as phasic contraction does) but gives the muscle a certain firmness, assisting the stability of joints and the maintenance of posture, while keeping the muscle ready to respond to appropriate stimuli. Muscle tone is usually absent only when unconscious (as during deep sleep or under general anesthesia) or after a nerve lesion resulting in paralysis. Phasic Contraction: There are two main types of phasic (active) muscle contractions: (1) isotonic contractions, in which the muscle changes length in relationship to the production of movement, and (2) isometric contractions, in which muscle length remains the same —no movement occurs, but the force (muscle tension) is increased above tonic levels to resist gravity or other antagonistic force. The latter type of contraction is important in maintaining upright posture and when muscles act as fixators or shunt muscles.
- 18. FUNCTIONS OF MUSCLES Muscles serve specific functions in moving and positioning the body: A prime mover (agonist) is the main muscle responsible for producing a specific movement of the body. It contracts concentrically to produce the desired movement, doing most of the work (expending most of the energy) required. A fixator steadies the proximal parts of a limb through isometric contraction while movements are occurring in distal parts. A synergist complements the action of a prime mover. It may directly assist a prime mover, providing a weaker or less mechanically advantaged component of the same movement, or it may assist indirectly, by serving as a fixator of an intervening joint when a prime mover passes over more than one joint, for example. An antagonist is a muscle that opposes the action of another muscle. A primary antagonist directly opposes the prime mover, but synergists may also be opposed by secondary antagonists.
- 19. A joint (articulation) A joint (articulation) is a union or junction between two or more bones or rigid parts of the skeleton. Joints exhibit a variety of forms and functions. Some joints have no movement; others allow only slight movement, and some are freely movable, such as the glenohumeral (shoulder) joint
- 20. Classification of Joints Joints are classified both structurally and functionally. Structural classifications of joints take into account whether the adjacent bones are strongly anchored to each other by fibrous connective tissue or cartilage, or whether the adjacent bones articulate with each other within a fluid-filled space called a joint cavity. Functional classifications describe the degree of movement available between the bones, ranging from immobile, to slightly mobile, to freely moveable joints. The amount of movement available at a particular joint of the body is related to the functional requirements for that joint. Thus immobile or slightly moveable joints serve to protect internal organs, give stability to the body, and allow for limited body movement.
- 21. Structural Classification of Joints- 1. A fibrous joint is where the adjacent bones are united by fibrous connective tissue, and thus the bones do not have a joint cavity between them. There are three types of fibrous joints. A suture, syndesmosis joint and gomphosis (a narrow fibrous joint between the roots of a tooth and the bony socket in the jaw into which the tooth fits)
- 22. Structural Classification of Joints- cont‘d 2. Cartilaginous joint: The adjacent bones are united by cartilage, a tough but flexible type of connective tissue. These types of joints lack a joint cavity and involve bones that are joined together by either hyaline cartilage (synchondrosis joint) or fibrocartilage (symphysis).
- 23. Structural Classification of Joints- cont‘d 3. Synovial Joints: The joint is surrounded by an articular capsule that defines a joint cavity filled with synovial fluid. Also unlike fibrous or cartilaginous joints, the articulating bone surfaces at a synovial joint are not directly connected to each other with fibrous connective tissue or cartilage. This gives the bones of a synovial joint the ability to move smoothly against each other, allowing for increased joint mobility.
- 24. Types of Synovial Joints -based on the shapes of the articulating surfaces of the bones that form each joint. Pivot, Hinge, Condyloid, Saddle, Plane, and Ball-and Socket-joints
- 25. Functional Classification of Joints- 1. Synarthrosis: is an immobile or nearly immobile joint. The immobile nature of these joints provide for a strong union between the articulating bones. This is important at locations where the bones provide protection for internal organs. Examples include sutures, the fibrous joints between the bones of the skull that surround and protect the brain
- 26. Functional Classification of Joints- cont‘d 2. An amphiarthrosis is a joint that has limited mobility. An example of this type of joint is the cartilaginous joint that unites the bodies of adjacent vertebrae. Filling the gap between the vertebrae is a thick pad of fibrocartilage called an intervertebral disc. Each intervertebral disc strongly unites the vertebrae but still allows for a limited amount of movement between them. However, the small movements available between adjacent vertebrae can sum together along the length of the vertebral column to provide for large ranges of body movements.
- 27. Functional Classification of Joints- cont‘d 3. Diarthrosis: A freely mobile joint is classified as a diarthrosis. These types of joints include all synovial joints of the body, which provide the majority of body movements. Most diarthrotic joints are found in the appendicular skeleton and thus give the limbs a wide range of motion. These joints are divided into three categories, based on the number of axes of motion provided by each. An axis in anatomy is described as the movements in reference to the three anatomical planes: transverse, frontal, and sagittal. Thus, diarthroses are classified as uniaxial (for movement in one plane), biaxial (for movement in two planes), or multiaxial joints (for movement in all three anatomical planes).
- 28. Aging and the Joints Arthritis is a common disorder of synovial joints that involves inflammation of the joint. This often results in significant joint pain, along with swelling, stiffness, and reduced joint mobility. There are more than 100 different forms of arthritis. Arthritis may arise from aging, damage to the articular cartilage, autoimmune diseases, bacterial or viral infections, or unknown (probably genetic) causes. Vascular Supply and Lymphatic Drainage and Innervation: Joints receive blood from periarticular arterial plexuses whose numerous branches pierce the fibrous capsules to form subsynovial vascular plexuses. A movable joint is innervated by articular branches of the nerves which supply the muscles acting on the joint (Hilton's law).
- 29. Terms of Movement Flexion indicates bending or decreasing the angle between the bones or parts of the body. For joints above the knee, flexion involves movement in an anterior direction. Extension indicates straightening or increasing the angle between the bones or parts of the body. Occurs in condyloid, saddle, and ball- and-socket joints Flexion and extension.
- 30. Abduction and adduction Abduction and adduction movements generally occur in a frontal plane around an anteroposterior axis Except for the digits. Abduction means moving away from the median plane (e.g., when moving an upper limb laterally away from the side of the body) and adduction means moving toward it. In abduction of the digits (fingers or toes), the term means spreading them apart Occurs at condyloid, saddle, and ball-and-socket joints
- 31. Circumduction Circumduction is a circular movement that involves sequential flexion, abduction, extension, and adduction (or in the opposite order) in such a way that the distal end of the part moves in a circle. Circumduction can occur at any joint at which all the above-mentioned movements are possible (e.g., the shoulder and hip joints). Occurs in biaxial condyloid and saddle joints, and at multiaxial ball-and-sockets joints
- 32. Rotation Rotation involves turning or revolving a part of the body around its longitudinal axis, such as turning one’s head to face sideways. Medial rotation (internal rotation) brings the anterior surface of a limb closer to the median plane, whereas lateral rotation (external rotation) takes the anterior surface away from the median plane. Occurs in a Pivot joint
- 33. Supination and pronation Pronation and supination are the rotational movements of the forearm and hand that swing the distal end of the radius (the lateral long bone of the forearm) medially and laterally around and across the anterior aspect of the ulna (the other long bone of the forearm) while the proximal end of the radius rotates in place Pronation rotates the radius medially so that the palm of the hand faces posteriorly and its dorsum faces anteriorly. When the elbow joint is flexed, pronation moves the hand so that the palm faces inferiorly (e.g., placing the palms flat on a table). Supination is the opposite rotational movement, rotating the radius laterally and uncrossing it from the ulna, returning the pronated forearm to the anatomical position.
- 34. Dorsiflexion and Plantar Flexion Dorsiflexion describes flexion at the ankle joint, as occurs when walking uphill or lifting the front of the foot and toes off the ground. Plantarflexion bends the foot and toes toward the ground, as when standing on your toes. Extension of a limb or part beyond the normal limit— hyperextension (overextension)—can cause injury, such as “whiplash” (i.e., hyperextension of the neck during a rear-end automobile collision). Occurs at the hing joint
- 35. Inversion and eversion Involves complex movements that involve the multiple plane joints. Eversion moves the sole of the foot away from the median plane, turning the sole laterally. When the foot is fully everted, it is also dorsiflexed. Inversion moves the sole of the foot toward the median plane (facing the sole medially). When the foot is fully inverted, it is also plantarflexed.
- 36. Protraction and retraction Protrusion is a movement anteriorly (forward) as in protruding the mandible (chin), lips, or tongue. Retrusion is a movement posteriorly (backward), as in retruding the mandible, lips, or tongue. The similar terms protraction and retraction are used most commonly for anterolateral and posteromedial movements of the scapula on the thoracic wall, causing the shoulder region to move anteriorly and posteriorly
- 37. Depression and elevation Elevation raises or moves a part superiorly, as in elevating the shoulders when shrugging, the upper eyelid when opening the eye, or the tongue when pushing it up against the palate (roof of mouth). Depression lowers or moves a part inferiorly, as in depressing the shoulders when standing at ease, the upper eyelid when closing the eye, or pulling the tongue away from the palate.
- 38. Excursion Excursion is the side to side movement of the mandible
- 39. Opposition and Reposition Opposition is the movement by which the pad of the 1st digit (thumb) is brought to another digit pad. This movement is used to pinch, button a shirt, and lift a teacup by the handle. Reposition describes the movement of the 1st digit from the position of opposition back to its anatomical position. Occurs at saddle joint
- 40. Movements of the Joints (Table 1) Type of Joint Movement Example Pivot Uniaxial joint; allows rotational movement Atlantoaxial joint (C1–C2 vertebrae articulation); proximal radioulnar joint Hinge Uniaxial joint; allows flexion/extension movements Knee; elbow; ankle; interphalangeal joints of fingers and toes Condyloid Biaxial joint; allows flexion/extension, abduction/adduction, and circumduction movements Metacarpophalangeal (knuckle) joints of fingers; radiocarpal joint of wrist; metatarsophalangeal joints for toes Saddle Biaxial joint; allows flexion/extension, abduction/adduction, and circumduction movements First carpometacarpal joint of the thumb; sternoclavicular joint Plane Multiaxial joint; allows inversion and eversion of foot, or flexion, extension, and lateral flexion of the vertebral column Intertarsal joints of foot; superior- inferior articular process articulations between vertebrae Ball-and- socket Multiaxial joint; allows flexion/extension, abduction/adduction, circumduction, and medial/lateral rotation movements Shoulder and hip joints
- 41. Review Questions Describe the Anatomical position Identify the planes commonly used in the study of anatomy Describe the muscular system List and explain six (6) types of body movement Identify 5 types of joints and the movements they undergo, giving examples of each.
- 42. References Susan Standring. Grey’s Anatomy. The Anatomical Basis of Clinical Practice. 41st Edition. Elsevier Churchill Livingstone. Moore, Keith L.; Dalley, Arthur F. Clinically Oriented Anatomy, 8th Edition, Copyright ©2017. Lippincott Williams & Wilkins. OpenStax, Anatomy & Physiology. OpenStax CNX. Feb 26, 2016. http://cnx.org/contents/14fb4ad7-39a1-4eee-ab6e- 3ef2482e3e22@8.24 F r a n k h . n e t t e r , m d, atlas of human anatomy, seventh edition, 2019. Elsevier inc.