4. General Anatomy and physiology 4; Ann-2021.pptx

Good notes

1. GENERAL ANATOMY (Arthrology and Myology) DEPARTMENT OF HUMAN ANATOMY JKUAT

2. Arthrology-Study of Joints Joint - Is a point at which two or more parts of the skeleton (bones and/or cartilages) are jointed or link-up together i.e (point of bones articulation). Broad Classification of Joints Joints are broadly classified according to the structure of the articular surfaces as follows: i ). Immovable joints- synostosis ii). Movable joints- diarthrodial joints 1. Immovable joints : These joints are immobile or permit only slight movement .(e.g. fibrous and cartilaginous joints ) 2. Movable joints: These joints permit maximum degree of movement e.g. synovial joints

3. Immovable joints They may not or they may permit only slight movements and they include; Fibrous joint : Bones are joined together by fibrous connective tissue. 2. Cartilaginous joint: Bones are joined together by cartilage in between the articular surfaces of two bones.

4. 1. Fibrous joints T ypes of fibrous joints (a)Sutures Are found in skull and are immobile. Sutural membrane is present between two bones, which is attached peripherally to periosteum.

5. (b) Syndesmosis Bones are connected by a strong modified interosseous ligament, e.g. inferior tibiofibular joint.

6. (c) Gomphosis Is a p eg and socket type of joint, e.g. tooth in its socket .

7. 2. Cartilaginous Joints Types of cartilaginous joints (a)Primary Cartilaginous joints ( synchodroses ) The related bones are united by hyaline cartilage. They occur at ossification centers. e.g. (i). Costochondral joints (between ribs and coastal cartilage (ii). Joint between epiphysis and diaphysis (epiphyseal growth plate) of a growing long bone.  

8. (b)Secondary Cartilaginous Joints (symphyses) These joints occur in median plane. The bone ends are covered by hyaline cartilage and are connected by a disc of fibrocartilage e.g. Symphysis pubis, Intervertebral joint between vertebral bodies, Manubro-sternal joint (Sternal angle of Louis, Xiphisternal joint).

9. Synovial joints-(movable joints) Structure of synovial joints: i) . Articular surfaces of bone are covered by articular (hyaline) cartilage ii).Between articular surface is joint cavity , containing synovial fluid secreted by synovial membrane for; a). Lubrication of joint. b). Nourishes the articular cartilage. iii). Joint capsule- Made of d ense fibrous connective tissue R esembles a sac-like envelope that forms a sleeve around the synovial joint and encloses its cavity Joint capsule together with the ligaments stabilize the joint

10. Synovial joint

11. Types of Synovial joints The different types of synovial joints includes: Arthrodial/gliding/ plane synovial joint Flat surfaces are in contact. The movement possible is bones sliding/ glinding over each other, e.g. ( acromial clavicular joints, Sterno-clavicular joints).

12. (b) Hinge joint Movements take place around a transverse axis, e.g. joint between humerus and ulna (Elbow joint). They can extend to a maximum of 180

13. (c) Pivot joint/rotatory joint A bony pivot like process moves within a ring . Movements are possible only around longitudinal axis through center of pivot, e.g. median atlantoaxial joint

14. ’ d) Condylar/ellipsoid joint A condyle (articular surface) moves within an elliptical articular surface. e.g. metacarpophalangeal joint.

15.   e ) Saddle Joint Articular surfaces are both concavo-convex with the shapes complementing one other and allowing wide range of movement. Movements permitted are same as in condylar type with some rotational movement, e.g., carpometacarpal joint of thumb, ankle joint.  

16. f. Ball and socket Articular surfaces are globular head which fits into a cup like cavity. Movements are possible in every direction around a common center e.g., hip joint

17. Factors influencing joint stability: Shape of the articular surface. Muscles surrounding the joint Ligaments reinforcing the joint Muscle tone.

18. MYOLOGY

19. Myology-(study of Muscles) Muscles are bundles of fibrous tissue in a human body that has the ability to i). C ontract and can be excited ii). P roduce movement iii). Maintain the position of parts of the body. Muscles can be classified in two two broad categories:- Those that function as single cells/unit (Unicellular) 2 . Those that function in groups of muscle fibres (multicellular)

20. Unicellular muscles They are comprised of; myo-e pitheliocytes - lines the glands to expel secretions

21. b) Myo-fibroblasts Are cells that have a contractile role in addition to being able to secrete collagen . They are dominant in areas where tissues undergo repair by altering tissue tension c) Pericytes - a re smooth muscle cells line the blood vessels

22. Multicellular muscles They are comprised of; 1. skeletal muscles They a re voluntary muscles that move the bones and support the skeleton. The muscle tissue is connected to the skeleton Characteristics 1. Are voluntary muscles 2. Has many nuclei 3. Fibres are long and cylindrical 4. Are present in skeletal muscles 5. Contains many mitochondria 6 . Has striations ( alternating dark and light bands) due to regular arrangement of contractile proteins (actin and myosin) . Actin is a globular contractile protein that interacts with myosin for muscle contraction

23. b) smooth muscles Are muscles  in the body serving a variety of functions .Examples of the areas where they are found in the body include the bladder , intestine ,  stomach , uterus etc. (they line hollow organs in the body). Characteristics Are found in viscera (hollow organs mostly). contracts without any voluntary control . Are s pindle-shaped ( are longer than they are wide ), "fusiform“ tapered at each end, and widest in the middle Cells are un-striated. Has single ovoid  nucleus  located in centre of a cell. Are innervated by Autonomic Nervous System.

24. Smooth muscle

25. 3. cardiac muscles C ardiac muscle tissues forms the muscle surrounding the heart. T hey function to cause the mechanical motion of pumping blood throughout the rest of the body Characteristics Are involuntary muscles Are innervated by Autonomic nervous system Are striated Has branching fibres Are present in the heart Have single central nuclei

26. Skeletal muscles Functions of Skeletal Muscle 1. Movement : muscle pulls tendons to move the skeleton 2. Control swallowing, defecation and urination 3. Maintain posture 4. Stabilize joints 5. Generate Heat Properties of Muscle 1. Contractibility – ability to shorten when an adequate stimulus is received 2. Extensibility – ability to stretch when an adequate stimulus is received 3. Elasticity – ability to return to normal shape

27. Skeletal Muscle Action Prime mover: A muscle is a prime mover when it is the chief muscle or member of a chief group of muscles responsible for a particular movement Antagonist: Any muscle that opposes the action of the prime mover is an antagonist Fixator: A fixator contracts isometrically (contraction increases the tone but does not in itself produce movement) to stabilize the origin of the prime mover so that it can act efficiently. Synergist: In many locations in the body, the prime mover muscle crosses several joints before it reaches the joint at which its main action takes place. Synergist stabilizes the intermediate joints that are crossed by the prime movers.

28. The skeletal muscles attachments When defining skeletal muscle attachments, the following terms are used Origin and insertion:- The origin of a muscle is the point where the muscle has least movement while insertion is the point where a muscle moves most. 2.  Belly: The fleshy/widest part of a muscle 3.  Tendon: These are cords of fibrous tissue at the end of a muscle that attach it to bones 4. Aponeurosis: these are thin but strong sheets of fibrous tissue that attaches muscles to bones.

29. Classification of skeletal muscles:   They are classified according to structure as:- 1. Unipennate muscles :- fibres run straight to the line of pull e.g. tibialis anterior muscle. 2. Bipennate muscle :- Tendon lies in the center of the muscle and muscle fibres ran to it from two sides e.g rectus femoris muscle. 3. Multipennate muscle:- These are a series of Bipennate muscle with fibres arranged alongside one another. E.g. deltoid muscle

30. www.LabScience.org

31. - Classification - Relative to the Midline RECTUS = parallel to the midline Rectus Abdominus TRANSVERSE = perpendicular to midline Transverse Abdominus OBLIQUE = diagonal to midline External Oblique

32. Classification - relative to structure near which muscle is found FRONTALIS = near FRONTAL bone OCCIPITALIS = near OCCIPITAL bone

33. Classification - relative to size of the muscle MAXIMUS = largest; Gluteus Maximus MEDIUS = middle; Gluteus Medius MINIMUS = smallest; Gluteus Minimus LONGUS = longest; Fibularis Longus BREVIS = short; Fibularis Brevis TERTIUS = shortest; Fibularis Tertius

34. Classification - relative to shape of the muscle DELTOID = triangular shape Δ RHOMBOIDEUS = rhomboid shape  SERRATUS = saw-toothed ♒ TRAPEZIUS = trapezoid shape

35. Classification - relative to n umber of tendons of origin BICEPS = Two Biceps Brachii Biceps Femoris TRICEPS = Three Triceps Brachii QUADRICEPS = Four Quadriceps Femoris

36. Classification - relative to o rigin and insertion ILIO COSTALIS = Attaches to the ilium & ribs (costal = ribs) CORACO-BRACHIALIS – From coracoid process to the brachium (upper limb).

37. NAME ACTION EXAMPLE FLEXOR Decrease angle at a joint Flexor Carpi Radialis EXTENSOR Increase angle at a joint Extensor Carpi Ulnaris ABDUCTOR Move bone away from midline Abductor Pollicis Longus ADDUCTOR Move bone toward midline Adductor Longus LEVATOR Produce upward movement Levator Scapulae DEPRESSOR Produce downward movement Depressor Labii Inferioris SUPINATOR Turn palm upward/anterior Supinator PRONATOR Turn palm downward/posterior Pronator Teres Classification – related to function