PT 500 Overview Anatomy PDF

1 PT 500 Overview 1. Review of Terminology a. Anatomical Position i. Standing upright ii. Head, gaze (eyes), and toes directed ante...

1 PT 500 Overview 1. Review of Terminology a. Anatomical Position i. Standing upright ii. Head, gaze (eyes), and toes directed anteriorly (forward). iii. Arms adjacent to the sides with the palms facing anteriorly. iv. Lower limbs close together with the feet parallel. b. Planes i. Median sagittal 1. vertical anteroposterior plane dividing it into right and left halves ii. Sagittal 1. vertical planes passing through the body parallel to the median plane 2. Also creates a longitudinal section iii. Frontal 1. vertical planes dividing the body into anterior (front) and posterior (back) parts iv. Transverse 1. horizontal planes dividing the body into superior (upper) and inferior (lower) parts 2. Creates a transvers section Section 1a.1  2 c. Relationships / Comparisons Section 1a.1  3 d. Movements/ Positions Section 1a.1  4 Section 1a.1  5 PT 500 Overview 1. Epithelial Tissue A. Overview of Epithelia i. Major Types of Epithelia a. Covering b. Glandular ii. Functions of Epithelia a. protection b. absorption c. secretion d. Excretion e. sensation f. transport iii. Proliferative Capacity of Epithelia a. Permanent (non-renewable) 1) No cell division in mature cells 2) Lens of eye, hair cells of inner ear b. Stable 1) Mature cells only divide if damaged c. Labile 1) Cells continuously proliferate to replace lost cells 2) Epidermis, intestinal epithelia iv. Classification System for Epithelia a. Description of Layers 1) Stratified, pseudostratified, simple b. Shape of cells 1) Squamous, cuboidal, columnar c. Specialized Features 1) Cilia, goblet cells, keratinized, microvilli B. Covering Epithelia i. Stratified a. Stratified Squamous 1) Found in epidermis 2) Many layers, good for protection 3) Functions? Section 1a.2  6 2. Connective Tissue Overview A. Types i. Connective Tissue Proper ii. Bone iii. Cartilage iv. Specialized Connective Tissue B. General Components1 i. Cells: Fibroblasts, mast cells, macrophages, plasma cells, adipocytes ii. Fibers: Collagen, Elastin, Reticular Fibers (mesh framework) iii. Extracellular Matrix: ground substance, extracellular fluid, proteoglycans 3. Connective Tissue Proper A. Loose Connective Tissue i. Adipose tissue: a. Hypodermis, “packing” around organs b. shock absorbing, insulating, energy storage ii. Specialized Connective Tissue a. Reticular Tissue 1) Fine fiber networks in: glands, organs, lymphoid tissues b. Elastic Tissue c. Serous and Synovial membranes1 1) Loose CT with covering epithelium 2) Fluid secretion and nutrition d. Mucous Connective Tissue1 1) Primarily embryonic, few cells or fibers (umbilical cord) B. Dense Connective Tissue i. Dense Regular Connective Tissue a. Tendons, Ligaments, Aponeuroses, Retinacula b. Parallel alignment of collagen bundles c. Maximal tensile strength in primarily one direction ii. Dense Irregular Connective Tissue a. Dermis, deep fascia organ capsules, GI tract (deep to epithelium) b. Varying directions of collagen bundles c. Withstand tension in multiple directions Section 1a.2  PT 500 Overview: Integumentary System Structure 1. Overview of the Integumentary System A. Components: skin, hair, nails, sweat glands, sebaceous glands, subcutaneous fat, deep fascia, mucous membranes B. Two classes of skin i. Thin hairy skin: most of the body ii. Thick hairless (glabrous) skin: palms, sole of feet, flexor surface of digits 2. Functions of the Integumentary System A. Protection: physical barrier from abrasions, protection from chemical substances, UV protection, reduces fluid loss i. Immune Defense: turn over of cells (healing), initiation of immune responses, barrier to micro-organisms B. Regulation: Thermoregulation via sweat and blood flow regulation, insulation via hypodermal adipose tissue C. Communication: between body and environment, sensory receptors D. Synthesis/Secretion (endocrine): Vitamin D synthesis, synthesis of growth factors E. Excretion: via sweat glands 3. Layers of the Skin A. Epidermis i. Stratified Squamous Keratinized Epithelium ii. Many layers for protection B. Dermis i. Primarily Dense Irregular Connective Tissue C. Hypodermis i. Loose Connective Tissue, often adipose ii. Superficial Fascia iii. Mediates mobility of the skin, shock absorbing, thermal insulation Section 1a.3  8 PT 500 Overview 2. Skeletal System a. Divisions of the skeleton i. Axial Skeleton 1. cranium, vertebral column, ribs, and sternum. There are 7 cervical, 12 thoracic, 5 lumbar, 5 sacral (fused) and 3-4 coccygeal (fused) vertebrae ii. Appendicular Skeleton 1. clavicle, scapula, humerus, radius, ulna, carpals, metacarpals, phalanges of the hand, pelvis, femur, patella, tibia, fibula, tarsals, metatarsals, and phalanges of the foot. b. Function of bone i. Protection ii. Support iii. Movement iv. Formation of blood cells v. Storage of salts c. Types of bone i. Long Bones iii. Flat Bones 1. Epiphysis and iv. Pneumatic bones Epiphyseal plate v. Sesamoid bones 2. Metaphysis (functions?) 3. Diaphysis vi. Accessory bones 4. Periosteum vii. Heterotropic bones ii. Short Bones (mostly hand and foot) d. Types of Bony Landmarks i. Capitulum vii. Spinous process ii. Condyle 1. Projecting spine- 1. Rounded knuckle- like part like articular area viii. Trochanter iii. Crest 1. Large blunt 1. Ridge of bone elevation iv. Facet ix. Trochlea 1. Smooth flat area x. Tubercle v. Fossa 1. Small raised vi. Groove eminence xi. Tuberosity 1. Large rounded elevation Section 1a.4  9 3. Cartilage a. Functions of Cartilage i. Shock absorption ii. Distribute Loads iii. Reduce Friction iv. Growth and development of bone b. Types of Cartilage (more on this in lab) i. Hyaline Cartilage 1. Articular surfaces, respiratory passages, epiphyseal growth plates 2. Proteoglycan matrix and collagen fibers, chondrocytes in lacunae 3. Shock absorbing, friction reducing (articular) ii. Fibrocartilage 1. Annulus fibrosis of IV discs, Knee menisci, Connecting tendon and bone 2. Strong collagen bundles, rows of chondrocytes 3. Resistant to compression and tension, load bearing iii. Elastic Cartilage 1. External ear, epiglottis 2. Network of elastic fibers 3. High level of flexibility c. Neurovascular Supply to Cartilage i. Mostly avascular and aneural ii. Relies on diffusion for nutrition iii. Perichondrium has vascular, lymphatic and blood supply (no perichondrium on articular surfaces) Section 1.1.4  10 4. Arthrology a. Classification of Joints Structure Function sutures Fixed (Synarthroses) schindylesis Fibrous syndesmoses Slightly Moveable gomphoses symphyses Slightly Moveable synchondroses Cartilaginous joints can also be classified as primary cartilaginous Cartilaginous joints (e.g., developing bone where ossification centers are separated by hyaline cartilage, such as at growth plates) or secondary cartilaginous joints (e.g., those with intervening fibrocartilage pads or discs) Plane (gliding) Hinge (ginglymi) Pivot (trochoid) Synovial Freely Moveable Bichondylar Ellipsoid Sellar (saddle) Spheroidal (ball and socket) b. For Freely Moveable joints, consider if the joint is: i. Uniaxial (one degree of freedom) ii. Biaxial (two degrees of freedom) iii. Triaxial (three degrees of freedom) c. For freely moveable joints, the types of movement allowed i. Types of movement 1. Gliding/sliding 2. Angular movement 3. Rolling or spinning ii. Role of the joint surface 1. Joint surface (type of curvature, convex/concave, flat…) will affect the types of movement allowed 2. Getting a good picture of the joint surface structure will help you as you move on in kinesiology and orthopedics Section 1.1.4  PT 500 Overview 5. Muscular System a. Types of Muscle and their functions: Overall function = contraction i. Skeletal (generally voluntary control, bundles of striated muscle fibers) 1. Movement 2. Heat production 3. Postural control 4. Protection ii. Smooth 1. Found in glands, the muscular layers of the viscera and vasculature; involuntary, non-striated 2. Non-striated fusiform cells with a single nucleus 3. Function = Maintain homeostasis iii. Cardiac 1. Striated parallel fibers with intercalated discs between; produces involuntary, rhythmic contractions 2. 1-2 nuclei per cell 3. Function = Pump blood b. Classification of Skeletal Muscle i. Motor Unit: a motor neuron and all of the muscle fibers it innervates ii. Muscle Architecture (more on this in biomechanics) 1. Pennate (appears feather like) a. Unipennate: ex Extensor Digitorum Longus b. Bipennate: ex Gastrocnemeus c. Multipennate: ex Deltoid 2. Fusiform (spindle shaped, thick belly, tapered ends) a. Ex Biceps Brachii 3. Quadrate (four equal sides) a. Ex Pronator quadratus 4. Circular (sphinteral: surround an opening) a. Ex Orbicularis oris 5. Mulit-headed or Multi-bellied a. Biceps brachii (two heads) b. Gastroc (two bellies) Section 1a.5  Examples of Muscle Architecture: Adapted from More & Dalley 2006 c. Skeletal Muscle Considerations i. When learning (or re-learning) the names and functions of skeletal muscles, try to understand how various descriptive terms are used. For example, ‘major’ and ‘minor’ typically refer to larger and smaller muscles in the same region (e.g., pectoralis major and pectoralis minor). The flexor digitorum ‘superficialis’ lies superficial to the flexor digitorum ‘profundus’ (profound=deep). ‘Teres’ (e.g., pronator teres) refers to a round-shape; ‘quadratus’ (e.g., pronator quadratus) refers to a quadrangular shape, and so on. Furthermore, muscles may be named for the number of muscle bellies, or heads, they have or the region of the body they occupy (e.g., biceps brachii, biceps femoris). Section 1a.5 6. Fascia a. Connective tissue that surrounds muscles and separates them from other tissues b. Many varieties of fascia: i. Thin and membranous (fascial sheathes around tendons) ii. Infiltrated with adipose tissue (subcutaneous superficial fascia/ hypodermis) iii. Tough and fibrous (intermuscular septa) iv. Can play a role in coordinating muscle pull (retinacula, thoracolumbar fascia) c. Functions i. Creates compartmentalization to allow one structure to move independent of another ii. Can create a space that holds fluids d. Layers of fascia covering/surrounding muscles: i. Superficial fascia ii. Investing fascia iii. Deep fascia (may attach directly to bone) e. Clinical Considerations for Fascia i. Injury can create adhesions 1. What might be the consequences of fascial adehesions on mobility? ii. What is compartment syndrome? What is the role of fascia in compartment syndrome? Section 1a.5  PT 500 Overview 7. Overview of entire nervous system a. Central Nervous System (CNS): Brain and spinal cord i. At what vertebral level does the spinal cord end? ii. What is the name of the terminal structure of the spinal cord? b. Peripheral Nervous System (PNS): spinal and cranial nerves i. Portions of the autonomic nervous system (ANS) travel with the peripheral nerves ii. For review: 1. What is the ANS? What are its divisions? 2. What are the functions of the ANS? 3. What is the relationship between the spinal nerves and the ANS? Section 1a.6 8. Organization of the Peripheral Nervous System (PNS) a. Spinal Nerves i. Spinal Nerve Structure 1. Individual nerve fibers (axons) surrounded by endoneurium (connective tissue) a. Endoneurium = loose connective tissue 2. Fascicle = bundle of nerve fibers (covered by perineurium) a. Perineurium = dense irregular connective tissue b. Tight junctions between cells in the perineurium contribute to the blood-nerve barrier 3. Nerve = bundle of fascicles covered by epineurium a. Blood vessels (blood supply to the nerve) travel in the epineurium then dive into the perineurium to supply the tissue b. The epineurium is continuous with the dura of the CNS. What implications for PT might this create? Section 1a.6  ii. Overview of Spinal Nerve Organization 1. Roots a. Dorsal (sensory) Root b. Ventral (motor) Root 2. The two roots joint to form the mixed spinal nerve at the level of the intervertebral foramen a. In the thoracic, lumbar and sacral regions, spinal nerve roots exit distal to the corresponding vertebrae b. How is this different in the cervical region? 3. The mixed spinal nerve then divides into two primary rami a. The Anterior Primary Rami (APR) i. Innervate anterior portion of the trunk (thoracic and abdominal walls), sensory and motor ii. Participate in plexuses to serve the extremities b. The Posterior Primary Rami (PPR) i. Innervate deep muscles of the back and posterior neck and provide sensory innervation to the skin overlying the back and posterior neck Section 1a.6  iii. Sensory Innervation 1. Sensory information from peripherally located receptors (in the skin, muscles, joints, organs) is conveyed along fibers that enter the spinal cord at the dorsal root 2. Review where the cell bodies for peripheral sensory nerves are located 3. A dermatome is the area of skin with sensory innervation from a single spinal nerve root a. What is the difference of the dermatomal distribution and the sensory distribution of an individual peripheral nerve? b. Why is this so? 4. Review the dermatomal distributions and begin to familiarize yourself with them (you will use this information through the rest of your PT career!) Section 1a.6 Section 1a.6 Section 1a.6  iv. Motor Innervation 1. Skeletal muscle receives motor innervation via impulses from anterior horn cells, traveling through the ventral roots to spinal and peripheral nerves 2. What is a myotome? a. Why is it important for you, as a PT, to know which muscles receive innervation from each spinal nerve root? 9. Spinal Nerves versus Named Peripheral Nerves a. Peripheral nerves are made up of components of spinal nerves i. In the trunk 1. Many peripheral nerves innervating the anterior portion of the trunk are simply continuations of the APRs of the spinal nerves (intercostal and thoracoabdominal nerves) a. Some abdominal muscles (and skin in the vicinity) are innervated by named peripheral nerves from the lumbar plexus (such as iliohypogastric and ilioinguinal) 2. Very few of the nerves innervating the intrinsic back muscles have specific names, most are simply continuations of the PPRs 3. Trunk muscles that act on the upper extremity (pectoralis major, latissimus dorsi, rhomboids etc) are innervated by branches of the brachial plexus a. Trapezius, however, is innervated by cranial nerve XI Section 1a.6  ii. In the extremities 1. Most peripheral nerves in the extremities arise from plexuses (networks networks of nerves) 2. A single peripheral nerve typically receives poritons multiple APRs of spinal nerves 3. For example: The femoral nerve (which primarily serves the anterior thigh) receives contributions from the L2-L4 nerve root APRs) a. L2-L4, however contribute to other peripheral nerves (such as obturator) b. Most peripheral nerves have both sensory and motor fibers i. The sensory and motor fibers may become separated as they approach their targets ii. Compare and contrast the dermatomes with the sensory distributions of the peripheral nerves iii. Also compare and contrast motor distributions of the peripheral nerves with the myotomes 10. Nerve Plexuses a. A plexus is a network of nerves that is formed from the ventral/anterior rami (APRs) of nerve roots in the corresponding regional area b. For example: The brachial plexus receives input from C5-T1 and gives off 5 primary terminal branches and numerous smaller branches. (more on this later in the semester!) Section 1a.6 Section 1a.6 11. Relevance to PT a. Many injuries create varying degrees of compromise to spinal and peripheral nerves b. As a PT it is important to understand how to differentiate spinal nerve root injuries from peripheral nerve injuries as well as where along the course of a nerve the damage is. i. A thorough understanding of the organization, paths, and functions of the spinal and peripheral nerves will enable you to carry out this skill c. How might you differentiate damage to a nerve root from damage to a peripheral nerve in the same vicinity? d. How might you determine where along the course of a peripheral nerve the damage is? e. What is neural tension (adverse mechanical tension)? Why will a solid understanding of the organization of the nervous system help you assess and treat patients with this condition? Section 1a.6 12. Summary/Review a. Nervous system is composed of the Central Nervous System (CNS, Brain and Spinal Cord) and the Peripheral Nervous System (PNS, cranial and spinal/peripheral nerves). b. The Autonomic Nervous System (ANS) is comprised of components of both the CNS and the PNS and includes the parasympathetic division (craniosacral division, “rest and digest”) and the sympathetic division (thoracolumbar, “flight or fight”). The pre- ganglionic neurotransmitter for both is usually ACh; the post-ganglionic neurotransmitter for the parasympathetic system is also ACh, but usually norepinephrine or epinephrine for the sympathetic system. c. The ventral root contains motor axons that exit the spinal cord; the dorsal root contains sensory fibers that enter the spinal cord. d. The ventral and dorsal roots combine to form a mixed spinal nerve root at each level of the spinal cord. These nerve roots exit via the intervertebral foramina. e. The spinal nerve root branches into anterior primary rami, which carry both motor and sensory fibers and form the peripheral nerves that innervate the extremities and anterolateral trunk, and posterior primary rami, which carry both motor and sensory fibers and provide segmental innervations to the deep back and neck muscles and the skin overlying them. f. A dermatome is the area of skin that receives its cutaneous sensory innervation from one spinal nerve root segment (e.g., C5 dermatome=skin overlying the shoulder). Dermatomes follow developmental patterns of growing nerves, resulting in a sort of “striped” distribution. g. A myotome is the muscle or group of muscles that get their primary motor innervations from one spinal nerve root segment (e.g., C5 myotome includes the deltoid and other muscles that externally rotate the humerus). h. Named peripheral nerves in the extremities are formed from contributions of a nerve plexus; most peripheral nerves fibers from parts of 2 or 3 nerve roots; they may be cutaneous/sensory (e.g., medial cutaneous nerve of the arm), motor (anterior interosseous nerve), or mixed (median, ulnar, radial nn). i. The cutaneous distribution of a peripheral nerve often includes parts of 2-3 dermatomes. 13. Review Questions a. Be able to give examples of the various types of bones; identify and describe the components of immature and mature bones. b. Identify and characterize the various types of muscle and cartilage. Where is each found? What are the components? c. Give an example of each type of skeletal muscle and describe how its structure relates to its function. d. How do fascia, cartilage, bone, and muscle work together functionally? e. Explain to your classmate the difference between a spinal nerve and a peripheral nerve. Why is it that when we learn the innervation to any muscle we learn the peripheral nerve and the spinal nerve roots? Section 1a.6 Section 1a.6