Introductory Topics in Anatomy Anatomical Position o The body stands erect with eyes facing forward. The upper limbs and hands are to the side with the palms facing forward (they are supinated). The fingers are extended anteriorly and the thumbs are the most lateral digits. Feet are flat with toes pointed forward. 3 Standard Anatomical Planes o Sagittal Plane o Any plane that divides the body into left and right portions (always parallel to long axis of body) o Midsagittal: divides into equal L and R halves o Parasagittal: divides into unequal L and R halves o Frontal Plane (Coronal plane) o Any plane that divides the body into anterior and posterior portions; it is always parallel to long axis of body; it is used in context of discussing the cephalic region o Horizontal Plane (Transverse or aka. Cross-sectional plane) o Any plane that divides the body into superior and inferior portions; this plane is always parallel to horizon o Oblique plane o Any plane that is not parallel to any standard anatomical plane Abdominal Quadrants o 4 Abdominal Quadrants o Right Upper Quadrant (RUQ) o Left Upper Qudrant (LUQ) o Transumbilical Plane divides horizontally o Right Lower Quadrant (RLQ) o Left Lower Quadrant (LLQ) o Median Plane divides vertically o 9 Abdominopelvic Body Regions o Do not need to know for this exam but know that R&L midclavicular (parasagittal planes) divide vertically and Subcostal Plane passes through inferior margin of 10th rib horizontally and Supracristal plane passes through highest point of iliac crests on pelvis horizontally. Ventral and Dorsal Cavities o Body cavities are confined spaces within the body whose function is to cushion, protect and permit changes in the shape, volume, or position of internal (visceral) organs. o Ventral . Aka. Coelom . Larger than the dorsal cavity; contains the viscera. All subdivisions of the ventral Cavity are lined by serous membranes A) Thoractic Cavity: found in the chest, bounded by the chest wall and inferiorly by the diaphragm o 1. Mediastinum: contains pericardial cavity which surrounds the heart, thymus, trachea, esophagus, and major blood vessels; Pericardium Serous Membrane surrounds o 2. Right Pleural Cavity: surrounds the right lung; Pleura Serous Membrane surrounds o 3. Left Pleural Cavity: surrounds left lung; Pleura Serous Membrane surrounds B) Abdominopelvic Cavity: contains the peritoneal sac and two cavities o 1. Abdominal Cavity: most of the digestive tract, kidneys, and pancreas o 2. Pelvic Cavity: bladder, reproductive organs and rectum o Dorsal . Protects the CND A) Cranial Cavity: contains brain, meninges and CSF B) Spinal Cavity: contains spinal cord, meninges, and CSF Trunk Body Wall Layers o This is the order from Superficial to Deep o 1. Skin (aka cutaneous membrane = epidermis and dermis) . Permanent tattoos are injected into dermis . Epidermis is continually sloughed off o 2. Superficial fascia (aka hypodermis or subcutaneous tissues) . Thicker in females than males o 3. Deep investing Fascia of skeletal muscles tissues . Ensheathes all surfaces and sides of skeletal muscles o 4. Internal Fascia (aka subserosa fascia) o 5. Parietal Layer of serous membrane . Secrets a slipper serous fluid . Found in ventral body cavities o 6. Water thing space o 7. Organs o Via skeletal muscle shortening (contraction = when a muscle is active using ATP), move bones producing movement at joints o Support o Maintain posture, balance, support soft tissue o Thermoregulation o Produce heat via shivering when body is cold; a by-product of muscle contraction o Glucose Homeostasis o Uptake and storage of glucose o Cannot release glucose into bloodstream between meals like liver can do Skeletal Muscle Anatomy o Epimysium o Deep investing fascia; surround entire skeletal muscle (like a pillowcase) o Perimysium o Surrounds a group of skeletal muscle cells (fiber) o Called a fascicle o Endomysium o Surrounds each skeletal muscle fiber (cell) Primary Skeletal Muscle Actions o Agonist (aka prime mover) o The primary muscle whose contraction produces a specific allowable motion at a joint o Synergist (“helper muscle”) o The combined effort is greater than the sum of the individual muscles o Fixators: stabilize a joint while agonist is active o Antagonists o The muscle would produce the opposing motion of agonist o This muscle is passively stretching while agonist is actively contracting How skeletal muscle are named o BY LOCATION (body regions) o 1. Brachialis o 2. Biceps Brachii o 3. External Abdominal Oblique o 4. Rectus Femoris o BY FUNCTION o Flexor Carpi Radialis o Adductor Magnus o Supinator o BY SHAPE o Deltoid (triangle) o Pronator Teres (round) o Pronator Quadratus (rectangle) o Trapezius (trapezoid) o BY NUMBER OF HEADS (-cep=head) o Biceps (two heads) o Triceps (three heads) o Quadriceps (four heads) o BY FIBER DIRECTION o Rectus Abdominus (rectus = straight) o Internal Abdominal Oblique (oblique = at an angle) o BY ATTACHMENT POINTS o Sterno-cleido mastoid o Brachio-radialis o Ilio-costalis o BY SIZE o Gluteus Maximus (biggest) o Adductor Brevis (brevis = short) Axial Muscles Know the locations and Actions of…. o Sternocleidomastoid (SCM) o Bilateral Contraction: neck and head flexion o Unilateral contraction: produces contralateral and ipsilateral contraction o It is superficial to large vessels and nerves of the neck o WRYNECK is caused by shortened and tightened SCM of a newborn. It is a result of trauma during birth and can be treated by stretching, physical therapy, or surgery. o Intrinsic Back Muscles o The longest mm. are more SUPERFICIAL o The shortest mm. are DEEPER o SUPERFICIAL LAYER: SPLENIUS M (only neck) . Travel superior-laterally from superior process to Transverse Process . Bilateral contraction: extends head and neck . Unilateral contraction: ipsilateral rotation and flexion o INTERMEDIATE LAYER: ERECTOR SPINAE . Consists of 3 vertical columns of muscle . 2 of the 3 muscles travel super-laterally from superior process to transverse process . Spinalis: most medial group . Longissimus . Iliocostalis: most lateral group . Bilateral: extend the VC, important postural mm. Unilateral: same side flexion (ipsilateral flexion) o DEEP LAYER: TRANSVERSOSPINALIS GROUP . Travel superior-medially from transverse process to spinous process . Semispinalis (most superficial) Span 4-6 vertebrae Attach inferior TP to superior SP Bilateral: stabilization of VC; extend VC and head Unilateral: opposite side rotation (contralateral) . Multifidus Span 2-4 Vertebrae Attach Inferior TP to superior SP Bilateral: stabilization of VC; extend the VC and head Unilateral: opposite side rotation (Contralateral) . Rotatores (DEEPEST) Span 1-2 vertebrae Attach inferior TP to superior SP Bilateral: stabilization of VC; extend the VC and head Unilateral: opposite side rotation (Contralateral).