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August 06, 2024 GEN ANA 1 LAB About General Anatomy DIRECTION “anatomy” The most basic anatomy concept, and equally - “ana” = apart...

August 06, 2024 GEN ANA 1 LAB About General Anatomy DIRECTION “anatomy” The most basic anatomy concept, and equally - “ana” = apart the most important, is orientation. All structures - “tome” = cutting and the relationships between them are  derived from Greek roots that means “to referenced to the standard anatomical position. cut apart.” Anatomic Positions Human Anatomy A standard position to which description of  Deals with the study of shapes & any part of the body are based upon structures of the human body with special  Body is standing erect facing the emphasis on the relationships of the observer different parts.  The face & eyes are directed forward Human anatomy is the scientific study of the  The arms are hanging at the side body’s structures. Some of these structures are  Palms are facing forward with the very small and can only be observed and thumb pointing laterally analyzed with the assistance of a microscope.  The heels are together & feet flat on Other larger structures can readily be seen, the floor manipulated, measured, and weighed. Human anatomy was first studied by observing ANATOMICAL PLANES the exterior of the body and observing the At times, it is conceptually useful to discuss the wounds of soldiers and other injuries. Later, body in reference to a series of physicians were allowed to dissect the bodies of planes/imaginary flat surfaces passing through the dead to augment their knowledge. When a it. Sectioning the body is a way to “look inside” body is dissected, its structures are cut apart to and observe the body’s structures. observe their physical attributes and their 1. SAGITTAL/MEDIAN PLANE relationships to one another. Dissection is still A sagittal plane / median plane runs used in medical schools, anatomy courses, and vertically through the body and separates in pathology labs. To observe structures in living it into right and left parts. people, however, several imaging techniques Median plane is a sagittal plane that have been developed. passes through the midline of the body, Materials used to study anatomy dividing it into equal right and left halves. a) Books 2. TRANSVERSE/HORIZONTAL PLANE b) Charts, drawings & atlases Transverse plane/horizontal plane runs c) Human model/cadavers parallel to the surface of the ground, d) Living body dividing the body into superior and 4 Basic Reference System inferior parts. 1. Direction 3. FRONTAL/CORONAL PLANE 2. Anatomical planes The frontal plane/coronal plane runs 3. Cavities vertically from right to left and divides the 4. Structural units – cells, tissues, organs, body into anterior and posterior parts. systems  August 06, 2024 DIRECTIONAL TERMS BODY CAVITIES & MEMBRANES B. Ventral Cavity The ventral cavity, the interior space in the front of the body, contains many different organ systems. The organs within the ventral cavity are also called viscera. The ventral cavity has anterior and posterior portions divided by the diaphragm; a sheet of skeletal muscle found beneath the lungs. 1. Thoracic A. Dorsal Cavity The thoracic cavity is the anterior ventral body The dorsal cavity is a continuous cavity located cavity found within the rib cage in the torso. It on the dorsal side of the body. It houses the houses the primary organs of the cardiovascular organs of the upper central nervous system, and respiratory systems, such as the heart and including the brain and the spinal cord. The lungs, but also includes organs from other meninges is a multi-layered membrane within systems, such as the esophagus and the the dorsal cavity that envelops and protects the thymus gland. The thoracic cavity is lined by two brain and spinal cord. types of mesothelium, a type of membrane 1. Cranial tissue that lines the ventral cavity: the pleura The cranial cavity is the anterior portion of the lining of the lungs, and the pericadium lining of dorsal cavity consisting of the space inside the the heart. skull. This cavity contains the brain, the The mediastinum is a partition containing the meninges of the brain, and cerebrospinal fluid. heart, thymus, trachea, esophagus. The lungs 2. Vertebral/Spinal are located on each side of mediastinum. The vertebral cavity is the posterior portion of Pericardial cavity – houses the heart the dorsal cavity and contains the structures and contains the ff membranes: within the vertebral column. These include the  Pericardium – 2 layered membrane spinal cord, the meninges of the spinal cord, and which enfolds the heart the fluid-filled spaces between them. This is the  Visceral layer – inner layer which most narrow of all body cavities, sometimes forms the surface of heart itself described as threadlike.  Parietal layer – outer layer  Pericardial cavity – space that separates the 2 layers  August 06, 2024  Pericardial fluid REGIONS OF THE BODY  Pleural cavity – houses the 2 lungs and Axial Region contains the ff membranes: a. Head  Pleura – 2 layered membrane which b. Neck (cervical) enfolds the two lungs c. Trunk  Visceral layer – inner layer which a. Thoracic region – above forms the surface of lung itself diaphragm  Parietal layer – outer layer b. Abdominal region  Pleural cavity – space that separates - Divided into nine regions the 2 layers Left and right hypochondriac  Pleural fluid region, epigastric region, left and 2. Abdominopelvic Cavity right lumbar region, umbilical The abdominoplevic cavity is the posterior region, left and right iliac/inguinal ventral body cavity found beneath the thoracic region cavity and diaphragm. The abdominopelvic - Divided into quadrants cavity is lined by a type of mesothelium called a. RUQ the peritoneum. It is generally divided into the b. RLQ abdominal and pelvic cavities. c. LUQ  Abdominal Cavity d. LLQ The abdominal cavity is not contained within c. Pelvic region bone and houses many organs of the digestive Appendicular Region and renal systems, as well as some organs of a. upper limbs/ appendages/ extremities the endocrine system, such as the adrenal a. arm (brachial region) glands. b. forearm (antebrachial) Contains the ff: c. wrist (carpal region)  Digestive organs, Spleen, Kidneys, d. hand Ureters e. fingers (digits)  Peritoneum – serous membrane b. lower limbs  Parietal peritoneum – lines cavity wall a. thigh (femoral)  Visceral peritoneum/ mesentery b. leg (crural)  Peritoneal cavity c. ankle (tarsal)  Peritoneal fluid d. foot  Retroperitoneal e. toes (digits) o Kidneys c. segment – region between one joint and o Ureters the next o Adrenal glands o Most of pancreas o Abdominal portions of 2 major blood vessels (aorta and inf vena cava)  Pelvic Cavity Located inferiorly to the abdominal cavity, the pelvic cavity is contained within the pelvis and houses the bladder and reproductive system. Contains the ff:  Rectum, Urinary bladder, Urethra, Reproductive organs  August 06, 2024 ANATOMICAL TERMINOLOGIES BODY SYSTEMS August 06, 2024  August 06, 2024 SUMMARY Anatomy is the study of the structures of the body. The eleven organ systems are integumentary, skeletal, muscular, lymphatic, respiratory, digestive, nervous, endocrine, circulatory, urinary, and reproductive systems. A human standing erect with the face directed forward, the arms hanging to the sides, and the palm's facing forward is in the anatomical position. The body can be divided into the head, neck, trunk, upper limbs, and lower limbs. The abdomen can be divided superficially into 4 quadrants or 9 regions Sagittal plane divides the body into left and right parts, transverse plane into superior and inferior parts, and frontal plane into anterior and posterior parts. The thoracic cavity is bounded by the ribs and the diaphragm. The mediastinum divides the thoracic cavity into two parts. The abdominal cavity is bounded by the diaphragm and the abdominal muscles. The pelvic cavity is surrounded by the pelvic bones.  August 2024 The Integumentary System f) Stem cells divide and give rise to Layers of the Integumentary System keratinocytes that migrate toward the surface 1. Epidermis - Stratified squamous epithelium and replace lost epidermal cells 2. Dermis - Deeper connective tissue 2. STRATUM SPINOSUM Hypodermis – connective tissue below Thickest stratum in most places except in dermis; not part of the skin palms and soles (stratum corneum) Deepest cells continue dividing but cease to EPIDERMIS do so as they’re pushed farther Keratinized stratified squamous epithelium Keratinocytes bound together by tight Surface consists of dead cells junctions which make an essential Keratin –tough fibrous protein contribution to water retention by the skin lacks blood vessels Desmosomes attach keratinocytes together Depends on diffusion of nutrients from which accounts for the toughness of underlying connective tissue epidermis Sparse nerve endings bridge from cell to cell giving each cell a spiny appearance. Cells of the Epidermis 3. STRATUM GRANULOSUM 1. KERATINOCYTES a. 3-5 layers of flat keratinocytes – more in thick a. Great majority of epidermal cells skin b. Synthesizes keratin b. Keratinocytes contain coarse, dark staining 2. MELANOCYTES KERATOHYALIN GRANULES a. At stratum basale 4. STRATUM LUCIDUM b. Synthesize brown to black pigment MELANIN a. Thin zone seen only in thick skin c. Continually shed melanin containing b. Densely packed keratinocytes with clear fragments called MELANOSOMES from their protein called ELEIDIN tips c. No nuclei/ organelles d. These dark granules shield the DNA from d. Pale, featureless appearance with indistinct ultraviolet rays cell boundaries 3. MERKEL CELLS 5. STRATUM CORNEUM a. associated with sensory nerve endings a. layers of dead, scaly, keratinized cells that 4. LANGERHANS CELLS form a durable surface layer a. macrophage-like dendritic cells b. Resistant to abrasion, penetration, and water loss Layers of the Epidermis 1. STRATUM BASALE/GERMINATIVUM DERMIS a) Deepest layer Fiber types: collagen, elastic, reticular b) Single row of cells attached to dermis Well-supplied with blood vessels, cutaneous c) Youngest cells glands, and nerve endings d) Deepest layer thermoregulation e) Melanocytes, tactile cells, stem cells Hair follicles and nail roots skeletal muscles attach to dermal collagen fibers Gen Ana 1 Lab - Prelim  August 2024 Dermal papillae c. Hair matrix – mitotically active cells above Upward waves of fingerlike extensions the papilla; growth center; all cells higher up between epidermis and dermis are dead Raised areas Epidermal ridges Microscopic Parts: Downward epidermal waves between the a. Medulla – core of loosely arranged cells and air papillae spaces; most prominent in thick hairs e.g. FRICTION RIDGES – wavy boundary on eyebrows; narrower in hairs of medium thickness fingertips producing fingerprints and absent from thinnest hairs of scalp and elsewhere Layers of Dermis b. Cortex – most of the bulk of hair; several layers A. Papillary Layer – thin zone of areolar tissue in of keratinized cells and near the dermal papillae c. Cuticle – multiple layers of thin, scaly cells that Loosely organized tissue which allows for overlap each other like roof shingles with their mobility of leukocytes and other defenses against free edges directed upward; keep hairs separated organisms introduced through breaks in the so they don’t become matted together epidermis; rich in small blood vessels b. Reticular layer Hair receptors – nerve fibers that entwine each Dense irregular connective tissue follicle and respond to hair movements Fibrous Arrector muscle – PILOMOTOR MUSCLE/ Thicker bundles of collagen ARRECTOR PILI; smooth muscle cells ext from Less ground substance dermal collagen fibers to CT root sheath of the follicle in response to cold, fear, touch, or other HYPODERMIS stimuli Beneath the skin Also known as subcutaneous tissue/ 2. NAILS superficial fascia nail plate – hard part, includes free edge More areolar and adipose tissue a. nail body – visible attached part Pads the body and binds skin to underlying b. nail root – extends proximally under the tissues overlying skin Drugs can be introduced here by injection as c. nail fold – surrounding skin that rises above it is highly vascular and absorbs drugs quickly the nail d. nail bed – skin underlying the nail plate SKIN APPENDAGES a. hyponychium – epidermis 1. HAIR e. nail matrix – thickening of stratum basale at A. Shaft – portion of hair above the skin the proximal end of the nail B. Root – beneath the surface a. Penetrates deeply into dermis/ hypodermis Cutaneous Glands and ends with a dilation called bulb 1. Apocrine sweat glands b. Dermal papilla – vascular CT where bulb in groin, anal region, axilla, and areola, beard grows around; provides hair with its sole area source of nutrition Gen Ana 1 Lab - Prelim  August 2024 use exocytosis mode of secretion (same as ∙ Keeps eardrum pliable, waterproofs the eccrine) canal, kills bacteria, coats guard hairs making thicker, milkier due to presence of more fatty them sticky and more effective in blocking acids foreign particles from entering the canal scent glands respond to stress and sexual stimulation 5. Mammary Gland not active until puberty ∙ Breasts are present in males and females secrete sex pheromones ∙ Mammary glands are the milk-producing exert subtle effects on sexual behavior glands that develop within the female breast and physiology of other people during pregnancy and lactation hair serves to retain the aromatic ∙ Modified apocrine glands secretion and regulate its rate of ∙ In most mammals, 2 rows of mammary glands evaporation from the skin form along the mammary ridges or milk lines 2. Eccrine sweat glands END a. widely distributed over entire body b. abundant on palms, soles, forehead c. cools body d. leads to a sweat pore myoepithelial cells - at deep end of apocrine/ eccrine glands - contractile properties similar to smooth muscle ∙ perspiration – 99% water and has a pH ranging from 4-6 ∙ acid mantle – inhibits bacterial growth in skin 3. Sebaceous Glands Produce an oily secretion called sebum Opens into hair follicle; some directly onto skin surface Holocrine glands Sebum – keeps skin and hair from being dry, brittle and cracked 4. Ceruminous Glands ∙ Modified apocrine glands ∙ External ear canal ∙ Yellow, waxy secretion combined with sebum and dead epidermal cells => earwax/ cerumen ∙ Lead to hair follicles on skin surface of ear Gen Ana 1 Lab - Prelim  August 2024 The Skeletal System Osseous tissue - hard, dense connective tissue that forms most of the adult skeleton, the internal support structure of the body. The term bone has two meanings in anatomy—an entire organ such as the femur and mandible, or just the osseous tissue. Bones - osseous tissue, cartilage, bone marrow, dense irregular connective tissue, and other tissue types. Bone Cells OSTEOGENIC CELLS Haversian canal (central osteonic canal) - Blood Stem cells that give rise to most other bone cell vessels and nerves travel through these canals types Lamellae - onionlike layers around each canal Occur in the endosteum where bone matrix is deposited Some become osteoblasts Osteon – a central canal and its surrounding OSTEOBLASTS lamellae Bone-forming cells Synthesize organic matter Promote bone’s mineralization Osteogenesis OSTEOCYTES Former osteoblasts trapped in the matrix the deposited Reside in lacunae which are interconnected by canaliculi OSTEOCLASTS Bone-dissolving/ bone-resorbing cells on bone surfaces Osteolysis Most compact bone is arranged in cylinders of tissue Stem cells may fuse to form osteoclasts that surround central (osteonic) canals, which run longitudinally through the shafts of long bones such as the femur. Osteocyte – mature bone cells Canaliculi – radiate from each lacuna and allow communication between osteocytes 2 forms of osseous tissue SPONGY/ TRABECULAR BONE COMPACT (DENSE) BONE Gen Ana 1 Lab - Prelim  August 2024 AXIAL SKELETON o The Facial or visceral cranium which is made up  forms the axis of the human body of 14 bones.  Top of the head to tail bone Zygomatic - 2 Maxillae -2  80 bones: skull, vertebral column, sternum, ribs, Nasal -2 Lacrimal - 2 ear ossicles, hyoid bone Vomer -1 Palatine -2  Framework to support and protect Inferior Concha- 2 Mandible -1  Surface for muscle attachments Cranial Bones - 8 Bones forming the Axial Skeleton: Cranial bones are those that enclose the brain; Skull collectively, they compose the cranium (braincase). Cranial bones The delicate brain tissue doesn’t come directly into Facial bones contact with the bones but is separated from them by Cavities – brain, eyes, ears, nose, mouth three membranes called the meninges. Ear ossicles – sound production 1. Frontal Bone Hyoid bone – attachment for tongue and muscles - forms the forehead and superior surface of each eye of mastication socket or orbit Vertebral Column/ Spinal Column 2. Parietal Bone Flexible column from neck to trunk - On either side of the skull, found posterior to the About 71cm frontal bone. Anterior flexion, extension, lateral flexion and - forms the roof and superior walls of the cranium at rotation the sagittal suture. Sternum/ Breastbone 3. Occipital Bone Flat bone at chest midline - forms the posterior and inferior portions of the Forms rib cage together with the ribs cranium. - Along its superior margins, the occipital bone contacts to parietal bones at the lambdoidal suture 3a. Foramen magnum - admits the spinal cord to the cranial cavity 3b. Occipital condyle - where the skull rests on the vertebral column. 4. Temporal Bone - Lying below the parietal bones and contributing to the sides and base of the cranium. As it comes in The Skull contact with the parietal bone it forms the squamosal the most modified part of the axial skeleton. It is suture. the entire skeleton of the face including the 5. Sphenoid Bone mandible - forms the floor of the cranium. It also acts as a bridge Functions: uniting the cranial and facial bones, and it braces the Support brain and organs of special senses sides of the skull. Protect brain from external impacts 6. Ethmoid Bone Barrier against stresses from powerful - consists of two honeycombed masses of bone. masticatory and axial musculature - It forms part of the cranial floor, contributes to the Continuous isolation for cerebral circulation (rigid medial surface of the orbit of each eye, and forms the cranial walls) roof and the sides of the nasal cavity. Contain openings that lead to digestive tract, respiratory tract, and skull Divisions of the Skull Bone – 22 bones o Cerebral cranium or cranial bones or braincase which is made up of 8 bones. Frontal - 1 Parietal - 2 Occipital - 1 Temporal - 2 Sphenoid - 1 Ethmoid - 1 Gen Ana 1 Lab - Prelim  August 2024 Facial Bones - 14 1. Maxillary Bones - articulate with all other facial bones except the mandible. 2. Palatine Bones - form the posterior surface of the bony hard palate, or the roof of the mouth. 3. Zygomatic Bones - articulates with the frontal bone and the maxilla to complete the lateral wall of the orbit. 4. Nasal Bones - Forming the bridge of the nose midway between the orbits, the nasal bones articulate with the frontal bone and the maxillary bones. 5. Lacrimal Bones - Lacrimal bones are found within the medial wall of the orbit. They articulate with the frontal, ethmoid and maxillary bones. 6. Inferior Nasal Conchae - The paired inferior nasal conchae projects from the lateral wall of the nasal cavity. 7. Mandible - It forms a broad, horizontal curve that on either side extends into two vertical processes. - The more posterior process articulates with the mandibular fossa of the temporal bone on that side. - The articulation is quite mobile, and the disadvantage of such mobility is that the jaw can be easily dislocated. Gen Ana 1 Lab - Prelim  August 2024 The Ossicles - 6 False or fixed vertebrae - bones comprising the - A chain of three mobile ossicles, transfers sound sacral and coccygeal regions which in adult fuse waves across the tympanic cavity from its membrane into the sacrum and coccyx respectively to the inner ear. 1. the malleus, 2. incus and 3. stapes The auditory ossicles — named the malleus (hammer), incus (anvil), and stapes (stirrup) Curvatures of the Vertebral Column The Primary Curves - Appear in late fetal development, as the thoracic and abdominal viscera enlarge. Characteristics: concave anteriorly exists in fetal life * For accommodation of the thoracic and pelvic organs 1. Thoracic Curve The Hyoid Bone – 1 - concave forwards or kyphotic. - A small U-shaped bone hangs that below the skull, - extends between the T2 to T12, with the apex lying suspended by ligaments from the styloid processes of between the sixth and the ninth thoracic vertebrae. the temporal bones. 2. Pelvic Curve Functions: - concave anteroinferiorly a. serves a base for muscles associated with the - involves the sacrum and the coccygeal vertebrae, tongue and larynx, - extends from the lumbosacral junction to the apex of b. supports and stabilizes the position of the larynx. the coccyx. The Secondary Curves The Vertebral Column - 26 - These spinal curves do not appear until months after - comprises some 33 vertebral segments, each birth. separated by fibrocartilaginous discs. Characteristics: - support the trunk and to protect the spinal cord. - convex anteriorly - lies in the general vertebrate plane and is median and - develops after birth posterior to the whole body. - for the maintenance of balance in the upright position Classification of Vertebra 1. Cervical Curve 1. According to the region they occupy - convex forwards and the least marked. 8% of the whole body length for the cervical, - extends from the atlas to the second thoracic 20% for the thoracic, vertebra, with its apex between the fourth and fifth 12% for the lumbar, and cervical vertebrae. 8% for the sacrococcygeal. - developed when an infant can support its head at 2. According to mobility three to four months. True or movable vertebra - these are bones 2. Lumbar Curve comprising the cervical, thoracic, and lumbar - convex forward. regions which maintain separate throughout life. - has greater magnitude in females and extends from the twelfth thoracic vertebra to the lumbosacral angle, - Its apex is at the level of the third lumbar vertebra. Gen Ana 1 Lab - Prelim  August 2024 Abnormal Distortions of the Spinal Column They act as levers for muscles which control Kyphosis – exaggerated thoracic curve. It results posture and active movements (flexion/extension, from the erosion of the anterior portion of one or lateral flexion and rotation) of the vertebral more vertebral body. column. Lordosis – exaggerated lumbar curve. It is accompanied by the downward rotation of the The Cervical Vertebrae pelvis. Physiologically, it is seen in the later stages - smallest of the movable vertebrae, of pregnancy. - are typified by a foramen on each transverse Scoliosis- an abnormal lateral curve usually to processes. the right. It involves rotation of the column in - The first, second, and seventh cervical vertebrae which the spinous process of vertebrae turn have special features. toward the concavity of the curvature. - The third, fourth, and fifth are almost identical - the sixth, while typical in its general features, has General Vertebral Features minor differences which usually enable its 1. Body distinction from others. varies in size, shape and proportion in different regions Typical Cervical Vertebra The complete column of bodies and intervertebral small, relatively broad ventral body, discs forms a strong but flexible central axis of the pedicles projects posterolaterally, body supporting the full weight of the head and the longer and broader laminae, trunk. triangular vertebral foramen which It also transmits even greater forces due to accommodates the enlargement of the spinal muscles attached to it directly or indirectly. cord 2. Vertebral Arch the spinous processes are short and bifid extends by a lever-like processes which has on transverse foramen on each transverse each side a vertically narrower ventral part, a processes. pedicle, and a dorsally broader lamina. 3. Vertebral Foramen Atlas/ First Cervical Vertebra/ C1 - which is formed by a series of vertebrae enclosing the supports the head and unique in that it fails to spinal cord incorporate a centrum, the expected position of 4. Paired superior and inferior articular processes which is occupied by a cranial protuberance of the which arise from the vertebral arch at the axis known as the dens. pedicolaminar junctions. The superior articular No body processes projects cranially while the inferior Anterior arch is slightly convex anteriorly and articular processes bulge caudally. carries a roughened anterior tubercle to which is 5. Pedicles attached the anterior longitudinal ligament. It are short, thick, rounded projections from the presents a facet for the dens of the axis which superior part of the body at the junction of its forms a pivot around which the head rotates. lateral and dorsal surfaces Posterior arch forms three-fifths of the 6. Transverse Processes circumference of the atlantal ring. It bears a small project laterally from the pedicolaminar junctions bony projection called the posterior tubercle. as levers of muscles and ligaments particularly Transverse processes are longer than those of all concerned with rotation and flexion. the cervical vertebrae except the seventh cervical. 7. Laminae Superior articular facet is larger, oval and directly continuous with pedicles, are vertically concave for articulation with the occipital flattened and curve dorsomedially to complete, condyles with the base of the spinous process, a vertebral foramen. Axis/ Epistropheus/ C2 8. Spine the second cervical vertebra, is an axle for rotation projects dorsally and often caudally from the of the atlas and the head around the strong dens junction of the laminae. (odontoid process), which projects cranially from Spines vary much in size, shape and direction. the superior surface of the body. Gen Ana 1 Lab - Prelim  August 2024 Presence of dens which projects upward from the The inferior articular processes are thin and body into the anterior section of the vertebral long, except the more substantial fifth. foramen of the atlas. A small accessory process marks the The body consists of less compact bone than the posteroinferior aspect of the root of each dens. transverse process. The pedicles are stout, with superior surface carrying part of the superior articular facet, which THE SACRUM also projects laterally and downwards on to the large, triangular fusion of five vertebrae transverse process. posterosuperior wall of the pelvic cavity The transverse processes are pointed and articulates with the coccyx and its superior, a wide project inferiorly and laterally, arising from the base with the fifth lumbar vertebra at the peducololaminar junction and the lateral aspect lumbosacral angle of the interarticular area of the pedicle. dorsal surface being convex, the pelvic, concave The laminae are thick. posterosuperior wall of the pelvic cavity The spinous process is large, with a bifid tip and a Between the apex and the base are dorsal, lateral, broad base, concave inferiorly. and pelvic surfaces and a sacral canal In childhood, individual sacral vertebrae are 7th Cervical Vertebra (C7) connected by a cartilage The spinous process of this cervical vertebra is not Pelvic Surface bifid. - sacral foramina - transverse ridges. THE THORACIC VERTEBRAE The twelve thoracic vertebrae increase in size Dorsal Surface caudally like other vertebrae, due to increased - median sacral crest loading from above. - sacral hiatus All their bodies present lateral costal facets for - dorsal sacral foramina the head of the rib, - Intermediate sacral crests Bodies are larger than the cervical vertebrae, - lateral sacral crest All but the lowest two or three transverse - sacral cornua processes also have facets for the tubercle of the rib, The Lateral Surface The vertebral foramen is small and circular, - Auricular /Articular surface Pedicles do not diverge, Laminae are short, thick, and broad overlapping THE COCCYX from above, downwards small triangular bone The spinous process slants downwards. four fused rudimentary vertebrae but the number varies from five to three THE LUMBAR VERTEBRA the first being separate The five lumbar vertebrae are distinguished by descends ventrally from the sacral apex, its pelvic their large size and absence of costal facets and surface being tilted upwards and forwards, its transverse foramina. They are located in the dorsum downwards and backwards. Orientation posterior abdominal wall. varies with its mobility. The vertebral foramen is triangular, larger than The primary purpose of the coccyx is to provide an thoracic but smaller than cervical. attachment site for a muscle that closes the anal The body is wider transversely and deeper in front. The pedicles are short. opening The spinous process is almost horizontal, base, transverse process, and rudimentary quadrangular, and thickened along its posterior vertebral bodies. and inferior borders. The superior articular processes bear a vertical concave articular facets facing posteromedially, with rough mamillary process on their posterior borders. Gen Ana 1 Lab - Prelim  August 2024 The Thorax 4. Floating Ribs (Vertebral Ribs) - are ribs 11 and 12 an osteocartilaginous frame around the principal as they are free at their anterior ends. organs of respiration and circulation narrow above, broad below, flattened THE TYPICAL RIB anteroposteriorly, and longer behind shaft The posterior, vertebral end has a head neck and Location of the Thorax tubercle. Posteriorly the thorax includes thoracic vertebrae The head presents two facets articulates with the and posterior parts of the ribs. body of the corresponding vertebra, Anteriorly are the sternum, anterior parts of the The neck is the flat part beyond the head, ribs and costal cartilages The tubercle Laterally the thorax is convex and formed by ribs The posterior angle alone. The external surface The internal surface is smooth and marked by a THE STERNUM costal groove, consists of cranial manubrium ( prosternum), The costal groove intermediate body (mesosternum), and a caudal xiphoid process (metasternum) THE FIRST RIB highly vascular trabecular bone enclosed by a Most acutely curved and usually shortest compact layer thickes in the manubrium between broad and flat clavicular notches its surfaces superior and inferior, its borders medulla contains red bone marrow. internal and external slopes obliquely down and forwards to the sternal Manubrium Sterni end. - jugular (suprasternal) notch - clavicular notches -------- Mesosternum (Body) – Longer, narrower, and thinner than the manubrium, Xiphoid Process (xiphisternum, metasternum) - The smallest and most variable sternal element THE RIBS elastic arches connected posteriorly with the vertebral column forming much of the thoracic skeleton highly vascular trabecular bone, enclosed in a thin layer of compact bone and containing large amounts of bone marrow twelve pairs may be increased by cervical or lumbar ribs or reduced to eleven by the absence of the last pair. CLASSIFICATION OF RIBS 1. True ribs (vertebrosternal ribs) – these are ribs 1 to 7 as they are connected to the sternum by costal cartilages and posteriorly to the thoracic vertebrae. 2. False Ribs – these are ribs 8 to 12 as they are not directly attached to the sternum but to the preceding cartilage. 3. False Ribs Proper (Vertebrochondral ribs) - are ribs 8 to 10 whose cartilages joints the suprajacent costal cartilage of the 7th rib Gen Ana 1 Lab - Prelim  August 2024 Appendicular Skeleton > The appendicular skeleton includes the bones of the upper and lower extremities. > All together there are 126 appendicular bones: 64 associated with the upper limb and 62 for the lower limb. The Upper Extremity THE BONES OF THE UPPER EXTREMITY Scapula - 2 Clavicle - 2 Humerus - 2 Ulna - 2 Radius - 2 The Scapula Carpals - 16 > The scapula is a large, flat, triangular bone, Metacarpals - 10 overlaps in part of the second to the seventh ribs on Phalanges - 28 the posterolateral thoracic aspect. 64 bones > It articulates with the humerus and the clavicle. Costal and Dorsal Surfaces: * three borders - superior, lateral and medial borders * three angles: 1. Inferior angle - overlies the seventh rib or intercostals space. 2. Superior angle - located at the junction of the superior and medial borders. 3. Lateral angle - truncated and broad, is the head, bearing the glenoid cavity and forming a glenohumeral joint with the humerus. Just above the glenoid cavity is a small, round supraglenoid tubercle which encroaches on the root of the coracoid process. * three processes – spinous, acromion, and The Pectoral Girdle coracoid: 1. Dermal and endochondral development Acromion process - broad and flattened, extending 2. Two principal components, clavicle and scapula, laterally and anteriorly overhanging the shoulder. which remain separate Spine of the scapula- a triangular plate of bone 3. No articulation with the vertebral column attached by its anterior border to the dorsum of the 4. No direct ventral articulation (clavicles connected scapula. only by interclavicular ligament) Coracoid process - this arises from the summit of the 5. Articulations of the clavicles with the axial scapular head and hooks slightly laterally and skeleton (sternum) are relatively small, mobile and forwards. ventral * three fossae: 6. Comparatively lightly built for mobility 1. Supraspinous fossa - depression above the spine 7. Resilient to thrust and contains the supraspinatus muscles. 8. Shallow joint with limb, allowing wide range of 2. Infraspinous fossa - depression below the spine movement and contains the infraspinatus muscle. 3. Subscapular fossa - concavity on the anterior or costal surface and contains the subscapularis muscle. The Clavicle > The clavicle extends laterally and almost horizontally across the neck from the manubrium to the acromion, being wholly subcutaneous. Gen Ana 1 Lab - Prelim  August 2024 - The non-articular condyle includes medial and > Its lateral, acromial end articulates with the medial lateral epicondyles, olecranon, coronoid, and radial aspect of the acromion; the enlarged medial, sternal fossae. end articulates with the manubrial clavicular facet 1. Capitulum - It articulates with the discoid radial and first costal cartilage. head, which abuts the inferior surface in full > It struts the shoulder and enables the limbs to extension but slides on the anterior surface during swing clear of the trunk, transmitting part of its flexion. weight to the axial skeleton. 2. Trochlea - It articulates with the trochlear notch of > The shaft is sinuous, being convex forwards in its the ulna medial two-thirds, and concave forwards lateral to 3. The medial epicondyle - A blunt medial projection this. on the medial condyle, it is subcutaneous and usually visible during passive flexion. The medial humeral border ends at the medial epicondyle and is distal to the medial supracondylar ridge. 4. The lateral epicondyle - the lateral non-articular part of the condyle. It does not project beyond the lateral border. The lateral humeral border ends at the lateral epicondyle, from which, extending proximally, is its distal part, the lateral supracondylar ridge Olecranon Coronoid and Radial fossae. The Humerus > The humerus is the longest and largest bone in the upper limb, it has expanded ends and a shaft. > Proximally a round head forms with the scapular glenoid cavity > The distal end, loosely termed ‘condylar’, is adapted to the forearm bones at the elbow joint. The Proximal Head Head - at the proximal end is slightly less than half a spheroid. The articular surface is covered by hyaline cartilage, thicker centrally and is directed posteromedially and upwards towards the glenoid cavity in the pendant arm. The anatomical neck - directly adjoining the articular head’s margin The humeral proximal ends taper into the shaft as an ill-defined ‘surgical neck’. The lesser tubercle (tuberosity) - this is anterior and just beyond the anatomical neck The Radius The greater tubercle (tuberosity) - This is the most > The radius, lateral in the forearm, has expanded lateral part of the proximal end of the humerus proximal and distal ends, the distal much broader. Between the tubercles is the intertubercular sulcus. The shaft widens rapidly towards its distal end; is The Shaft convex laterally and concave anteriorly in its distal 1. The anterior /posterior border part. 2. The lateral border a. The head is discoid, its proximal surface has a 3. The medial border shallow cup for the humeral capitulum. The Distal End b. Its smooth articular periphery is vertically deepest - Basically, a modified condyle medially, where it contacts the ulnar radial notch. - It is wider transversely and has articular and non- c. The neck is the constriction distal to the head, articular parts. which overhangs it, especially on the lateral side. - The articular part joins with the radius and ulna at the elbow and divided into a lateral, convex capitulum and a medial pulley-shaped trochlea. Gen Ana 1 Lab - Prelim  August 2024 d. The tuberosity is distal to the medial part of the The Proximal End neck; it is posteriorly rough but anteriorly usually a. The olecranon process is bent forwards at its smooth. summit like beak, which enters the humeral The Shaft olecranon fossa in extension. a. This has lateral convexity but only its b. The coronoid process projects anteriorly distal to interosseous border is sharp. the olecranon process b. The anterior border is obvious at both ends but c. Distal to which, on the lateral surface, is a shallow, rounded and indefinite between them. smooth, oval radial notch for articulation with the > The posterior border is well-defined only in its radial head. middle third d. The coronoid’s anterior surface is triangular, its > The posterior surface, between the interosseous distal part being the tuberosity of the ulna. and posterior borders, is largely flat but may be e. The trochlear notch articulates with the trochlea slightly hollow in the proximal area. of the humerus > The lateral surface is greatly convex f. The radial notch, an oval proximal depression on The Distal End the lateral aspect of the coronoid, articulates > Its lateral surface is slightly rough, projecting with the periphery of the radial head. distally as a styloid process palpable when tendons The Shaft around it are slack. a. The interosseous border is a conspicuous lateral > Distal is the smooth carpal articular surface, crest in its middle half. divided by a ridge into medial and lateral areas. b. Proximally continuous with the posterior border of > The anterior surface is a thick, prominent ridge, a depression distal to the radial notch as the palpable even through overlying tendons. supinator crest. > The medial surface is the ulnar notch, smooth, c. The rounded anterior border commences medial anteroposteriorly concave for articulation with the to the ulnar tuberosity, ulna’s head. d. The posterior border, also rounded The Distal End a. The head is visible in pronation on the posteromedial carpal aspect and can be gripped when the supinated hand is flexed. b. The latter, the styloid process a short round, posterolateral projection of the ulna’s distal end. The Ulna > The ulna is medial to the radius in the supinated forearm. > Its proximal end is a massive hook, concave forwards. > The shaft’s lateral border is a sharp crest. > The bone diminishes progressively from its The Carpals proximal mass throughout almost its whole length, > The carpus contains eight bones in proximal and but at its distal end expands into a small, rounded distal rows of four. end and styloid process. > Proximally, in lateral to medial order, are the: - the scaphoid – also called navicular, the scaphoid is the largest element in the proximal row, has a long Gen Ana 1 Lab - Prelim  August 2024 axis which is distal, lateral and slightly palmar in The Phalanges direction. > There are 14 phalanges, three in each finger, two - the lunate - the lunate is approximately semilunar, in the thumb. Each has a head, shaft and proximal moon-shaped, articulates between the scaphoid and base. triquetral in the proximal carpal row. - the triquetral - somewhat pyramidal or triangular in shape, bears an oval isolated facet for articulation with the pisiform on its distal palmar surface. - and the pisiform - the pisiform, as the name implies, is shaped like a pea, with a dorsal flat articular facet for the triquetral. > Distal row, are composed of: - trapezium - or greater multiangular, has a tubercle and groove on its rough palmar surface. - trapezoid – or lesser multangular, the trapezoid, small and irregular, has a rough palmar surface narrower and smaller than its rough dorsal surface, the former invading the lateral aspect. - capitate - the capitate, the central and largest carpal bone, is head-like and articulates with the third metacarpal base, its triangular distal surface The Lower Extremity concavoconvex for this. THE BONES OF THE LOWER EXTREMITY - and hamate - the hamate is cuneiform with an Pelvic Bone - 2 unciform hamulus (hook), projecting from the distal Femur - 2 part of its rough palmar surface. Tibia - 2 Fibula - 2 Tarsals - 14 Metatarsals - 10 Phalanges - 28 62 bones INNOMINATE BONE OR OS COXA OR HIP BONE OR PELVIC BONE > large, irregular, constricted centrally and expanded above and below > acetabulum - deep, cup-shaped found lataerally The Metacarpals articulating with femoral head > The metacarpus is composed of five metacarpal > large oval or triangular obturator foramen bones, conventionally numbered in lateromedial > bone widens into a plate with a sinuously curved order. These are miniature long bones with a distal iliac crest above the acetabulum head, shaft, and expanded base. Gen Ana 1 Lab - Prelim  August 2024 Pelvic Girdle curving posteroinferiorly to end near the apex of the > bone articulates in front with its fellow, to form the greater sciatic notch. pelvic girdle > completed posteriorly by the sacrum and the coccyx > bony basin at the lower end of the trunk known as the pelvis. 1. Entirely endochondral 2. Three components, pubis, ilium, and ischium, which fused into single innominate bone 3. Articulates with the sacral vertebrae 4. Direct ventral articulation at the pubic symphysis 5. Articulations of the innominate bones with the axial skeleton (sacrum) are relatively large, capable of limited movement only, and dorsal 6. Massively constructed for resistance to stress rather than for mobility > Ilium, ischium, and pubis connected by cartilage in Sacropelvic Surface youth but united as one bone in adults, the principal Auricular Surface union being in the acetabulum. Pelvic Surface Ilium * Pelvic surface is the term for any surface of any > upper and lower parts and three surfaces > The smaller, lower part forms a little less than the pelvic bone that faces the pelvic cavity. The upper two-fifths of the acetabulum, the upper part pelvic cavity is the space below the abdomen that is being much expanded, with gluteal, sacropelvic, and defined by the pelvic bones. The pubic arch is iliac surfaces. located immediately inferior to the pubic symphysis Iliac Borders and is formed by the paired ischiopubic rami. - Iliac Crest - Pubis 1. anterior superior iliac spine 2. posterior superior iliac spine - Symphyseal Surface - Anterior Border: - Pubic crest 1. anterior inferior iliac spine, immediately above the - Pubic Rami acetabulum. - superior - Posterior Border: - inferior 1. posterior superior iliac spine 2. posterior inferior iliac spine 3. greater sciatic notch - Medial Border: 1. articular surface for the sacrum 2. arcuate line 3. iliopubic (iliopectineal) eminence, marking the union of the ilium and pubis. Gluteal Surface > bounded above by the iliac crest > below by the acetabular border, anterior and posterior borders > rough and curved, convex in front, concave behind > three gluteal lines. Posterior Gluteal Line: is the shortest, descending from the external lip of the crest and ending in front Ischium of the posterior inferior iliac spine - Ischial Tuberosity Anterior Gluteal Line: the longest, begins near the - Greater sciatic notch midpoint of the superior margin of the lip, a little anterior to its tubercle. - Lesser sciatic notch Inferior Gluteal Line: rarely well-marked, begins - Ischial ramus posterosuperior to the anterior inferior iliac spine, - Ischial spine Gen Ana 1 Lab - Prelim  August 2024 Skeletal Pelvis - Lateral condyle > pelvis, ‘a basin’ - Lateral epicondyle > skeletal ring formed by the innominate bone and - Medial condyle sacrum, the cavity within them and even the entire - Medial epicondyle region where the trunk and lower limbs meet. > massive because its primary function is to withstand compression and other forces due to body weight and powerful musculature, mechanisms considered elsewhere. Patella > largest sesamoid > embedded in the tendon of the quadriceps femoris anterior to the knee joint bone > Flat, distally triangular, proximally curved, it has anterior and posterior surfaces, three borders and an apex. Anterior surface The Femur Posterior surface > longest and strongest bone in the human body. Superior border > length is associated with a striding gait, its strength Medial and lateral borders with weight and muscular forces. > shaft, almost cylindrical in most of its length and bowed forward, has a proximal round, articular head projecting mainly medially on its short neck, a medial curvature of the proximal shaft. > The distal extremity is more massive being a “double knuckle” or condyle articulating with the tibia. The Proximal End a. Femoral Head b. Fovea Capitis Femoris The Tibia c. Femoral Neck > medial to and much stronger than the fibula d. Greater Trochanter > exceeded in length only by the femur e. Lesser Trochanter > anterior, medial and larger of the two bones of the f. Intertrochanteric Line leg. g. Intertrochanteric Crest The Proximal End The Distal End - Medial condyle - Condyles - Lateral condyle - Intercondylar fossa - Tibial tuberosity - Patellar surface - Intercondylar area Gen Ana 1 Lab - Prelim  August 2024 intercondylar eminence - lateral and medial Tarsals intercondylar tubercles. > seven tarsal bones The Shaft > occupy the proximal half of the foot - Anterior border > tarsus and carpus are homologous, but tarsal - Interosseous border elements are larger to support and distribute weight - Medial border > tarsal bones are arranged in proximal and distal - Medial surface rows, but medially is a single tarsal element. - Lateral surface 1. Talus, Astralagus or Ankle Bone - Posterior surface - This is the second largest tarsal bone. The talus is The Distal End the link between the foot and the leg, through the - Medial malleolus ankle joint. Its rounded distal head, proximal - Fibular notch trochlear surface for the tibia, facet for the lateral - Tarsal articular surface malleolus, and its neck and body are its main features. 2. Calcaneus or Heel Bone - The calcaneus, the largest tarsal bone, projects posterior to the tibia and fibula as a short lever for muscles of the calf attached to its posterior surface. It is irregularly cuboidal, its long axis inclined distally upwards and laterally. 3. Navicular or Scaphoid - The navicular articulates between the talar head and cuneiforms distally. 4. Cuboid - The cuboid, most lateral in the distal row, is between the calcaneus proximally and the fourth and fifth metatarsals distally. Fibula or Peroneal Bone 5. Cuneiforms > More slender than the tibia, not being directly The wedge-like cuneiform bones articulate with the involved in the transmission of weight navicular proximally and the bases of the first to the > proximal head, a long shaft, and a distal lateral third metatarsals distally; the medial is the largest, malleolus intermediate the smallest. > A thinner part near the head is the neck 5.1. Medial Cuneiform - Articulating with the > shaft varies in form, being variably molded by navicular and first metatarsal base, it has a rough, attached muscle. narrow dorsal surface. 5.2. Intermediate Cuneiform - Articulating with the navicular and distally with the second metatarsal base, it has a narrow, plantar surface receiving a slip from the tendon of the tibialis posterior. 5.3. Lateral Cuneiform - This is between the intermediate cuneiform and the cuboid, articulating also with the navicular, and distally with the third metatarsal base. Gen Ana 1 Lab - Prelim  August 2024 > base is concave for articulation with the metatarsal head and the head is a trochlea for a middle phalanx. > Middle phalanges are small and short but broader than the proximal > Distal phalanges resemble those in the fingers, but are smaller and flatter > broad base for a middle phalanx and an expanded distal end > a rough tuberosity on the plantar aspect of the latter is an attachment for the pulp, and a wider area Metatarsals for weight bearing. > The five metatarsal bones, distal in the foot, connect the tarsus and the phalanges. Like the End. metacarpals, they are miniature long bones, with a shaft, proximal base and distal head. a. the shafts are long and slender, longitudinally convex on the dorsal and concave on the plantar aspects. b. The bases articulate with the distal row and with each other. c. The heads articulate with the proximal phalanges, each by a convex surface passing farther on to its plantar aspect, where it ends on the summits of two eminences. Phalanges > resemble those in the hand > two in the hallux, and three in each of the other toes > much shorter and their shafts, especially those of the proximal set, are compressed from side to side > compressed shaft is convex dorsally, with a plantar concavity Gen Ana 1 Lab - Prelim  September 2024 The Articular System o Syndesmosis > Articular system refers to the study of the > Articulation between 2 parallel bones joined structures that hold bones allowing body together by either an interosseous membrane or movement in varying degrees. a ligament as seen from the joint between the > A joint or articulation is a connection formed by radius and ulna 2 bones. A joint links with the skeletal system and o Gomphosis/Peg and Socket Joint muscular system to function for locomotion. > Articulation formed by the insertion of a conical > Aside from its function in movement it also process into a socket as in the root of the tooth serves for stability and protection of the internal into the alveolus organs o Schindylesis > Articulation between a thin plate of bone A joint is classified according to the structural received into a groove or slit of another bone as material that unites a joint and according to seen in between the sphenoid & perpendicular functional movement. Structural classifications plate of ethmoid with vomer, between the are fibrous, cartilaginous and synovial joints. perpendicular plate of ethmoid into the fissure between maxilla & palatine Functional movement classification includes synarthrosis with little or no movement at all, Amphiarthrosis amphiarthrosis with slight movement and the > Joints with limited mobility. The space that freely movable joint, diarthrosis. exists between articulating surfaces of bones permits cartilage to fit into the gap allowing little Structural Classification of Joints movements between the joints. Fibrous Joint o Synchondrosis > A fibrous joint is united by dense irregular > Articulation under this classification may either connective tissue that is rich in collagen fibers. be a temporary or a permanent joint. Cartilaginous Joint > Temporary synchondrosis means that the joint > A cartilaginous joint can either be cartilage or a is converted into a bone, or it ossifies before hyaline cartilage which is avascular, flexible reaching adult life forming a synostosis rendering connective tissue that provides support and the joint immobile cushioning for adjacent tissues. > Permanent synchondrosis refers to the cartilage Synovial Joint that remains as such throughout life because it > This is the most common type of joint in the did not ossify with age human body. Unlike the previous joint, the bones o Symphyses in a synovial joint are enclosed within a cavity and > Articulation between bones permits little enclosed by an articular capsule. mobility because the thickness of the fibrocartilage uniting the joint. Functional Classification of Joint Synarthrosis Diarthrosis > Immobile joint but the most stable of all the > Freely movable joints but the weakest of all. joints. The absence of cavities between bones Most diarthrotic joints are found in the makes the joint immobile. This joint functions for appendicular skeleton and thus give the limbs a protection of organs as can be seen from the wide range of motion. articulated bones of the skull and at the joint between the sternum and manubrium Anatomical Movements of the Body o Sutures Gliding Movement > A form of articulation which is found only in the > The opposed surfaces are flat or only slightly skull curved, so that the bones slide against each other in a simple and limited way General Anatomy 1 - Lab  September 2024 > Example: head is tilted forward and back; head Dorsiflexion- bending at the ankle such that is tilted from side to side the toes are lifted toward the knee as in Angular Movement applying a toenail polish > Commonly seen in long bones where there is a Plantarflexion - bending at the ankle when change in the angle formed between the joints. the heel is lifted, such as when standing on a. Flexion or bending - when the angle between the toes the bones decreases as in moving the forearm Supination - movement of the forearm so that upward at the elbow or moving the wrist to move the palm faces anteriorly or the hand toward the forearm. upward. (lateral rotation of forearm) b. Extension - when the angle between the bones Pronation - movement in which the palm of a joint increases like straightening a limb after faces posteriorly or downward. (Medial flexion. Extending a part of the body past the rotation of forearm) normal anatomical position is referred to as Opposition - movement of the thumb toward hyperextension the fingers of the same hand c. Abduction - when a bone moves away from the midline of the body as in moving the arms or legs laterally to lift them straight out to the side d. Adduction- when a bone moves toward the midline of the body as in moving the limbs inward after abduction e. Rotational Movement- the bone rotates around its longitudinal axis.  medial rotation means rotating towards the midline  lateral rotation means rotating away from the midline f. Circumduction- movement of a limb in a circular motion, as in swinging an arm around Anatomical Movements - Special Movements Inversion- means moving the soles of the feet inward, toward the midline of the body (medial rotation of foot) Eversion- means moving of the sole of the foot outward, away from the midline of the body (lateral rotation of foot) Protraction- is the anterior movement of a bone in the horizontal plane Retraction – it occurs as a joint move back into position after protraction. Elevation- movement of a bone upward, such as shrugging the shoulders or lifting the scapulae. In the mandible it means closing the jaw. Depression - involves moving the bone downward, such as after the shoulders are shrugged and the scapulae return to their normal position from an elevated position. In the mandible, it means opening the jaw General Anatomy 1 - Lab