Anatomy Reviewer (Finals) PDF

ANAPHY REVIEWER ( FINALS ) 1. Long Bone - are longer than they are wide STRUCTURE AND SKELETAL TISSUES and have knobby ends where the articulations form. EXTRACELLULAR MATRIX - contains substances...

ANAPHY REVIEWER ( FINALS ) 1. Long Bone - are longer than they are wide STRUCTURE AND SKELETAL TISSUES and have knobby ends where the articulations form. EXTRACELLULAR MATRIX - contains substances - Long bones are hollow in the middle and that are essential for the make-up of our bones more solid on ends. since the cartilages, tendons, ligaments, and - At each ends also includes a thin layer of even our bones, are connective tissues. hyaline cartilage called articular cartilage, - For instance, collagen, as one of the which further articulates it other bones to form substances, is a tough and rope-like protein a joint. Their slightly curved structure gives the giving our tendons, ligaments and cartilages strength. great amount of strength like steel bars - Long bones include those of the arms, legs, reinforced in a concrete. fingers, and toes. - The mineral component, like the concrete itself, gives the bone compression like weight- Periosteum – the dense connective tissue bearing strength. that covers the outside of the diaphysis - Most of the mineral in bone is in the form of Endosteum – Thin epithelial membrane lining calcium phosphate crystals called the inside of the medullary cavity Hydroxyapatite Long bones have several parts: Proteoglycans - are large molecules consisting of polysaccharides attached to core proteins Diaphysis – central shaft-like or body - The proteoglycans form large aggregates, much as pine branches combine to form a Epiphysis – head of each end of a long bone whole tree. Medullary cavity – marrow cavity or space - Proteoglycans can attract and retain large that contains yellow marrow amounts of water between their polysaccharide “needles.” 2. Short bones - are equal in length and width, making them nearly cube-shaped. Classification of Bones : ( Four categories of Ex : include most bones of the ankles and the bone, based on their shape ) wrists. 3. Flat bones - are thin and provide both protection and surfaces for muscle attachments. - The bones of the skull, sternum, and ribs are all at bones. 4. Irregular bones - have complex shapes, such as those of the face and vertebral column.  and lungs, and it protects other soft tissues of the body. 3. Movement - It assists in body movement by providing attachments for muscles that pull on the bones that act as levers. 4. Blood cell production - It manufactures blood cells. Red bone marrow - a connective tissue within bone, produces red blood cells, white blood cells, and platelets in a process called hemopoiesis. 5. Storage - It is a storage area for mineral salts, especially phosphorus and calcium, and fats. Yellow bone marrow - within bone is composed mostly of adipose cells, which store triglycerides (fats). In a newborn, all bone marrow is red, but it eventually changes into yellow marrow with increasing age. DEVELOPMENT ( Bone Histology ) OSTEOBLASTS - which function in the formation of bone, as well as in the repair and remodeling of bone. OSTEOCYTES - When osteoblasts become surrounded by matrix. OSTEOCLASTS - are also present and contribute to bone repair and remodeling by removing existing bone. Lamellae – where bone is formed in thin sheets of extracellular matrix with osteocytes located between the lamellae within spaces called FUNCTIONS OF THE SKELETAL SYSTEM lacunae. 1. Support - It supports and stabilizes surrounding tissues such as muscles, blood and Canaliculi – a tiny canals wherein cell processes lymphatic vessels, nerves, fat, and skin. extend from the osteocytes across the extracellular matrix of the lamellae 2. Protection - It protects vital organs of the body such as the brain, spinal cord, the heart,  Compact bone - is strong and dense, provides protection and support, and resists the stresses produced by weight and movement. - is found beneath the periosteum of all bones and makes up the bulk of long bones. - is made of cylindrical units called osteons. Each osteon consists of concentric lamellae, concentric layers that surround a central canal, or Haversian canal, containing blood and lymph vessels. - Between the lamellae are spaces called lacunae, which contain osteocytes, and smaller channels called canaliculi that radiate out from the lacunae. These canaliculi allow nutrients and wastes to be passed more easily from one osteocyte to another within the osteon. Cancellous bone - has many open spaces, giving it a spongy appearance and in these spaces, bone marrow can be found. There are two types of bone tissue: - contains irregular lattices of thin bone 1. COMPACT BONE OR DENSE BONE columns called trabeculae. 2. CANCELLOUS OR SPONGY BONE - Trabeculae form a supportive framework that is firm but not exceedingly strong. This tissue must be covered by compact bone or cartilage because it could be damaged easily if exposed. - The spaces between the trabeculae of some bones are filled with red bone marrow - the functions of the trabeculae are to support and protect the red bone marrow. - Spongy bone is found mostly in short, at, and irregular bones. In long bones, spongy tissue forms the majority of the epiphyses and is also found around the inner rim of the diaphysis. Bone Ossification - The process of bone - In both types of tissue, the osteocytes are the formation same, but the arrangement of how the blood - Bone is formed during ossification and supply reaches the bone cells is different. maintained by remodeling. The two types of tissue have different it occurs in four situations: functions. 1. Initial formation of bones in the embryo and fetus. 2. bone growth during infancy, childhood, and The following section highlight how bones adolescence prior to adulthood. grow in length and in thickness: 3. There is also bone remodeling, which occurs Growth in length: as old bone tissue is replaced with new bone Within the epiphyseal plate (cartilage) are tissue throughout life. chondrocytes that divide and form additional cartilage. 4. Repair of broken bones such as fractures New chondrocytes form on the epiphyseal throughout life. side, while the cartilage on the diaphyseal side is replaced by bone. Bones form initially in the embryo by two The thickness of the epiphyseal plate remains processes: the same, but the bone lengthens. (1) intramembranous ossification - bone forms Cartilage growth stops at adulthood, and directly from mesenchyme. bone replaces the remaining cartilage to form the epiphyseal line. Intramembranous ossification occurs in the at bones of the skull, mandible, and clavicle. Growth in thickness: As the bone lengthens, it also thickens. (2) endochondral ossification - bone forms Cells in the perichondrium differentiate into within and replaces cartilage. osteoblasts, which secrete extracellular matrix Intramembranous ossification is the simpler of that calcifies. these two processes. Osteoblasts differentiate into osteocytes as new lamellae are formed. Osteoclasts break down the inner surface of the medullary cavity but at a slower rate than the bone forms on the outer surface. So, the medullary cavity grows in diameter as the bone thickens. Bone Growth - During infancy, childhood, and adolescence, long bones grow in both length and thickness.  - Calcitonin stimulates formation of osteoblasts. - The Human growth hormone (hGH) and Insulin - like growth factor (IGF) stimulates cartilage and bone growth. Sex hormones (estrogen and testosterone) influence sex-related differences in skeletal growth. Certain minerals contribute to our osseous tissues: calcium magnesium phosphorus. This is congruent to the importance of Vitamins: Vitamins A, C, and D. - but this doesn’t mean that all depends on the afore mentioned factors. This is because our Bone Remodeling - an ongoing process activity level and diet play a major role on how wherein bone is constantly made and our body can synthesize these hormones, destroyed vitamins and minerals. - At various stages of life, osteoblasts and osteoclasts regulate bone formation and bone Bone Repair - Bones can reform after being destruction. fractured (broken). - During some stages, such as childhood, The classification of fractures depends on formation exceeds destruction, allowing for whether the bone is splintered (partial), growth of the skeleton. entirely broken (complete), or comminuted. If - For a short period of time after ossification the broken bone protrudes through the skin, it processes cease, formation and destruction are is an open fracture. If it remains within the skin, fairly equivalent. it is a closed fracture - As a person ages, destruction often exceeds formation, leading to bone loss. Rates of remodeling vary depending on the location within the body. - The remodeling process allows for mineral homeostasis, as well as repair of damaged bone tissue. Remodeling is affected by many factors: Hormones as one of the major factors affect bone remodeling - Parathyroid hormone (PTH) stimulates osteoclasts 4.4 DIVISION OF THE SKELETAL SYSTEM - Anatomists use several common terms to describe the features of bones. ANATOMICAL TERMS FOR FEATURES OF For example: BONES FORAMEN - a hole in a bone is 4.4.1 Axial Skeleton - usually exists in a bone because some - The skull, which consists of 22 bones, rests on structure, such as a nerve or blood vessel, top of the vertebral column. passes through the bone at that point. - If the hole is elongated into a tunnel-like passage through the bone, it is called a canal or a meatus. FOSSA - A depression in a bone. TUBERCLE OR TUBEROSITY - A lump on a bone PROCESS - a projection from a bone - Most tubercles and processes are sites of muscle attachment on the bone. Increased muscle pull, as occurs when a person lifts weights to build up muscle mass, can increase the size of some tubercles. CONDYLE - The smooth, rounded end of a bone, where it forms a joint with another bone - It has two groups of bones: 8 cranial bones and 14 facial bones. CRANIAL BONES - protect the brain and form arches to form a doorway. It contains attachment points for the meninges on the sphenoidal sinuses, which drain into the nasal interior and the muscles that move the head on cavity. the exterior. PITUITARY GLAND - sits in a depression of the FACIAL BONES - house the openings to the sphenoid bone called the sella turcica. The airways and the digestive system, protect the optic nerve passes through its optic foramen, sensory organs and provide attachments for and the mandibular nerve passes through its facial muscles. foramen ovale. FRONTAL BONE - forms the forehead, roofs of ETHMOID BONE - forms the anterior part of the eye sockets, and front part of the cranial the cranial floor, the medial part of the eye floor. The mucous membrane–lined spaces sockets, and superior portions of the nasal (frontal sinuses) deep within it resonates cavity. It has 3 to 18 ethmoidal sinuses (air sound. spaces) and mucus-lined conchae that warm and moisten inhaled air and trap foreign PARIETAL BONES (2) - form the sides and roof particles. of the cranium CRISTAL GALLI - a ridge on the superior portion TEMPORAL BONES (2) - form the lower side of the ethmoid bone, serves as an attachment of the cranium and part of the cranial floor. point for the meninges. This is surrounded by The temporal bones have several features: the cribriform plate through which the nerves associated with the receptors for smell pass - They form joints with the jawbone (mandible) from the nose into the brain. called the temporomandibular joints (TMJ). FACIAL BONES - The external auditory meatus is the canal - Your face changes and grows from the time that leads to the middle ear. you are born until around age 16. Your teeth - The mastoid process is a point of attachment form and erupt, the cranial bones grow, and the for some of the muscles involved in head paranasal sinuses expand. movement. - The carotid artery passes through a foramen called the carotid foramen. - The styloid process serves as a point of attachment for the tongue and neck muscles. OCCIPITAL BONE - forms the back part of the skull and most of the cranial floor. The medulla, spinal cord, and vertebral and spinal arteries all pass through its foramen magnum. The first cervical vertebra attaches to the occipital bone at two processes called the occipital condyles. SPHENOID BONE - is in the middle of the cranial floor and is where all the other cranial bones attach, like the keystone joining two  NASAL BONES (2) form the bridge of the nose. MAXILLAE (2) form the upper jawbone and join with all the other facial bones except the mandible (lower jawbone): - Each maxilla has a maxillary sinus that empties into the nasal cavity. - The alveolar process forms the arch that contains the sockets (alveoli) for the teeth. - The maxillae form the anterior three-fourths of the roof of the mouth (hard palate). PALATINE BONES (2) form the posterior portion of the hard palate, part of the lower eye sockets, and part of the floor and the sides of the nasal cavity. MANDIBLE is the largest, strongest facial bone and the only one that moves: - Each condylar process forms a temporomandibular joint with each temporal bone. - the mandible has an alveolar process for the lower teeth. MENTAL FORAMINA are holes that allow passage of the mental nerve. - Dentists use the mental foramina as landmarks to inject anesthetics into the mental nerve. ZYGOMATIC BONES or cheekbone (2) -form the cheek prominences and part of the wall of the eye sockets. They form joints with the frontal, maxilla, sphenoid, and temporal bones. LACRIMAL BONES (2) are the smallest, thinnest bones on the medial eye socket. They house the tear ducts, which tunnel through to runs when you cry. INFERIOR NASAL CONCHAE (2) project into Your facial bones include the following: the nasal cavity to filter air before it passes toward the trachea and lungs. - The vomer joins with the maxillae and the HYOID BONE -is located in the neck, between palatine bones to form the floor of the nasal the mandible and larynx. It is suspended from cavity. Along with cartilage and the ethmoid the styloid process of each temporal bone by bone, the single vomer forms the nasal septum, ligaments and muscle. which divides the nasal cavity into right and left - It supports the tongue, stabilizes the airways, sides. and provides attachment points for tongue, FEATURES OF THE SKULL neck, and pharyngeal muscles. - has unique features, such as sutures, sinuses, VERTEBRAL COLUMN and fontanels (soft spots at birth and early - The vertebral column (also called the spine, infancy): spinal column, or backbone) protects the spinal cord, supports the head and neck, permits SUTURE - is a special type of immovable joint movement, and provides attachment points for that joins most of the skull bones. the back muscles, ribs, and pelvis. The vertebral There are 4 major sutures in the skull: column consists of 26 bones called vertebrae. 1. CORONAL SUTURE unites the frontal bone Vertebrae have the following general and two parietal bones. structures : 2. SAGITTAL SUTURE attaches the two parietal The body is the thick, disc-shaped anterior bones. portion that bears weight. 3. LAMBDOID SUTURE joins the parietal bones VERYEBRAL ARCH - extends posteriorly from to the occipital bone. the body. It consists of two short, thick processes called pedicles that project backward 4. SQUAMOUS SUTURE - seal the parietal and join with two at parts called laminae. bones to the temporal bones. VERTEBRAL FORAMEN - is an opening through PARANASAL SINUSES - are found in the which the spinal cord passes. sphenoid, frontal, ethmoid, and maxillary bones. Seven processes arise from the vertebral arch: - They produce mucus, lighten the weight of SPINOUS PROCESS (1) projects from the the skull, and serve as echo chambers, which laminae; it serves as attachment point for produce the unique sounds of your voice. muscles. FONTANELS - are mesenchyme-filled spaces TRANSVERSE PROCESS (2) are lateral between the cranial bones of infants at birth. extensions that serve as attachment points for - These soft spots compress as the baby passes muscles. through the birth canal. For a short time after birth, the fontanels also provide room for the SUPERIOR ARTICULAR PROCESSES (2) attach brain to grow. Within the first two years of life, to vertebra above. they are replaced by bone via INFERIOR ARTICULAR PROCESSES (2) attach intramembranous ossification. As the fontanels to vertebra below. close, the bones of the skull fuse to form the sutures. The exact shape and structure of the vertebrae vary with the region where they are located:  CERVICAL VERTEBRAE (7) are in the neck region. Each cervical vertebra has three openings (foramina): a larger, central opening (vertebral foramen) for the spinal cord, and two transverse foramina, passages for blood vessels and nerves. THORACIC VERTEBRAE (12) are posterior to the chest cavity and serve as attachments for the ribs. LUMBAR VERTEBRAE (5) form the lower back. SACRUM - consists of 5 fused vertebrae and forms the posterior wall of the pelvis. Blood vessels and nerves pass through the openings. COCCYX - sometimes referred to as the tailbone, consists of 4 fused vertebrae. Note that the adult vertebral column has four curved regions: cervical, thoracic, lumbar, and sacral. The curves develop from a single, concave curve in the fetus. When the infant begins holding its head erect (at approximately three months of age), the cervical curve develops. The lumbar curve develops later, when the child starts sitting up, standing, and walking. - Sometimes, abnormal curvatures develop in the spine due to uneven growth or weakening of the bones and/or musculature associated with the spine. SCOLIOSIS—A lateral curvature that causes the spine to “lean” to one side more than the other. This condition is seen more commonly in females than in males. KYOHOSIS—An exaggeration of the thoracic curve that forms a “humpback” appearance. LORDOSIS—An exaggeration of the lumbar curve that causes a “sway back.” THORACIC CAGE  APPENDICULAR SKELETON PECTORAL GIRDLE - the shoulder girdles or pectoral girdles which attach the upper limbs to the axial skeleton. The clavicle, or collarbone, attaches to the manubrium of the sternum and the scapula, or shoulder blade. CORACOID PROCESS - of the scapula serves as a point of attachment for muscles GLENOID CAVITY - forms the shoulder joint with the head of the humerus (upper arm bone). Upper Limbs The ribs and sternum form the framework for the thorax. The sternum is made of three parts that fuse by age 25. The manubrium articulates with the collarbone, or clavicle, and the first rib. The body articulates with part of the second rib and ribs 3 through 10. The xiphoid process is made of cartilage that ossifies by age 40. No ribs attach to this pointed structure, which rescuers use to locate the proper hand position for cardiopulmonary resuscitation (CPR). - The sternum attaches directly to the first through seventh pairs of ribs by a form of hyaline cartilage called costal cartilage. The remaining pairs of ribs either attach indirectly to the sternum (pairs 8–12) or do not attach at all (pairs 11–12). Ribs are named based on how they attach to the sternum; rib pairs 1 through HUMERUS - attached to the scapula and the 7 are called true ribs, rib pairs 8 through 12 are longest bone in the upper body called false ribs, and rib pairs 11 and 12 are - has a rounded head that fits into the glenoid referred to as floating ribs. The bones of the cavity of the scapula. The distal end of the thorax protect the heart and lungs and provide humerus attaches to the two bones of the attachment points for muscles, especially those forearm, the ulna and radius. involved in breathing. - The ulna is medial to the radius. The proximal predominantly because the female must pass end of the radius is rounded and articulates the baby through the pelvis during childbirth. with the humerus, to allow approximately 180° The angle formed inferior to the pubic bones of forearm rotation. at the pubic symphysis (pubic arch) is wider in - Distal to the ulna and radius are the bones of women (> 90°) than in men (< 90°). the wrist, the carpals (8 bones), which are The pelvic inlet—the superior opening into arranged in two rows of 4 bones each. the bony pelvis—is heart-shaped in males and - The distal row attaches to the bones of the oval in females. palm of the hand (metacarpals), whose distal The sacrum is wider and more posteriorly heads form the knuckles. placed in the female than in the male. - the metacarpals attach to the bones of the Lower Limbs fingers, the phalanges. There are 2 phalanges in the thumb and 3 in each finger. PELVIC GIRDLE - which consists of the two hip bones. The hip bones, also called the coxal bones or os coxa, attach to the sacrum of the vertebral column posteriorly and with each other anteriorly to form the pubic symphysis. - Each coxal bone is composed of an ilium, and ischium, and a pubis that have fused to form a single unit. ACETABULUM - the “socket” for the hip joint that articulates with the femur from the leg. BOWL SHAPED PELVIS - is formed by the coxal bones, sacrum, and coccyx. PELVIC BRIM - forms the boundary between the upper pelvis (false pelvis) and the lower LOWER LIMB - is composed of a single bone pelvis (true pelvis). proximally with increasing numbers of bones as FALSE PELVIS - is part of the abdomen and one moves distally. contains the urinary bladder and the uterus. FEMUR ( THIGH BONE) - Attached to each coxal TRUE PELVIS - surrounds the pelvic cavity. bone, the longest single bone in the body. OBTURATOR FORAMINA - where Blood vessels - has a rounded, proximal head where it fits and nerves to the legs pass through openings in into the acetabulum of the pelvis. the lower pelvis - bends medially and attaches distally to the There are a number of structural differences patella (knee cap) and the tibia. between the male and female pelvis. This is TIBIA - is the large medial bone of the shin and bears most of the weight. It attaches proximally with the femur and fibula and distally with the fibula and the talus of the ankle. PATELLAR LIGAMENT - which holds the patella in place, attaches to the tibia at the tibial tuberosity. FIBULA - The lateral bone of the shin - The proximal end of the fibula articulates with the tibia and its rounded distal end and forms a joint with the talus of the ankle. ANKLE BONES OR TARSALS - consist of 7 bones. Two of these bones, the talus and the calcaneus, are on the posterior part of the foot. The talus is part of the ankle joint, while the calcaneus forms the heel of the foot. The rest of the tarsals are anterior to these and attach to the metatarsals. METATARSALS (5) - are like the metacarpals of the hand. Attached to the metatarsals are the phalanges (toes), which have a structure similar to the phalanges in the hand. The calcaneus forms the posterior portion of the foot. The foot has two raised bends, or arches, in it: LONGITUDINAL ARCH - spreads from anterior to posterior, TRANSVERSE ARCH - goes from side to side. - The arches are flexible and springy. They absorb shocks, distribute body weight over the foot, and provide leverage while walking.