BIOL 235 Chapter 7, questions and answers with verified content

BIOL 235 Chapter 7, questions and answers with verified content What is the axial skeleton? Consists of bones around the longitudinal axis of the body (80 bones, including skull, auditory ossicles, hyoid, ribs, sternum, vertebral column) What is the appendicular skeleton? Consists of bones of the extremities and girdles that connect limbs to the axial skeleton (126 bones) What is a long bone? Bones that are longer than they are wide (slightly curved), have a shaft (diaphysis) and epiphyses Consist mostly of compact bone tissue (diaphysis), epiphyses contain spongy bone tissue (e.g. femur, tibia, fibula, humerus, ulna, radius, phalanges) What is a short bone? A cube-shaped bone with nearly equal length and width, consists of spongy bone tissue (e.g. carpals and tarsals) What is a flat bone? Thin bones composed of 2 parallel plates of compact bone enclosing a layer of spongy bone (e.g. cranium, ribs, scapulae) What is an irregular bone? Have complex shapes (not grouped into any other category), vary in amount of compact and spongy bone tissue (e.g. vertebrae, hips, some facial bones, calcaneus) What is a sesamoid bone? Bones that develop in certain tendons where there is a lot of friction/stress (e.g. palms or soles) and may not be completely ossified Patellae are always present, but others can vary from person to person Protect tendons from excessive wear What is a sutural bone? Small bones located in sutures between cranial bones (number varies between people) What are surface markings? Structural features on bones that are adapted for specific functions (develop in response to forces, not present at birth) What are depression/opening surface markings? Sites allowing passage of soft tissue (blood vessels, nerves, tendons, ligaments) or form joints What is a fissure? A narrow slit between adjacent parts of bones (blood vessels or nerves pass through) What is a foramen? A hole/opening (blood vessels, nerves or ligaments pass through) What is a fossa? A shallow depression What is a sulcus? A furrow along bone surface that accommodates blood vessels, nerves, or tendons What is a meatus? A tube-like opening What are processes? A type of bone surface marking; projections that help form joints or attachment points for connective tissue What is a condyle? A large, round protuberance with a smooth articular surface at the end of bone (forms joints) What is a facet? A smooth, flat concave or convex articular surface (forms joints) What is a head process? A rounded articular projection supported on the neck of a bone (forms joints) What is a crest process? A prominent ridge or elongated projection (attachment point) What is an epicondyle? Typically a rough projection above a condyle (attachment point) What is a line process? A long, narrow ridge or border (less prominent than a crest) that serves as an attachment point What is a spinous process? A sharp, slender projection (attachment point) What is a trochanter? A very large projection for attachment What is a tubercle? A variably sized rounded projection (for attachment) What is a tuberocity? A variably sized projection with a rough, bumpy surface (for attachment) What is the skull? Bones of the head (22 bones) includes, 8 cranial bones that protect brain (frontal, parietal, temporal, occipital, sphenoid, ethmoid) 14 facial bones that form the face (nasal, maxillae, zygomatic, mandible, lacrimal, palatine, inferior nasal conchae, vomer) Explain the parts and location of the frontal bone Part of the skull that forms the forehead, roofs of the orbits, and anterior part of the cranial floor (united by the metopic suture after birth) Includes the supraorbital margin (thickened part above orbits), foramen (where supraorbital nerve/artery pass), and notch (incomplete foramen) Also includes the frontal sinuses deep to the frontal squama Explain the parts and location of the parietal bones Part of the skull that form most of the cranial sides and roof (internal part contains many protrusions and depressions for blood vessels supplying the dura mater) Explain the parts and location of the temporal bones Part of the skull that form inferior lateral aspects of the cranium and cranial floor, includes: Zygomatic process (articulates with zygomatic bone), zygomatic arch, mandibular fossa (socked on zygomatic process for the mandible), external auditory meatus (ear canal), mastoid process (point of attachment for neck muscles), internal auditory meatus, and styloid process (point of attachment for tongue/neck muscles and ligaments) Explain the parts and location of the occipital bone Part of the skull that forms the posterior part of the cranium (base), includes the foramen magnum (medulla oblangata, meninges, accessory nerve, arteries pass through), occipital condyles (articulate with the atlas to form the atlanto-occipital joint), and external occipital protuberance (most prominent midline projection above foramen magnum) Explain the parts and location of the sphenoid bone Main part of the skull base (cranial floor), that articulates with all other cranial bones and is shaped like a butterfly Includes the sella turcica (bony saddle-shaped structure on superior part) and the optic foramen What are the parts of the sella turcica? Turculum sellae: ridge forming the anterior ('horn') part Hypophyseal fossa: a depression ('seat') that contains the pituitary gland Explain the parts and location of the ethmoid bone Part of the skull in the anterior part of the cranial floor, medial to the orbits, forms the superior part of the nasal septum (major supporting structure of nasal cavity) What are the superior and middle nasal conchae (turbinates)? Two thin, scroll-shaped projections in the lateral part of the ethmoid (help cleanse inhaled air by causing it to swirl, superior conchae increase surface area for smelling) Explain the parts and location of the nasal bones Two small, flattened, rectangular facial bones forming the bridge of the nose (protect upper entry to nasal cavity) Explain the parts and location of the lacrimal bones Two thin (smallest) facial bones, forming the medial wall of each orbit Lacrimal fossa: vertical tunnel that houses the lacrimal sac (gathers tears) Explain the parts and location of the palatine bones Two L-shaped facial bones forming the posterior part of the hard palate/floor and lateral wall of the nasal cavity Explain the parts and location of the inferior nasal conchae (turbinates) Facial bones that form part of the inferior lateral wall of the nasal cavity (help increase surface area of nasal cavity and swirl air) Explain the parts and location of the vomer A triangular facial bone on the floor of the nasal cavity that forms the inferior part of the nasal septum Explain the parts and location of the maxillae Two facial bones that form the upper jawbone and articulate with every facial bone except the mandible Maxillary sinus: empty into nasal cavity Infraorbital foramen: allows passage of blood vessels/nerve Explain the parts and location of the zygomatic bones Cheekbones (also part of wall and floor of orbits) Explain the parts and location of the mandible The lower jawbone (largest/strongest facial bone), the only moveable skull bone Parts include: body (curved part), rami (perpendicular portions), angle (where rami meets the body), condylar process (articulate to form TMJs), coronoid process (attachment for temporalis muscle), and alveolar process (sockets for lower teeth) Explain the parts and location of the nasal septum A vertical partition separating the nasal cavity into left/right (includes the vomer, septal cartilage, and perpendicular plate) Explain the parts and location of the orbital cavities/orbits Eye sockets (contain eyeball and other structures) formed from the frontal/sphenoid bones (roof), zygomatic/sphenoid (lateral wall), maxilla/zygomatic/palatine bones (floor), and medial wall What are the 5 openings associated with the orbit? Optic foramen, superior orbital fissure, inferior orbital fissure, supraorbital foramen, lacrimal fossa What is a suture? Immovable joints that hold skull bones together (movable in children) What is the coronal suture? Unites the frontal and parietal bones What is the sagittal suture? Unites parietal bones on superior midline of skull What is the lambdoid suture? Unites parietal and occipital bones What are the squamous sutures? Unite the parietal and temporal bones (on lateral aspects) Explain the location and functions of the paranasal sinuses Cavities within cranial and facial bones near the nasal cavity, lined with mucous membranes (allow the skull to grow and serve as resonating chambers for sounds and voice quality) What are fontanels? Incompletely developed cranial bones (6 soft spots) that is eventually replaced by bone (collagenous tissue becomes sutures); serve as spacers for skull growth and give flexibility for birth What is the hyoid bone? A bone suspended from the styloid processes of temporal bones by ligaments and muscles (doesn't articulate with any other bone); supports the tongue and serves as an attachment point for the tongue and neck muscles Name the 3 parts of the hyoid bone Body: horizontal part (muscles and ligaments attach here) Lesser horns: paired attachment point projections Greater horns: paired attachment point projections What is the vertebral column? The spine (consists of bone and connective tissue), surrounds and protects the spinal cord, supports the head, attachment point for ribs, pelvic girdle and muscles List the normal curves of the vertebral column Curves increase strength, maintain balance, absorb shocks, and protect vertebrae Cervical: convex (anterior) secondary curve (develops when children can hold their head up) Thoracic: concave (posterior) primary curve Lumbar: convex (anterior) secondary curve (develops when children can sit up, stand, and walk) Sacral: concave (posterior) primary curve What type of vertebral curve does a fetus have? A single anteriorly concave curve throughout the spine What are invertebral discs? Connective tissue between vertebrae that consist of an outer fibrous ring (annulus fibrosus) and an inner, soft, pulpy elastic substance (nucleus pulposus) What is a vertebrate? Bones of the spine (children have 33, adults have 26) Consists of 7 cervical, 12 thoracic, 5 lumbar, 1 sacrum, 1 coccyx What is a vertebral body? The thick, disc-shaped, weight-bearing part of a vertebrae What is the vertebral arch? Formed when pedicles (short processes) project from the vertebral body and meet with laminae (forms the foramen) What is a vertebral foramen? Formed by the vertebral arch and artery to surround the spinal cord, connective tissue, and vessels What is the vertebral (spinal) canal? Formed by all vertebral foramen What is an invertebral foramen? Formed by staked vertebral notches, permits passage of a single spinal nerve What is a transverse process? Project laterally on vertebrae, formed by the joining of the lamina and pedicle What is the spinous process of a vertebrae? Single posterior projection from laminae junction What is a superior articular process? Articulate with the inferior articular processes of the vertebrate above them by facts Describe the cervical vertebrae The smallest vertebrae (C1-C7) Atlas (C1): lacks a body and spinous process Axis (C2): has a body, the dens projects through it (Dens or Odontoid process makes a pivot for the axis and head, so you can shake 'no') Describe the thoracic vertebrae Larger, stronger vertebrae (T1-T12) that articulate with the ribs (at vertebrocostal joints) Describe the lumbar vertebrae The largest and strongest unfused vertebrae (L1-L5) with short, thick projections and spinous processes that are adapted to attach large back muscles What is the sacrum? A triangular bone that is the foundation for the pelvic girdle (females' are shorter/wider) made of the fusion of 5 sacral vertebrae (S1-S5), fusion is completed around age 30 What are the anterior sacral foramina? Four pairs of foramina at the end of transverse lines that mark the joining of sacral vertebrae What is the median sacral crest? The fused spinous processes of upper sacral vertebrae What are the posterior sacral foramina? Four pairs of foramina on the convex, posterior part that allow passage of nerves and blood vessels What is the sacral canal (hiatus)? A continuation of the vertebral canal (called a hiatus when laminae fail to meet) What is a sacral promontory? The anteriorly projecting border of the sacrum base (used for measuring the pelvis) What is a sacroiliac joint? Formed when the sacrum articulates with the ilium of each hip bone What is the lumbosacral joint? Formed when the sacrum base articulates with the L5 body What is the coccyx? Tail bone; formed by the fusion of coccygeal vertebrae (Co1-Co4) that fuse between age 20-30 It articulates with the sacrum What is the thorax? The entire chest region What is the thoracic cage? The bony enclosure formed by the sternum, ribs, costal cartilages, and bodies of thoracic vertebrae What is the sternum? Breastbone; located in the centre of the anterior thoracic wall What is the manubrium? The superior handle-like part of the sternum What is the body of the sternum? The middle and largest part of the sternum What is the xiphoid process? The inferior, sword-shaped and smallest part of the sternum (made of hyaline cartilage in infancy, ossifies by age 40); provides attachment for some muscles What is the sternal angle? The junction of the manubrium and body of the sternum What is the suprasternal notch? A depression on the superior manubrium of the sternum What are clavicular notches? Notches lateral to the suprasternal notch that articulate with the medial ends of the clavicles (form sternoclavicular joints) What are ribs? Paired bones in the thoracic cage, numbered 1-12 from superior-inferior What is costal cartilage? A strip of hyaline cartilage that attaches rib pairs 1-7 to the sternum (contribute to elasticity of thoracic cage and prevent fractures) What are vertebrosternal (true) ribs? Rib pairs 1-7 have costal cartilage and attach directly to the sternum