Chapter 7 Flashcards
The human body is composed of ____ bones and cartilage
*206
Basic parts of the Skeletal System
Axial & Appendicular
Axial Skeleton
*longitudinal axis and encases body cavities
The skull contains ____ bones (__ cranial and __ facial) in the Axial Skeleton
- 22 bones
- 8 cranial
- 14 facial
- SKULL ENCASES THE BRAIN & FORMS FACE
Vertebral Column of the Axial Skeleton
- 33 bones
- 24 INDIVIDUAL VERTEBRAE (protects spinal cord)
- REMAINING VERTEBRAE FUSE and FORMS SACRUM & COCCYX
Thoracic Cage of Axial Skeleton
- RIB CAGE
- 12 pairs of Ribs, Sternum, and part of Vertebral Column
- Encases & protects lungs, heart, and the thoracic cavity contents (SOME)
Appendicular Skeleton
- Bones of Pectoral girdle, Upper limb, Pelvic girdle, and Lower limb;
- Suited for Movement, Support, and Muscle attachment
Pectoral Girdle of Appendicular Skeleton
- Clavicle and Scapula;
- Anchors Upper limb to Trunk
Upper Limb of Appendicular Skeleton
*3 parts: Arm [HUMERUS], Forearm [RADIUS & ULNA], and Wrist & Hand [CARPALS, METACARPALS, and PHALANGES]
Pelvic Girdle of Appendicular Skeleton
- 2 Pelvic bones and Sacrum;
* PELVIS: ANCHORS LOWER LIMB TO TRUNK
Lower Limb of the Appendicular Skeleton
*3 Parts: Thigh [FEMUR], Leg [TIBIA & FIBULA], and Ankle & Foot [TARSALS, METATARSALS, and PHALANGES]
Bone Markings
- SURFACE FEATURES:
- Depressions: pathways for blood vessels and nerves or sites for joints between the bones
- Openings: enclose delicate structures and allow them to travel through the bones
- Projections: sites where bones articulate or where ligaments & tendons attach
Skull
*22 BONES in 2 GROUPS: CRANIAL & FACIAL
Cranial Bones of Skull
- CRANIUM
- 8 BONES
- 4 SINGLE bones: FRONTAL, OCCIPITAL, ETHMOID, & SPHENOID
- 2 PAIRED bones: TEMPORAL & PARIETAL
Facial Bones of Skull
- 14 TOTAL that FORMS FRAME OF FACE
- 6 PAIRED bones: MAXILLARY, ZYGOMATIC, NASAL, LACRIMAL, PALATINE, and INFERIOR NASAL CONCHAL
- 2 SINGLE bones: MANDIBLE & VOLMER
Overview of Skull Structure
- ALL BONES OF SKULL ARE FUSED TO ONE ANOTHER AT IMMOVABLE JOINTS (sutures), EXCEPTION OF MANDIBLE
- MANY SKULL BONES contain AIR-FILLED SPACES, SINUSES; 4 bones around NASAL CAVITY, [PARANASAL SINUSES]
Cranial Vault
- CALVARIUM
- Superior portion of Cranial Cavity
Cranial Base
-Inferior portion, divided into 3 indentations: ANTERIOR, MIDDLE, & POSTERIOR CRANIAL FOSSAE -> * where brain fits
Cranial Cavity
- Formed by: CRANIAL BONES, and the Surrounding Brain housing sense Organs
- ORBITS: CONTAIN EYEBALLS
- NASAL CAVITY: HOUSES SENSORY RECEPTORS FOR SMELL
- ORAL CAVITY: SURROUNDS TEETH & TONGUE
- Other SMALL CAVITIES Containing ORGANS FOR HEARING & BALANCE
Cavities of Skull
-Orbit: 7 FUSED BONES; FORMS walls that encase EYEBALL, LACRIMAL GLAND, & associated BLOOD VESSELS, MUSCLES, & NERVES
Frontal Bone
-SUPERIOR & POSTEROSUPERIOR ORBITAL WALL
Maxilla
-POSTEROINFERIOR WALL with small contribution from PALATINE BONE
Zygomatic Bone
-ANTEROLATERAL WALL
Sphenoid Bone
-POSTERIOR WALL
Ethmoid, Lacrimal, and Palatine Bones
-MEDIAL WALL
Nasal Cavity of Skull Cavities
- SEVERAL bones LINED with MUCUS MEMBRANES forming WALLS
* FIRST PART OF RESPIRATORY TRACT
Posterior Wall
-Sphenoid body & Pterygoid process
Lateral Wall
-ETHMOID and perpendicular plate of PALATINE, Inferior NASAL CONCHAE, and MAXILLA
Roof
-CRIBRIFORM plate of ETHMOID
Floor/Hard Palate
-PALATINE & PALATINE PROCESSES of MAXILLAE
Anterior Wall
-CARTILAGE & CONNECTIVE TISSUE of NOSE that is ATTACHED to margins of NASAL BONE and MAXILLAE
Nasal Septum
- POSTERIOR to PERPENDICULAR plate of ETHMOID bone and VOLMER;
- ANTERIOR to HYALINE CARTILAGE
- DIVIDES NASAL CAVITY into new NASAL FOSSA
Paranasal Sinuses
- WITHIN FRONTAL, SPHENOID, ETHMOID, and MAXILLARY bones
- Communicates with adjacent NASAL CAVITY through small body openings
- ALLOWS AIR to FLOW IN & OUT of SINUSES
Mucous Membranes
- Lines SINUSE filter, WARM, and HUMIDIFIES AIR
- Cavities REDUCE WEIGHT of SKULL and ENHANCES VOICE RESONANCE
Tongue, Teeth, and Salivary Glands (MOST) within Oral Cavity:
- FIRST PART OF DIGESTIVE TRACT
- ROOF is INFERIOR surface of bones that FORMS FLOOR of NASAL CAVITY [HARD PALATE]
- ANTERIOR & LATERAL WALLS of cavity are MAXILLAE and MANDIBLE
- POSTERIOR WALL and BONY FLOOR are ABSENT; REPLACED by SOFT TISSUES [MUSCLES & CONNECTIVE TISSUE]
Fetal Skull
- NOT FUSED TO ONE ANOTHER
- Soft Spots: [FONTANELS] that are membranous AREAS BETWEEN fetal CRANIAL bones; PRESENT UNTIL child’s CRANIAL bones complete development at 18-24 MONTHS
- Fontanels & UNFUSED structures ALLOW FLEXIBILITY; ENABLE skull to FIT through VAGINA during birth and ALLOWS SKULL to ENLARGE with normal brain GROWTH
Fontanels
- Anterior Fontanel: BETWEEN developing FRONTAL & PARIETAL BONES where CORONAL & SAGITTAL SUTURES MEET; METOPIC SUTURE DIVIDES FRONTAL BONE (fuses at birth from SINGLE BONE)
- Posterior Fontanel: BETWEEN developing PARIETAL & OCCIPITAL bones at APEX of LAMBDOID SUTURE
Two Sphenoid Fontanels
-on LEFT & RIGHT sides of TEMPLE where SPHENOID bone MEETS other CRANIAL BONES
Two Mastoid Fontanels
- at JUNCTION where LAMBDOID and SQUAMOUS SUTURES of developing PARIETAL, TEMPORAL, and OCCIPITAL bone MEET
Hyoid Bone
- Grouped with skull bones DUE TO its PROXIMITY even though it DOESN’T articulate with SKULL BONES
- C-SHAPED in SUPERIOR NECK; SUSPENDED by LIGAMENTS that attach it to the STYLOID PROCESS of TEMPORAL bone & LARYNX (voice box)
- PROVIDES numerous ATTACHMENT POINTS for MUSCLES involved in SWALLOWING & SPEECH
Forensic Skull Anatomy
- 4 DIFFERENCES:
1. MALE skull FOREHEAD is SLOPED & FEMALES STRAIGHT
2. MALES SUPRAORBITAL RIDGE is more PROMINENT
3. Mandibular angle of MALE is closer to 90 degrees and FEMALE is CLOSER to or GREATER than 90 degrees
4. Mastoid process of MALE is LARGER & more PROMINENT
Forensic Skull Anatomy (pt. 2)
- SIZE of SKULL, SUTURE APPEARANCE, and TEETH can approximate individuals AGE
- PROVIDE CLUES to individuals ETHNICITY
- Once analyzed, artist can develop a picture of what that individual LOOKED LIKE
Vertebral Column
- SPINE
- 33 BONES [VERTEBRAE]
- Vertebrae: classified by STRUCTURE & LOCATION; Each individual Vertebrae is given a LETTER-> REGION and NUMBER-> POSITION
Space between Movable Vertebrae of Vertebral Column
- Space between is INTERVERTEBRAL FORAMEN; VISIBLE from LATERAL VIEW of the Column
- SPINAL NERVE ROOTS pass through FORAMINA
Vertebral Classification
- 7 CERVICAL: IN NECK; 4th vertebrae is c4
- 12 THORACIC: RIBS; 11th vertebrae is t11
- 5 LUMBAR: LOWER BACK; 3rd vertebrae is L3
- 5 FUSED SACRAL [Sacrum]: articulates with PELVIC bones
- 3-5 FUSED COCCYGEAL [Coccyx]: AT MOST INFERIOR end of VERTEBRAL column
Spinal Curvatures
- C-SHAPED vertebral column of NEWBORN develops into a series of S-SHAPED secondary curvatures as INFANT GROWS
- Lends BALANCE & SUPPORT needed to WALk on BOTH LEGS
Primary Curvatures
- THORACIC & SACRAL
- PRESENT during FETAL PERIOD of development
Secondary Curvatures
- CERVICAL & LUMBAR
- DEVELOP AFTER FETAL PERIOD
- Development of Secondary Curvatures is CRITICAL to species ability to WALK UPRIGHT
Cervical Curvature
- ALLOWS us to HOLD our HEADS UP
* LUMBAR CURVATURE shifts WEIGHT of BODY ONto SACRUM
Abnormal Spinal Curvatures
SCOLIOSIS: ABNORMAL LATERAL curvature in Vertebral Column
LORDOSIS: [SWAYBACK] exaggerated CERVICAL & LUMBAR curvatures
KYPHOSIS: exaggerated THORACIC curvature, RESULTING in HUNCHBACK appearance
Structure of Vertebrae
- ALL vertebrae HAS FEATURES: reflect functions of spinal cord (PROTECT & SUPPORT head and neck)
Body of Vertebrae
- CENTRUM
- WEIGHT BEARING surface; MOST ANTERIOR
- Intervertebral Discs: BETWEEN adjacent bodies that ABSORB SHOCK or running and jumping
Vertebral Foramen Structure
- POSTERIOR to BODY; LARGE opening through which SPINAL CORD & TISSUES TRAVEL
- ALL FORMINAE FORM [VERTEBRAL CANAL]
2 Pedicles border the Vertebral Foramen laterally and project posteriorly from body:
- MERGES with 2 LAMINAE -> borders vertebral foramen posteriorly
- TOGETHER it FORMS [VERTEBRAL ARCH]
Inferior Vertebral Notch & Superior Vertebral Notch
- On INFERIOR side of EACH PEDICLE [IVN]
- On SUPERIOR side, FORMING [INTERVERTEBRAL FORAMINA]
Superior & Inferior Articular Processes
- At EACH JUNCTION of EACH PEDICLE & LAMINA
- FACETS FORM joints BETWEEN VERTEBRAE
Transverse Processes
- Project from LATERAL sides of Vertebral Arch
* MUSCLE ATTACHMENT SITES