Lab Bones Flashcards
skull is composed of how many bones
22
8️⃣ cranial
14 facial
immovable joints which are visible as seams on the surface of the skull
sutures
Bones of the skull have holes that allow passage for nerves and blood vessels
foramina (singular, foramen)
In flat bones, the spongy bone is called the
diploё
In the skull contains 6 prominent cavities
The largest is the CRANIAL CAVITY, which encloses the brain
• orbits (eye sockets)
• nasal cavity
• oral (buccal) cavity
• middle- and inner-ear cavities
• paranasal sinuses—the frontal, sphenoid, ethmoid, and maxillary sinuses
Cranial fossae x3
Posterior
Middle
Anterior
Opening in the skull where the spinal cord goes through
Foramen Magnum
Bone functions 7
• Support
• Protection
• Anchorage
• Mineral and growth factor storage
• Blood cell formation
• Fat storage
• Hormone production
Ligaments
hold bones together at the joints (bone to bone)
Tendons
attach muscle to bone; stabilize a joint
Cartilage Types
Hyaline
Elastic
Fibrocartilage
Axial skeleton
skull
auditory ossicles
hyoid bone
vertebral column
thoracic cage (ribs and sternum).
Appendicular skeleton
bones of the upper limb
bones of the lower limb
pectoral girdle
pelvic girdle.
Long Bone Structure
Outer shell of dense compact bone
• Encloses the medullary cavity-contains bone marrow
• central space is occupied by spongy bone
Diaphysis→shaft (provides leverage)
Epiphysis→expanded head at each end (strength to the joint and attachment area)
Articular cartilage: hyaline cartilage at the joint surface (bone-to-bone cushion)
Osteogenic cell
Develops into osteoblasts
Osteoblasts
forms bone tissue
Osteocytes
Maintains bone tissue
Osteoclasts
Ruffled border
Resorption
Destruction of bone matrix
Osteon
Haversian system
Regulation of blood calcium low
Parathyroid hormones (gets calcium from bones when we need it)
breakdown of bone by osteoclasts
Blood calcium level increases
Normal blood calcium level
Regulation of blood calcium high
Thyroid
Calcitonin (also stores calcium when we have too much)
Buildup of bone by osteoblasts
Blood calcium level decreases
Normal blood calcium level
The Frontal Bone
From the forehead back to a prominent coronal suture,
crosses the crown of the head from right to left
joins the frontal bone to the parietal bones
The smooth just above the root of the nose is called the
Glabella
supraorbital foramen, notch or margin
passage for a nerve, artery, and veins
Parietal Bones
right and left parietal bones form most of the cranial roof and part of its walls
Temporal Bones has 4 parts
The squamous part→squamous suture
• the zygomatic process
• the mandibular fossa
mastoid part
tympanic part
petrous part
Occipital Bone
• the rear of the skull (occiput) and much of its base
The foramen magnum→admits the spinal cord to the cranial cavity.
• Has a smooth knob called the occipital condyle→the skull rests on the vertebral column.
A ridge, the superior nuchal line→ defines the superior limit of the neck and provides attachment to the skull for several neck and back muscles
Sphenoid Bone
a pair of sphenoid sinuses
• Sella turcica→houses the pituitary gland (hypophysis)
Looks like a butterfly
Study a picture
Ethmoid Bone
anterior cranial bone located between the eyes and has three major portions:
The vertical perpendicular plate
A horizontal cribriform plate
• crista galli, an attachment point for the dura mater
• cribriform (olfactory) foramina→ olfactory nerves
The labyrinth, a large mass on each side of the perpendicular plate
Maxillae
Maxillae→They form the upper jaw and meet each other at a median intermaxillary suture
• Alveolar processes grow into the spaces between the bases of the teeth
• Infraorbital foramen→blood vessel to the face and a nerve that receives sensations from the nasal region and cheek
The palate forms the roof of the mouth and floor of the nasal cavity→separate the nasal cavity from the oral cavity
• Bony hard palate anteriorly→extensions of the maxilla (palatine processes)
• Fleshy soft palate posteriorly
Zygomatic Bones
• form angles of the cheeks at the inferolateral margins of the orbits and part of the lateral wall of each orbit; extend about halfway to the ear
• The prominent zygomatic arch that flares from each side of the skull is formed mainly by the union of the zygomatic bone, temporal bone, and maxilla
Mandible
strongest bone of the skull and the only one that can move significantly
• The horizontal portion is called the body
• the vertical to oblique posterior portion is the ramus (plural, rami)
• Condylar process, bears the mandibular condyle—an oval knob that articulates with the mandibular fossa of the temporal bone→the temporomandibular joint (TMJ)
• coronoid process, is the point of insertion for the temporalis muscle
Vertebral column sections
Cervical 1-7
Thoracic 1-12
Lumbar 1-5
Sacrum (5) fused
Coccyx (4) fused
Vertebra C1
the atlas
supports the head allow for its movements
Vertebra C2
the axis
allows rotation of the head
Has a prominent anterior knob called the dens or odontoid process, it projects into the vertebral foramen of the atlas
Hyoid bone
• U-shaped bone
• Lies above the thyroid cartilage
• Only bone in the body that doesn’t articulate directly with any other bone
• Anchored by ligaments
Thoracic cage
Flat bones
Components:
• Ribs
• Sternum
• Costal cartilage
• Thoracic vertebrae
It protects the vital organs such as heart, lungs and great vessel
Sternum
• “chest bone”
• Fusion of 3 bones:
• Manubrium
• Body
• Xiphoid process
Ribs
12 pairs of ribs in total:
• 1-7 directly attached to the sternum by individual costal cartilage (True Ribs)
• 8-12 attach indirectly to the sternum or not at all (False Ribs)
• 11 and 12 don’t attach at all and are called Floating ribs and false ribs
Pectoral Girdle
(shoulder girdle) supports the arm and links it to the axial skeleton:
The clavicle (collarbone)
• Articulates (medial end) with the sternum→sternoclavicular joint
• Articulates (lateral end) with the scapula→acromioclavicular joint
The scapula (shoulder blade)
• Articulates with the humerus→ glenohumeral joint
Scapula
Is a triangular plate
only direct attachment to the thorax is by muscles
it glides across the rib cage as the arm and shoulder move.
The three sides of the triangle:
1. Superior border
2. Medial (vertebral) border
3. Lateral (axillary) borders
• Suprascapular notch in the superior border →passage for a nerve
• Subscapular fossa→is the anterior surface of the scapula
• The posterior surface has a transverse ridge called the spine, it has indentations: the supraspinous fossa, and the infraspinatus fossa
• The lateral angle, has three main features:
1. The acromion
2. The coracoid process
3. The glenoid cavity is a shallow socket that articulates with the head of the humerus→ glenohumeral joint
Upper Limb four segments
- The brachium (arm proper), from shoulder to elbow
•only one bone, humerus - The antebrachium (forearm), from elbow to wrist
• Two bones:radius and ulna
• In anatomical position, the radius is lateral to the ulna - The carpus (wrist), contains 8 carpal bones in two rows
- The manus (hand), contains 19 bones in two groups:
5 metacarpals in the palm
14 phalanges in the fingers
Humerus
humerus has a head that articulates with the glenoid cavity of the scapula
• The greater and lesser tubercles →muscle attachment
• Intertubercular sulcus between them→tendon of the biceps muscle
• The shaft has a rough area called the deltoid tuberosity on its lateral surface→deltoid muscle of the shoulder
distal end of the humerus has two smooth condyles
• Capitulum (lateral)→articulates with the radius
• Trochlea (medial)→articulates with the ulna
• The humerus flares out to form:
• Lateral epicondyle
• Medial epicondyle (protects the ulnar nerve) “funny bone”
• The distal end of the humerus also shows 3 pits:
1. olecranon fossa (posterior)
2. coronoid fossa (medial)
3. radial fossa (lateral)
Radius
distinctive discoid head at its proximal end
• the edge of the disc spins on the radial notch of the ulna (forearm rotation)
• Has a narrower neck and a prominence, the radial tuberosity, on its medial surface→tendon of the biceps muscle
• The distal end of the radius has the Styloid process
Ulna
the proximal end of the ulna is a C- shaped trochlear notch that wraps around the trochlea of the humerus
• Posterior part is formed by a prominent olecranon
• Anterior side is formed by a less prominent coronoid process
The head of the ulna has a radial notch, which accommodates the edge of the head of the radius.
• At the distal end of the ulna is a medial styloid process
The radius and ulna are attached along their shafts by a ligament called the
interosseous membrane (IM)
Carpal Bones
Two rows of four bones each:
• Proximal row, starting at the lateral (thumb) side:
• Scaphoid
• Lunate
• Triquetrum
• Pisiform (sesamoid bone, tendon of the flexor carpi ulnaris)
• Distal row, starting on the lateral side:
• Trapezium
• Trapezoid
• Capitate
• hamate
Metacarpal Bones
• Bones of the palm
• The proximal end of a metacarpal bone is called the base, the shaft is called the body, and the distal end is called the head
• The heads of the metacarpals form knuckles when you clench your fist
Phalanges
bones of the fingers are called phalanges, in the singular, phalanx
• There are 2 phalanges in the pollex (thumb) and three in each of the other digits.
• The three parts of a phalanx are the same as in a metacarpal: base, body, and head
Pelvic Girdle
Consist of a complete ring composed of three bones:
• Two hip (coxal) bones, also called ossa coxae
• articulate with each other on the interpubic disc (fibrocartilage)→ symphysis pubis
• Joined to the vertebral column at the sacroiliac joint
• The sacrum
Hip bones:
- The iliac crest
- Acetabulum
- Obturator foramen
metaphyses (singular: metaphysis)
are the wide portions of long bones and the regions of the bone where growth occurs. Growth occurs at the section of the metaphysis that is adjacent to the growth plate (physis). The metaphysis is located between the diaphysis and epiphysis
lacrimal bone
perhaps the most fragile bone of the face and one of the smallest bones in the body. Spanning between the middle of each eye socket, each lacrimal is thin and scalelike and serves as support for the eye. The pair of lacrimal bones are two of the fourteen facial bones.
vomer bone
form the nasal septum together with the perpendicular plate of the ethmoid bone and the nasal septal cartilage. In addition, it provides grooves for the passageway of the neurovascular structures of the nasal cavity.
Sutures
Saggital
Coronal
Lamboid
Squamous
Squamous
Between parietal and temporal
Lamboid
Between the parietals and occipital
Coronal suture
Between the parietals and frontal
Sagittal
Between the parietals
Hyaline cartilage 2 types purpose and location
flexibility and resilience
• Articular→cover the ends of most bones at movable joints
• Costal→connect the ribs to the sternum
Elastic cartilage purpose and location
repeat bending (external ear and epiglottis)
Fibrocartilage purpose and location
compressive with tensile strength (bundles of collagen)
• Menisci
• Intervertebral discs
tympanic part of temporal bones
borders the external acoustic meatus, opening into the ear canal
mastoid part of temporal bone
lies posterior to the tympanic part
mastoid process, is filled with small air sinuses that communicate with the middle-ear cavity
petrous part of temporal bones
separates the middle cranial fossa from the posterior fossa
• internal acoustic meatus→allows passage of the vestibulocochlear nerve (hearing and balance) from the inner ear to the brain
squamous part of temporal bones
squamous suture
• the zygomatic process, which extends anteriorly to form part of the zygomatic arch (cheekbone)
• the mandibular fossa, a depression where the mandible articulates with the cranium
Parietal bones bordered by four sutures:
- a sagittal suture between the parietal bones
- the coronal suture at the anterior margin
- the lambdoid suture at the posterior margin
- the squamous suture laterally
General Structure of a Vertebra
Body—a mass of spongy bone and red bone marrow covered with a thin shell of compact bone
• Vertebral foramen→collectively form the vertebral canal, a passage for the spinal cord
• bordered by a vertebral arch composed of two parts on each side: a pillar like pedicle and platelike lamina
• the apex of the arch: a projection, the spinous process
• transverse process extends laterally from the point where the pedicle and lamina meet
Acetabulum
(the hip socket)
iliac crest
from the anterior superior spine to the posterior superior spine (dimples in the buttock)
Obturator foramen
(closed by the obturator membrane) in the pelvic
The adult hip bone forms by the fusion of three childhood bones
ilium, ischium, and pubis
Greater sciatic notch
Houses the sciatic nerve
ischial tuberosity
supports your body when you are sitting (bone that hurts during spinning class!)
Female pelvis
Pubic arch greater than 90 degrees
Sacrum tilted back
Big pelvic outlet
Ilia spread wider
Male pelvis
Pubic arch less than 90 degrees
Sacrum tilted forward
Ilia closer together
Small pelvic outlet
Lower Limb Is divided into four regions:
The femoral region (thigh)
The crural region (leg proper)
The tarsal region (tarsus), or ankle
The pedal region (pes), or foot
femoral region (thigh) of the lower limb
• from hip to knee and contains the femur • the patella (kneecap) is a sesamoid bone
crural region (leg proper) of the lower limb
• from knee to ankle and contains the tibia and fibula
tarsal region (tarsus), or ankle of the lower limb
• is the union of the crural region with the foot
pedal region (pes), or foot, of the lower limb
is composed of 7 tarsal bones, 5 metatarsals, and 14 phalanges in the toes.
Femur
•has a hemispherical head
• articulates with pelvis acetabulum
→ball-and-socket joint
• Distal to the head is a neck and 2 massive, rough processes called greater and lesser trochanters
• midpoint on shaft a posterior ridge called the linea aspera
• upper end→lateral gluteal tuberosity
• The medial and lateral epicondyles are the widest points of the femur at the knee
• At the distal end of the femur are 2 smooth round surfaces of the knee joint, the medial and lateral condyles, separated by a groove called the intercondyla fossa
Patella
roughly triangular sesamoid bone embedded in the ligament of the knee
• quadriceps femoris tendon extends from the anterior quadriceps femoris muscle of the thigh to the patella, and it continues as the patellar ligament from the patella to the tibia (tibial tuberosity)
Tibia
• The leg has two bones:
• tibia on the medial side
• fibula on the lateral side
• Its broad superior head has two articular surfaces, the medial and lateral condyles, separated by a ridge called the intercondylar eminence
• The tibial tuberosity, can be palpated just below the patella
• At the ankle, it has:
• Medial malleolus→part of the tibia
• Lateral malleolus→part of the fibula
Fibula
• The fibula, helps to stabilize the ankle
• It does not bear any of the body’s weight
• The distal expansion is the lateral malleolus
• The tibia and fibula are joined by an interosseous membrane along their shafts.
Ankle and Foot
• The tarsal bones:
• The calcaneus which forms the heel
• attachmentforthecalcaneal(Achilles) tendon from the calf muscles
• The talus, the anterior surface articulates with the navicular
• The distal group: medial, intermediate, and lateral cuneiforms and the cuboid
• The metatarsal bones
• The phalanges
Synovial Joints
• The facing surfaces are covered with articular cartilage (hyaline cartilage)
• These surfaces are separated by a space, the joint (articular) cavity, containing a slippery lubricant called synovial fluid
• A connective tissue joint (articular) capsule encloses the cavity and retains the fluid
• Inner lining, cellular synovial membrane:
• fibroblast-like cells that secrete the fluid, and is populated by macrophages that remove debris from the joint cavity.
Bursae
fibrous sac filled with synovial fluid
Sinovial Joints: Ball-and-socket joints
Ball-and-socket joints→the shoulder and hip joints—the only multiaxial joints in the body
• One bone (the humerus or femur) has a smooth hemispherical head that fits into a cuplike socket on the other (the glenoid cavity of the scapula or the acetabulum of the hip bone)
Knee Joint
• The anterior aspect is covered by the patellar ligament and the lateral and medial patellar retinacula (extensions of the tendon of the quadriceps femoris muscle)
• The knee is stabilized mainly by the quadriceps tendon in front and the tendon of the semimembranosus muscle on the rear of the thigh
The joint cavity contains two C-shaped cartilages called the lateral and medial menisci (singular, meniscus) joined by a transverse ligament
• The menisci absorb the shock of the body weight
Knee Joint ligaments posterior popliteal region of the knee is supported by
• The extracapsular ligaments:
1. fibular (lateral) collateral ligament
2. tibial (medial) collateral ligaments
The two intracapsular ligaments lie deep within the joint, they cross each other in the form of an X:
1. anterior cruciate ligament (ACL)
2. posterior cruciate ligament (PCL)
The skull also has about how many named openings (foramina, canals, fissures, etc.)
85
eight cranial bones are the
paired parietal and temporal bones
the unpaired frontal
occipital
sphenoid
ethmoid bones.
