Lesson 3: Division of the Skeletal System & Lesson 4: Articulations Flashcards
How many bones are there in a human skeleton?
206 Bones
Two Principal Divisions of Bones
Axial Skeleton
Appendicular Skeleton
Bones that are on the longitudinal (vertical line that runs through the
middle of the body) axis of the human body
Axial Skeleton
consists of upper and lower limbs, bones forming girdles
Appendicular Skeleton
How many bones are there in the Axial Skeleton?
80 bones
Identify the Cranial Bones
Frontal
Parietal - 2
Temporal - 2
Occipital
Sphenoid
Ethmoid
Identify the Facial Bones
Nasal - 2
Lacrimal - 2
Palatine - 2
Zygomatic - 2
Maxilla - 2
Mandible
Vomer
Nasal Concha - 2
the largest and strongest facial bone
Mandible
Identify the Auditory Ossicles
Stapes - 2
Incus - 2
Malleus - 2
hold the bone of skull together
Sutures
Identify the Sutures of the Skull
Sagittal
Lambdoidal
Squamous
Frontal / Coronal
responsible for growth of head after birth
allow flexibility during birth processes
Fontanels
Identify the Fontanels
Anterior / Bregmatic
Posterior / Occipital
Anterolateral
Posterolateral
diamond-shaped
largest and located at the junction of sagittal and coronal sutures
closes at 16-18 months
Anterior / Bregmatic
triangular shaped
lies between sagittal and lamboidal
closes between 3 to 4 months (6 months)
Posterior / Occipital
One at each side
closure begins at 1-2 month and complete closure is at 12 months
Posterolateral
Closes at 3 mos.
Anterolateral
floating bone
attachment for throat and tongue muscles
horseshoe shaped
Hyoid
Identify the Bones in the Vertebral Column
Cervical - 7
Thoracic - 12
Lumbar - 5
Sacral / Sacrum
Coccygeal / Coccyx
What is the name of the first cervical vertebra?
C1 - Atlas
What is the name of the second cervical vertebra?
C2 - Axis
vertebra type containing foramina in the transverse processes, through which the vertebral arteries ascend to reach the brain
Cervical Vertebra
dens here provides a pivot for rotation of the first cervical vertebra
C2 - Axis
transverse process faceted for articulation with ribs; spinous process pointing sharply downward
Thoracic Vertebra
composite bone; articulates with the hip bone laterally
Sacrum
massive vertebra; weight-sustaining
Lumbar Vertebra
“tail-bone”; vestigial fused vertebrae
Coccyx
supports the head; allows rocking motion in conjunction with the occipital condyles
C1 - Atlas
Which bone in the vertebral column is composed of 5 fused bones?
Sacral / Sacrum
Which bone in the vertebral column is composed of 4 fused bones?
Coccygeal / Coccyx
bones that form a protective cage for the heart, lungs, and other internal organs
Ribs
ribs that are directly attached to the sternum
True Ribs / Vertebrosternal Ribs
ribs that are attached to the 7th true rib
False Ribs / Vertebrochondral Ribs
ribs that are attached only to the vertebrae–and not to the sternum
Floating Ribs
What are the parts of the Sternum?
Manubrium
Body
Xiphoid Process
- Suprasternal Notch
- Clavicular Notch
- Sternal Angle
How many bones are there in the Appendicular Skeleton?
126 bones
Identify the division of bones in the Appendicular Skeleton
Pectoral Girdle / Shoulder Girdle
Upper Limb
Pelvic Girdle
Lower Limb
S-shaped
Its medial (sternal) end articulates with the manubrium of the sternum and
its lateral (acromial) end articulates with the acromion of the scapula.
Clavicle / Collarbone
a flat bone that is located in the superior
part of the posterior thorax between the second and seventh ribs.
Scapula
most movable joint in the body
Shoulder Joint
Process in the Scapula;
- Just below the clavicle
- attachment for arm muscles
Coracoid Process
Fossa in the Scapula;
- receives the head of the humerus
Glenoid Fossa
Process in the Scapula;
- forms the point of the shoulder
Acromion Process
How many bones are there in the Upper Limb?
60 bones
How many bones are there in the Upper Limb?
60 bones (30 on each side)
articulates with the scapula proximally and with the radius and ulna distally
Humerus
located on the lateral (thumb) side of the forearm. The
articulation of its head with the capitulum of the humerus and with the ulna allows the forearm to rotate.
Radius
located on the medial(little finger) side of the forearm.
Ulna
are 8 small bones connected to each other
by ligaments.
Carpals / Wristbone
Identify the bones in the Carpals
Proximal Row;
Scaphoid
Lunate
Triquetrum
Pisiform
Distal Row;
Trapezium
Trapezoid
Capitate
Hammate
make up the palm and back of the hand.
They are numbered I through V (or 1–5) starting with the thumb.
Their bases articulate with the distal carpals while their heads
articulate with the proximal phalanges.
Metacarpals
are the bones of the digits (fingers)
There are 14 in all. The thumb contains 2 (proximal and distal) while
the other 4 fingers contain 3 each (proximal, middle and distal).
Phalanges
made up of two hip bones/coxae (os coxa, coxal
bones) that articulate with the sacrum posteriorly.
supports the trunk and provides the attachment of legs
Pelvic Girdle
ring of bones
hipbone -2
union of 3 bones
Coxae / Coxal / Hip Bones
Part of the Coxal;
- uppermost and largest bone of the pelvis
- superior, broad and expanded bone of the pelvis
Ilium
Part of the Coxal;
- lowest and strongest
- posterior and inferior
Ischium
Part of the Coxal;
- anterior
- joined together by a joint
Pubis
a joint that joins together the pubis
Symphysis Pubis
receives the head of the femur
Acetabulum
The area of the bony pelvis superior to the pelvic brim
False (greater) Pelvis
The area of the bony pelvis inferior to the pelvic brim
True(lesser) Pelvis
Identify the Bones in the Lower Limb
Femur - 2
Tibia - 2
Fibula - 2
Patella - 2
Tarsals - 14
Metatarsal - 10
Phalanges - 28
does not bear any weight but muscles attach to it
Fibula
a triangular bone that develops in the quadriceps
tendon. It articulates on its posterior surface with the femur.
Patella / Kneecap
- heel
- biggest of tarsals
Calcaneus
a place where two bones (adjacent) meet
effectiveness of the articular system involves the coordination of muscular, nervous
and skeletal system.
Joint / Articulation
Classifications of Joints
Fibrous Joint / Synarthroses
Cartilaginous Joints / Amphiarthroses
Synovial Joint / Diarthroses
immovable joints
tightly joined- no synovial cavity. no synovial fluid
Fibrous Joint / Synarthroses
freely movable joints
ends of bones are covered with articular cartilage
Joint is lubricated by thick synovial fluid
joint enclosed by a flexible articular capsule
Synovial Joint / Diarthroses
e.g. shoulder joint
slightly movable joints
united by a plate of hyaline cartilage or fibrocartilagenous disc
Cartilaginous Joint / Amphiarthroses
fibrous joints made up of peg and socket
e.g. root of tooth and fibrous periodontal socket
Gomphoses
movement can occur in fetuses and young children
in adult, connective tissue replaced by bones end they become
permanently fused (synastosis) - sealed joint
Suture / Skull Type
bones are close together but not touching
held by collagenous fibers
e.g. radius and ulna
Syndesmoses
two bony surfaces are covered by a thin layer of hyaline cartilage
between them are a disc of fibrocartilage which functions as a shock absorber
Symphyses / Secondary Synchondrosis
e.g. intervertebral discs, symphysis pubis
joint composed of epiphyseal plate of hyaline cartilage that joins the
diaphyses and epiphysis
adult synchondroses replaced by bone –synostosis
few synchondroses are not replaced by bone: sternoclavicular joint
growth, not movement
Synchondroses
contains synovial membrane that secretes synovial fluid (lubrication)
Synovial Cavity / Joint Cavity
covers epiphysis
reduce friction
end on long bones
shock absorber
cannot replace itself when destroyed
Articular Cartilage
fibrous capsule that lines the synovial cavity
pliable -> permits movement
Articular Capsule
fibrous tissue that connect bone to adjacent bone
contains rich supply of sensory nerves
inelastic but permits movement
Ligaments
attaches bone to muscle
Tendons
resemble flattened sacs
cushion certain muscles
filled with synovial fluid
Bursae
A modification of bursae found in wrist, palms and finger muscles
long cylindrical sacs filled with synovial fluid
reduce friction at joint surfaces
Tendon Sheathes