Skeletal System Flashcards
We get new skeleton every
7 to 10 years
Bones are organs because they contain more than
1 type of tissue
Bone are made of:
o, c, m, n, e
osseous (bone) tissue cartilage muscle nervous epithelial tissues
Bones help maintain homeostasis by regulating ___ levels and producing the ____
blood calcium - hormone
Person suffers ____ bone loss every month
1 to 2%
Human body contains ____ bones ranging in shape and size from the tiny shapes
206
Two subdivisions of the skeleton
axial
appendicular
4 Parts of the skeletal system
b, j, c, L
Bones (skeleton)
Joints
Cartilages
Ligaments
80 bones
divided into skull, vertebral column, and thoracic cage regions
Axial
126 bones
such as limbs, pelvis (ilium, pubis, ischium), and shoulder blades (scapulae)
Appendicular
2 basic types of osseous (bone) tissue
Compact bone
Spongy bone
Dense, smooth, and homogeneous
Have dense, smooth-looking external layers of compact or cortical bone around a porous, honeycomb-looking area of spongy bone
Compact bone
Small needlelike pieces of bone
Many open spaces
Made up of tiny cross-hatching supports (trabeculae) that help the bone resist stress.
Where you can find bone marrow
Spongy bone
2 types of bone marrow
Red bone marrow
Yellow bone marrow
produce blood cells
Red bone marrow
stores energy as fat
Yellow bone marrow
4 groups of bone shape
L, F, S, I
Long
Flat
Short
Irregular
Bone-shaped bones
Contain mostly compact bone; spongy bone at ends
All of the bones of the limbs (except wrist, ankle, and kneecap bones)
Shaft with enlarged ends
Long bones
Examples: ◦ Femur ◦ Humerus ◦ fibula and tibia ◦ metacarpals
Long bones
Thin, flattened, and usually curved
Two thin layers of compact bone sandwich a layer of spongy bone between them
cube-shaped bones
Flat bones
Examples: ◦ Most bones of the skull ◦ Ribs ◦ Sternum ◦ sternum and scapulae ◦ bones make the brain case
Flat bones
cube-shaped
Contain mostly spongy bone with an outer layer of compact bone
Sesamoid bones are a type of the bone that form within tendons (patella)
Short bones
Examples: ◦ Carpals (wrist bones) ◦ Tarsals (ankle bones) ◦ talus, cuboid (foot) ◦ lacunate/scaphoid (wrist)
Short bones
Do not fit into other bone classification categories
weirdly-shaped
Irregular bones
Examples:
◦ Vertebrae
◦ Hip bones
Irregular bones
Outside covering of the diaphysis
Fibrous connective tissue membrane
Perforating fibers secure periosteum to underlying bone
Periosteum
Makes up most of bone’s length
Composed of compact bone
Shaft of the bone
Diaphysis (shaft)
Composed mostly of spongy bone enclosed by thin layer of compact bone
Flared ends in bone; where red marrow is concentrated; bookend the bone’s shaft or diaphysis
Epiphysis (ends)
Covers the external surface of the epiphysis
Made of hyaline cartilage
Decreases friction at joint surfaces
Thin layer of hyaline cartilage covering a bone where it forms a joint (articulation) with another bone
Articular cartilage
Remnant of the epiphyseal plate
Seen in adult bones
Epiphyseal line
Flat plate of hyaline cartilage seen in young, growing bone
Causes lengthwise growth of a long bone
Epiphyseal plate
Lines the inner surface of the shaft
Made of connective tissue
Endosteum
Cavity inside the shaft
Contains yellow marrow (mostly fat) in adults
Contains red marrow for blood cell formation in infants until age 6 or 7
Medullary cavity
The process of bone formation
Occurs on hyaline cartilage models or fibrous membranes
Ossification
Bone building cells / bone makers
cover hyaline cartilage model with bone matrix
Osteoblasts
In a fetus, the enclosed cartilage is digested away, opening up a ____
medullary cavity
- grow out from the bone surface
* Terms often begin with “T”
Projections or processes
- indentations
* Terms often begin with “F”
Depressions or cavities
By birth, most cartilage is converted to bone
Except for 2 regions in a long bone
Ac, Ep
- Articular cartilages
* Epiphyseal plates
Basic structural unit of the bone
Composed of tubes inside of tubes
A unit of bone containing central canal and matrix rings
Osteons
also called Concentric tubes
Filled with collagen fibers that run in the same direction
Lamellae
Bone needs nourishment like any other tissue, so running along the length of each osteon are ___ which holds nerves and blood vessels
Opening in the center of an osteon (Haversian system)
Runs lengthwise through bone
Carries blood vessels and nerves
central canals
between the layers of lamellae are tiny oblong spaces
houses the osteocytes
lacunae
mature bone cells that monitor and maintain bone matrix.
Pass commands to skeleton’s
2 main workhorses
Osteocytes
2 main workhorses
Osteoblasts and Osteoclasts
Bone-breakers
Osteoclasts
They create a perfect balance that allows your bones to regenerate
Osteoblasts and Osteoclasts
These cells work in a kind of similar way, in a process that I’d argue is less stressful than home improvement
bone remodeling
supervisors which kick things off when they sense stress and strain, or respond to mechanical stimuli
osteocytes
Bone is resorbed by ____
osteoclast
Bone is added by ____
osteoblasts
Bone is resorbed by ____
osteoclast
in the periosteum add bone matrix to the outside of the diaphysis
Osteoblasts
in the endosteum remove bone from the inner surface of the diaphysis
Osteoclasts
Bone growth is controlled by
hormones
Bones are remodeled throughout life in response to 2 factors
C, PGM
Calcium ion
Pull of gravity and muscles
___ level in the blood determines when bone matrix is to be broken down or formed
Calcium ion
___ on the skeleton determines where bone matrix is to be broken down or formed
Pull of gravity and muscles
Released when calcium ion levels in blood are low
Activates osteoclasts
Parathyroid hormone (PTH)
high blood calcium levels
prompts calcium storage to bones by osteoblasts
Hypercalcemia
break in a bone
Fracture
Types of bone fractures
Closed (simple) fracture
Open (compound) fracture
is a break that does not penetrate the skin
Closed (simple) fracture
is a broken bone that penetrates through the skin
Open (compound) fracture
Bone fractures are treated by ___ and ___
reduction - immobilization
bones are manually coaxed into position by physician’s hands
Closed reduction
bones are secured with pins or wires during surgery
Open reduction
blood-filled swelling, or bruise
Hematoma
replaces the fibrocartilage callus
Bony callus
Forms the longitudinal axis of the body
Axial Skeleton
Axial Skeleton
Divided into 3 parts
S, VC, BT
Skull
Vertebral column
Bony thorax
Hold eyes in anterior position
Allow facial muscles to express feelings
Bones are joined by sutures
Skull
Two sets of bones form the skull
- Cranium bones enclose the brain
* Facial bones
In the skull, only the ___ is attached by a freely movable joint
mandible
8 Cranial Bones Protect the Brain
Frontal bone Occipital bone Ethmoid bone Sphenoid bone Parietal bones Temporal bones
In cranial bones, bones that are single:
FOES
Frontal
Occipital
Ethmoid
Sphenoid
In cranial bones, bones that have pairs are:
PT
Parietal bones
Temporal bones
14 facial bones
N, L, P, INC, V, Z, M, M
Nasal Lacrimal Palatine Inferior nasal conchae Vomer Zygomatic Maxillae Mandible
In facial bones, bones that have pairs are:
Maxillae Palatine bones Lacrimal bones Zygomatic bones Nasal bones Inferior nasal conchae
In facial bones, bones that are single:
Vomer bone
Mandible
Hollow portions of bones surrounding the nasal cavity
Paranasal sinuses
Closely related to mandible and temporal bones
The only bone that does not articulate with another bone
Serves as a movable base for the tongue
Aids in swallowing and speech
Hyoid bone
provides axial support
Extends from skull to the pelvis
Vertebral Column (Spine)
26 vertebral bones are separated by ____
intervertebral discs
26 vertebral bones
7 cervical vertebrae (neck) 12 thoracic vertebrae (chest) 5 lumbar vertebrae (lower back) Sacrum (formed by fusion of 5 vertebrae) Coccyx (formed by fusion of 3–5 vertebrae)
Spinal curvatures of the thoracic and sacral regions
Present from birth
Form a C-shaped curvature in newborns
Primary curvatures
Spinal curvatures of the cervical and lumbar regions
Develop after birth
Form an S-shaped curvature in adults
Secondary curvatures
Bony thorax
protects organs of the thoracic cavity
Thoracic Cage
Thoracic cage Consists of 3 parts
SRTv
Sternum
Ribs
Thoracic vertebrae
3 Ribs
True ribs (pairs 1–7) False ribs (pairs 8–12) Floating ribs (pairs 11–12)
Composed of 126 bones
Limbs (appendages)
Pectoral girdle
Pelvic girdle
Appendicular Skeleton
Also called a pectoral girdle
Light, poorly reinforced girdle
Allows the upper limb an exceptional flexibility
omposed of 2 bones that attach the upper limb to the axial skeletal
Shoulder Girdle Bone
Shoulder Girdle Bone composed of 2 bones that attach the upper limb to the axial skeletal
- Clavicle
* Scapula
Forms the arm
Single bone
Upper Limbs Bone
The forearm has two bones
Ulna
Radius
medial bone in anatomical position
Proximal end articulation
Coronoid process and olecranon articulate with the humerus
Ulna
lateral bone in anatomical position
Proximal end articulation
Head articulates with the capitulum of the humerus
Radius
3 parts of Hand
Carpals
Metacarpals
Phalanges
wrist bones
8 bones arranged in two rows of 4 bones in each hand
Carpals
palm bones
5 per hand
Metacarpals
fingers and thumb
14 phalanges in each hand
Phalanges
For Phalanges…
In each finger, there are __ bones
3
For Phalanges…
In the thumb, there are only __ bones
2
Formed by two coxal (ossa coxae) bones
Composed of 3 pairs of fused bones
Pelvic Girdle Bone
3 pairs of fused bones in Pelvic Girdle Bone
I, I, P
Ilium
Ischium
Pubis
,
,
two coxal bones, sacrum, coccyx
Pelvis
The total weight of the upper body rests on the ___
___ protects several organs:
•Reproductive organs
•Urinary bladder
•Part of the large intestine
Pelvis
Inlet is larger and more circular
Shallower, on the whole, and the bones are lighter and thinner
Ilia flare more laterally
Sacrum is shorter and less curved
Ischial spines are shorter and farther apart; thus, the outlet is larger
Pubic arch is more rounded because the angle of the pubic arch is greater
Female’s pelvis
thigh bone
The heaviest, strongest bone in the body
Femur
lower leg has 2 bones
Tibia
Fibula
Shinbone
larger and medially oriented
Tibia
thin and sticklike
lateral to the tibia
Has no role in forming the knee joint
Fibula
3 parts of Foot
Tarsals
Metatarsals
Phalanges
7 bones in foot
Tarsals
Two largest tarsals are the:
C,T
- Calcaneus (heel bone)
* Talus
5 bones form the sole of the foot
Metatarsals
14 bones form the toes
Phalanges
Bones of the foot are arranged to form three strong arches
MLT
Medial longitudinal arch
Lateral longitudinal arch
Transverse arch
Occur where two or more bones meet
Joints
2 classification of Joints
Functionally
Structurally
happen when muscles contract across joints moving 1 bone toward another
Body movements
8 cranial bones - 14 facial bones
Body’s most complex bony structure. Protect brain, help see, smell, hear, eat, have a face
Axial bones
The 33 irregular bones in your vertebral column starts with ___
atlas vertebra
hold the skull
atlas vertebra
Upper and lower limb appendages
Pectoral and pelvic girdles that attach to the axial skeleton at the shoulder and the thigh
Appendicular bones
The Pectoral Girdle consists of the
PS, AC
Posterior Scapula and Anterior Clavicle
is formed by the coxal or hip hobes and the sacrum which is technically part of axial skeleton
Pelvic or Hip Girdle
Immovable joints; non-moving joints
Synarthroses
Slightly movable joints
Amphiarthroses
Freely movable joint
Diarthroses
Generally immovable
Fibrous joints
Immovable or slightly movable
Cartilaginous joints
Freely movable
Synovial joints
Bones are united by fibrous tissue
Connect bones with dense fibrous connective tissue, and are mostly immovable
Fibrous joints
3 Types Fibrous joints
SSG
Sutures
Syndesmoses
Gomphoses
Immobile
Sutures
Allow more movement than sutures but still immobile
Found on the distal ends of tibia and fibula
Syndesmoses
Immobile
Found where the teeth meet the facial bones
Gomphoses
Bones are connected by fibrocartilage
Unite bones using cartilage, they don’t move very much, and they lack a joint cavity
Cartilaginous joints
2 Types Cartilaginous joints
Synchrondrosis
Symphysis
Immobile
Found in epiphyseal plates of growing long bones
Synchrondrosis
Slightly movable
Found in the pubic symphysis, intervertebral joints
Symphysis
Articulating bones are separated by a joint cavity
fluid is found in the joint cavity
Family of joints that make all the sports, and the entire art of breakdancing and yoga possible
Are the freely movable
Synovial joints
4 distinguishing features of synovial joints
Articular cartilage
Articular capsule
Joint cavity
Reinforcing ligaments
flattened fibrous sacs
Lined with synovial membranes
Filled with synovial fluid
Not actually part of the joint
Bursae
Elongated bursa that wraps around a tendon
Tendon sheath
6 Types of synovial joints (based on shape)
Plane joint, Hinge joint, Pivot joint, Condylar joint, Saddle joint, Ball-and-socket joint
If that bending motion decreases the angle of the joint and brings those bones together, like when I bend my arm together
Flexion
When I bend it back, I’m increasing that angle
Extension
Uniaxial movement
Hinge joint
Multiaxial movement
Hip and shoulder joints use a ball-and-socket design that allow rotational movement, but the more flexible a joint is, the more unstable and fragile it is – which is one reason why you see so many dislocated shoulders and hip replacements
Ball and socket joint
If I continue that motion beyond my normal anatomical positioning, and it’s somewhat dangerous
hyperextension
Biaxial movement
movements are just special and unique and weird, and only occur in a few select joints – especially in your hands, feet, and jaw
Saddle joint
Uniaxial movement
between your radius and ulna allow you to rotate your palm forward or anteriorly in a motion called supination, and turning it backward or posteriorly is called pronation
Pivot joint
lasso movement
combination of all 5 of those movements that allow the forearm to move in a circle while the elbow joint stays relatively stable
Circumduction
First “long bones” of a fetus are
hyaline cartilage
Earliest “flat bones” of the fetal skull are
fibrous membranes
Known as “soft spots”
Fetal skull
Bone-thinning disease afflicting
Osteoporosis
- results in kyphosis
* also known as “dowager’s hump”
Vertebral collapse
Sites of attachments for muscles, tendons, and ligaments
Passages for nerves and blood vessels
Bone markings
