Ch. 12 Flashcards
What two types of connective tissues does the skeletal system consist of?
Bone and cartilage
Ligaments
Formed of fibrous connective tissue, join the bones
What are the functions of the skeleton?
Supports the body, moves the body, protection, produces blood cells, stores minerals and fat
Diaphysis
Shaft of the bone
Medullary cavity
Inside the diaphysis, its walls are made of compact bone, the cavity is lined with the endosteum and is filled with yellow bone marrow
Epiphysis
Expanded end of a long bone, composed of spongy bone that contains red bone marrow, it is coated with a thin layer of hyaline cartilage, and is also called articular cartilage because it occurs at a joint
Metaphysis
Between the epiphysis and diaphysis, contains the epiphyseal plate, a region of cartilage that allows for bone growth
Periosteum
Connective tissue covering all bones, continuous with ligaments and tendons
What are the two types of bone tissue?
Compact and Spongy
Compact bone
Highly organized and composed of tubular units called osteons
Osteocytes
Bone cells, they lie in lacunae
Lacunae
Tiny chambers arranged in concentric circles around a central canal, matrix fills the space between the rows
Canaliculi
Tiny canals, which connect the lacunae with one another and with the central canal
Spongy bone
Contains numerous thing plates called trabeculae
Red bone marrow
In the spaces of spongy bone, produces all types of blood cells
Cartilage
Not as strong as bone, but is more flexible, matrix contains collagen and elastic fibers, has no nerves or blood vessels so takes time to heal
Chondrocytes
Cartilage cells; lie within lacunae
What are the three types of cartilage?
Hyaline, fibrocartilage, and elastic cartilage
Where can you find Hyaline cartilage?
Ends of long bones, nose, ends of ribs, larynx, and trachea
Where can you find Fibrocartilage?
Disks between vertebrae and in the knee
Where can you find Elastic cartilage?
Ear flaps and epiglottis
Fibrous connective tissue
Made of rows of fibroblasts separated by bundles of collagenous fibers, makes up ligaments and tendons
Red marrow
Mostly in axial skeleton, produces all types of blood cells
Yellow marrow
Mostly in appendicular skeleton, stores fat
Axial skeleton
Follows midline of the body, consists of the skill, hyoid bone, vertebral column, and the rib cage
Skull
Formed by the cranium and the facial bones
Cranium
Contains and protects the brain
What are the bones of the cranium?
Frontal, parietal, occipital, temporal, sphenoid, ethmoid
Foramen magnum
A hole in the occipital bone through which the spinal cord passes
External auditory canal
In each temporal bones; leads to the middle ear
Orbits
Eye sockets
Sinuses
Air spaces in some cranial bones, lined with mucous membrane, reduce the weight of the skill
Mastoid sinuses
Smaller set of sinuses, drain into the middle ear
Mandible
The only moveable bone in the skull
Maxillae
Forms the upper jaw and a portion of the orbits as well as the herd palate and the floor of the nose (joined by palatine bones)
Zygomatic bones
Form the cheekbones
Nasal Bones
Forms the bridge of the nose
Ethmoid and Vomer
Are a part of the nasal septum, which divides the interior of the nose into nasal cavities
Lacrimal bone
Contains the opening for the nasolacrimal canal, which drains tears from the eyes to the nose
Hyoid bone
Not part of the skull, but is part of the axial skeleton, it anchors the tongue and serves as the site for the attachment of muscles associated with swallowing
Vertebral Column
Consists of 33 vertebrae, there are four curvatures that provide more strength for an upright posture than a straight column
Scoliosis
Abnormal sideways curvature of the spine
Kyphosis
Abnormal posterior curvature (hunchback)
Lordosis
Abnormal anterior curvature (swayback)
Vertebral canal
In the center of the column; the spinal cord pass through
Intervertebral foramina
On each side of the column, spinal nerves travel through the
Spinal nerves
Control skeletal muscle contraction, among other things; if the spinal cord/nerves are injured, there can be paralysis or even death
Spinous processes
of the vertebrae, bony long the midline of the back, serve as attachment sites for muscles
Transverse processes
Extend laterally, serve as attachment sites for muscles
Cervical vertebrae
In the neck
Atlas
First cervical vertebra; holds up the head (up and down)
Axis
Second cervical vertebra (side to side)
Thoracic vertebrae
Connect to the ribs
Lumbar vertebrae
Lower back
Sacral vertebrae
Fused
Coccygeal vertebrae
More noticeable in animals with tails
Intervertebral disks
Composed of fibrocartilage, prevent the vertebrae from grinding, absorb shock caused by movement (running, walking, etc.) allows the vertebrae to move as we bend forward, backward, side to side, and become weaken with age and can herniate and rupture
Thoracic cage
Rib cage, composed of the thoracic vertebrae, the ribs and their associated cartilages, and the sternum; Is part of the axial skeleton, protects the heart and lungs
How many pairs of ribs are there?
Twelve (12) pairs; all connect directly to the thoracic vertebrae in the back
True ribs
Ribs 1-7; Connect directly to the sternum by means of a long strip of hyaline cartilage called costal cartilage
False ribs
Ribs 8 to 12; their costal cartilage does not connect directly to the sternum
Floating ribs
Ribs 11 to 12; they have no connection with the sternum
Sternum
Breastbone, along with the ribs, it helps protect the heart and lungs
What three bones is the Sternum composed of?
Manubrium, body, and xiphoid process
Pectoral girdle
Consists of a scapula and a clvaicle
Scapula
Shoulder blade
Clavicle
Collarbone, joins with the sternum and the acromion process of the scapula
Glenoid cavity of the scapula
Articulates with the head of the humerus, the upper arm bone
Rotator cuff
Tendons that extend to the humerus from four small muscles originating on the scapula
The upper limb
Humerus in the arm and the radius and ulna in the forearm
The humerus
The single long bone in the arm, has a smoothly rounded head that fits into the glenoid cavity of the scapula; the shaft of the humerus has a tuberosity where the deltoid, a shoulder muscle, attaches
What are the two protuberances the far end of the humerus has?
Capitulum and the trochlea
What is the bump at the back of the elbow?
Olecranon process of the ulna (your funny bone)
Carpal bones
8 bones in the wrist
Metacarpal bones
5 bones in the palm
Phalanges
The bones of the fingers, thumbs, and toes
Pelvic girdle
Hip girdle, consists of two coxl bones (hip bones)
Pelvis
Composed of the pelvic girdle, sacrum, and coccyx; bears the weight of the body, protects the organs wihtin the pelvic cavity, and is the place of attachment for the legs
What are the three parts of the coxal bone
Ilium, ischium, and pubis, which are fused in the adult
Acetabulum
The hip socket; where the coxal bones three parts meet
Ilium
The largest of the coxal bone
Ischium
Has a posterior spine, called the ischial spine, for muscle attachment
Pubic symphysis
A fibrocartilaginous joint that joins the two pubic bones
The pelvic girdle (Woman vs. men)
Different, in the female the iliac bones are more flared, and the pelvic cavity is shallower, but the outlet is wider; these adaptions facilitate the birthing process
The bones of the leg; lower limb
The femur in the thigh, the tibia and fibula in the lower leg
Femur
Longest, strongest bone in the body; the head of the femur articulates with the coxal bones at the acetabulum; the neck better positions legs for walking
What are the two large processes of the femur?
The greater and the lesser trochanters; these are places of attachment for thigh muscles, buttock muscles, and hip flexors.
Distal femur
Has medial and lateral condyles that articulate with the tibia
Patella
(kneecap) held in place by the quadriceps tendon, which continues as a ligament that attaches to the tibial tuberosity
Medial malleolus
At the distal end of the tibia
Fibula
The slenderer bone in the leg; has a head that articulates with the tibia and a distal lateral malleolus that forms the outer bulge of the ankle
Tarsal bones
Seven bones in the ankle
Talus
Joins the tibia and fibula
Calcaneus
Heel bone
Metatarsal bones
Five bones in the instep.
Articulations (joints)
Where bones come together; most fibrous joints are immovable
What are the three classifications for articulations (joints)
Fibrous, cartilaginous, or synovial
Cartilaginous joints
Connected by hyaline cartilage (costal cartilages) or fibrocartilage
Synovial joints
Are freely moveable, ligaments support and strengthen joints
Joint capsule
Formed by ligaments, surrounds the joint
Synovial membrane
Lines the joint capsule, secretes synovial fluid for lubrication
Bursae
Fluid-filled sacs that ease friction
Menisci
C-shaped fibrocartilage; give stability and absorb shock
Ball-and-socket joints
Allow movement in all places, even rotational movement
Hinge joints
Permit movement in only one direction (elbow, knee)
Osteoarthritis
Degeneration of articular cartilage
Rheumatoid arthritis
An autoimmune disease that causes inflammation in joints
Osteoblasts
Bone-forming cells; secrete the organic matrix of bone and promote the deposition of calcium salts into the matrix
Osteocytes
Mature bone cells; when osteoblasts surround themselves with calcified matrix, the become osteocytes within lacunae
Osteoclasts
Bone-absorbing cells; break down bone; return calcium and phosphate to the blood
Ossification
The formation of bone; bones form during embryonic development in two distinctive ways
What are the two was bones form during embryonic development
Intramembranous ossification and endochondral ossification
Intramembranous ossification
Forms flat bones (bones of the skull) Bones develop between sheets of fibrous connective tissue; osteoblasts in the periosteum carry out further ossification
Endochondral ossification
Forms most bones (long bones ex. tibia) Calcified bone matrix replaces the hyaline cartilage models of the bones, bone formation spreads from the center of the bone to the ends
The cartilage model
In the embryo, chondrocytes form cartilage models (hyaline cartilage shaped like the future bones)
The bone collar
Osteoblasts secrete the matrix, which then calcifies
What are the steps of endochondral ossification?
- The primary ossification center
- The medullary cavity and secondary ossification sites
- The epiphyseal (growth) plate
Step one of Endochondral ossification
Blood vessels bring osteoblasts to a region called a primary ossification center, the first center for bone formation
Step two of endochondral ossification
Spongy bone in the diaphysis is absorbed by osteoclasts, forming the medullary cavity
Step three of endochondral ossification
A band of cartilage remains between the primary ossification center and each secondary center; the limbs keep increasing in length as long as the epiphyseal plates are present
What are the four layers the epiphyseal plate contain?
Resting zone, proliferating zone, degenerating zone, and ossification zone
Resting zone
The layer nearest the epiphysis where cartilage remains
Proliferating zone
Chondrocytes are producing new cartilage cells
Degenerating zone
Cartilage cells are dying off
Ossification zone
Bone is forming, increasing the length of the bone
Final size of the bone
When the epiphyseal plates close, bone lengthening can no longer occur
Vitamin D
Formed in the skin when exposed to sunlight; is converted to a hormone that is necessary for absorption of calcium from food
Growth hormone
Stimulates bone growth, need concurrent action of thyroid hormone to stimulate metabolism
Dwarfism
Too little GH in childhood
Gigantism
Excess GH in childhood
Acromegaly
Excess GH in adults; growth of bones in the hands and face
Sex hormones
Increase growth during adolescence
Bone remodeling
Osteoclasts break bone down; osteoblasts build it up; recycles 18% of bone each year
Paget disease
New bone in generated at a faster than normal rate; produces softer and weaker bones and can lead to deformities, fractures, and pain
Parathyroid hormone
Stimulates osteoclasts to dissolve bone if needed to increase blood calcium levels; promotes calcium absorption in the small intestine and kidney increasing blood calcium levels
Calcitonin
Has opposite effects of PTH; tones down Ca2+ in the blood and deposits it into bones
Estrogen
Increases the number of osteoblasts; reduction of estrogen in older woman can cause osteoporosis
Osteoporosis
Bones are weakened due to decreased bone mass, skeletal mass increases until age 30
What are the steps of bone repair?
- Hematoma
- Fibrocartilaginous callus
- Bony callus
- Remodeling
Hematoma
Forms 6 to 8 hours after the fracture; blood clot between broken bones
Fibrocartilaginous callus
Forms in 3 weeks; fibrocartilage callus between broken bones
Bony callus
Forms in 3 to 4 months; cartilaginous callus turns in bone
Remodeling
Osteoblasts build new compact bone at the periphery, osteoclasts absorb the spongy bone, creating a new medullary cavity
What are the types of bone fractures?
Complete, incomplete, simple, compound, impacted, and spiral
Complete fracture
The bone is broken clear through
Incomplete fracture
The bone is not separated into two parts
Simple fracture
It does not pierce the skin
Compound fracture
It does pierce the skin
Impacted fracture
The broken ends are wedged into each other
Spiral fracture
The break is ragged due to twisting of the bone
