Exam 2 Flashcards
Cartilage falls under what main branch of ct?
Supportive
_____ produce the matrix of cartilage.
Chondroblasts
Why is cartilage avascular?
Chondrocytes within the cartilage release an antiangiogenesis factor.
Chondrocytes in cartilage exist within the _____.
Lacunae
What are the three functions of cartilage?
Structural support for soft tissue, protection at points of articulations, and scaffolding for bone development.
Cartilage has two forms of growth:
Appositional and interstitial
What growth is described:
chondrocyte within lacunae exhibits mitotic activity to produce double chondroblasts (1=2, 2=4, 4=8)
Interstitial growth of cartilage
What cartilage growth is described:
Undifferentiated stem cells located in the perichondrium. Committed cells produced by stem cell mitosis differentiates into chondroblasts.
Appositional growth
The perichondrium is where _____ activity occurs.
Mitotic
Interstitial and appositional growth occur during _____ development. Both growth cycles do not appear in _____ cartilage.
Embryonic, adult
Bone tissue is:
-static
Or
-dynamic
Dynamic (always changing)
_____ connect bone to bone
Ligaments
_____ is found between two bones
Cartilage
The skeletal system is composed of three things:
Bones, ligaments, and cartilage
List the five functions of bone tissue:
Protection, support, red blood cell production, locomotion, and storage
_____ : closer to the mid line
Proximal
_____ : distant to the midline
Distal
_____ : in front of the mid line
Anterior
_____ : behind the mid line
Posterior
_____ : above the mid line
Superior
_____ : below the mid line
Inferior
_____ : Closer to the surface (compared to deep)
Superficial
_____ refers to the ends of bones. _____ refers to the shaft. _____ refers to the space in between.
Epiphysis, diaphysis, metaphysis
What are the two types of bone?
Spongy and compact
Are osteons in compact bone, spongy bone, or both?
Compact bone only
What type of bone is the epiphysis and lining of the medullary cavity?
Spongy
Why type of bone contains trabeculae?
Spongy
What (type of) bones contain red bone marrow? All other bones contain _____ marrow.
Long bones, ilium, and the sternum (ex) / spongy bone ; yellow marrow
?
Osteons are also called :
Haversion system
What are the four cell types in bone tissue?
Osteoprogenitors, osteoblasts, osteocytes, and osteoclasts
What is the function of an osteoprogenitor and where are they located?
They are the stem cells of bones, and they are located where ever there is endosteum and periosteum
What is the function of an osteoblast?
To secrete osteoid and form bone matrix
Where are Osteocytes found and what is their function?
In lacunae ; maintain bone matrix
What is the function of an Osteoclast?
Bone reabsorption (breakdown)
What cells are produced from osteoprogenitor stem cells?
Osteoblasts —-> osteocytes only. NOT osteoclasts
_____ refers to the process of osteoprogenitors developing into osteoblasts and osteoblasts developing into osteocytes.
Osteogenesis
How much of the matrix of bone tissue is made up of organic material? How about inorganic material?
1/3 organic, 2/3 inorganic
What is the function of organic material? What is the function of inorganic material?
Organic: tensile strength (resists pulling apart/ over bending)
Inorganic: compressional strength
Organic material is made of _____ fibers.
Collagen
Inorganic material is made up of:
Calcium hydroxide and calcium phosphates, together they form hydroxyapatite.
What is hydroxyapatite made of?
Calcium hydroxide and calcium phosphate
What are the two types of bone matrix?
Organic and inorganic
What two things do osteoclasts need to break down (organic and inorganic) bone tissue?
Proteolytic enzymes: organic /collagen
hydrochloric acid: inorganic/ hydroxyapatite
The outer portion of periosteum is _____ while the inside is _____.
Fibrous, cellular
The fibers between the circumferential lamellae and the cellular layer of the periosteum are referred to as:
Perforating fibers
What type of cell is the cellular layer of the periosteum made of?
Osteoprogenitor cells
The inner most layer of bone tissue (around the central canal) is called ____ and it is made up of what type of bone?
Endosteum; spongy
Name the lamellae that makes up the osteons?
Concentric lamellae
The lamellae closest to the periosteum is called:
Circumferential lamellae
You must _____ in order to ossify.
Calcify
The deposition of calcium ions and salts into tissue
Calcification
The conversion of a tissue into bone tissue
Ossification
Intramembranous ossification occurs where?
In the FLAT bones of the skull, mandible and clavicle
The liquidy version of bone material is an _____.
Osteoid
Endo- means:
Within
The process of turning hyaline cartilage into bone is called:
Endochondral ossification
What kind of growth does the epiphysis do?
Interstitial growth
The epiphyseal plate has 5 different microscopic zones. Name each one.
Zone 1 - zone of resting hyaline cartilage (closest time articular cartilage)
Zone 2 - zone of proliferating (meaning: interstitial growth) cartilage
Zone 3 - zone of hypertrophic cartilage / cells get bigger
Zone 4 - zone of calcified cartilage / chondrocyte lay down calcium salts
Zone 5 - zone of ossification (o.blasts take ca. Cartilage and ossified it
The rate of ossification in zone ___ is matched by the rate of interstitial growth in zone ___.
5,2
When an adult reaches their final height, zone ___ continues to ossify while zone ___ shuts down. All of the growth plates ossify and this will continue upward until ossification is against the _____.
5, epiphyseal line
Interstitial growth refers to ____ while appositional growth refers to _____.
Choose:
Length or width
Length, width
Which type of bone growth continues for life and which one ends with the epiphyseal line?
Appositional: life
Interstitial: epiphyseal line
Osteoclasts eat away at the medullary cavity while osteoblasts add new bone under the periosteum. Thickness of compact bone increases as well as the overall diameter. This describes what type of bone growth?
Appositional
Osteoblast and osteoclast activity is _____. Calcium salts are removed or replaced mainly by osteo_____.
Balanced, osteocytes
What hormones affect bone thickness?
Growth hormones, thyroxine, and sex hormones
High levels of growth hormones during bone growth can cause:
Gigantism
Low levels of growth hormones during bone growth can cause:
Pituitary dwarfism
High levels of growth hormones after bone growth can cause:
Acromegaly
Where are chief cells located?
In the parathyroid gland
What hormone is released from the parathyroid gland?
Parathyroid hormone (PTH)
If calcium levels are (high : low) in blood, chief cells in parathyroid gland release PTH
Too low
Where are parafollicular cells (C-cells) located and what hormone do they release?
In the thyroid gland; calcitonin
Do osteoblasts or osteoclasts have a PTH receptor?
Osteoblasts only.
PTH directly stimulates _____ to retain calcium ions, and PTH indirectly stimulates _____ to release stored calcium ions from bone into the blood stream to increase blood ca levels.
Kidneys; osteoclasts
When PTH binds to the receptor, osteoblasts release _____ which attaches to osteoclast receptor and increases osteoclast activity
RANKL
PTH makes kidneys release _____ which goes into the small intestine and increases calcium absorption
Calcitriol
To decrease blood calcium levels, _____ allows you to pee calcium out and FIX the problem.
Calcitonin
Calcitonin directly affects _____ to be inhibited while _____ continue to lock calcium in the bone matrix.
Osteoclast ; osteoblast
The region of bone that allows a bone to grow in length is:
Metaphysis
Primary ossification centers are located in the:
Diaphysis
Endochondral ossification begins with the formation of:
A cartilage model
What type of cartilage do epiphyseal plates contain?
Hyaline cartilage
Secondary ossification centers are associated with the:
Epiphysis
The hormone involved in increasing the level of calcium in the blood would increase the activity of:
Osteoclasts
The hormone _____ is involved in increasing the blood levels of calcium
Parathyroid
Calcitonin _____ osteoclast activity
Inhibits
The meniscus is made up of:
Fibrocartilage
The type of cartilage that makes up a symphysis joint is:
Fibrocartilage
The ligament that helps to stabilize the knee with anterior and posterior movement are the _____ ligaments
Cruciate
The femurs attachment to the hip bone is an example of a _____ _____.
Synovial joint
The tarsal bones are an example of a _____ _____.
Plane joint
_____ describes the amount of movement in a joint.
Synarthroses
A joint that is classified as synarthroses is _____ _____:
Not moveable
_____: The midway point to osteoporosis, as bones begin to grow thinner and weaker with age.
Osteopenia
When do macrophages appear?
6-8 hours after a fracture when the tissue had begun to die
What do macrophages do?
Eat dead bone tissue
