Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
208 Cards in this Set
- Front
- Back
|
cytoskeleton associated with cilia
|
axoneme: 9MT doublets with 1 MT doublet in the middle
accessory protein = dynein |
|
|
axoneme is associated with
|
cilia
|
|
|
cytoskeleton associated with microvilli
|
actin microfilaments
terminal web |
|
|
terminal web is associated with
|
microvilli
|
|
|
where are microvilli found anatomically (2)
|
GI
kidney |
|
|
zonula adherens integral transmembrane linker glycoprotein
|
cadherin
|
|
|
which junctions use cadherins
|
zonula adherens
macula adherens (desmosomes) |
|
|
which junctions use integrins
|
hemidesmosomes
focal contacts |
|
|
where are zonula adherens, macula adherens, junction complexes "well developed"
|
SI
skin SI |
|
|
what is the intracellular attachment protein for macula adherens
|
proteinaceous plaque
|
|
|
what is the intracellular attachment protein for hemidesmosomes
|
proteinaceous plaque
|
|
|
which structures are associated with proteinaceous plaques
|
desmosomes and hemidesmosomes
|
|
|
cytoskeletal component of zonula adherens
|
actin
|
|
|
cytoskeletal component of focal contacts
|
actin
|
|
|
actin is associated with which cell-cell junctions
|
zonula adherens
focal contacts |
|
|
cytoskeletal component of desmosomes
|
intermediate filaments
|
|
|
cytoskeletal component of hemidesmosomes
|
intermediate filaments
|
|
|
intermediate filaments are associated with which cell-cell junctions
|
desmosomes and hemidesmosomes
|
|
|
where are claudins found
|
tight junctions
|
|
|
proteins associated with tight junctions
|
claudins
|
|
|
structure associated with Gap junctions
|
connexon
|
|
|
3 components of zonula adherens
|
1. Cadherins
2. Actin binding proteins Actin microfilaments |
|
|
anatomical location where simple squamous epithelium is found
|
alveoli
endothelium mesothelium |
|
|
anatomical location where simple cuboidal is found
|
glands
|
|
|
anatomical location where simple columnar is found
|
stomach and intestine (where there are microvilli)
fallopian tubes (ciliated) |
|
|
where is pseudostratified epithelium found
|
respiratory tract
|
|
|
what kind of epithelia is found in the urinary bladder
|
transitional
|
|
|
draw the flowchart of CT components
|
(see slides)
|
|
|
function of CT cells
|
produce CT matrix
|
|
|
ordinary CT AKA
|
CT proper
|
|
|
cells in ordinary CT
|
fibrocytes
|
|
|
type of CT in which fibrocytes are found
|
CT proper (ordinary)
|
|
|
cells in cartilage (basic cell type)
|
chondrocytes
|
|
|
Characteristics of cartilage ECM (5)
|
Abundant
Firm Gel like Resilient Smooth |
|
|
being able to bounce back after being stretched
|
resilient
|
|
|
Why you keep tubes (ex. resp tract) open with cartilage and not bone (2)
|
Malleable - tubes can bend
Resilient - can deform and will bounce back |
|
|
why collagen needs to be smooth
|
In places where you want low friction (ex. joints)
|
|
|
proportion of cartilages surrounded by perichondrium
|
most
|
|
|
3 characteristics of cartilage
|
avascular
no lymphatic vessels no nerves |
|
|
implications of avascularity of cartilage
|
doesn't repair rapidly
|
|
|
how do chondrocytes get energy
|
diffusion through ground substance from vessels in surrounding perichondrium and/or ordinary CT
mainly aerobic glycolysis |
|
|
Why does it hurt when you tear cartilage (though there are no nerves in it)
|
Because you tear the perichondrium
|
|
|
What differentiates the different types of cartilage
|
Composition of the matrix
|
|
|
Ground substance components of collagen (3)
|
1. Rich in aggrecan (a PG unique to cartilage) which links to hyaluronic acid forming aggrecan aggregates
2. High water content resists compression 3. Adhesive glycoproteins bind cells with components of the matrix |
|
|
Fibres found in cartilage
|
Collagen type II
|
|
|
Where are cells found in cartilage
|
In lacunae within the matrix
|
|
|
Roles of cartilage cells (3)
|
Produce fibres
Maintain fibres Produce organic components of the GS |
|
|
What happens to cells and fibre production as we age
( in cartilage) |
Stop producing fibres
'maintain' them instead If cells die, cartilage degenerates |
|
|
What does perichondrium have that cartilage does not (3)
|
BVs
Ns Ls |
|
|
Role of perichondrium (3)
|
Cartilage growth and attachment (provides nourishment)
|
|
|
2 layers of perichondrium
|
1. Outer fibrous
2. Inner cellular |
|
|
Components of outer fibrous layer of perichondrium (2)
|
Collagen fibres
Fibroblasts |
|
|
Components of inner cellular layer
|
Chondroblasts that synthesize the organic components of the matrix
contributes to cartilage growth |
|
|
What happens to the inner cellular layer of perichondrium as you age
|
Cells are less 'prominent': have less cytoplasm because they are less active in cartilage production
Because cartilage stops growing |
|
|
Fibroblasts mature to become
|
Fibrocytes
|
|
|
2 ways that cartilage grows
|
Interstitially
Appositionally |
|
|
Interstitial growth of cartilage
|
1. mesenchymal cells differentiate into chondroblasts
2. chrondroblasts secrete organic components of matrix 3. they surround themselves with matrix, moving away from each other and becoming isolated in their lacunae 4. chondrocytes may divide, and cause cartilage to grow from the inside 5. isolated chondroblasts become quiescent and maintain matrix as chondrocyes |
|
|
When do chondroblasts become chondrocytes
|
When they stop secreting matrix and maintain it instead
|
|
|
Appositional growth
|
1. Mesenchymal cells at the surface of the newly formed cartilage differentiate into fibroblasts, which form the fibrous layer of the perichondrium
2. Mesenchymal cells deep to this layer differentiate into chondroblasts, forming the cellular layer of the perichondrium (these cells are big in young people) 3. Chondroblasts secrete matrix onto the surface of the newly forming cartilage |
|
|
Hyaline cartilage has 2 claims to fame
|
1. Most common
2. weakest |
|
|
fibres of hyaline cartilage
|
type II collagen
|
|
|
Implication of hyaline cartilage being weakest
|
Not found in places that experience tensile forces
|
|
|
Articular cartilage =
|
Cartilage at joints
|
|
|
What is weird about articular cartilage
|
1. Has no perichondrium because if it did you would feel your bones rubbing together and it would bleed
Has a free surface (others are attached to something) |
|
|
Where is costal cartilage
|
Ribs
|
|
|
Why hyaline cartilage is super smooth and slick
|
You don't want friction at your joints
|
|
|
Where is hyaline cartilage found (5)
|
Articular cartilage
Tracheal rings Costal cartilage Immature skeleton Nasal cartilage |
|
|
Function of elastic cartilage
|
flexibility
Resiliency - tissue snaps back when deformed |
|
|
Where is elastic cartilage found (3)
|
Pinna of external ear
Epiglottis Pharyngotympanic tube |
|
|
Pharyngotympanic tube
|
Connects ear to back of throat
|
|
|
What does fibrocartilage consist of
|
1. Interwoven collagen type I fibres arranged in perpendicular arrays
2. Chondrocytes arranged in rows between bundles of collagen type I fibres |
|
|
Fibrocartilage is intermediate in strength between _____ and _____
|
Hyaline cartilage
Dense regular CT |
|
|
Why is fibrocartilage stronger than hyaline cartilage
|
Collagen type I is stronger than type II
|
|
|
Why is fibrocartilage weaker than dense regular CT
|
Has some resiliency
|
|
|
Why are the collagen type I fibres in fibrocartilage arranged in perpendicular arrays
|
Need to resist forces in different directions
|
|
|
Role of fibrocartilage
|
Resists tension and compression
|
|
|
Where is fibrocartilage found (4)
|
Where is fibrocartilage found
Anulus fibrosis of intervertebral disks Pubis symphysis Intra-articular disks Tendon and ligament insertions |
|
|
Intra-articular disk
|
wedges of cartilage that sit inside joints
|
|
|
Intra-articular disk in knee
|
meniscus
|
|
|
forces for the different types of cartilage
|
hyaline:
NOT tension resists compression reduces friction flexible weakest elastic flexible resilient fibrocartilage resists tension resists compression |
|
|
which type of cartilage has little ground substance
|
fibro
|
|
|
leverage
|
A lever amplifies an input force to provide a greater output force
|
|
|
hematopoiesis
|
production of blood cells
|
|
|
What happens to our need for RBCs as we age
|
Decreases because we are not growing
|
|
|
Implication of our decreasing needs for RBCs as we age
|
Red marrow is converted to yellow marrow
|
|
|
Bone is 1/3 ____ and 2/3 ____
|
1/3 organic matter 2/3 inorganic matter
|
|
|
Organic matter that comprises bone is called _____
|
Osteoid
|
|
|
Composition of osteoid (4)
|
95% collagen type I
Glycoproteins Proteoglycans Small amount of tissue fluid |
|
|
Role of osteoid
|
Imparts tensile strength
Flexibility |
|
|
Role of inorganic matrix
|
Compressional strength
Mineral storage |
|
|
Composition of inorganic matrix
|
Calcium and phosphate in the form of hydroxyapatite
|
|
|
Characteristic of bone that is low in osteoid
|
Brittle
|
|
|
Where do osteoprogenitor cells come from
|
Embryonic mesenchyme
|
|
|
Role of osteoblasts
|
Produce, secrete, and calcify osteoid
|
|
|
Shape of osteoblasts
|
Range from cuboidal to squamous
|
|
|
When does an osteoprogenitor become an osteoblast
|
Actively secreting osteoid
|
|
|
Where are osteoblasts found
|
Surface of bone matrix
|
|
|
When do osteoblasts become osteocytes
|
Cells being to "lag behind" in the newly secreted matrix
Becomes osteocyte once it is completely surrounded by matrix |
|
|
What surrounds osteocytes
|
Small amount of unmineralized matrix
|
|
|
How are osteocytes arranged with relation to each other
|
Cell processes connect to each other and communicate via gap junctions
|
|
|
Where are cell processes of osteocytes found
|
within canaliculi
|
|
|
Function of osteocytes (2)
|
Maintain surrounding bone tissue
Sense mechanical stresses (compression, tension) and organize bone remodelling accordingly |
|
|
Implication of space between cell process and canaliculi
|
There is a small amount of tissue fluid surrounding the cell processes
This is continuous with the tissue fluid surrounding the BV |
|
|
Why osteocytes don't continue to secrete matrix
|
Bone is too rigid
|
|
|
What would happen to bone if there were no osteocytes
|
It would degenerate
|
|
|
Lineage from which osteoclasts arise
|
Monocyte/macrophage cell lineage
Monocytes leave the blood, enter the tissue, and a bunch of them combine to become osteoclasts |
|
|
Structure of osteoclasts
|
Multinuclear
|
|
|
Where are osteoclasts found
|
At bone surface in Howship's (resorption) lacunae
|
|
|
2 things secreted by osteoclasts
|
Acids
enzymes |
|
|
What is released following osteolysis
|
Calcium
Phosphate |
|
|
Do osteoclasts proliferate locally
|
No - replenished from the blood
|
|
|
What happens to the morphology of a more active osteoclast
|
More prominent ruffled border - because more surface area for activity
|
|
|
2 types of bone tissue (2 names, 3 names)
|
1. Compact/lamellar
2. Spongy/trabecular/cancellous |
|
|
Compact/lamellar bone is arranged in _____
|
Osteons
|
|
|
Spongy/trabecular/cancellous bone is arranged in ______
(2) |
anastamosing spicules
trabeculae |
|
|
Where is compact bone found
|
Bony surfaces (cortices)
|
|
|
Where is spongy bone found
|
Core of all bones
|
|
|
Lamella =
|
Layer
|
|
|
Matrix composition is the same between compact/lamellar and spongy/cancellous/trabecular bone, but ___ differs
|
Organization of the matrix
|
|
|
Anastamosis
|
Repeatedly coming together and going apart
|
|
|
5 classifications of bones
|
1. Long
2. Short 3. Flat 4. Irregular 5. Sesamoid |
|
|
Long bone
|
Longer than they are wide
|
|
|
Short bones
|
Length and width are equal
|
|
|
Irregular bones
|
not long, short, flat, or sesamoid
|
|
|
sesamoid bones
|
develop within a tendon due to friction
|
|
|
type of bone that develops within a tendon due to friction
|
sesamoid
|
|
|
example of sesamoid bone
|
kneecap
|
|
|
what type of bone is the kneecap
|
sesamoid
|
|
|
label the bone pic in ur notes
|
ok
|
|
|
What covers the part of bone that is not covered by periosteum
|
Articular cartilage
|
|
|
Where does the nutrient artery enter the bone
|
Diaphysis
|
|
|
What happens to the nutrient artery after it enters the bone
|
Ramifies -> breaks into branches that go up and down the bone
These break further into branches that run horizontally through the bone |
|
|
Implication of the nutrient artery
|
Bone is fed from the inside out
|
|
|
Other arteries in bone
|
Epiphyseal arteries just feed the epiphysis
|
|
|
Layers of periosteum
|
Outer fibrous layer
Inner cellular layer |
|
|
Shape of osteons
|
Cylindrical (parallel to long axis of bone)
|
|
|
Osteon
|
Layers of bone matrix surrounding a core which contains
Neurovascular bundle |
|
|
Why are bones cylindrical
|
To resist compressional forces (think of straw)
|
|
|
Where can you find other lamellae (outside of the osteons)
|
External circumferential internal circumferenti
|
|
|
Name of horizontal branches of the bone vasculature
|
Perforating canals
|
|
|
Name of vertical branch of bone vasculature
|
central canal
|
|
|
Where are osteocytes found within an osteon
|
Between lamellae within lacunae
|
|
|
How is the matrix strengthened within an osteon
(structural feature of the osteon) |
By alternating orientation of collagen fibres
|
|
|
Relationship of lamellae
within an osteon (structural/anatomical only) |
concentric
|
|
|
Implication of space between cell process and canaliculi
|
There is a small amount of tissue fluid surrounding the cell processes
This is continuous with the tissue fluid surrounding the BV |
|
|
what is missing from trabeculae compared to osteon
|
Central canal
|
|
|
What canaliculi open into in compact vs. spongy bone
|
Compact: tissue fluid around NV bundle
Spongy: red marrow |
|
|
What covers trabeculae of spongy bone
|
Endosteum
|
|
|
Arrangement of matrix in spongy bone
|
lamellae
|
|
|
Functional implications of spongy bone
(3) |
Lightweight
Trabeculae orient across stress lines Resist compression from many directions |
|
|
Mature vs. young bone
|
Mature bone has just a layer of spongy bone inside the cortex
Younger bone shafts contain mostly spongy bone |
|
|
Endosteum
|
Covers inner surfaces of a bone
Connective tissue |
|
|
Where is lots of endosteum found
|
epiphyses
|
|
|
Orientation of trabeculae
|
Varies depending on what direction they have to resist force from epiphyses experience force from varying directions
|
|
|
What covers the outer layer of bone
|
periosteum
|
|
|
2 layers of periosteum
|
Superficial (fibrous)
Deep (cellular) |
|
|
What type of tissue is the fibrous layer of periosteum
|
Dense irregular CT
Includes fibrocytes |
|
|
what type of cells are in the fibrous layer of the periosteum
|
fibrocytes
|
|
|
What type of cells are in the cellular layer of periosteum
|
Osteoprogenitor
Osteoblasts Osteoclasts |
|
|
What type of cells are not found in the cellular layer of periosteum
|
Osteocytes - because osteoblasts don't become osteocytes until they are completely surrounded by matrix
|
|
|
How is periosteum held tightly to bone
|
Perforating (sharpey's fibres) - collagen type 1 from the fibrous layer of the periosteum goes through the cellular and intro the matrix of the superficial lamellae
|
|
|
Role of periosteum in bone repair
|
If, following an injury, the periosteum is intact, healing is faster (because cells of the periosteum repair bone)
You can take out a rib and as long as the periosteum remains intact, you can grow the rib back |
|
|
the collagen network
|
Network of collagen type 1
The collagen fibres of the tendon intermingle and become the collagen fibres of the periosteum, which then intermingle and become the collagen fibres of the bone |
|
|
What lines the inner surfaces of bone
|
Endosteum
|
|
|
3 inner surfaces of bone lined by endosteum
|
Marrow cavity
Trabeculae of spongy bone Central and perforating canals of compact bone |
|
|
Fun fact about structure of endosteum
|
incomplete layer
|
|
|
Components of endosteum
|
Osteoblasts
Osteoclasts Osteoprogenitor cells |
|
|
Function of endosteum
|
Bone growth and repair
|
|
|
Purpose of bone remodelling
|
respond to stress
adjust Ca levels |
|
|
what happens after osteoclasts break down matrix
|
they release cytokines and GFs which stimulate osteoblasts to synthesize new matrix
|
|
|
what determines change in bone mass
|
balance in osteoblast/osteoclast activity
|
|
|
why bone adapts to applied force
|
to achieve maximal strength with minimal mass
|
|
|
at what point does our bone mass stop icreasing
|
mid 20s
|
|
|
how does bone respond to pressure
|
resorption at that point
|
|
|
how does bone respond to tension
|
production at that point
|
|
|
what is bone called when it is newly aid down
|
woven bone
|
|
|
how does woven bone compare to spongy or compact bone
|
not organized into osteons or trabeculae
|
|
|
What happens after bone is laid down
|
Osteoclasts will drill a tunnel through newly formed matrix
Osteoblasts follow up the tube and lay down matrix The tunnel gets narrower and narrower |
|
|
in an osteon which lamella is produced first
|
outermost
|
|
|
Conversion of a tissue to bone is called
|
ossification
|
|
|
ossification
|
conversion of a tissue to bone
|
|
|
Which bones are formed by intramembranous ossification
|
flat
short sesamoid contributes to the formation of long bones |
|
|
process of intramembranous ossification
|
In the embryo
1. Ossification centre forms from condensations of mesenchymal cells within mesenchymal tissue (embryological CT) 2. Mesenchymal cells differentiate into osteoblasts and start producing matrix 3. Osteoblasts move apart but maintain their intercellular attachments 4. Ossification centres may fuse 5. Osteoid undergoes calcification 6. Osteoblasts become osteocytes 7. Woven/immature bone is formed with entrapped BVs 8. Mesenchyme forms periosteum on outer surface, endosteum on inner surface 9. Immature bone is remodelled to form mature spongy or compact bone 10. Osteoclasts will drill a tunnel through newly formed matrix 11. Osteoblasts follow up the tube and lay down matrix The tunnel gets narrower and narrower |
|
|
Endochondral ossification (7 steps)
|
1. hyaline model of cartilage grows interstitially and apositionally
2. perichondrium around diaphysis converts to periosteum 3. intramembranous ossification produces a bone collar 4. chondrocytes lose nutrient supply and die 5. cartilage degenerates 6. matrix calcifies 7. blood vessels invade diaphysis, bringing mesenchymal cells 8. mesenchymal cells differentiate into bone and blood vessel forming cells 9. Remodelling creates the marrow cavity 10. Osteogenesis proceeds toward both ends 11. Secondary ossification centre forms in each epiphysis |
|
|
type of cartilage involved in endochondral ossification
|
hyaline
|
|
|
what is the area in the diaphysis where bone formation begins called
|
primary ossification centre
|
|
|
where is the primary ossification centre
|
diaphysis
|
|
|
endochondral means
|
within cartilage
|
|
|
What is the epiphyseal plate
|
Wedge of cartilage that separates diaphysis from epiphysis
|
|
|
epiphyseal plate vs. epiphyseal line
|
plate = wedge of cartilage
line = leftover when the cartilage is gone |
|
|
Implication of presence of epiphyseal plate within a bone
|
That bone can still grow
|
|
|
What happens when we reach maximum height
|
Last of the epiphyseal plate is converted to bone
|
|
|
What remains when the epiphyseal plate has been converted to bone
|
Epiphyseal line is left over
|
|
|
mixed spicule
|
degenerating cartilage combined with newly formed bone
|
|
|
How bone increases in length
|
1. epiphyseal plate of cartilage grows on the epiphyseal side (interstitial growth)
2. |
|
|
what kind of growth occurs within the cartilage at the epiphyseal plate
|
interstitial
|
|
|
what kind of growth occurs within the cartilage that is an early model of bone
|
both
|
|
|
Does thickness of epiphyseal plate change as bone grows
|
No because the diaphyseal side is continually getting remodelled to bone
|
|
|
How does the epiphyseal plate close
|
Ossification overtakes cartilage growth
|
|
|
How does bone increase in diameter
|
Intramembranous ossification on the diaphyseal surface
Simultaneous osteoclast activity at the inner surface enlarges the marrow cavity |
|
|
What doesn’t change when bone increases in diameter
|
Ratio of diameter of diaphysis: diameter of marrow cavity
|
|
|
5 factors that affect bone growth, maintenance and repair
|
1. Balance of osteoblast/osteoclast activity
2. Nutrition 3. Hormones 4. Exercise 5. Age |
|
|
What is required for absorption of Ca
|
Vit D
|
|
|
What happens in children who get insufficient Ca or vit D
|
Rickets - soft bones improperly mineralized bone bowlegged
|
|
|
Effect of GF on bone growth, maintenance, repair
|
Stimulates growth of epiphyseal plate
|
|
|
PTH and calcitonin
|
PTH stimulates bone resorption
Calcitonin _____ (google it when internet is working) |
|
|
Role of estrogen
|
Helps maintain bone mass
|
|
|
Osteoporosis
|
Less bone
The bone is not different from normal bone |
