Bone tissue and skeletal system Flashcards

Question

what is a bone marrow transplant

Answer 1

taking healthy bone marrow (usually from hip) and transplanting it into another person person who cannot create hematopoietic stem cells ex. person with leukemia (WBC cancer) needs BM transplant they need the stem cells so that they can differentiate

Answer 2

the development of bone two types: intramembranous ossification endochondrial ossification

Answer 3

bone development that occurs within a membrane (mesenchyme) develops all flat bones

Answer 4

bone development that occurs within cartilage and then forms bone develops all long bones building the cartilage model and replacing it with bone begins at about the 6th week of fetal development ends at around 20 years of age

Answer 5

cleavage of a zygote into the eight cell stage which cleaves into a blastula gastrulation of the blastula to form the gastrula gastrula possesses the ectoderm (outside) mesoderm (middle) and endoderm (inside) --> primary germ layers

Answer 6

the three layers (ectoderm, mesoderm, and endoderm) of the gastrula from which tissues arise ectoderm - epidermis and nervous system endoderm - lining of digestive and respiratory tract mesoderm - forms into the mesenchyme

Answer 7

a loosely organized tissue that forms connective tissues (including bone tissue) where all bone development begins typically very vascularized possess a lot of different stem cells which dictate what kind of tissue it will become

Answer 8

sandwich of spongy bone with compact bone as bread in detail: periosteum with fibroblasts osteogenic stem cells compact bone endosteum with osteogenic stem cells spongy bone endosteum with osteogenic stem cells compact bone osteogenic stem cells periosteum with fibroblasts

Answer 9

1. the mesenchyme condenses mesenchyme possesses fibroblasts and osteogenic stem cells blood vessels form into the mesenchyme which feed it 2. the blood vessels form the framework the osteogenic cells begin to surround the blood vessels 3. the osteogenic cells lay down bone the osteogenic cells do mitosis and differentiate into osteoblasts which lay down bone (trabiculae) along blood vessels the remaining mesenchyme becomes bone marrow this is spongy bone 4. blood vessels migrate away from mesenchyme the osteogenic cells move with the blood vessels, building osteons (compact bone) as they go this happens from both sides of the mesenchyme, forming the compact bone bread fibroblasts travel through the blood vessels and build the periosteum after the layer of osteogenic stem cells on both sides

Answer 10

1. the hyaline cartilage model is formed a long bone possesses lacunae with chondrocytes (just hyaline cartilage) 2. blood vessels bring osteogenic stem cells form the bony collar (layer of bone outside of cartilage)(basically ice cream coated with hardened chocolate layer) there needs to be room inside of the cartilage for the blood vessels and osteogenic cells to get in 3. chondrocytes in lacunae undergo hypertrophy they grow super duper big and break down the matrix, weakening the cartilage model blood vessels are then able to get into the model osteogenic stem cells follow and build spongy bone in the same process as IM ossification (forming trabiculae and then osteons) this first happens in the middle (forming primary cavity) and then happens at both ends (forming secondary cavities)

Answer 11

secondary marrow cavity surrounded by compact bone hyaline cartilate (epiphyseal plate) primary marrow cavity surrounded by compact bone hyaline cartilage (epiphyseal plate) secondary marrow cavity surrounded by compact bone

Answer 12

happens after bones have developed 2 types: interstitial growth (growing longer) appositional growth (growing wider)

Answer 13

happens at epiphyseal plate under x rays, you can see the epiphyseal plate in children but in adults it is all gone (you can still see the epiphyseal line) there are two ends of the epiphyseal plate: metaphysis this is where the bone growth happens: mitosis of the catilage which lengthens and ossifies to create more bone

Answer 14

1. zone of reserve cartilage just regular hyaline cartilage that isnt in the metaphysis 2. zone of cell proliferation - chondrocytes multiplying and lining up in rows of small, flattened lacunae 3. zone of cell hypertrophy - cessation of mitosis, enlargement of chondrocytes, and thinning of lacunae walls 4. zone of calcification - temporary calcification of cartilage matrix between columns of lacunae so that the growing cartilage does not collapse bc its not strong enough to hold your body up 5. zone of bone deposition - breakdown of lacunae walls, leaving open channels, death of chondrocytes, bone deposition by osteoblasts, forming trabeculae of spongy bone blood vessels with osteogenic cells go in and do all of that stuff to form osteons

Answer 15

pituitary dwarfism - everything is proportional but everything is just smaller all bones stop growing due to a growth hormone deficiency in the pituitary gland which normally will cause interstitial growth achondroplastic dwarfism - possess a proportional torso of average size but appendages arent proportional long bones stop growing during childhood no problem with development of flat bones hyaline cartialge in long bones cant do interstitial growth

Answer 16

growing in girth from superficial surface deposition of new osseous tissue at the bone surface by osteogenic cells that are in the periosteum they become osteoblasts and build bone appositionally (in diameter) this is what creates the circumferential (outer) lamellae which surrounds ALL of the osteons in the middle

Answer 17

IS and APP growth can happen at the same time APP growth can always happen without IS growth

Answer 18

stress fracture - due to abnormal stress (falls, impact, etc.) pathological fracture - bone is weakened due to disease (cancer, osteoporosis, etc.) and breaks as a result closed - doesnt break through skin compound - breaks through skin in position - no reducing required out of position/displaced - requires the bone to be reduced incompletely broken/greenstick - bone hasnt broken all the way through but is bent comminuted - bone broken in 3+ pieces, usually also displaced

Answer 19

reducing a bone is putting it back in its place so that it wont be deformed when it heals out of position bones need reducing

Answer 20

8-12 weeks

Answer 21

1. formation of a hematoma broken blood vessels form a blood mass that possesses fibroblasts, macrophages (clears broken bone fragments), and osteoclasts (smooths bone over the rough breakage) osteogenic cells become abundant (in periosteum and endosteum) within 48 hours (undergo massive mitosis to help build bone back blood clot forms into granulation tissue 2. formation of soft callus osteogenic cells differentiate into chondroblasts which build cartilage produces a soft callus of fibrocartilage model (NOT HYALINE) this is similar to endochondrial ossification and interstitial growth 3. conversion to a hard callus osteogenic cells produce osteoblasts which produce the hard callus hard callus is a bony collar which outlines joint where the bone is broken (not in model, but around it) acts as a temporary joint that solidifies and supports regrowth of new bone you wear a cast for 4-6 weeks so that you can form this similar to building a bone collar in endochondrial ossification 4. remodeling hard callus persists for 3-4 months then forms into bone --> exactly like IS growth the osteoblasts deposit spongy bone and superficially it becomes compact bone the remnant of the hard callus can be seen after healing on an x ray (appears as a little bump over the place where the break happened)

Answer 22

bone is constantly exchanging between self maintenance, growth and remodeling and exchange of calcium and phosphorous with the body by way of blood vessels

Answer 23

how bone tissue exchanges minerals with the body mineral deposition builds bone minerals are extracted from blood plasma and deposited into bone tissue (lower amount of Ca and P in the blood) bone forms this way (calcification/mineralization) mineral resorption breaks down bone minerals are extracted from bone tissue and released into blood plasma (higher amount of Ca and P in the blood)

Answer 24

most cells have uniport Ca pumps using ATP pump calcium out of cells

Answer 25

osseous tissue in places other than bone can be anywhere forms a calculus - a calcified mass in a soft organ ex. arteriosclerosis plaque buildup in endothelium of blood vessels can cause a heart attack ex. kidney stones are calculi

Answer 26

osteoclasts possess ruffled borders (foldings of plasma membrane) which increase surface area for resorption they possess hydrogen pumps which secrete H+ into the matrix of bone Cl- is electrically attracted to H forms HCl (pH=4) which dissolves bone minerals (bone experiment in lab --> acid pulls out minerals making bone flimsy) secretes acid phosphatase which digests collagen breaks down collagen and minerals have no where to crystallize and they can then go into the blood stream

Answer 27

there is balance between osteocytes and osteoblasts which do mineral deposition and osteoclasts which do resorption ^^ creates the balance of continual turnover of bone about 10% of skeletal tissue is remodeled per year ^ releasing minerals into blood repairing micro-fractures reshaping bones due to use

Answer 28

leg muscles that attach to tibial tuberosity increased muscle movement increases the size of the tibial tuberosity in order to support the muscles the hip muscles that are involved in walking are attached to the greater trochanter of the femur infants dont have a greater trochanter since they dont walk but it forms once they start learning how to walk braces

Answer 29

releasing minerals into blood (osteoclasts breaking down bone) repairing micro fractures (dont even know that it has happened reshaping of bones due to use - change in use of muscles changes shape of bones

Answer 30

teeth are embedded in the spongy bone of the mandible - they dont actually touch bone, they are connected by the periodontal ligament braces are needed when the alignement is off and they are trying to move the teeth they attach a wire to teeth and pull it to one side or another very slow process there is a compression side and a tension side. the compression side is where the orthodontic force is pulling the teeth to - causes more osteoclasts to be expressed and therefore more bone to be broken down on that side the tension side is where the orthodontic force is pulling the teeth away from - causes more osteoblasts to be expressed and therefore more bone to be produced on that side.

Answer 31

severe loss of bone density over time one of the most common bone diseases occurs to a point where the bones are so brittle that they can have pathological fractures

Answer 32

mostly develops in the 40s and shows symptoms in the 60-70s there is no way to prevent it -- everybody gets it as you age post menopausal women are at higher risk

Answer 33

menopause is the stopping of the reproductive cycle when this happens, estrogen levels decrease normally, ovulation causes the release of estrogen and estrogen inhibits osteoclasts from breaking down bone without this there is no proper regulation of osteoclasts

Answer 34

about 30-50% of bone tissue is lost by about 70 years old affects mostly spongy bone can cause spine problems -- spine compression -- kyphosis -- very convex (hunchback) spine can happen to everyone

Answer 35

injections of Denosumab (active ingredient of things like Prolia, Xgeva, etc.) this behaves just like estrogen (competitively inhibits RANKL receptor) without the hormonal effects of actual estrogen.

Answer 36

DNA, RNA, ATP, phospholipids, acid base homeostasis, etc.

Answer 37

communication, exocytosis, muscle contraction, blood clotting communication between neurons -- the release of a neurotransmitter through exocytosis is triggered by Ca Ca has to bind to a protein (troponin) so that actin and myosin can bind leading to muscle contraction maintaining the resting membrane potential ^^outside of the cell is positive and inside of the cell is negatively charged all cells need this to function, especially muscle and nervous cells

Answer 38

receptor activator of nuclear factor Kappa beta-ligand is a chemical ligand that is released when they want to stimulate the development of osteoclasts

Answer 39

osteoblasts/cytes do two things: make and deposit collagen, and make and release RANKL (receptor activator of nuclear factor Kappa Beta-ligand) when RANKL is released into the ECM, they travel to the transmembrane protein RANKL receptor on a hematopoietic stem cell this causes the stem cell to differentiate into osteoclasts

Answer 40

estrogen acts as a competetive inhibitor on the RANKL receptor. It binds to this receptor on a hematopoietic stem cell so that RANKL cannot bind therefore, there is no differentiation of the stem cell into osteoclasts estrogen prevents osteoclast overproduction (with a lack of estrogen (like in postmenopausal women) osteoclasts are produced too much)

Answer 41

by hormones hypercalcemia and hypocalcemia

Answer 42

rare disease too much blood Ca2+ levels makes it hard to send messages less excitability of nervous and muscle tissue sluggish reflexes, depression, coma there are so many Ca ions on the outside of the cell blocking the negative glycolipids that the positive charge on the outside is so large compared to the negative inside charge

Answer 43

too little blood Ca2+ has a wide variety of causes - vitamin D deficiency - diarrhea (short term hypocalcemia) - thyroid tumors and underactive parathyroids - pregnancy and lactation can lead to physiological problems excess excitability of nervous and muscle tissue tremors, spasms, cardiac failure too easy to send messages there are not enough Ca2+ ions on the outside of the cell so that the charge is a smaller positive than what it should be since the difference in charge is so little, it is much easier to send messages (its almost spontaneous)

Answer 44

maintaining the balance of the membrane potential involves dietary intake, urinary/fecal loss, exchanges with bone in a healthy person -if you ingest too much Ca, you will excrete it or store it in bone -if you dont ingest enoguh Ca, you will take it from bone and put it in blood

Answer 45

calcitriol (vit d) parathyroid hormone calcitonin

Answer 46

glands that are highly vascularized an secrete hormones into the blood stream so that they can have their physiological effect

Answer 47

the reverse of sorbtion (the binding of two things) pulling Calcium off of collagen and putting it in blood

Answer 48

taking something outside of the body and taking in anything with the digestive tract (tubes not cells) once it is in the cells, it is absorbed

Answer 49

reabsorbing something that was in the body but is about to be excreted as waste

Answer 50

calcitriol is the active form of vitamine D (produced in the skin, liver, and kidneys) behaves like a hormone but is not derived from an endocrine gland (^) calcitriol raises blood Ca levels -increases Ca absorption by the small intestine -increases Ca reabsorption in the kidneys (not excreting it out) -increases Ca resorption from the skeleton

Answer 51

increases the production of osteoclasts indirectly calcitriol is a steroid hormone (it can pass through the PM (lipid soluble)) calcitriol goes into an osteocyte/blast and activates kinases which activate enzymes which activates RANKL production RANKL then goes on to activate the RANKL receptor on hematopoietic stem cells, causing their differentiation into osteoclasts (secreting H+ and acid phosphatase) this is why we need vitamin D found in supplements its also put in milk bc a lot of people used to drink milk (now its put into orange juice)

Answer 52

parathyroid hormone is secreted by the parathyroid gland which sits posterior to the thyroid gland and lateral to the pharynx (and trachea/esophagus) increases calcium levels in 4 ways: 1. increases osteoclasts for more bone resorption in the same way as calcitriol - it is not steroid based so it cannot pass through the plasma membrane -PTH binds to a PTH receptor (transmembrane protein) on the PM of an osteocyte/blast -when it binds, it stimulates the release of a G protein which travels to adenylate cyclase which converts ATP into cAMP -cAMP goes on to activate kinases which activates enzymes which increases RANKL production (just like calcitriol does) 2. promotes Ca2+ reabsorbtion in kidneys -less Ca is lost into the urine (increases blood Ca levels) 3. promotes the final step of calcitriol synthesis - the hydroxylating of calcidiol in the kidneys - enhances the amount and effect of calcitriol 4. inhibits collagen synthesis by osteoblasts - inhibiting bone deposition - conservation of calcium

Answer 53

hormone secreted by the thyroid gland (anterior to the trachea) lower Ca2+ levels in 2 mechanisms: 1. osteoclast inhibition -less Ca resorption from skeleton -stops osteoclasts in two ways: --- in HP stem cells, there are calcitonin receptors that, when calcitonin binds, release a G protein which turns off adenylate cyclase (no ATP is converted into cAMP and no mitosis and differentiation) --- in osteoclasts, there are calcitonin receptors that, when calcitonin binds, the G protein is relesed and activates adenylate cyclase to convert ATP to cAMP, activating kinases which activates enzymes which shuts down the H+ pumps and shuts down the release of acid phosphatase 2. osteoclast stimulation -more deposition of Ca into the skeleton - calcitonin tells osteoblasts to make more collagen through a more complicated secondary messenger system

Answer 54

antagonistically to balance blood Ca levels so that it is just right for the membrane potential

Bone tissue and skeletal system Flashcards

(79 cards)