Class Test 2

Front 1

name the three types of joints, classified by function

Back 1

1. synarthroses (immovable)
2. amphiarthroses (slightly movable) - cartil
3. diarthroses (freely movable)

Front 2

Describe the three types of
synarthroses joints.
Give examples.

Back 2

1. Sutures – Skull sutures, like seams, wavy interlocking joints, protect and allow growth

2. Syndesmosis - Fibula/Tibia. Ligaments connect two bones and allow the joint to “give” but will not allow movement. Radius/ulna ligament allows rotation of radius on the ulna.

3. Gomphosis - Teeth in skull. Tooth is imbedded in bony socket like a nail pounded into wood.

Front 3

Describe the two types of cartilaginous joints (amphiarthroses).
Give examples.

Back 3

1. Synchondrosis – a bar or plate of hyaline cartilage unites the bones.
ex: 1st ribs to sternum or Epiphyseal Discs – Hyaline cartilage disc or growth plate allows little movement.
2. Symphysis – pad of fibrocartilage, slightly movable, shock absorber.
ex: pubis and intervertebral discs

Front 4

List the typical structure of a synovial joint. (5-6)

Back 4

1. Articular, hyaline, cartilage
2. Joint, synovial cavity
3. Joint, articular, capsule
4. Synovium (synovial fluid)
5. Reinforcing Ligaments
6. (optional) fatty pads or articular discs (menisci)

Front 5

What are three factors that determine the stability of synovial joints?

Back 5

1. the shapes of the articulating surfaces.
2. the number and positioning of ligaments.
3. muscle tone

Front 6

What is important about skeletal cartilage?

Back 6

- variety of cartilage tissue, which has high water content
- responsible for resilience.
- no nerves or blood vessels.
- surrounded by perichondrium (dense irregular connective tissue). - acts like a girdle and contains blood vessels
- nutrients diffuse through to reach the cartilage cells.

Front 7

Describe perichondrium

Back 7

- (dense irregular connective tissue). - acts like a girdle and contains blood vessels
- nutrients diffuse through to reach the cartilage cells.

Front 8

Where is hyaline cartilage found in the skeleton?

Back 8

hyaline: frosted glass. support w flexibility and resilience MOST
- articular cartilage (cover the ends of bones at movable joints)
- costal cartilage (connect ribs to sternum)
- respiratory cartilage (larynx – voicebox)
- nasal cartilage (external nose)

Front 9

Where is elastic cartilage found in the skeleton?

Back 9

- elastic cartilage: can bend repeatedly
- only in external ear and epiglottis (flap for swallowing)

Front 10

Where is fibrocartilage found?

Back 10

- fibrocartilage: highly compressible, great tensile strength. intermediate between hyaline and elastic.
- menisci of knee, intervertebral discs.

Front 11

Name five functions of bones.

Back 11

1. Support & framework
2. Movement
a. provides attachment for muscles. bones are levers
b. articulations (joints) act as levers
3. Storage
a. calcium and phosphate in hard tissue
1) very important in electrolyte balance
2) Ca2+ and PO44+ are constantly being stored in/removed
b. lipid in soft tissue (yellow marrow)
4. Blood cell production - hematopoesis - rbc, wbc, and platelets are made in red marrow
5. Protection
a. for soft organs (e.g. rib cage, pelvis, orbitals of skull, cranium)
b. detoxification - removes heavy metals (toxic) from blood and they are stored in bone and slowly released

Front 12

Describe compact bone. (three facts)

Back 12

a. made of lamellae surrounding a central canal (osteonic canal or Haversian canal

b. osteon - made of a central canal, lamellae & osteocytes

c. makes up outer walls of the diaphyses of long bones overlaying spongy (cancellous) bone

Front 13

What is the diaphysis and what are its important features? (3)

Back 13

- central shaft of long bone
- has hollow center called medullary cavity (marrow cavity)
1) yellow marrow - mostly fat storage - in adult only
2) red marrow - in medullary cavity of all EXCEPT long bones

Front 14

What is the epiphyses and what are its important features? (3)

Back 14

- articulating, enlarged mass at ends of long bones - covered with articular cartilage (hyaline)

- made of cancellous bone covered by compact bone

- contains mainly red marrow

Front 15

What is the epiphyseal plate and how does it work?

Back 15

- a plate of hyaline cartilage between the diaphysis and epiphysis (“growth plate”) in youth where bones elongate

- adult bones no longer grow so are ossified into epiphyseal line

Front 16

What are the two layers of the periosteum?

Back 16

1. fibrous layer of dense irregular connective tissue.
surrounds cartilage, acts like a girdle and contains blood vessels… nutrients diffuse through to reach the cartilage cells. This mode of delivery limits cartilage thickness.
2. inner osetogenic layer has osteoblasts and osteoclasts.

Front 17

What is the nutrient foramen?

Back 17

Periosteum richly supplied with nerve fibers, lymphatic vessels, blood vessels which enter diaphysis via the nutrient foramen

Front 18

What are the four cell types in bone tissue?

Back 18

osteogenic (actively mitotic)
osteoblasts
osteocytes
osteoclasts
surrounded by an extracellular matrix of their own making.

Front 19

What are osteogenic cells?

Back 19

stem cells that arise from embryonic fibroblasts in the inner layer of periosteum, multiply continually - some of them differentiate into osteoblasts which are nonmitotic

Front 20

What is the structural unit of compact bone?

Back 20

the osteon or haversian system
each osteon is an elongated cylinder oriented parallel to the long axis of the bone.... tiny weight bearing pillars.
...like the growth ring of a tree.
contains lamellae - collagen fibers
and a central canal which has arteries, veins, nerve fibers running in it.

Front 21

What are osteoclasts?

Back 21

specialized wbc’s that break down bone tissue and release Ca2+ into blood inhibited by calcitonin, but stimulated by PTH

Front 22

What are osteocytes?

Back 22

mature osteoblasts that do not secrete or break down matrix

Front 23

What are osteoblasts?

Back 23

immature bone cells that actively secrete bone tissue and are stimulated by calcitonin - turn into osteocytes when they stop secreting hydroxyapatite (bone tissue)

Front 24

What is hydroxyapatite?

Back 24

A major component and an essential ingredient of normal bone and teeth. Hydroxyapatite makes up bone mineral and the matrix of teeth. It is hydroxyapatite that gives bones and teeth their rigidity.

Hydroxyapatite molecules can group together (crystalize) to form microscopic clumps. If these tiny crystals of hydroxyapatite are deposited by mistake in or around joints, they may cause inflammation of the joints and nearby tissues, such as tendons and ligaments, particularly causing rotator cuff problems in the shoulder.

Front 25

What are the two types of bone development (aka
osteogenesis and
ossification)?

Back 25

intramembranous ossification

endochondral ossification

Front 26

Generally, what is Intramembranous Bone Formation? What bones are formed this way?

Back 26

- when a bone develops from a fibrous membrane.
- forms the cranial bones of the skull and clavicles. All are flat bones.

Front 27

List the 7 steps of intramembranous bone formation.

Back 27

1. Layers of membrane-like connective tissue form where future bone will be.
2. Connective tissue cells in these layers differentiate into osteogenic cells which become osteoblasts
3. Osteoblasts secrete matrix (hydroxyapatite & collagen) around themselves. These are called ossification centers.
4. The osteoblasts become completely surrounded by matrix. They form lacunae and canaluculi.
5. The osteoblasts stop secreting matrix and thereby become osteocytes
6. Trabeculae form as bony matrix is deposited. This forms cancellous bone.
7. Osteoblasts in the periosteum secrete more matrix on the surface of the bone to fill in spaces between trabeculae. This forms an outer layer of compact bone.

Front 28

List the 9 steps of endochrondrial bone formation.

Back 28

1. A hyaline cartilage “model” of the bone is formed in the fetus.
2. The lacunae in the cartilage enlarge & the cartilage begins to calcify.
3. The chondrocytes die & decompose.
4. Connective tissue cells from the periosteum invade the dying cartilage & differentiate into osteoblasts.
5. The osteoblasts lay down bone matrix (hydroxyapatite & collagen) around themselves. These are called ossification centers
6. The osteoblasts become completely surrounded by matrix. They form lacunae and canaluculi.
7. The osteoblasts stop secreting matrix & thereby become osteocytes
8. Trabeculae form as bony matrix in deposited. This forms cancellous bone.
9. Osteoblasts in the periosteum secrete more matrix on the surface of the bone to fill in spaces between trabeculae. This forms an outer layer of compact bone.

Front 29

During infancy and childhood, what is the single most important stimulus of epiphyseal plate activity?

Back 29

growth hormone released by the anterior pituitary gland.

then at puberty, sex hormones initially promote growth and later induce epiphyseal plate closure..ending longitudinal bone growth.

Front 30

Bone Remodeling and Repair
statistics

Back 30

- every week, we recycle 5 - 7% of our bone mass.
- .5 gr calcium enter/leave skeleton daily.
- spongy bone replaced every 3-4 years.
- compact bone every 10 years.

Front 31

hydroxyapatite
hydro xya pa tite

Back 31

calcium and phosphate from blood is stored in hydroxyapatite in bone strengthening bone & lowers calcium levels in blood - by osteoblasts

Front 32

Describe first loop of calcium and phosphate metabolism

Back 32

1. Mineral deposition
a. calcium and phosphate from blood is stored in hydroxyapatite in bone strengthening bone & lowering calcium levels in blood - by osteoblasts
2. Mineral resorption
a. dissolving of bone carried out by osteoclasts, releases Ca2+ into blood
b. weakens bone & raises calcium levels in blood

Front 33

What is Calcitriol? What does it do?

Back 33

Calcitriol (active form of vitamin D)
- Hormone produced by the skin & supplemented in some foods
- Needed to carry Ca2+ from intestine into blood

Front 34

Describe the effects of Parathyroid hormone - PTH - on calcium homeostasis.

Back 34

1. released when blood levels of calcium decline.
2. PTH stimulates osteoclasts to resorb bone – which releases CA to the blood.
3. As blood concentrations of CA rise, stimulus for PTH release ends.
4. which causes blood levels of CA to fall.

Front 35

Describe the effects of Calcitonin on calcium homeostasis.

Back 35

1. secreted when blood calcium levels rise.
2. inhibit bone resorption, encourages CA deposit in bone … reduces blood CA levels.
3. as blood CA levels fall, calcitonin release wanes.

Front 36

Describe effect of Parathyroid hormone - PTH in bone remodeling

Back 36

1) Stimulates conversion of vitamin D to calcitriol
2) Stimulates osteoclasts - Inhibits osteoblasts
3) Raises blood calcium, decreases Ca2+ deposition in bone
4) Increases absorption of Ca2+ in digestive system
5) Decreases kidney excretion of Ca2+ in urine.

Front 37

Describe effect of Calcitonin in bone remodeling

Back 37

1) Produced by the thyroid gland
2) Inhibits osteoclast activity - Stimulates osteoblast activity
3) Antagonistic to PTH
4) Most active in childhood

Front 38

Describe effect of Thyroxins (T3 & T4) in bone remodeling

Back 38

1) Promotes normal growth of skeleton
2) Helps to keep the epiphyseal discs open until late puberty

Front 39

Describe effect of Growth Hormone (GH) in bone remodeling

Back 39

1) Stimulates long bone growth
2) Keeps epiphyseal discs cartilagenous

Front 40

Describe effect of Gonadotropic Hormones in bone remodelin

Back 40

1) Act to stimulate growth in early puberty
2) Ossify epiphyseal discs in late puberty

Front 41

Describe the steps (5) in bone repair.

Back 41

1. hematoma formation - blood clots in the area. Bone cells die.
2. phagocytosis of dead cells and formation of soft callus (capillaries, invading osteoblasts from intact periosteum)
3. Collagen fibers form spanning the space between the pieces of bone.Cartilage forms the fibrocartilagenous callus.
4. Cartilagenous callus is converted into bony callus within a week.
5. Bony callus is remodeled over time by reacting to stresses to appear similar to original bone.

Front 42

Wolff's Law

Back 42

A bone grows or remodels in response to the demands placed on it.

Front 43

Observations explained by Wolff's Law

Back 43

- long bones are thickest midway along the diaphysis (bending stresses greatest there)
- curved bones are thickest where they are likely to buckle
- trabeculae form trusses (struts) along lines of compression
- large, bony projections occur where heavy, active muscles attach.

Front 44

Name four types of bone fractures.

Back 44

nondisplaced/displaced fractures – refer to bone end positions

complete/incomplete fracture – broken through?

linear/transverse – orientation of the break relative to the long axis of the bone.

open/closed – did the bone end penetrate the skin?

Front 45

Name the 5 steps in fracture repair

Back 45

1. hematoma formation - blood clots in the area. Bone cells die.

2. Phagocytosis of dead cells and formation of soft callus (capillaries, invading osteoblasts from intact periosteum)

3. Collagen fibers form spanning the space between the pieces of bone. Cartilage forms the fibrocartilagenous callus.
4. Cartilagenous callus is converted into bony callus within a week.

5. Bony callus is remodeled over time by reacting to stresses to appear
similar to original bone.

Front 46

Common Types of Fractures

Back 46

Comminuted: bone fragments into 3 or more pieces, espec in aged.

Compression: bone is crushed

spiral: ragged break, common in sports

epiphyseal: separates

greenstick: incomplete break, children

depressed: typical of skull fracture

Front 47

Describe osteoporosis

Back 47

- bone resorption outpaces bone deposit. Bone becomes porous and light.
- Loss of Ca2+ usually due to age &/or sex hormone deficiencies, but also may be due to lack of exercise, poor diet, smoking, genetic diseases.

Front 48

Describe osteomalacia & rickets

Back 48

- calcium salts are not deposited. pain when weight is put on the affected bones.
- caused by insufficient calcium or a Vitamin D deficiency.
- drinking vitamin D fortified milk + sunlight cures.

Front 49

Describe Paget's Disease

Back 49

- excessive and haphazard bone deposit and resorption.

- abnormally high ratio of spongy bone to compact bone.

- causes spotty weakening.

Front 50

What is the most important functional characterisic of muscles?

Back 50

their ability to transform chemical energy (ATP) into directed mechanical energy.

Front 51

Name 5 Functions of Muscle Tissue

Back 51

1. Movement of skeleton & skeletal muscle, contents of body and organs, Respiration, circulation, digestion, defecation, childbirth, Visceral and cardiac muscle
2. Stability: maintain posture, hold articulating bones in place
3. Communication: facial expressions, body language, speech, writing
4. Control of body openings and passages: sphincter muscles 5. Heat production: up to 85% of body heat produced by muscle movement; heat is a byproduct of muscle contraction, ex. shivering when you are cold

Front 52

What are muscle organs?

Back 52

Consist of two main tissue types:
a. Connective
b. Muscle
c. Also contains nerves and blood vessels

Front 53

define sarcolemma

Back 53

muscle fiber (cell) membrane

Front 54

define sarcoplasma

Back 54

muscle fiber cytoplasm

Front 55

define muscle fiber

Back 55

elongated skeletal and smooth muscle cells. not cardiac

Front 56

Describe the structure & functions of connective tissue in muscle.

Back 56

Connective Tissue
a. Dense fibrous - dense regular - white fibrous
b. Found throughout the organ (“gristle”) gives internal support.
c. Found surrounding the organ
- Continuous with ligaments, tendons & aponeuroses

Front 57

Name the 6 types of connective tissue found in muscles.

Back 57

1. Endomysium – thin layer of areolar and reticular fibers tissue surrounding each individual muscle fiber (cell)
2) Perimysium: divides each organ into fascicles (bundles of muscle fibers) and contains blood vessels and nerves
3) Epimysium: completely surrounds the entire organ; thick, strong, and very collagenous; continuous with the fascia
4) Fascia; dense fibrous connective tissue around each muscle
5) Tendon; one way muscle attaches to bone; rope-like; is a continuation of the collagen fibers of the epimysium; forms the end of a very strong and continuous collagenous network
6) Aponeurosis; broad, flat sheet of connective (dense fibrous) connective tissue; attaches muscle to bone or muscle to muscle (e.g. abdominal muscles)

Front 58

Define origin/insertion

Back 58

Origin; also called the head, muscle attachment at the stationary end

Insertion – muscle attachment at the end that moves

Front 59

Describe a T-Tubule

Back 59

Transverse tubules; tunnel-like infoldings of the sarcolemma into the interior of the muscle fiber
- carries the action potential from the cell surface into the muscle fiber

Front 60

Describe the contents of the sarcoplasm.

Back 60

a. cytoplasm
b. full of myofibrils
c. lots of mitochondria and sarcoplasmic reticulum

Front 61

What are myofibrils? What is their makeup?

Back 61

are contractile fibers made of (1) contractile proteins
- actin – double helix with active sites to attract myosin heads
- myosin – heads with ATPase to release energy from ATP
and
2) regulatory proteins

Front 62

What are the regulatory proteins in a myofibril?

Back 62

a) troponin complex – small globular protein that covers the active sites on actin when in the resting state.

b) tropomyosin – double strand wraps around actin helix to stiffen actin.

Front 63

What is a sarcomere?

Back 63

repeating striations on skeletal and cardiac muscles made of alternating actin and myosin myofibrils

Front 64

What is the sarcoplasmic reticulum and what does it do?

Back 64

a. smooth endoplasmic reticulum
b. forms a network around each bundle myofibril and alongside T-tubules
c. serve as a reservoir for calcium ions

Front 65

What is the Terminal cisternae?

Back 65

Terminal cisternae
a pair runs alongside T-tubules
- full of calcium ions

Front 66

Name some of the functional characteristics of muscle (4)

Back 66

1. excitability or responsiveness or irritability: response is generation of an impulse.
2. contractility; ability to shorten
3. extensibility: ability to be stretched or extended.
4. elasticity ability to recoil and resume its resting length after being stretched.

Front 67

Describe the nerve and blood supply of a muscle.

Back 67

In general, each muscle is served by one nerve, an artery and one or more veins, all of which enter or exit near the central part of the muscle & branch profusely through its connective tissue sheaths.

Front 68

define
endomysium
perimysium and fascicles
epimysium

Back 68

endomysium: each muscle fiber, areolar & reticular fibers. endo = within

perimysium and fascicles: muscle fibers grouped into fascicles, which are surrounded by fibrous connective perimysium.peri = around

epimysium: overcoat of dense irregular connective surrounds whole muscle. epi=outside

Front 69

What is in great amounts in the sarcoplasm of a muscle cell?

Back 69

unusually large amounts of glycosomes (granules of stored glycogen) and
myoglobin (a red pigment that stores oxygen and is similar to hemoglobin)

Front 70

What are other special organelles only found in the sarcoplasm?

Back 70

myofibrils
sarcoplasmic reticulum

Also, T Tubules are unique modifications of the sarcolemma.

Front 71

What is the sarcomere?

Back 71

Smallest contractile unit of the muscle aka thefunctional unit of muscle.
Starts at Z disc
half an i band
A band
half an i band

Front 72

What do the myosin heads contain?

Back 72

myosin heads contain
- actin binding sites and
- ATP-ase enzymes that generate energy for muscle contraction.

Front 73

Describe actin.

Back 73

- double helix with active sites to attract myosin heads.
- two strands of tropomyosin (a rod shaped protein) spiral about the acin core and help stiffen it..
- when relaxed, the tropomyosin blocks the myosin binding sites on the actin.

Front 74

Describe sarcoplasmic reticulum properties and function.

Back 74

- smooth endoplasmic reticulum
- forms a network around each bundle myofibril and alongside T-tubules
- serve as a reservoir for calcium
ions
- regulates levels of calcium. stores & releases on demand.

Front 75

Describe terminal cisternae

Back 75

"end sacs" occur in pairs at Aband-Iband junctions.
- full if calcium ions.

Front 76

Describe the structure and function of
T tubules

Back 76

At each Aband-Iband junction.
Lumen is continuous with the extracellular space.
- runs between the paired terminal cisternae of the SR so that TRIADS are formed. (cisterna, T tubule, cisterna)
T Tubules are rapid telegraph system, signaling muscle contraction.

Front 77

What are triads?

Back 77

sites of close contact of
terminal cisterna
T tubule
terminal cisterna

Front 78

What is muscle contraction ultimately controlled by?

Back 78

Nerve initiated electrical impulses that travel along the sarcolemma.
B/c T tubules are continuations of the sarcolemma, the conduct impulses to the deepest regions of the muscle cell & to every sarcomere.

The impulses signal for the release of CA from the adjacent terminal cisternae.

Front 79

When does contraction end?

Back 79

When the cross bridges become inactive and the tension generated declines.

Front 80

What is the sliding filament theory of contraction?

Back 80

During contraction, the thin filaments slide past the thick ones so that the actin and myosin filaments overlap to a greater degree.

Front 81

Define motor unit

Back 81

one motor neuron and all the muscle fibers controlled by it
a. can be small - about 20 muscle fibers – fine movement, controlling eye muscles
- can be large - about 1,000 muscle fibers – gross movement - controlling leg muscles

Front 82

Define twitch. What are steps?

Back 82

single contraction/relaxation of one muscle fiber
a. Latent period – time between stimulation and contraction when substance involved are diffusing (acetylcholine, Na+, K+, Ca++)

b. Contraction – shortening of a muscle fiber – Impulse must be strong enough to reach threshold – then the muscle cell will contract.

c. Relaxation – muscle fiber returns to resting potential and lengthens – takes longer to relax than to contract.

Front 83

Define tetany. What are steps?

Back 83

a. Unfused/incomplete – quivering action due to increased summation – more Ca++ is being released than is reabsorbed so more shortening occurs

b. Fused/complete – builds to rigidity – may result in fatigue when all the substances are in full use and can’t cause more contraction, wastes build, ATP runs out, muscle is unable to contract any more

Front 84

Define recruitment

Back 84

more neurons involved stimulating more motor units

Front 85

Define treppe

Back 85

successive stimuli results in more recruitment and the muscle is able to do more work. Increase of contraction in a step-wise way

Front 86

Define isotonic

Back 86

moving the muscle – contracting it to move

Front 87

Define isometric

Back 87

doesn’t shorten, usually when moving a very heavy object -–or pushing/pulling against an immovable object

Front 88

What are the three ways to regenerate ATP?

Back 88

ATP is the ONLY energy source used directly for contractile activites… must be regenerated as fast as it is broken down if contraction is to continue.
After ATP hydrolyzed to ADP + P, it is regenerated Quick by three pathways.
1. ADP + creatine phosphate
2. anaerobic: glycolysis
3. aerobic respiration

Front 89

define muscle fatigue

Back 89

the inability to contract even though the muscle may be still receiving stimuli.

Front 90

define oxygen debt

Back 90

the extra amount of oxygen that the body must take in for restorative processes.

Front 91

What influences the force of muscle contraction? (4 items)

Back 91

1. the number of muscle fibers stimulated.
2. the relative size of the fibers.
3. the frequency of stimulation.
4. the degree of muscle stretch.

Front 92

Define oxygen debt (#2)

Back 92

the difference between the resting rate of oxygen consumption and the elevated rate following an exercise
- extra oxygen taken in after exercise is generally used for
- replacing oxygen reserves in blood and nonmuscle tissues
- replenishing the phosphagen system – produce more CP
- oxidizing lactic acid to pyruvic acid (reenters the aerobic phases of chemical respiration)
- servicing the increased metabolic rate