Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

MCAT Biological Sciences > Chapter 11- The Musculoskeletal System > Flashcards

Chapter 11- The Musculoskeletal System Flashcards

You may prefer our related Brainscape-certified flashcards:
MCAT flashcards
1
Q

3 types of muscle

A
  1. skeletal (supporting body/ voluntary movement)
  2. smooth (involuntary movement/ peristalsis)
  3. cardiac (maintain rhythmic contraction of heart w/o NS input)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

sarcomeres

A

basic contractile unit of skeletal muscle. made of thick and thin filaments. thick are bundles of myosin. thin are made of actin (troponin and tropomyosin help regulate interaction b/w thin and thick)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

different fibers in skeletal muscle

A 
red fibers (aka. slow-twitch fibers)- high myoglobin content
white fibers (aka. fast-twitch fibers)- contain less myoglobin
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

smooth vs skeletal muscle nuclei

A

skeletal- multinucleated

smooth- single nucleus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

tonus

A

constant state of low-level contraction by smooth muscle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

myogenic activity

A

smooth muscle can contract without NS input. muscle cells contract directly in response to stretch or other stimuli. both smooth and cardiac exhibit myogenic activity.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

cardiac muscle characteristics

A

autonomic NS. appears striated. may contain two nuclei, usually only one. each cell is connected by intercalated discs which contain gap junctions (cytoplasm is shared b/w those cells)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

what is required for muscle contraction?

A

Ca2+ and ATP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

I-band

A

only thin filaments

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

H-zone

A

only thick filaments

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

which band always remains constant with respect to size

A

A-band

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

which structure separates each sarcomere

A

Z-line

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

sarcoplasmic reticulum (SR)

A

cover myofibrils. modified endoplasmic reticulum with high Ca2+ concentration.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

sarcolemma

A

cell membrane of myocyte. capable of propagating and distributing action potential.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

myocyte

A

muscle cell

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

where does Acetylcholine bind during an action potential

A

receptors on the sarcolemma, causing depolarization

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

what is responsible for the powerstroke in muscle movement

A

the dissociation of ADP and P from myosin. the binding of ATP is required for releasing the myosin head from the actin filament.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

without Ca2+…

A

myosin-binding sites will be covered by tropomyosin and contraction will be prevented

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

tetanus

A

very frequent contractions so that the muscle is unable to relax. this can cause muscle fatigue

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

creatine phosphate

A

created by transferring phosphate from ATP to creatine during times of rest (1 way to reserve energy b/c it can be reversed quickly to generate ATP quickly)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

axial skeleton

A

skull, vertebral column, ribcage, hyoid bone (small bone in anterior of neck used for swallowing.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

appendicular skeleton

A

bones of limbs, pectoral girdle, and pelvis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

skeleton is created from 2 major components

A

bone and cartilage

24
Q

3 major segments of bone

A
  1. epiphysis (ends)
  2. metaphysis(near the end)
  3. diaphysis (middle long part)
25
Q

epiphysis

A

epiphyseal plate (growth plate, site of longitudinal growth), spongy bone, periosteum (muscle attachment here/ fibrous sheet that surrounds long bones)

26
Q

diaphysis

A

periosteum, compact bone, marrow cavity

27
Q

compact bone vs. spongy/cancellous bone

A

compact- strong and dense, outermost bone

s/c- lattice structure with trabeculae filled with bone marrow, internal core of bone

28
Q

bone marrow

A

red marrow- hematopoietic stem cells (generate all cells in blood)
yellow marrow- made of fat and is relatively inactive

29
Q

tendons

A

attach muscle to bone

30
Q

ligaments

A

pieces of fibrous tissue that connect bones together at joints. strengthen movable joints.

31
Q

bone matrix

A

organic (collagen, glycoproteins, peptides) and inorganic (Ca, phosphate, hydroxide ions all together form hydroxyapatite crystals) components

32
Q

osteons/ Haversian systems

A

structural units of bony matrix.

33
Q

lamellae

A

each osteon contains concentric circles of bony matrix.

34
Q

Haversian canals

A

longitudinal channels (those with axis parallel to the bone)

35
Q

Volkmann’s canals

A

transverse channels (those with an axis perpendicular to the bone)

36
Q

lacunae

A

between lamellar rings are these small spaces. these house mature bone cells known as osteocytes.

37
Q

canaliculi

A

lacunae are interconnected by tiny channels which allow for the exchange of nutrients and wastes between osteocytes and the Haversian and Volkmann’s canals

38
Q

osteoblast vs. osteoclast

A

blast- builds bone (uses Ca and phosphate from bone)

clast- chew bone, macrophages of bone and resorb it.

39
Q

parathyroid hormone

A

peptide hormone released by the parathyroid glands in response to low blood Ca, promotes resorption of bone, increasing the concentration of Ca and phosphate in the blood

40
Q

Vitamin D

A

activated by parathyroid hormone also promotes the resorption of bone.

41
Q

calcitonin

A

a peptide hormone released by the parafollicular cells of the thyroid in response to high blood calcium, promotes bone formation, lowering blood calcium levels

42
Q

cartilage

A

chondrin (secreted by cells called chondrocytes)- softer and more flexible than bone

43
Q

endochondral ossification

A

hardening of cartilage into bone. responsible for formation of most long bones in body.

44
Q

intramembranous ossification

A

undifferentiated embryonic connective tissue (mesenchymal tissue) is transformed into and replaced by bone— this occurs in the skull

45
Q

immovable joints

A

bones fused together to form sutures or similar fibrous joints (found in head, anchor bones of skull together)

46
Q

movable joints

A

joints (elbow/ knee), ball-and-socket joints (shoulder/ hip)

47
Q

what do ligaments consist of

A

synovial capsule (encloses actual joint cavity-articular cavity)

48
Q

synovium

A

layer of soft tissue that secretes synovial fluid (lubricates movement of structures in the joint space)

49
Q

articular cartilage

A

contributes to the joint by coating the articular surfaces of the bones so that impact is restricted to the lubricated joint cartilage

50
Q

synergistic

A

working together to accomplish the same function

51
Q

flexor and extensor

A

antagonistic pairs. flexor- decreases angle across joint. extensor- increases this angle.

52
Q

abductor

A

moves part of body away from midline

53
Q

adductor

A

moves part of body toward the midline

54
Q

medial vs. lateral rotation

A

m- rotating axis toward midline

l- rotating axis away from midline

55
Q

what causes Ca2+ release from bones

A

parathyroid

MCAT Biological Sciences (12 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions