Muscle, Bone, SKin

Question 1

H Zone

Answer 1

Only has myosin. The middle zone

Question 2

M line

Answer 2

line going down the middle of the H zone

Question 3

A Band

Answer 3

The thick band. Has both actin and myosin. A band includes the H zone. Covers most of the sarcomere in the middle

Question 4

I band

Answer 4

only has actin. Thin band. Covers regions of two separate sarcomeres

Question 5

What makes up a muscle? From the smallest unit to a muscle. What’s a muscle cell, also known as muscle fiber?

Answer 5

Myofibril –> sarcomeres wrapped around in sheet, sarcolemma covering it up. Several myofibrils wrapped by sarcolemma have multiple nuclei and mitochondria embedded between above, and around the bundle of myofibrils. This bundle make up a muscle cell (muscle fiber). Several muscle cells make up a muscle fascicle, which is a bundle of muscle cells. Muscle fascicles then make up a muscle.

Question 6

Muscle fascicle

Answer 6

A bundle of muscle fibers which are bundles of muscle cells

Question 7

relationship between T-tubule and sarcoplasmic reticulum

Answer 7

the action potential is transferred from T-tubule to the sarcoplasmic reticulum to contract the muscle

the ion channels get activated in the sarcolemma creating an action potential that travels down into the T-tubules then into the sarcoplasmic reticulum which releases the calcium ions

Question 8

Physiology of skeletal muscle contraction. Describe the states of myosin when the ATP, and ADP+PI are on. What happens when ADP+PI is dislodged. What happens when the ATP is added on again?

Answer 8

myosin head is straight up with ADP+PI, its default mode. once tropomyosin exposes the binding site (calcium attached to troponin), the myosin head attaches to the actin binding site forming a cross bridge)`. The removal of ADP+PI causes the head to tilt, causing the contraction of the muscle.

Attachment of ATP to myosin dislodges the myosin from the actin. The head is still tilted. But catalysis of ATP to ADP+PI causes the head to tilt.

Question 9

Muscle fatigue

Answer 9

running out of ATP, unable to generate a muscle contraction

Question 10

Type I

Contraction time, force production, resistance to fatigue, activity

Aerobic or anaerobic

Where is it found?

Answer 10

Slow twitch

Red - lots of myoglobin

Contracts slowly, weak force production but resistant to fatigue; Force distributed over a long period of time

more efficient at using oxygen to generate more fuel (known as ATP) for continuous, extended muscle contractions over a long time. They fire more slowly than fast twitch fibers and can go for a long time before they fatigue - marathon and bicycle for a long time

Aerobic

postural muscles

Question 11

Type II - A

Contraction time, force production, resistance to fatigue, activity, myoglobin content, where it’s found

Long or short term; Aerobic or anaerobic oxidation

Answer 11

AKA: Fast/Oxidative twitch

Appears Red (lots of myoglobin)

Upper Legs

fast contraction time, strong force, easy to fatigue

short term anaerobic activity, can be aerobic

Question 12

Type II - B

Contraction time, force production, resistance to fatigue, activity, myoglobin content

Answer 12

AKA: glycolytic twitch - lots of glycogen

B - white (low myoglobin, lots of glycogen, appear white)

upper arms

Fast contraction time, really strong force, easy to fatigue,

long term anaerobic activity

Question 13

Cardiac muscle -

Is it striated?

multi or single nucleus

what is intercalated discs in cardiac muscle

Answer 13

Striated (has sarcomeres)

single nucleated

intercalated dics - has gap junctions that allow an easy electrical flow between the cells through the synapse, easy synchronization of the contraction of the cardiac muscle cells - make the cell function like a net that contracts upon it self like squeezing a fist

Question 14

Why is the repolarization time much longer in the heart? What is the importance of calcium in the heart contraction?

Answer 14

Calcium lingers much longer inside the cell - slow voltage gated calcium channels

It lengthens the time of the contraction - preventing a new action potential from starting in the middle of the previous contraction. This prevent tetanus that happens in the skeletal muscles which can be deadly in the heart

Question 15

Smooth muscle - striation, nucleation, structure

How does the smooth muscle contract?

Answer 15

No striation (no sarcomeres)

single nucleus

organized into dense bodies. contain intermediate filaments (like actin) which are attached to dense bodies distributed throughout the cell (network of highways). Upon contraction, this dense network system causes the smooth muscle cell to contract and shrink

Question 16

How are the single units of smooth muscle cells connected?

Answer 16

connected by gap junctions

Question 17

Osteoblast and osteocyte

Can they both multiply?

Answer 17

osteocyte is an osteoblast trapped in lacunae that communicate via canaliculi - differentiated version of osteoblast.

both can’t multiply

osteoblast secrete collagen (matrix - network it surrounds itself in).

Question 18

Differentiation of osteoblast

Answer 18

osteocyte

Question 19

Function of osteocyte

Answer 19

exchanges nutrients and waste with the blood. Osteoblast and osteocyte both can’t multiply. Specialized in mediating input and output

Question 20

Osteoclast are thought to have developed from what?

Answer 20

WBC - monocytes

Question 21

Epiphyseal plate

Answer 21

sheet of hyaline cartilage between metaphysis and epiphysis in the long bone

grows in response to growth hormone in childhood and adolescence

Question 22

long shaft of bone

Answer 22

diaphysis

Question 23

Spongy bone vs. compact bone

Answer 23

Spongy bone (trabecular bone) - contain red bone marrow; RBC formation and storage

Compact bone (cortical bone) - surrounds the hollow cavity called the medullary cavity, contain yellow bone marrow; adipose cells for fat storage

Question 24

Remodeling in the bone

Answer 24

formation of osteon by osteoclast and osteoblast

osteoclast tunnels and makes way, osteoblast then adds on the matrix on the tunnel wall, making concentric rings called the lamellae. Osteoblasts leave open space in the center of lamellae to for Haversian canals which include blood and lymph nodes

Question 25

Calcium solubility in blood

Answer 25

only slightly soluble in blood - not found in free forms in the blood usually bound to phosphates, and other anions

Question 26

Joint

Answer 26

where bones connect

Question 27

Fibrous joint

Answer 27

two bones held closely and tightly together by fibrous connective tissues. Extremely minimal movement; teeth connected to the mandible, skull bones

Question 28

Cartilaginous joints

Answer 28

two bones tightly connected by the cartilage such as the ribs and sternum. allow little movement

Question 29

Synovial joints What is it? Range of movement What is significant about synovial fluid? Function?

Answer 29

not directly bound b the intervening cartilage wide range of movement is possible; shoulder and knee two bones are separated by a capsule filled with synovial fluid that provide nourishment and lubrication to the cartilage. The synovial fluid contains phagocytic cells that remove microbes and particles.

Question 30

90% of epidermis is composed of _______

Answer 30

keratinocytes

Question 31

Keratinocytes where is it

Answer 31

cells that produce keratin epidermis

Question 32

Melanocytes where is it

Answer 32

transfer melanin to keratinocytes epidermis

Question 33

Langerhans cells where is it

Answer 33

interact with the helper T cells of the immune system epidermis

Question 34

Merkel cells where is it

Answer 34

attach to the sensory neurons and function in the sensation of touch epidermis

Question 35

The deepest layer of the epidermis contain _____ and _____ cells

Answer 35

Merkel cells, and stem cells

Question 36

tendon

Answer 36

muscle to bone

Question 37

ligament

Answer 37

bone to bone

Question 38

the origin of the muscle which part of the muscle, where it attaches to, and the breadth of movement, and how close it is to the midpoint of the body

Answer 38

point on the muscle that attaches to a larger bone and remains relatively stationary closest to the midpoint of the body

Question 39

the insertion of the muscle where it is on the muscle, where it attaches to, how close it is to the midpoint

Answer 39

farthest from the origin attached to small bones and farthest from the midpoint of the body

Question 40

how do synergistic muscles help the agonist muscles

Answer 40

help the agonist muscle by stabilizing the origin or by positioning the insertion bone during the movement

Question 41

The shivering reflex: what muscle does it contract? what is the purpose? and how does it affect the body?

Answer 41

the shivering reflex affects the skeletal muscles. it is controlled by the hypothalamus upon stimulation from the skin and spinal cord it happens because there is glycogen storage in the skeletal muscles so the body tries to release the energy so that it can provide heat for the body

Question 42

is there mitochondria and nucleus within the muscle fibril/muscle cell?

Answer 42

nope but around it between the muscle fibrils

Question 43

levels of organization of the muscle

Answer 43

from smallest to biggest bundles within bundles within bundles muscle cell/muscle fibril --> fiber --> fascicle

Question 44

distinction of heart's mitochondria

Answer 44

large and ample for production of ATP

Question 45

functionality of the slow repolarization of the heart muscle

Answer 45

it gives the heart enough time to refill with blood and prevents tetanus, the sustained contraction that can occur in skeletal muscle that could be deadly if it occurred in the heart

Question 46

where do intercalated discs occur

Answer 46

in the Z line - desmosomes and gap junctions forming a fused mass of cells

Question 47

What's responsible for the plateau after depolarization? and what is the charge inside the membrane? what is the purpose of slower rate of repolarization of the cardiac muscle?

Answer 47

slow voltage-gated calcium channels which allow calcium to enter and maintain the inside of the membrane at a positive potential difference as a result, the repolarization of the cardiac muscle is slower and more frequent than that of skeletal muscle The action potentials of cardiac muscle are unusually sustained. This prevents premature relaxation, maintaining initial contraction until the entire myocardium has had time to depolarize and contract

Question 48

are smooth muscles organized into sarcomeres?

Answer 48

nope

Question 49

what are dense bodies in the smooth muscle cells

Answer 49

dense bodies function as Z lines in the skeletal muscle containing actinin and Z-line proteins the intermediate filaments are attached to the dense bodies, being organized into a network

Question 50

single unit vs. multi-unit of smooth muscle

Answer 50

depends on the attachment of autonomic neuron to the smooth muscle cells. in a single unit, autonomic neuron attaches to a single mass of smooth muscle cells connected by gap junctions so that electrical activity travels down fast in multi unit, each muscle cell is attached to one or more than one neuron. each fiber is attached directly to a neuron so each group of multi-unit smooth muscle fibers can contract independently of other

Question 51

where are single unit smooth muscles found? where are the multi unit smooth muscles found?

Answer 51

single unit - small arteries, veins, stomach, intestines, uterus, urinary bladder multi unit - large arteries, bronchioles, pili muscle attached to hair follicles and the iris

Question 52

what is the dermis of the skin what does it contain

Answer 52

connective tissue derived from mesodermal cells blood vessels, nerves, glands, and hair follicles, collagen and elastin fibers sensation of touch: pressure, pain, temperature

Question 53

what is in the subcutaneous layer?

Answer 53

fat functioning as a heat insulator for the body some nerve endings reaching deep down into the fat layer

Question 54

in the epidermis: what is in the corneum, granulosum, spinosum, and basale

Answer 54

corneum: keratinized cells granulosum: granular cells spinosum: spinous cells

Question 55

what is cartilage mainly consisted of what happens if cartilage is worn out and bones grind against each other

Answer 55

collagen osteoarthritis

Question 56

what is a hyaline cartilage?

Answer 56

it's the most common type of cartilage that reduces friction and absorbs shock in joints

Question 57

fibrous joints

Answer 57

two bones held closely and tightly together by a fibrous connective tissue permitting minimal movement teeth with the mandible after early childhood, skull bones form fibrous joints with each other, strengthening and hardening the skull

Question 58

cartilaginous joints

Answer 58

little movement bones connected by cartilage ribs and sternum

Question 59

synovial joints

Answer 59

not bound directly by intervening cartilage so a wide range of movement is possible separated by a capsule called synovial fluids - lubrication and nourishment to the cartilage, contain phagocytotic cells that remove microbes and particles shoulder and knee between femur and tibia

Question 60

types of joints

Answer 60

differ by the range of movement what's holding the two bones together

Question 61

what do osteoblasts secrete are they capable of mitosis when they trap themselves with the matrix material they release, what do they differentiate to

Answer 61

secrete collagen and organic compounds upon which the bone is formed incapable of mitosis trap themselves and become osteocytes

Question 62

what do osteocytes do do they mutilply by mitosis?

Answer 62

exchange nutrients and waste materials with the blood. ex. release Ca2+ in response to PTH cannot under mitosis - can't multiply to replace more cells

Question 63

how do osteoclasts develop

Answer 63

develop from monocytes

Question 64

What is the myofibrils wrapped in

Answer 64

Sarcoplasmic reticulum

Question 65

Myofibril is wrapped in what layers?

Answer 65

Sarcoplasmic reticulum and sarcolemma

Question 66

Type 1 muscle

Answer 66

Red muscle, less powerful; slower of contract In the calf Slower to control and slower to fatigue; marathon

Question 67

Type 2 muscle

Answer 67

White, biceps Faster to contract and faster to fatigue

Question 68

Are cardiac muscles striated? Describe cardiac muscles

Answer 68

Yes Involuntary, intercalated discs, only one nucleus, not attached to a bone. They are connected via intercalated discs which has gap junctions between them.

Question 69

Smooth muscle

Answer 69

Dense bodies Actin filaments radiate from dense bodies One nucleus; NOT striated