Anatomy & Physiology exam 2

Muscle Fiber Contraction and Relaxation steps

A sarcomere, smallest contractile portion of a muscle. Myofibrils are composed of thick and thin filaments. Thick filaments are composed of the protein myosin; Thin filaments are composed of the protein actin. Troponin and tropomyosin are regulatory proteins. Muscle contraction = sliding filament model of contraction. ACh is the neurotransmitter that binds at the neuromuscular junction (NMJ) to trigger depolarization, and an action potential travels along the sarcolemma to trigger calcium release from SR. The actin sites are exposed after Ca++ enters the sarcoplasm from its SR storage to activate the troponin-tropomyosin complex so that the tropomyosin shifts away from the sites. The cross-bridging of myosin heads docking into actin-binding sites is followed by the "power stroke"—the sliding of the thin filaments by thick filaments. The power strokes are powered by ATP. The sarcomeres, myofibrils, and muscle fibers shorten to produce movement.

Muscle fatigue is caused by_______ A- BUILDUP OF ATP AND LACTIC ACID LEVELS B- EXAUSTATION OF ENERGY RESERVES AND BUILDUP OF LATIC ACIDS LEVELS C- BUILD ATP D- BUILD UP OF CREATINE

B- exhaustion of energy reserves and buildup of lactic acid levels

Which element is important in directly triggering contraction ? A-SODIUM(Na+) B-CALCIUM (Ca++) C-POTASSIUM (K+) D-CLORIDE (CL-)

Calcium (CA++)

cardiac, striated, and involuntary- autorhythmic

Cardiac Muscle

Vitamin D role in bone formation

Causes calcium + phosphorus to deposit in the bones Strengthens bones

Compact Bone vs. Spongy/Cancellous Bone

Compact bone is dense so that it can withstand compressive forces, while spongy (cancellous) bone has open spaces and supports shifts in weight distribution.

The neurotransmitter released by motor neurons that stimulates skeletal muscle is called A-ACETYLCHOLINE ESTERASE B-NON-EPINEPHRINE C-EPINEPHRINE D- NONE OF THE ABOVE

D- NONE OF THE ABOVE ( ACH-acetylcholine)

Muscle that has a striped appearance is described as being ________. a. elastic b. nonstriated c. excitable d. striated

D-STRIATED

Which of the following statements describes smooth muscle cells? a. They are resistant to fatigue. b. They have a rapid onset of contractions. c. They cannot exhibit tetanus. d. They primarily use anaerobic metabolism.

a. They are resistant to fatigue.

Which of the following statements describes smooth muscle cells? a. They are resistant to fatigue. b. They have a rapid onset of contractions. c. They cannot exhibit tetanus. d. They primarily use anaerobic metabolism.

a. They are resistant to fatigue.

The area of a bone where the nutrient foramen passes forms what kind of bone marking? a. a hole b. a facet c. a canal d. a fissure

a. a hole

Wolff's law, which describes the effect of mechanical forces in bone modeling/remodeling, would predict that ________ a. a right-handed pitcher will have thicker bones in his right arm compared to his left. b. a right-handed cyclist will have thicker bones in her right leg compared to her left. c. a broken bone will heal thicker than it was before the fracture. d. a bed-ridden patient will have thicker bones than an athlete.

a. a right-handed pitcher will have thicker bones in his right arm compared to his left.

Yellow marrow has been identified as ________. a. an area of fat storage b. a point of attachment for muscles c. the hard portion of bone d. the cause of kyphosis

a. an area of fat storage

Bones grow in length due to activity in the ________. a. epiphyseal plate b. perichondrium c. periosteum d. medullary cavity

a. epiphyseal plate

Which of the following hormones are responsible for the adolescent growth spurt? a. estrogen and testosterone b. calcitonin and calcitriol c. growth hormone and parathyroid hormone d. thyroxine and progesterone

a. estrogen and testosterone

Bones that surround the spinal cord are classified as ________ bones. a. irregular b. sesamoid c. flat d. short

a. irregular

Smooth muscles differ from skeletal and cardiac muscles in that they ________. a. lack myofibrils b. are under voluntary control c. lack myosin d. lack actin

a. lack myofibrils

Which category of bone is among the most numerous in the skeleton? a. long bone b. sesamoid bone c. short bone d. flat bone

a. long bone

The cells of muscles, myocytes, develop from ________. a. myoblasts b. endoderm c. fibrocytes d. chondrocytes

a. myoblasts

The fibrous membrane covering the outer surface of the bone is the ________. a. periosteum b. epiphysis c. endosteum d. diaphysis

a. periosteum

Striations, cylindrical cells, and multiple nuclei are observed in ________. a. skeletal muscle only b. cardiac muscle only c. smooth muscle only d. skeletal and cardiac muscles

a. skeletal muscle only

Depolarization of the sarcolemma means ________. a. the inside of the membrane has become less negative as sodium ions accumulate b. the outside of the membrane has become less negative as sodium ions accumulate c. the inside of the membrane has become more negative as sodium ions accumulate d. the sarcolemma has completely lost any electrical charge

a. the inside of the membrane has become less negative as sodium ions accumulate

All of the following play a role in calcium homeostasis except a. thyroxine b. calcitonin c. parathyroid hormone d. vitamin D

a. thyroxine

Calcium cannot be absorbed from the small intestine if ________ is lacking. a. vitamin D b. vitamin K c. calcitonin d. fluoride

a. vitamin D

Striations

actin and myosin filaments which form a banded pattern, alternate dark and light bands found on skeletal and cardiac muscle

During muscle contraction, myosin cross bridges attach to which active sites?

actin filaments

formation of new bone______

always stars us a cartilage bone

Which element is important in directly triggering contraction? a. sodium (Na+ ) b. calcium (Ca++) c. potassium (K+ ) d. chloride (Cl- )

b. Calcium (Ca++)

. How can a fractured diaphysis release fat globules into the bloodstream? a. The bone pierces fat stores in the skin. b. The yellow marrow in the diaphysis is exposed and damaged. c. The injury triggers the body to release fat from healthy bones. d. The red marrow in the fractured bone releases fat to heal the fracture

b. The yellow marrow in the diaphysis is exposed and damaged.

In endochondral ossification, what happens to the chondrocytes? a. They develop into osteocytes. b. They die in the calcified matrix that surrounds them and form the medullary cavity. c. They grow and form the periosteum. d. They group together to form the primary ossification center

b. They die in the calcified matrix that surrounds them and form the medullary cavity.

The nerve impulse travels down a(n) ________, away from the cell body. a. dendrite b. axon c. microglia d. collagen fiber

b. axon

Bones grow in diameter due to bone formation ________. a. in the medullary cavity b. beneath the periosteum c. in the epiphyseal plate d. within the metaphysis

b. beneath the periosteum

The skeletal system is made of ________. a. muscles and tendons b. bones and cartilage c. vitreous humor d. minerals and fat

b. bones and cartilage

Which of the following is most likely to be released when blood calcium levels are elevated? a. thyroxine b. calcitonin c. parathyroid hormone d. vitamin D

b. calcitonin

Which of the following can be found in areas of movement? a. hematopoiesis b. cartilage c. yellow marrow d. red marrow

b. cartilage

The diaphysis contains ________. a. the metaphysis b. fat stores c. spongy bone d. compact bone

b. fat stores

A fracture can be both ________. a. open and closed b. open and transverse c. transverse and greenstick d. greenstick and comminuted

b. open and transverse

Which cells do not originate from osteogenic cells? a. osteoblasts b. osteoclasts c. osteocytes d. osteoprogenitor cells

b. osteoclasts

Which function of the skeletal system would be especially important if you were in a car accident? a. storage of minerals b. protection of internal organs c. facilitation of movement d. fat storage

b. protection of internal organs

Which function of the skeletal system would be especially important if you were in a car accident? a. storage of minerals b. protection of internal organs c. facilitation of movement d. fat storage

b. protection of internal organs

The cell membrane of a muscle fiber is called ________. a. myofibril b. sarcolemma c. sarcoplasm d. myofilament

b. sarcolemma

Most of the bones of the arms and hands are long bones; however, the bones in the wrist are categorized as ________. a. flat bones b. short bones c. sesamoid bones d. irregular bones

b. short bones

During muscle contraction, the cross-bridge detaches when ________. a. the myosin head binds to an ADP molecule b. the myosin head binds to an ATP molecule c. calcium ions bind to troponin d. calcium ions bind to actin

b. the myosin head binds to an ATP molecule

The internal and external calli are replaced by ________. a. hyaline cartilage b. trabecular bone c. osteogenic cells d. osteoclasts

b. trabecular bone

Fascicle

bundle of muscle fibers within a skeletal muscle

Which of the following properties is not common to all three muscle tissues? a. excitability b. the need for ATP c. at rest, uses shielding proteins to cover actin-binding sites d. elasticity

c. at rest, uses shielding proteins to cover actin-binding sites

Why is cartilage slow to heal? a. because it eventually develops into bone b. because it is semi-solid and flexible c. because it does not have a blood supply d. because endochondral ossification replaces all cartilage with bone

c. because it does not have a blood supply

Muscle relaxation occurs when ________. a. calcium ions are actively transported out of the sarcoplasmic reticulum b. calcium ions diffuse out of the sarcoplasmic reticulum c. calcium ions are actively transported into the sarcoplasmic reticulum d. calcium ions diffuse into the sarcoplasmic reticulum

c. calcium ions are actively transported into the sarcoplasmic reticulum

Ligaments connect bones together and withstand a lot of stress. What type of connective tissue should you expect ligaments to contain? a. areolar tissue b. adipose tissue c. dense regular connective tissue d. dense irregular connective tissue

c. dense regular connective tissue

Skeletal muscle is composed of very hard working cells. Which organelles do you expect to find in abundance in skeletal muscle cell? a. nuclei b. striations c. golgi bodies d. mitochondria

c. golgi bodies

Which of the following occurs in the spongy bone of the epiphysis? a. bone growth b. bone remodeling c. hematopoiesis d. shock absorption

c. hematopoiesis

Which one of the following foods is best for bone health? a. carrots b. liver c. leafy green vegetables d. oranges

c. leafy green vegetables

Long bones enable body movement by acting as a ________. a. counterweight b. resistive force c. lever d. fulcrum

c. lever

Without red marrow, bones would not be able to ________. a. store phosphate b. store calcium c. make blood cells d. move like levers

c. make blood cells

The correct order for the smallest to the largest unit of organization in muscle tissue is ________. a. fascicle, filament, muscle fiber, myofibril b. filament, myofibril, muscle fiber, fascicle c. muscle fiber, fascicle, filament, myofibril d. myofibril, muscle fiber, filament, fascicle

c. muscle fiber, fascicle, filament, myofibril

From which embryonic cell type does muscle tissue develop? a. ganglion cells b. myotube cells c. myoblast cells d. satellite cells

c. myoblast cells

Which of the following are incapable of undergoing mitosis? a. osteoblasts and osteoclasts b. osteocytes and osteoclasts c. osteoblasts and osteocytes d. osteogenic cells and osteoclasts

c. osteoblasts and osteocytes

The first type of bone to form during fracture repair is ________ bone. a. compact b. lamellar c. spongy d. dense

c. spongy

If cardiac muscle cells were prevented from undergoing aerobic metabolism, they ultimately would ________. a. undergo glycolysis b. synthesize ATP c. stop contracting d. start contracting

c. stop contracting

Osteoblasts

cell responsible for forming new bone

osteoclast

cell responsible for resorbing bone

epiphyseal line

completely ossified remnant of the epiphyseal plate

Why are osteocytes spread out in bone tissue? a. They develop from mesenchymal cells. b. They are surrounded by osteoid. c. They travel through the capillaries. d. Formation of osteoid spreads out the osteoblasts that formed the ossification centers

d. Formation of osteoid spreads out the osteoblasts that formed the ossification centers

Which of the following represents the correct sequence of zones in the epiphyseal plate? a. proliferation, reserved, maturation, calcification b. maturation, proliferation, reserved, calcification c. calcification, maturation, proliferation, reserved d. Resting, Proliferative, hypertrophy, calcified

d. Resting, Proliferative, hypertrophy, calcified

. In a compound fracture, ________. a. the break occurs at an angle to the bone b. the broken bone does not tear the skin c. one fragment of broken bone is compressed into the other d. broken bone pierces the skin

d. broken bone pierces the skin

With respect to their direct effects on osseous tissue, which pair of hormones has actions that oppose each other? a. estrogen and testosterone b. calcitonin and calcitriol c. estrogen and progesterone d. calcitonin and parathyroid hormone

d. calcitonin and parathyroid hormone

According to the sliding filament model, binding sites on actin open when ________. a. creatine phosphate levels rise b. ATP levels rise c. acetylcholine levels rise d. calcium ion levels rise

d. calcium ion levels rise

Cardiac muscles differ from skeletal muscles in that they ________. a. are striated b. utilize aerobic metabolism c. contain myofibrils d. contain intercalated discs

d. contain intercalated discs

Cardiac muscles differ from skeletal muscles in that they ________. a. are striated b. utilize aerobic metabolism c. contain myofibrils d. contain intercalated discs

d. contain intercalated discs

Bone tissue can be described as ________. a. dead calcified tissue b. cartilage c. the skeletal system d. dense, hard connective tissue

d. dense, hard connective tissue

When calcium levels are too high or too low, which body system is primarily affected? a. skeletal system b. endocrine system c. digestive system d. nervous system

d. nervous system

Drug X blocks ATP regeneration from ADP and phosphate. How will muscle cells respond to this drug? a. by absorbing ATP from the bloodstream b. by using ADP as an energy source c. by using glycogen as an energy source d. none of the above

d. none of the above

In bone, the main cells are ________. a. fibroblasts b. chondrocytes c. lymphocytes d. osteocytes

d. osteocytes

In relaxed muscle, the myosin-binding site on actin is blocked by ________. a. titin b. troponin c. myoglobin d. tropomyosin

d. tropomyosin

compact bone

dense osseous tissue that can withstand compressive forces

ATPase

enzyme that catalyzes hydrolysis of ATP

Matrix

extracellular material which is produced by the cells embedded in it, containing ground substance and fibers

Periosteum

fibrous membrane covering the outer surface of bone and continuous with ligaments

ground substance

fluid or semi-fluid portion of the matrix

bone

hard, dense connective tissue that forms the structural elements of the skeleton

parathyroid hormone (PTH)

increases blood calcium levels

What's a binding site for ACH?

is located in the muscle cells. nAChRs nicotinic receptors at the muscular junctions

Myofibril

long, cylindrical organelle that runs parallel within the muscle fiber and contains the sarcomeres

The epiphyseal plate is responsible for

longitudinal bone growth

Sarcomere

longitudinally, repeating functional unit of skeletal muscle, with all of the contractile and associated proteins involved in contraction

myoblasts

muscle forming stem cells

myofibrils are composed of protein subunits called

myofilaments

Acetylcholine (ACh)

neurotransmitter that binds at a motor end-plate to trigger depolarization

intercalated discs

part of the sarcolemma that connects cardiac tissue, and contains gap junctions and desmosomes

sarcolemma

plasma membrane of a skeletal muscle fiber

Osteocytes

primary cell in mature bone; responsible for maintaining the matrix

T-tubules (transverse tubules)

projection of the sarcolemma into the interior of the cell

Myosin

protein that makes up most of the thick cylindrical myofilament within a sarcomere muscle fiber

Actin

protein that makes up most of the thin myofilaments in a sarcomere muscle fiber

troponin

regulatory protein that binds to actin, tropomyosin, and calcium

Tropomyosin

regulatory protein that covers myosin-binding sites to prevent actin from binding to myosin

What hormone is released when Blood Ca++ levels is low? (hypocalcemia)

release PTH - Parathyroid hormone

Sarcolemic Reticulum

releases calcium during muscle contraction and absorbs them during relaxation

ACh esterase

remove, decompose ACh left in the synaptic cleft after it stops being released- chemically destroy the molecules left over

Neurotransmitters

signaling chemical released by nerve terminals that bind to and activate receptors on target cells

skeletal, striated, and voluntary.

skeletal muscle

la cuna

small spaces in bone or cartilage tissue that cells occupy

sarcoplasmic reticulum (SR)

specialized smooth endoplasmic reticulum, which stores, releases, and retrieves Ca++

smooth muscle

Involuntary, moves internal organs, non-striated, each cell is a fiber, mononucleated muscle in the skin that is associated with hair follicles; assists in moving materials in the walls of internal organs, blood vessels, and internal passageways

calcitonin hormone

Lowers blood calcium levels

who activates or disactivates myosin light chains at smooth muscle?

ML chains needs to be activated before short contraction (phosphorylation) Kinase is the enzyme that activates Myosin light chains

cardiac muscle

striated muscle found in the heart, Involuntary, auto rhythmic, multinucleated, intercalated discs, pump blood through the circulatory system

troponin role

switch that controls the interaction between the actin filaments and myosin head

Triad

the grouping of one T-tubule and two terminal cisternae

thick filaments

the thick myosin strands and their multiple heads projecting from the center of the sarcomere toward, but not all to way to, the Z-discs

thin filament

thin strands of actin and its troponin-tropomyosin complex projecting from the Z-discs toward the center of the sarcomere

diaphysis

tubular shaft that runs between the proximal and distal ends of a long bone

muscle tissue

type of tissue that is capable of contracting and generating tension in response to stimulation; produces movement.

Epiphysis

wide section at each end of a long bone; filled with spongy bone and red marrow

bone tissue

Periosteum (strength to the bone provide attachment), Outermost covering, dense, irregular CT

The cell membrane of a muscle is called Sarcoplasm

Sarcolemma

Thin and thick filaments are organized into functional units called ________. A-MYOFIBRILS B-SARCOMERES C-T-TUBULES D-TERMINA CISTERNS

Sarcomeres

visceral, nonstriated, involuntary

Smooth Muscle

The place where calcium ions are restored back at the end of muscle contraction is called the__________ A- TRANVERSE TUBULES B- TROPONIN C- BACK IN BLOOD D-BONES E-TERMINA CISTERN

Termina Cistern

myosin role in muscle contraction

The globular heads of myosin bind actin, forming cross-bridges between the thick and thin filaments. uses energy from ATP (ATP hydrolysis-cross bridge formation)

During muscle contraction, myosin cross bridges detaches when______? A-THE MYOSIN HEAD HYDROLYZED ATP MOLECULE B-THE MYOSIN HEAD BINDS TO CREATINE MOLECULE C-THE MYOSIN HEAD BINDS TO CALCIUM D-THE MYOSIN ION BIND TO ACTIN E-CALCIUM IONS BIND TO TROPONIN

The myosin head hydrolyze ATP molecule

periosteum is made of?

The periosteum consists of an outer "fibrous layer" and inner "cambium layer".

Eletrical Signal travels

UMJ-LMN-NMJ

spongy bone

(also, cancellous bone) trabeculated osseous tissue that supports shifts in weight distribution (has open spaces)

ossification

(also, osteogenesis) bone formation

CA_++ Homeostasis

-Intraosseous CA++ (inside bone,*99% ) -Intracellular (0.001%) -Intra vascular (blood) -Interstitial fluid

bone repair steps

1-hematoma forms 2- cartilage callus forms 3-calcified bony callus formation 4-remoldeling the bone

Distal Epiphyseal plate (growth plate) flip

1-zone calcified bone formation 2-zone hypertrophied cartilage 3-zone proliferative cartilage 4-zone resting cartilage

proximal epiphyseal plate (growth plate)

1-zone resting cartilage 2-zone proliferative cartilage 3-zone hypertrophied cartilage 4-zone calcified bone formation