Chapter 6, 9, 10 Flashcards
Bones are repositories for calcium and phosphorous.
T or F
T
Osteoblasts come from mesenchymal precursor cells.
T or F
T
Osteocytes monitor and maintain the bone matrix. Osteoclasts break down the bone matrix.
T or F
T
Osteon are composed of concentric rings and are found in spongy bone.
T or F
F
all of the following are part of the bone matrix except: collagen muscle fibers hydroxyapatite calcium and phosphorous crystals
muscle fibers
Osteons are found in _____, while trabeculae are found in _____.
compact
spongy
Trabeculae are filled with
yellow and red marrow
The coating around bones is called the
periosteum
Parathyroid hormone (PTH) decreases blood Calcium. T or F
F
Calcitonin (CT) decreases blood Calcium.
T or F
T
While the level of blood calcium may change with age, normal blood calcium level should be between
8.5 to 10.2 mg/dL
Which of the following vitamins are needed for calcium and phosphorous absorption?
Vitamin D
An overactive parathyroid gland can cause
hypercalcemia
Once formed, bone is never broken down.
T or F
F
Calcitonin is produced by the parathyroid gland.
T or F
F
Which of the following tissues could be found on or within a bone, such as the humerus? adipose tissue nervous tissue cartilage osseous tissue
adipose tissue
nervous tissue
cartilage
osseous tissue
Which two minerals are stored in major quantities in bone tissue?
calcium and phosphorus
What is the correct sequence of development of bone cells?
osteoprogenitor cells → osteoblasts → osteocytes
Once osteoblasts have surrounded themselves with the extracellular matrix of bone tissue, they remain inside little chambers called __________ where they carry on the metabolic functions that maintain bone tissue. At this point, the cells are called osteocytes.
lacunae
Compact bone is composed of units called osteons. In contrast, spongy bone is composed of _____.
trabeculae
Which is secreted by osteoblasts during bone deposition?
collagen fibers
Mesenchyme cells become osteoblasts which then become osteocytes.
T or F
T
While most Trabeculae become compact bone, the center always remains spongy.
T or F
T
Fontanels in infant skulls allow for easy passage of the cranium through the birth canal.
T or F
T
Most of the bones of the skull are formed by this process.
intramembranous ossification
Bone tissue stores 99% of the body’s calcium. Calcium plays important roles beyond the mineralization of bones. The exchange of calcium between bone and body fluids (especially the blood) is regulated by several hormones. Which of the following is the most important hormone regulating calcium exchange?
parathyroid hormone (PTH)
Which of the following is a function of calcium in the body?
a. nerve cells require extracellular calcium ions (Ca2+) for proper functioning
b. Ca2+ is a cofactor needed for many enzymes to function properly
c. Ca2+ is required for the process of blood clotting
d. Ca2+ is needed by muscle cells for contraction
a. nerve cells require extracellular calcium ions (Ca2+) for proper functioning
b. Ca2+ is a cofactor needed for many enzymes to function properly
c. Ca2+ is required for the process of blood clotting
d. Ca2+ is needed by muscle cells for contraction
Bone can be classified as a connective tissue because it contains an extracellular matrix that surrounds widely spaced cells.
T or F
T
In a newborn, all bone marrow is red, which means all of the infant’s marrow can make blood cells.
T or F
T
During a needle biopsy of a person’s bone marrow, maybe to test for the presence of cancer, pain is felt when the needle passes through the periosteum because it is richly supplied with nerves.
T
The process of bone formation is referred to as ____.
ossification
The hollow, cylindrical space within the diaphysis that contains fatty, yellow bone marrow in adults is called the
medullary cavity
Which factors affect bone remodeling and growth?
minerals
vitamins
hormones
Calcitonin inhibits activity of osteoclasts, speeds blood calcium uptake by bone, and accelerates calcium deposition into bones.
T or F
T
Hematopoiesis takes place in the ________ of some adult bones.
red bone marrow
_______ contribute(s) to the hardness of bone while ________ give(s) it flexibility.
Mineral salts; collagen and other organics
Which of the following statements are true?
a. Compact bone contains osteons while spongy contains trabeculae.
b. Compact bone makes up most of the bone of the diaphysis while spongy bone makes up most of the epiphysis.
c. Spongy bone makes up most of the structure of short, flat and irregular bones and the inside of the epiphysis of long bones.
d. Spongy bones make bone lighter and aids in stress resistance.
a. Compact bone contains osteons while spongy contains trabeculae.
b. Compact bone makes up most of the bone of the diaphysis while spongy bone makes up most of the epiphysis.
c. Spongy bone makes up most of the structure of short, flat and irregular bones and the inside of the epiphysis of long bones.
d. Spongy bones make bone lighter and aids in stress resistance.
Because it is an immovable joint, the sagittal suture, which joins the two parietal bones of the skull, is classified as a _______.
synarthrosis
Most of the freely movable joints of the body could be classified both structurally and functionally as __________.
synovial and diarthroses
A gomphosis is which type of joint?
fibrous and a syndesmosis
Which of the following is a type of angular movement? flexion extension abduction adduction
flexion
extension
abduction
adduction
This joint is the largest and most complex of the body, and consists of three joints contained within its synovial cavity.
knee joint
A synarthrosis is a freely movable joint.
T or F
F
Adduction is the movement of bone away from the midline; abduction is movement of a bone toward the midline.
T or F
F
Shoulder and hip joints are examples of which type of synovial joint?
ball-and-socket joint
The difference between a sprain and a strain is that a sprain involves
overstretching ligaments while a strain is overstretching muscles
Hips, knees, and shoulders are most commonly replaced by arthroplasty.
T or F
T
Which type of muscle tissue is involuntary (can’t be consciously controlled)?
smooth muscle and cardiac muscle
During a muscle contraction, actin binds to myosin.
T or F
F
ATP is hydrolyzed by the myosin tail.
T or F
F
Titin is a very elastic molecule, which pulls the muscle back into its original position after contraction.
T or F
T
The myosin head detaches from the actin filament after new ATP binds to myosin.
T or F
T
Calcium binds to the troponin-tropomyosin complex and allows myosin to access the actin filaments.
T or F
T
Which protein does Calcium bind to?
troponin
A powerstroke is caused by the ATP hydrolysis and phosphate release, binding and movement of multiple _____ molecules.
myosin
What is the first step of a contraction cycle?
ATP is hydrolyzed by the myosin head.
The contraction cycle will end due to all of the following except
High Calcium levels.
Frequency of stimulation of a muscle cell is not a factor that influences tension.
T or F
F
Tension on a muscle increases with increasing sarcomere length.
T or F
F
In a motor unit, all muscle cells move together from a single stimulation.
T or F
T
Large motor units are required for the fine force control seen in the muscles of the hand.
T or F
F
Fused tetanus is caused by rapid muscle stimulations without muscle relaxation.
T or F
T
Alternate contractions allow for sustained contraction in a whole muscle.
T or F
T
During a muscle twitch, all of the following happen during the latent phase except
myosin contraction of actin filaments
A large motor unit would control which body part?
a muscle required for back support
Wave summation is when
a second stimulus excites a partially relaxed muscle.
Asynchronous recruitment allows for
a. An increase in ATP levels.
b. Possible relaxation of one or more motor units.
c. Sustained contraction in a muscle.
An increase in ATP levels.
Possible relaxation of one or more motor units.
Sustained contraction in a muscle.
Energy can be transferred in the muscle cell through the conversion of ATP into ADP.
T or F
T
Pyruvic acid is converted to lactic acid in the presence of adequate oxygen.
T or F
F
Creatine phosphate reserves are restored via phosphorylation by ATP during rest.
T or F
T
Anaerobic respiration can provide enough ATP to sustain muscle activity for minutes to hours.
T or F
F
The muscle only has enough stored ATP to sustain activity for 2-3 seconds.
T or F
T
Recovery removes lactic acid and other toxins built up during muscle use.
T or F
T
Through aerobic respiration in the mitochondria, one glucose molecule can create
30 or more ATP
Creatine phosphate provide enough additional energy to sustain muscle activity for
15 seconds.
Glycogen reserves can release glucose for cellular respiration. Glycogen reserves are typically found in
skeletal muscle and the liver.
Muscle fatigue is caused by all of the following except
aerobic respiration.
The point of contact between a somatic motor neuron and a muscle cell is called a neuromuscular junction.
T or F
T
Acetylcholine is released by the cells of the sarcolemma across the synapse.
T or F
F
Calcium ions entering the motor neuron cell cause the release of acetylcholine.
T or F
T
Acetylcholine activates gated ion channels on the sarcolemma, causing an influx of calcium ions into the muscle cell.
T or F
F
The sarcomere is made entirely of actin filaments.
T or F
F
Calcium binds to the troponin-tropomyosin complex and allows myosin to access the actin filaments.
T or F
T
Choose the correct sequence of events:
a. Action potential reaches synapse—Acetylcholine is released by motor neuron—Calcium ions enter motor neuron—Sodium ions flood into the muscle cell—Acetylcholine binds to gated ion channels on sarcolemma, transferring the action potential.
b. Action potential reaches synapse—Calcium ions enter motor neuron—Acetylcholine is released by motor neuron—Acetylcholine binds to gated ion channels on sarcolemma—Sodium ions flood into the muscle cell, transferring the action potential.
c. Action potential reaches synapse—Acetylcholine is released by motor neuron—Acetylcholine binds to gated ion channels on sarcolemma—Calcium ions enter motor neuron—Sodium ions flood into the muscle cell, transferring the action potential.
Action potential reaches synapse—Calcium ions enter motor neuron—Acetylcholine is released by motor neuron—Acetylcholine binds to gated ion channels on sarcolemma—Sodium ions flood into the muscle cell, transferring the action potential.
The sarcoplasmic reticulum contains
calcium
Muscle relaxation requires which enzyme in order to clear the action potential?
acetylcholinesterase
The sarcomere consists of all of the following except
the motor neuron
