A&P Lecture Exam 2
Differences between skeletal and smooth muscle include all of the following except: A) Skeletal muscle is involuntary while smooth muscle is voluntary B) Skeletal muscle is striated while smooth muscle is non-striated C) Skeletal muscle has sarcomeres while smooth muscle doesn't
A.
Which of the following statements about skeletal muscle cell contractions is true? A) in a relaxed state, the thick and thin filaments do not overlap as much as they do during contraction B) Cross bridge formation occurs when myosin heads bind to troponin contained in actin filaments C)Contraction is stimulated by the binding of sodium to calcium C) Troponin is found on actin filaments, while tropomyosin is found on is found on myosin filaments E) The creation of a cross bridge requires actin heads to bind with myosin active sites F) All of the above are true
A.
Bone grows in diameter
Appositional growth
Which of the following processes provides a muscle cell with the most energy A) Sequestering ATP from nearby adipose tissue B) Aerobic cellular respiration C) Creatinine phosphate posphorylation D) Lactic acid fermentation
B.
The canal that runs through the core of an osteon contains:
Blood vessels and nerve fibers
Which of the following is an elastic protein/elastic myofilament? A) Actin B) Troponin C) Myosin D) Titin E) Tropomyosin F) Collagen
D
Which of the following statements describing the medullary cavity of long bones is false? A) In larger bones of adults, the medullary cavity is filled with water to hydrate the body B) The plate-like bones of the skull have multiple medullary cavities C) The medullary cavity is also referred to as the perforating canal D) A-C are all false statements
D
While of the following processes could occur in the skeleton of a 54 year old person? (other three are impossible) A) Endochondral ossification B) intramembranous ossification C) Interstitial growth D) Appositional growth
D
Which of the following statements about pre-natal ossification is false: A) Endochondral ossification is responsible for formation fo most bones of the skeleton during development B) Intramembranous ossification produces flat bones C) In endochondral ossification, bone forms by replacing hyaline cartilage "models" D) In both endochondral and intramembranous ossification, existing cartilage must eventually be broken down and replaced by bone E) All are true statements
D.
T or F: Perimysium refers to the connective tissue sheathing that covers the exterior of muslce fibers
False
T or F: Sarcomeres are present in smooth muscle cells, but they do not possess action and myosin
False
T or F: Skeletal muscle tissue does not require nervous system stimulation for contraction to occur
False
T or F: The cell membrane of a muscle fiber is called an endosteum
False
T or F: The matrix of spongy bone is arranged in small tubular structural units called osteons
False
T or F: The periosteum of bone is avascular and non-innervated
False
T or F: The process of peristalsis is primarily controlled by skeletal muscle
False
T or F: The term osteoid refers to the mineralized extracellular matrix of compact bone tissue
False
What kind of tissue is the forerunner of the skull bones in the embryo?
Fibrous connective tissue
What hormone is the most important regulator of bone growth during infancy and childhood
Growth hormone
Where does the terminal axon (nerve ending) of a somatic motor neuron directly release its neurotransmitter at the neuromuscular junction?
Into the synaptic cleft
The correct sequence of events for skeletal muscle contraction
Neurotransmitters from neurons are received by the muscle fiber at the neuromuscular junction Action potential is propagated along the sarcolemma Action potential travels down the T tubules Change in voltage gated channels causes Ca++ ions to be released from the SR Released calcium initiates cross bridge cycling of myofilaments
The major function of the sarcoplasmic reticulum in a muscle fiber is
Storage and release of calcium ions
T or F: Collagen is the most common fiber found in bone tissue
True
T or F: Osteoclast activity releases calcium ions from bone matric (hint: think about what osteoclasts do)
True
T or F: Skeletal muscle fibers contain multiple nuclei
True
T or F: The inorganic components of bone matrix responsible for the hardness and resistance to compression seen in bone tissue are mineral salts called hydroxyapetities
True
Tor F: The release of calcium ions within a muscle cell must occur before cross-bridge formation between actin and myosin myofilaments can occur
True
striation in muscle fiber caused by the overlap of thick and thin filaments
a band
slightly moveable joints
amphiarthroses
small channels that radiate through osteons
canaliculi
a joint formed by cartilage
cartilaginous joints
freely moveable joints
diarthroses
a joint formed by dense fibrous connective tissue
fibrous joints
Which bones done intramembranous ossification produce
flat bones
Lengthwise long bone growth during infancy and youth is achieved exclusively through
interstital growth of the epiphyseal plates
Bone grows longitudinally
interstitial growth
layers of bone matrix
lamellae
Which bones does endochondral ossification produce
most of the bones in the body aka long, short, irregular
A skeletal muscle cell
muscle fiber
Rod-like contractile elements that occupy most of a skeletal muscle cell's volume
myofibril
The most common are actin and myosin
myofilament
Cells that produce bone matrix
osteoblasts
cells that can dissolve the bony matrix
osteoclasts
mitotically active stem cells found in bone membranes; give rise to other bone cells
osteogenic cells
Basic structural units of long bone
osteons
The plasma membrane of a skeletal muscle cell
sarcolemma
The basic contractile unit of a skeletal muscle cell
sarcomere
An elaborate smooth ER found in skeletal muscle cells; surrounds each myofibril
sarcoplasmic reticulum
immovable joints
synarthroses
a joint in which the bones are separated by a fluid filled cavity
synovial joints
basic structural units of spongy bone
trabeculae
