BIO FINAL EXAM

The cross bridge cycle is a series of molecular events that occur after excitation of the sarcolemma. What is a cross bridge? ATP bound to a myosin head Troponin bound to tropomyosin A myosin head bound to actin Calcium bound to troponin

A myosin head bound to actin Correct Yes! As soon as the activated myosin head forms a cross bridge with actin, the power stroke begins.

After a power stroke, the myosin head must detach from actin before another power stroke can occur. What causes cross bridge detachment? Acetylcholine binds to receptors in the junctional folds of the sarcolemma. ATP binds to the myosin head. ADP and inorganic phosphate are bound to the myosin head. Calcium ions bind to troponin.

ADP and inorganic phosphate are bound to the myosin head. Correct Yes! The binding of ATP to the myosin head weakens the bond between myosin and actin, forcing the myosin head to detach. ATP also provides the energy for the next power stroke.

We are told that every surface we touch is teeming with bacterial cells, and bacteria are found in the pools we swim in, the water we wash with, and on the hands of friends. Why are we not inundated with bacterial infections on our skin? Not all bacteria are harmful or thrive on the skin. The low pH of the skin secretions retards the multiplication of bacteria on the skin. All of these answers are correct. Many bacteria are killed by bactericidal substances in the sebum and sweat.

All of these answers are correct.

How is an action potential propagated along an axon? Stimuli from the graded (local) potentials from the soma and dendrites depolarize the entire axon. An influx of sodium ions from the current action potential depolarizes the adjacent area. An efflux of potassium from the current action potential depolarizes the adjacent area.

An influx of sodium ions from the current action potential depolarizes the adjacent area. Correct Yes, the influx of sodium ions depolarizes adjacent areas, causing the membrane to reach threshold and cause an action potential. Thus, the action potential is regenerated at each new area.

The binding of the neurotransmitter to receptors on the motor end plate causes which of the following to occur? Binding causes chemically gated potassium channels to open in the motor end plate. Binding of the neurotransmitter causes chemically gated sodium channels to open in the motor end plate. Binding causes voltage-gated sodium channels to open in the motor endplate. Binding causes potassium voltage-gated channels to open in the motor endplate.

Binding of the neurotransmitter causes chemically gated sodium channels to open in the motor end plate. Correct Yes, sodium enters the cell and causes depolarization. A small amount of potassium also leaves the motor end plate.

Calcium ions couple excitation of a skeletal muscle fiber to contraction of the fiber. Where are calcium ions stored within the fiber? Calcium ions are stored in the sarcoplasmic reticulum. Calcium ions are stored in the mitochondria. Calcium ions are stored in the nuclei. Calcium ions are stored in the transverse tubules.

Calcium ions are stored in the sarcoplasmic reticulum. Correct Yes! Sarcoplasmic reticulum is the specific name given to the smooth endoplasmic reticulum in muscle fibers. The sarcoplasmic reticulum is very elaborate in skeletal muscle fibers, allowing for significant storage of calcium ions.

What specific event triggers the uncovering of the myosin binding site on actin? Calcium ions bind to troponin and change its shape. Calcium release channels open in the sarcoplasmic reticulum, and calcium levels rise in the sarcoplasm. Sodium ions bind to troponin and change its shape. Calcium ions bind to tropomyosin and change its shape.

Calcium ions bind to troponin and change its shape. Correct Yes! The shape change caused by the binding of calcium to troponin shifts tropomyosin away from the myosin binding sites on actin.

What is the most important role of the arrector pili muscles in humans? Cause the hair follicle to stand erect Help retain heat Defense Force sebum out of the hair follicle to the skin surface

Cause the hair follicle to stand erect

Actin is the chief component of the thin myofilaments. True or false?

Correct Actin is the chief component of the thin myofilaments.`

Describe fibrous joints.

Correct In all three joints, bones are directly connected by dense fibrous tissue to form a joint lacking a cavity.

Which area, on a neuron, would contain an abundance of vesicles containing neurotransmitter?

Correct Neurotransmitters are stored in synaptic vesicles within axonal terminals for release into the synaptic cleft.

When does cross bridge cycling end? Cross bridge cycling ends when ATP binds to the myosin head. Cross bridge cycling ends when calcium ions are passively transported back into the sarcoplasmic reticulum. Cross bridge cycling ends when sufficient calcium has been actively transported back into the sarcoplasmic reticulum to allow calcium to unbind from troponin. Cross bridge cycling ends when calcium release channels in the sarcoplasmic reticulum open.

Cross bridge cycling ends when sufficient calcium has been actively transported back into the sarcoplasmic reticulum to allow calcium to unbind from troponin. Correct Yes! The sarcoplasmic reticulum contains Ca2+-ATPases that actively transport Ca2+ into the SR. Without Ca2+, troponin returns to its resting shape, and tropomyosin glides over and covers the myosin binding sites on actin.

Which structures of the dermis give rise to friction ridges (fingerprints)? epidermal ridges dermal papillae flexure lines dermal ridges

Dermal ridges Correct Dermal ridges cause the overlying epidermis to form epidermal ridges. Collectively these ridges are called friction ridges

Which skin appendages aid in cooling the body to prevent overheating on a hot day or during intense exercise? eccrine sweat glands apocrine sweat glands sebaceous glands ceruminous glands

Eccrine sweat glands Correct Eccrine (merocrine) sweat glands produce a watery secretion (called sweat) that is released onto the surface of skin in response to elevated body temperature. As body heat is used (thus removed) to convert the water of sweat to water vapor, body temperature decreases; this is called evaporative cooling.

The fibula is the major weight-bearing bone of the leg. True False

False

The layman's name for the scapula is the collarbone. True False

False

Hair and nails are made primarily of calcium. True False

False Correct The primary component of hair and nails is hard keratin (not calcium), produced by keratinocytes.

Unmyelinated fibers conduct impulses faster than myelinated fibers. True False

False. Correct Myelinated fibers (axons bearing a myelin sheath) conduct nerve impulses rapidly, whereas unmyelinated fibers conduct impulses more slowly. Note that myelin sheaths are associated only with axons; dendrites are always nonmyelinated.

Which is the largest, longest, and strongest bone in the body? os coxa tibia fibula femur

Femur Correct The femur is the largest, longest, and strongest bone in the body. Its durable structure reflects the stress exerted on the femur as it bears the weight of the body when standing, walking, or running.

Which of the following is NOT a difference between graded potentials and action potentials? Graded potentials can result from the opening of chemically gated channels; action potentials require the opening of voltage-gated channels. Spatial summation is used to increase the amplitude of a graded potential; temporal summation is used to increase the amplitude of an action potential. Greater stimulus intensity results in larger graded potentials, but not larger action potentials. Graded potentials occur along dendrites, whereas action potentials occur along axons.

Graded potentials can result from the opening of chemically gated channels; action potentials require the opening of voltage-gated channels. Spatial summation is used to increase the amplitude of a graded potential; temporal summation is used to increase the amplitude of an action potential.

Which of the following bones is a part of the appendicular skeleton? sternum hyoid bone mandible humerus

Humerus Correct The humerus is part of the appendicular skeleton.

Sodium and potassium ions can diffuse across the plasma membranes of all cells because of the presence of what type of channel? Ligand-gated channels Voltage-gated channels Sodium-potassium ATPases Leak channels

Leak channels Yes. Leak channels for Na+ and K+ are ubiquitous, and they allow for the diffusion of these ions across plasma membranes.

Choose the FALSE statement. Long bones include all limb bones except the patella. Sesamoid bones form within certain tendons. Irregular bones include the vertebrae and hip bones. The sternum is an example of a flat bone.

Long bones include all limb bones except the patella.

What prevents the Na+ and K+ gradients from dissipating? Na+ cotransporter Na+ and K+ leaks Na+-K+ ATPase H+-K+ ATPase

Na+-K+ ATPase Correct Yes! Also known as the Na+-K+ pump, or simply the pump, this transporter moves three Na+ out of the cell and two K+ into the cell for every ATP it hydrolyzes. This pumping action prevents the Na+ and K+ gradients from running down as these ions passively move through leak channels.

Ions are unequally distributed across the plasma membrane of all cells. This ion distribution creates an electrical potential difference across the membrane. What is the name given to this potential difference? Threshold potential Resting membrane potential (RMP) Positive membrane potential Action potential

Resting membrane potential (RMP) Correct Yes! The resting membrane potential is the baseline potential that can be recorded across the plasma membrane of an excitable cell prior to excitation.

The ________ articulate(s) with the hip bones of the pelvis. thoracic vertebrae coccyx sacrum lumbar vertebrae

Sacrum Correct The sacrum articulates with the hip bones of the pelvis

Which of the following peripheral nervous system (PNS) neuroglia form the myelin sheaths around larger nerve fibers in the PNS? oligodendrocytes Schwann cells satellite cells astrocytes

Schwann cells Correct Schwann cells (also called neurolemmocytes) surround all nerve fibers in the PNS and form myelin sheaths around the larger fibers. Myelin protects and electrically insulates nerve fibers, and it increases the transmission speed of nerve impulses.

Why, or why not, is swimming recommended as an exercise to prevent osteoporosis? Swimming is not recommended to prevent osteoporosis, as it is not considered a weight-bearing exercise. Swimming is recommended to prevent osteoporosis, as it is considered a weight-bearing exercise. Swimming is not recommended to prevent osteoporosis, as forces are applied in all directions on the bones simultaneously in swimming. Swimming is recommended to prevent osteoporosis, as forces are applied in all directions on the bones simultaneously.

Swimming is not recommended to prevent osteoporosis, as it is not considered a weight-bearing exercise.

Which of the following statements is INCORRECT? Melanin provides protection against ultraviolet (UV) radiation. Keratinocytes produce a fibrous protein to protect the epidermis. Langerhans cells activate the immune system. Tactile cells anchor the skin to the body.

Tactile cells anchor the skin to the body. This is the incorrect statement. Tactile cells, in conjunction with their sensory nerve endings, function as touch receptors. The hypodermis, not tactile cells anchors skin to the body.

Why does the action potential only move away from the cell body? The areas that have had the action potential are refractory to a new action potential. The flow of the sodium ions only goes in one direction—away from the cell body

The areas that have had the action potential are refractory to a new action potential. Correct Yes, sodium channels are inactivated in the area that just had the action potentia

What part of the neuron receives signals?

The dendrites and soma of the cell receive signals from other neurons.

How does the myosin head obtain the energy required for activation? The energy comes from the hydrolysis of GTP. The energy comes from oxidative phophorylation. The energy comes from the hydrolysis of ATP. The energy comes from the direct phosphorylation of ADP by creatine phosphate

The energy comes from the hydrolysis of ATP. Correct Yes! Myosin is a large, complex protein with a binding site for actin. It also contains an ATPase. The energy released during the hydrolysis of ATP activates the myosin head.

On average, the resting membrane potential is -70 mV. What does the sign and magnitude of this value tell you? The inside surface of the plasma membrane is much more negatively charged than the outside surface. The inside surface of the plasma membrane is much more positively charged than the inside surface. The outside surface of the plasma membrane is much more negatively charged than the inside surface. There is no electrical potential difference between the inside and the outside surfaces of the plasma membrane.

The inside surface of the plasma membrane is much more negatively charged than the outside surface. Correct Yes! The inside surface of the plasma membrane accumulates more negative charge because of the presence of Na+ and K+ gradients and the selective permeability of the membrane to Na+ and K+.

How are the male and female pelves different? The female pelvis has thicker bones with more prominent bone markings. The pelvic inlet is heart-shaped in the male. The male pelvis is usually wider, shallower, and lighter. The acetabula are larger and closer together in the female.

The pelvic inlet is heart-shaped in the male. Correct The female pelvis is modified for childbearing; it is wider, shallower and lighter than the male pelvis. The male pelvis has thicker/heavier bones with more prominent bone markings, acetabula that are larger and closer together, and a narrower, heart-shaped pelvic inlet.

Choose the FALSE statement. The female pelvis is tilted further forward than the male pelvis. The pelvic outlet is narrower in a female than in a male. The female pelvis is thinner than that of a male. The pubic arch is broader in the pelvis of a female than in the pelvis of a male.

The pelvic outlet is narrower in a female than in a male. Correct This is false; the pelvic outlet is narrower in a male than in a female. The female pelvis is modified for childbearing; it is wider, shallower and lighter than the male pelvis. The male pelvis has thicker/heavier bones with more prominent bone markings, acetabula that are larger and closer together, and a narrower, heart-shaped pelvic inlet.

The resting membrane potential depends on two factors that influence the magnitude and direction of Na+ and K+ diffusion across the plasma membrane. Identify these two factors. The presence of concentration gradients and voltage-gated channels The presence of concentration gradients and Na+-K+ pumps The presence of a resting membrane potential and leak channels The presence of concentration gradients and leak channels

The presence of concentration gradients and leak channels Correct Yes! The concentration gradient and the large number of K+ leak channels allow for rather robust K+ diffusion out of a cell. In contrast, the concentration gradient and the relatively few Na+ leak channels allow for much less Na+ diffusion into a cell.

What structure is the functional unit of contraction in a skeletal muscle fiber? The triad The junctional folds of the sarcolemma The cross bridge The sarcomere

The sarcomere Correct Yes! A sarcomere is a regular arrangement of thin and thick myofilaments that extends from one Z disc to the next. A myofibril consists of a series of sarcomeres.

The plasma membrane is much more permeable to K+ than to Na+. Why? There are many more voltage-gated K+ channels than voltage-gated Na+ channels. Ligand-gated cation channels favor a greater influx of Na+ than K+. There are many more K+ leak channels than Na+ leak channels in the plasma membrane. The Na+-K+ pumps transport more K+ into cells than Na+ out of cells.

There are many more K+ leak channels than Na+ leak channels in the plasma membrane. Correct Yes! More leak channels translates into more leakiness. Thus the outward flux of K+ is greater than the inward flux of Na+.

Each consecutive bone lamella has collagen fibers that wrap in alternating directions. True False

True

The structural unit of compact bone (osteon) resembles the growth rings of a tree trunk. True False

True

The epimysium continuous with the tendon that connects the muscle to a bone? True or false?

True Correct The dense connective tissue of the epimysium is continuous with the tendon that connects the muscle to a bone.

Calcium Ions bind to troponin to expose the actin for the cross bridge cycle. True or false?

True. Correct Binding of calcium by troponin (B) removes the blocking action of tropomyosin along the thin myofilament. This allows myosin to bind to actin and form the cross bridge illustrated in this figure.

What is the functional unit of a skeletal muscle called? the sarcoplasmic reticulum a myofibril a sarcomere a myofilament

a sarcomere

The velocity of the action potential is fastest in which of the following axons? a large unmyelinated axon a small unmyelinated axon a small myelinated axon

a small myelinated axon Correct Yes, the myelination acts as insulation and the action potential is generated only at the nodes of Ranvier. Propagation along myelinated axons is known as saltatory conduction.

What is moving a limb away from the median plane of the body along the frontal plane called? adduction inversion abduction dorsiflexion

abduction

What is the major function of the intervertebral discs? string the vertebrae together absorb shock prevent hyperextension of the spine prevent hyperextension

absorb shock

Melanocytes and keratinocytes work together in protecting the skin from UV damage when keratinocytes ________. maintain the appropriate temperature so the product of the melanocyte will not denature accumulate the melanin granules on their superficial portion, forming a UV-blocking pigment layer provide the melanocyte with a protective shield against abrasion maintain the appropriate pH in order for the melanocyte to synthesize melanin granules

accumulate the melanin granules on their superficial portion, forming a UV-blocking pigment layer

In a neuromuscular junction, synaptic vesicles in the motor neuron contain which neurotransmitter? serotonin acetylcholine (ACh) norepinephrine dopamine

acetylcholine (ACh) Correct Yes, acetylcholine is the neurotransmitter found in neuromuscular junctions

How is acetylcholine (ACh) removed from the synaptic cleft? a reuptake pump on the axon terminal acetylcholinesterase (AChE; an enzyme) diffusion away from the synaptic cleft

acetylcholinesterase (AChE; an enzyme) Correct Yes, this enzyme is present in the synaptic cleft and breaks down acetylcholine.

Which of the following is NOT a factor that contributes to joint stability? shape of the articulating surfaces number and positioning of reinforcing ligaments amount of muscle tone applied to tendons that cross the joint amount of synovial fluid in the joint cavity

amount of synovial fluid in the joint cavity Correct The amount of synovial fluid in the joint cavity is not a factor that contributes to joint stability. The major role of synovial fluid is to lubricate the joint surfaces of freely movable (synovial) joints

Which of the following is the conducting region of the neuron? dendrites soma terminal boutons axon

axon Correct Functionally, the axon is the conducting region of the neuron. It generates nerve impulses and transmits them, typically away from the cell body, along the plasma membrane, or axolemma.

The shoulder and hip are examples of ________. condylar joints pivot joints plane joints ball-and-socket joints hinge joints

ball-and-socket joints Correct The shoulder and hip are examples of ball-and-socket joints.

Which of the following is NOT a structural feature of synovial joints? reinforcing ligaments bone ends united by fibrocartilage bone ends covered with hyaline cartilage a fluid-filled joint cavity

bone ends united by fibrocartilage Correct In synovial joints, bone ends are covered, but not united with cartilage. Hyaline (articular) cartilage covers the bone ends. The fibrocartilage found in some synovial joints, such as the knee joint, provides additional cushioning between opposing bone ends.

What is the final stage in the healing of a bone fracture? formation of a bony callus formation of a fibrocartilaginous callus bone remodeling formation of a hematoma

bone remodeling Correct In order, here are the stages of bone fracture healing: (1) formation of a hematoma, (2) formation of a fibrocartilaginous callus, (3) formation of a bony callus, and (4) bone remodeling.

Osteoclasts ________. form skeletal cartilage calcify bone matrix break down bone form new bone

break down bone Correct Osteoclasts are bone-breaking (bone-resorption) cells.

Burns are devastating and debilitating because of loss of fluids and electrolytes from the body. How do physicians estimate the extent of burn damage associated with such dangerous fluid loss? by using the "rule of nines" by observing the tissues that are usually moist through blood analysis by measuring urinary output and fluid intake

by using the "rule of nines"

What part of the nervous system performs information processing and integration? sympathetic nervous system central nervous system parasympathetic nervous system somatic nervous system

central nervous system Correct The central nervous system, which consists of the brain and spinal cord, is the integrating and control center of the nervous system. It interprets sensory input and dictates motor output based on reflexes, current conditions, and past experience.

Which of the following does NOT form part of the thoracic cage? clavicle thoracic vertebrae sternum ribs

clavicle Correct The clavicle is a part of the pectoral girdle; it does not form part of the thoracic cage.

What indicates that a long bone has reached its adult length? the presence of osteoblasts the presence of hyaline cartilage on the ends of the bone the presence of osteons closure of the epiphyseal plate

closure of the epiphyseal plate Correct The epiphyseal plate is a zone of hyaline cartilage between the epiphysis and diaphysis of a long bone. When the cartilage is replaced with bone and the plate closes (becoming an epiphyseal line), the bone has reached its maximum length.

The structure of bone tissue suits the function. Which of the following bone tissues is adapted to support weight and withstand tension stress? irregular bone spongy bone trabecular bone compact bone

compact bone

A needle would pierce the epidermal layers of the forearm in which order? basale, spinosum, granulosum, corneum basale, spinosum, granulosum, lucidum, corneum granulosum, basale, spinosum, corneum corneum, granulosum, spinosum, basale

corneum, granulosum, spinosum, basale

The distance between Z discs ________ during muscle contraction. decreases increases decreases and then increases stays the same

decreases Correct During muscle contraction, the distance between Z discs decreases as the thin myofilaments slide across thick myofilaments, toward the M line in the center of each sarcomere. As the sarcomeres shorten, the myofibrils and, thus the myofibers shorten (contract).

The sliding filament model of contraction states that ________. during contraction the thin myofilaments slide past T tubules so that the Z discs are overlapping during contraction the thin myofilaments slide past the thick myofilaments so that calcium ions can be released from the sarcoplasmic reticulum during contraction the thin myofilaments slide past the thick myofilaments so that the actin and myosin myofilaments no longer overlap during contraction the thin myofilaments slide past the thick myofilaments so that the actin and myosin myofilaments overlap to a greater degree

during contraction the thin myofilaments slide past the thick myofilaments so that the actin and myosin myofilaments overlap to a greater degree Correct The sliding filament model of contraction states that during contraction, the thin myofilaments slide past the thick myofilaments so that actin and myosin myofilaments overlap to a greater degree. In a relaxed muscle fiber, the thick and thin myofilaments overlap only at the ends of the A band.

Sudoriferous (sweat) glands are categorized as two distinct types. Which of the following are the two types of sweat glands? sebaceous and merocrine eccrine and apocrine holocrine and mammary mammary and ceruminous

eccrine and apocrine

Which muscle characteristic describes the ability of muscle to respond to a stimulus? extensibility elasticity contractility excitability

excitability Correct Excitability, also termed responsiveness, is the ability to receive and respond to a stimulus, For example, skeletal muscle contracts in response to receiving chemical stimulation by a neurotransmitter called acetylcholine (ACh).

What means of membrane transport is used to release the neurotransmitter into the synaptic cleft? exocytosis a protein carrier a channel

exocytosis Correct Yes, the synaptic vesicles (where the neurotransmitter is stored) merge with the membrane and release the neurotransmitter by exocytosis.

Which movement increases the angle between articulating bones? adduction extension flexion supination

extension Correct Extension involves movement along the sagittal plane that increases the angle between the articulating bones and typically straightens a flexed limb or body part.

The articulation that most closely resembles a hinge in the body involves which bones? humerus-radius femur-fibula femur-tibia humerus-ulna

humerus-ulna

In symphysis joints the articular surfaces of the bones are covered with ________. hyaline cartilage synovial membranes tendon sheaths fibrocartilage

hyaline cartilage

Bending your head back until it hurts is an example of ________. flexion extension circumduction hyperextension

hyperextension

Apocrine glands, which begin to function at puberty under hormonal influence, seem to play little role in thermoregulation. Where would we find these glands in the human body? beneath the flexure lines in the body in the palms of the hands and soles of the feet in the axillary and anogenital area in all body regions and buried deep in the dermis

in the axillary and anogenital area

When neurotransmitter molecules bind to receptors in the plasma membrane of the receiving neuron, the receiving neuron becomes more negative inside. the receiving neuron becomes more positive inside. ion channels in the plasma membrane of the sending neuron open. ion channels in the plasma membrane of the receiving neuron open. vesicles in the synaptic terminal fuse to the plasma membrane of the sending neuron.

ion channels in the plasma membrane of the receiving neuron open.

Hyaline cartilage ________. is the rarest of the skeletal cartilages is found on the ends of bones that form movable joints forms "shock-absorbing" pads between the vertebrae gives shape to the external ear

is found on the ends of bones that form movable joints

Which of the following types of neurons carry impulses away from the central nervous system (CNS)? afferent association motor sensory

motor Correct Motor, or efferent, neurons carry impulses away from the CNS to the effector organs (muscles and glands) of the body periphery.

Which of the following is the correct sequence of events for muscle contractions? muscle cell action potential, neurotransmitter release, ATP-driven power stroke, calcium ion release from SR, sliding of myofilaments neurotransmitter release, muscle cell action potential, motor neuron action potential, release of calcium ions from SR, sliding of myofilaments, ATP-driven power stroke motor neuron action potential, neurotransmitter release, muscle cell action potential, release of calcium ions from SR, ATP-driven power stroke, sliding of myofilaments neurotransmitter release, motor neuron action potential, muscle cell action potential, release of calcium ions from SR, ATP-driven power stroke

motor neuron action potential, neurotransmitter release, muscle cell action potential, release of calcium ions from SR, ATP-driven power stroke, sliding of myofilaments

Which organelle contains the contractile elements found in skeletal muscle? myofibril sarcoplasmic reticulum sarcolemma glycosome

myofibril Correct The myofibrils contain the contractile elements of skeletal muscles, the sarcomeres. The sarcomeres contain even smaller rod-like structures called myofilaments.

A molecule that carries information across a synaptic cleft is a neurotransmitter. synapse. receiving neuron. sending neuron. synaptic cleft.

neurotransmitter. Correct Neurotransmitter molecules carry information across a synaptic cleft.

Rigor mortis occurs because ________. sodium ions leak into the muscle causing continued contractions the cells are dead proteins are beginning to break down, thus preventing a flow of calcium ions no ATP is available to release attached actin and myosin molecules

no ATP is available to release attached actin and myosin molecules

The periosteum is secured to the underlying bone by dense connective tissue called ________. Volkmann's canals the struts of bone known as spicules perforating (Sharpey's) fibers a bony matrix with hyaline cartilage

perforating (Sharpey's) fibers

Articular cartilage found at the ends of the long bones serves to ________. form the synovial membrane produce red blood cells (hemopoiesis) attach tendons provide a smooth surface at the ends of synovial joints

provide a smooth surface at the ends of synovial joints

If a herniated disc in the lumbar region is treated by surgically removing the intervertebral disc and doing a bone graft between the adjoining vertebrae, one of the consequences might be _________. reduced flexibility of the spine in the lower back gradual growth of a replacement intervertebral disc in the space between the vertebrae increased shock absorbance qualities in the intervertebral discs located immediately above and below the graft in order to compensate for the removal of the herniated disc All of the listed responses are correct.

reduced flexibility of the spine in the lower back Correct The intervertebral disc and space that it occupies provides room for vertebral bodies of adjacent vertebrae to flex and extend the vertebral column (spine).

Which of the following is NOT one of the basic functions of the nervous system? control the activity of muscles and glands integration of sensory input regulation of neurogenesis monitor changes occurring both inside and outside the body

regulation of neurogenesis Correct Most active during pre-natal development, neurogenesis (formation of neurons) is the process by which neurons are generated from neural stem cells. It is not one of the basic functions of the nervous system.

The axial skeleton includes the ________. bones of the arms hip bones ribs bones of the legs

ribs

Which joint has sacrificed stability to provide great freedom of movement? elbow ankle knee shoulder

shoulder Correct In the shoulder joint, stability has been sacrificed to provide the most freely moving joint in the body. The articulating bones provide minimal joint stability because of the size and "fit" of the articulating surfaces. The major stabilizing forces are soft tissue, in particular the tendons of the rotator cuff muscles (via muscle tone).

Which of the following is CORRECTLY paired? skeletal muscle: voluntary control smooth muscle: striated cardiac muscle: voluntary control cardiac muscle: nonstriated

skeletal muscle: voluntary control Correct Correct; skeletal muscle is under voluntary control.

Fibrous joints are classified as ________. hinge, saddle, and ellipsoidal pivot, hinge, and ball and socket symphysis, sacroiliac, and articular sutures, syndesmoses, and gomphoses

sutures, syndesmoses, and gomphoses

The small space between the sending neuron and the receiving neuron is the vesicle. synaptic cleft. synaptic terminal. neurotransmitter. calcium channel.

synaptic cleft. Correct The synaptic cleft is the small space between the sending neuron and the receiving neuron.

Which of the following refers to a joint that is immovable? diarthrosis synarthrosis synovial amphiarthrosis

synarthrosis Correct Synarthroses are immovable joints and include sutures and syndesmoses.

The action potential on the muscle cell leads to contraction due to the release of calcium ions. Where are calcium ions stored in the muscle cell? terminal cisternae of the sarcoplasmic reticulum T tubule sarcolemma cytosol

terminal cisternae of the sarcoplasmic reticulum Correct Yes, calcium is stored in the terminal cisternae of the sarcoplasmic reticulum until it is released by an action potential.

Functional classification of joints is based on ________. the amount of movement allowed by the joint whether a joint cavity is present the size of the joint the location of the joint

the amount of movement allowed by the joint Correct Functional classification is based on the amount of movement allowed by a joint. Structural classification focuses on the material binding the bones together, and whether a joint cavity is present.

The antebrachium is composed of which of the following two bones? the humerus and the radius the scapula and the clavicle the radius and the ulna the humerus and the clavicle

the radius and the ulna

If a signal from a sending neuron makes the receiving neuron more negative inside, the sending neuron becomes more positive inside. the receiving neuron is less likely to generate an action potential. the receiving neuron immediately generates an action potential. the sending neuron becomes more negative inside. the receiving neuron is more likely to generate an action potential

the receiving neuron is less likely to generate an action potential. Correct If the receiving neuron is more negative inside, it is less likely to generate an action potential.

The smallest contractile unit of a muscle fiber is ________. troponin the sarcomere the elastic filament the myofilament

the sarcomere Correct The sarcomere is the smallest contractile unit of a muscle fiber, and the smallest functional unit of muscle. A sarcomere is the region of a myofibril between two successive Z discs; it primarily consists of thin and thick myofilaments.

Which of the following allows us to consciously control our skeletal muscles? the parasympathetic division of the autonomic nervous system the sympathetic division of the autonomic nervous system the somatic nervous system the afferent division of the nervous system

the somatic nervous system Correct The somatic nervous system is composed of somatic motor nerve fibers that conduct impulses from the central nervous system to skeletal muscles. It is often referred to as the voluntary nervous system because it allows us to consciously control our skeletal muscles.

Which of the following does NOT protect the skin from bacteria? cathelicidins defensins the low pH of the skin dermcidin the temperature of the skin

the temperature of the skin Correct The temperature of the skin does not protect the skin against bacteria. In fact, the temperature of the skin is ideal for many types of bacteria.

When calcium ions enter the synaptic terminal, neurotransmitter molecules are quickly removed from the synaptic cleft. they cause an action potential in the sending neuron. the inside of the receiving neuron becomes more negative. they cause vesicles containing neurotransmitter molecules to fuse to the plasma membrane of the sending neuron. the inside of the receiving neuron becomes more positive.

they cause vesicles containing neurotransmitter molecules to fuse to the plasma membrane of the sending neuron.

The ribs that attach to the sternum are called ________. floating ribs true ribs vertebral ribs false ribs

true ribs Correct The superior seven rib pairs, called true ribs, attach directly to the sternum by individual costal cartilages.

The type of muscle found in the walls of most hollow organs is ________. unitary smooth muscle cardiac muscle skeletal muscle multi unit smooth muscle

unitary smooth muscle Correct Smooth muscle is generally classified as being either unitary smooth muscle or multi unit smooth muscle. The type of muscle found in the walls of most hollow organs is unitary smooth muscle.

When an action potential arrives at the axon terminal of a motor neuron, which ion channels open? voltage-gated potassium channels voltage-gated sodium channels chemically gated calcium channels voltage-gated calcium channels

voltage-gated calcium channels Correct Yes, the action potential opens voltage-gated calcium channels and calcium rushes into the axon terminal, leading to the release of the neurotransmitter.

The epiphyseal plate is ________. where long bone lengthening occurs the long axis of a bone where yellow bone marrow is produced the site of red bone marrow production

where long bone lengthening occurs Correct Long bones elongate from growth at the epiphyseal plate, a layer of hyaline cartilage between the epiphyses and diaphysis of long bones