Bone and cartilage Flashcards
(23 cards)
Which of the following pairs accurately matches a type of bone cell with its function?
a) Osteoblast - bone resorption
b) Osteocyte - maintenance of bone tissue
c) Osteoclast - bone formation
d) Chondroblast - calcification of bone matrix
b) Osteocyte - maintenance of bone tissue
Which of the following features is NOT characteristic of a typical long bone?
a) Length greater than breadth
b) Presence of a medullary cavity containing bone marrow
c) Formation through intracartilaginous ossification
d) Horizontal placement within the body
d) Horizontal placement within the body
The propagation of action potentials in myelinated axons is faster than in unmyelinated axons due to:
a) Continuous conduction of the electrical signal along the entire axon length.
b) Saltatory conduction, where the signal jumps between Nodes of Ranvier.
c) A higher concentration of sodium channels in myelinated axons.
d) A greater diameter of myelinated axons.
b) Saltatory conduction, where the signal jumps between Nodes of Ranvier.
Which of the following statements about graded potentials is TRUE?
a) They are all-or-none responses, meaning they always have the same amplitude.
b) They are propagated over long distances without decrement.
c) They can be either depolarising or hyperpolarising.
d) They are generated by the opening of voltage-gated sodium channels.
c) They can be either depolarising or hyperpolarising.
What distinguishes sesamoid bones from other bone types?
a) They contain air spaces and are located around the nasal cavity.
b) They form through intracartilaginous ossification.
c) They lack a periosteum and a direct blood supply.
d) They are the largest and strongest bones in the body.
c) They lack a periosteum and a direct blood supply.
A patient with a history of chronic alcohol abuse exhibits muscle weakness and difficulty with coordination. Neurological examination reveals impaired sensory perception and loss of reflexes. Which of the following cellular components of the nervous system is most likely affected in this patient, explaining the observed symptoms?
a) Neurons, the primary cells responsible for transmitting electrical signals.
b) Neuroglia, the supporting cells that provide insulation, nourishment, and protection to neurons.
c) Synapses, the junctions between neurons where signals are transmitted.
d) Ion channels, proteins embedded in the neuronal membrane that regulate the flow of ions.
b) Neuroglia, the supporting cells that provide insulation, nourishment, and protection to neurons.
Damage to which of the following cranial nerves would most likely result in impaired eye movements?
a) Olfactory nerve (I), responsible for the sense of smell.
b) Vestibulocochlear nerve (VIII), involved in hearing and balance.
c) Oculomotor nerve (III), controlling several eye muscles and pupil constriction.
d) Hypoglossal nerve (XII), responsible for tongue movements.
c) Oculomotor nerve (III), controlling several eye muscles and pupil constriction.
A research study investigates the impact of a novel drug on nerve regeneration. The drug is found to enhance the transport of essential molecules and organelles along the axon. Which of the following neuronal processes is most directly influenced by this drug?
a) Synaptic transmission, the communication between neurons at the synapse.
b) Generation of action potentials, the electrical signals transmitted along axons.
c) Axonal transport, the movement of materials within the axon.
d) Myelination, the formation of the myelin sheath around axons.
c) Axonal transport, the movement of materials within the axon.
Which of the following statements accurately describes the relationship between osteons and the structural integrity of compact bone?
a) Osteons, found primarily in spongy bone, provide lightweight yet sturdy support.
b) Osteons run perpendicular to the long axis of the bone, resisting bending forces.
c) The absence of osteons in certain bones, such as the clavicle, contributes to their increased flexibility.
d) The organised arrangement of osteons in concentric layers provides compact bone with its strength and resistance to stress.
d) The organised arrangement of osteons in concentric layers provides compact bone with its strength and resistance to stress.
A patient presents with persistent pain and stiffness in their knee joint. Examination reveals a reduction in the smooth, gliding surface of the joint. Which of the following components of cartilage is most likely affected, contributing to the observed symptoms?
a) Chondroblasts, the cells responsible for cartilage formation.
b) Perichondrium, the outer covering of cartilage.
c) Hyaluronic acid, a key component of the cartilage matrix that provides lubrication and shock absorption.
d) Elastic fibres, responsible for the flexibility of cartilage.
c) Hyaluronic acid, a key component of the cartilage matrix that provides lubrication and shock absorption.
During endochondral ossification, what role does the epiphyseal plate play in the growth of long bones?
a) It serves as a site for the deposition of calcium and phosphate, leading to bone hardening.
b) It provides a protective covering for the bone, preventing damage during growth.
c) It is a layer of cartilage where chondrocytes proliferate and undergo hypertrophy, contributing to longitudinal bone growth.
d) It is the primary centre of ossification, where bone formation begins in the diaphysis.
c) It is a layer of cartilage where chondrocytes proliferate and undergo hypertrophy, contributing to longitudinal bone growth.
A histological examination of a tissue sample reveals chondrocytes arranged in clusters within lacunae, surrounded by a matrix rich in collagen fibres. This tissue is most likely:
a) Elastic cartilage, known for its flexibility and presence of elastic fibres.
b) Hyaline cartilage, the most common type of cartilage found in joints and supporting structures.
c) Fibrocartilage, characterized by its dense collagenous matrix and ability to withstand tensile forces.
d) Bone, a highly vascularized tissue with a calcified matrix.
b) Hyaline cartilage, the most common type of cartilage found in joints and supporting structures.
Which of the following scenarios would most likely lead to an increase in the frequency of action potentials generated by a neuron?
a) Hyperpolarisation of the neuron’s resting membrane potential.
b) A stronger stimulus applied to the neuron’s receptive segment (dendrites and perikaryon).
c) Inhibition of voltage-gated sodium channels, preventing sodium influx.
d) Prolonged activation of potassium channels, leading to potassium efflux.
b) A stronger stimulus applied to the neuron’s receptive segment (dendrites and perikaryon).
An individual experiences a sudden loss of sensation in their left arm and leg. Which of the following structures is the most likely site of injury, considering the lateralisation of the symptoms?
a) Peripheral nerves in the left arm and leg.
b) The cerebellum, responsible for coordination and balance.
c) The right side of the brain, where sensory information from the left side of the body is processed.
d) The spinal cord at the cervical level, where nerves supplying the arms originate.
c) The right side of the brain, where sensory information from the left side of the body is processed.
Botulinum toxin, a potent neurotoxin, exerts its effect by blocking the release of acetylcholine at the neuromuscular junction. Which of the following steps in muscle contraction is directly inhibited by this toxin?
a) The binding of calcium ions to troponin, exposing the myosin-binding sites on actin filaments.
b) The power stroke, where the myosin head pulls the actin filament, shortening the sarcomere.
c) The generation of an action potential in the muscle fibre, triggered by the binding of acetylcholine to its receptors.
d) The reuptake of acetylcholine into the presynaptic neuron, terminating the signal.
c) The generation of an action potential in the muscle fibre, triggered by the binding of acetylcholine to its receptors.
A 6-year-old child presents with bowed legs and a noticeable delay in growth. Blood tests reveal a deficiency in vitamin D.
Question: Based on these findings, what is the most likely diagnosis for this child?
a) Osteomalacia
b) Rickets
c) Osteoporosis
d) Scurvy
b) Rickets
A histological examination of a tissue sample shows chondrocytes arranged in clusters within lacunae, embedded in a matrix abundant in collagen fibres, but lacking blood vessels.
Question: What type of connective tissue is most likely being observed in this histological sample?
a) Hyaline cartilage
b) Bone
c) Elastic cartilage
d) Fibrocartilage
a) Hyaline cartilage
A 30-year-old athlete suffers a severe knee injury during a football match. An MRI scan reveals a complete tear of the anterior cruciate ligament (ACL).
Question: What is the most likely reason that surgical intervention is required to repair the athlete’s torn ACL?
a) The ACL is a modified long bone, lacking a medullary cavity, hindering its healing capacity.
b) The ACL is a pneumatic bone containing air spaces, making it susceptible to infections if left untreated.
c) The ACL is primarily composed of dense connective tissue, with a limited blood supply, leading to poor natural healing.
d) The ACL is a sesamoid bone, embedded within a tendon, lacking a periosteum and direct blood supply, impeding its regenerative ability.
c) The ACL is primarily composed of dense connective tissue, with a limited blood supply, leading to poor natural healing.
A patient presents with weakness and numbness in their right leg following a fall. Neurological examination reveals damage to a major nerve in the leg.
Question: Which of the following structures, essential for nerve impulse conduction, is most likely affected in this patient?
a) Periosteum
b) Axon
c) Lacunae
d) Lamellae
b) Axon
An individual sustains a head injury in a motor vehicle accident, resulting in damage to cranial nerve VIII.
Question: What type of nerve is cranial nerve VIII, and what sensory function is it primarily associated with?
a) Motor nerve, controlling eye movements
b) Mixed nerve, controlling facial expressions and taste
c) Sensory nerve, responsible for hearing and balance
d) Motor nerve, controlling tongue movements
c) Sensory nerve, responsible for hearing and balance
A medical student is examining a cross-section of a long bone under a microscope. They observe a central canal surrounded by concentric rings of bone matrix called lamellae.
Question: What is the name of the functional unit being observed by the medical student?
a) Trabecula
b) Osteon
c) Lacuna
d) Canaliculus
b) Osteon
A histological slide shows a type of cartilage with chondrocytes scattered within a matrix rich in elastic fibres.
Question: Where in the body would this type of cartilage most likely be found?
a) Intervertebral discs
b) Menisci of the knee joint
c) Articular surfaces of long bones
d) External ear
d) External ear
A patient presents with persistent pain and stiffness in their hip joint. X-ray imaging reveals significant wear and tear of the articular cartilage.
Question: What is the primary function of articular cartilage within a joint?
a) To provide attachment sites for muscles
b) To store minerals like calcium and phosphate
c) To provide a smooth, low-friction surface for movement
d) To produce red blood cells within the bone marrow
c) To provide a smooth, low-friction surface for movement
