A 75-year-old woman has been suffering from

right hip pain for a long time. An X-ray showed signs of severe osteoarthritis.

Therefore, the patient underwent total hip replacement. Histological

examination of the surgical specimen revealed a significantly damaged articular

surface with marked cartilage degeneration. Which of the following factors is

primarily responsible for the poor regeneration of articular cartilage?

A 29-year-old woman comes to

the doctor for repeated infections caused by Anaplasma (bacteria).

Unfortunately, this particular species is resistant to most antibiotics, so it

is necessary to prescribe an antibiotic from the tetracycline group. These

antibiotics have a high ability to build into the mineral component of newly

formed bone as well as tooth enamel and dentin, thereby damaging these hard

tissues. Given the properties of these antibiotics, what can prevent the use of

a drug from this group?

The researcher would like to study the process

of cartilage tissue formation (chondrification). However, chondrogenesis is a

process that takes place only to a very limited extent after birth, and

therefore it is decided to study it during prenatal development. If he knows

the approximate location of the formation of cartilage. What tissue in a given

place should he expect before the formation of cartilage?

Two healthy individuals have a healthy son. His

physical, motor, psychological, and social development fully corresponded to

his age. Now at the age of two, the patient is admitted for a suspected

fracture of the right tibia. The injury is negative and the mechanism of

fracture is unknown. In addition, he was already hospitalized once 5 months ago

for a left radius fracture. The mechanism of fracture was not identified here

either. Physical examination reveals limited mobility of the right lower

extremity, soreness in the lower tibia and gluteal region and a relatively

greater amount of bruising on the body overall. Slightly bluish sclerae are

noticeable. X-ray confirms the diagnosis of a fracture of the right tibia.

Basic laboratory findings (blood count and biochemistry) are normal. Genetic

testing shows that the disease is caused by a mutation and defect in collagen

formation associated with, among other things, increased bone fragility. This

is the disease

The 69-year-old man's condition has deteriorated

greatly in the last few days. He feels very tired, faint, and weak. For the

third day, he still has a fever that is not responding to medication, but he

has no other symptoms of infection. He has developed small petechiae (spotty

bleeding) on his limbs and has had epistaxis (nosebleeds) several times. He is

now coming to the doctor because these symptoms are compounded by shortness of

breath and non-specific neurological symptoms. The GP immediately sends the

patient to the hospital, where the results of the blood count suggest a lot

about the patient's diagnosis. The patient has anaemia, thrombocytopenia and

leukopenia, but immature forms of white blood cells, called blasts, are present

in the blood. It is very likely that this patient has some form of acute

leukaemia. However, red bone marrow sampling is necessary to confirm and

establish a specific diagnosis. In which bones in adulthood does red bone marrow

remain and is it therefore possible to perform the necessary sampling from

them?

A 33-year-old man visits a general

practitioner's office complaining of loss of smell, frequent nosebleeds,

difficulty swallowing, and hoarseness. During the interview he admits to

cocaine use since his college days. Subsequent examination in the ENT clinic,

to which the patient is referred, reveals the presence of severe inflammation

of the nasal mucosa and a disrupted cartilage structure in the nasal septum.

What type of collagen predominates in this type of cartilage?

Achondroplasia is an

autosomal dominant disease that leads to a disorder of endochondral

ossification. A typical picture is a disproportionate growth disorder. However,

the trunk is almost normal length, the limbs are very short. Another feature is

a brachycephalic skull (pear-shaped), a broad forehead, and supraorbital

arches. Which type of cartilage is the model for the newly formed bone?

The 69-year-old man's condition has deteriorated

greatly in the last few days. He feels very tired, faint, and weak. For the

third day, he still has a fever that is not responding to medication, but he

has no other symptoms of infection. He has developed small petechiae (spotty

bleeding) on his limbs and has had epistaxis (nosebleeds) several times. He is

now coming to the doctor because these symptoms are compounded by shortness of

breath and non-specific neurological symptoms. The GP immediately sends the

patient to the hospital, where the results of the blood count suggest a lot

about the patient's diagnosis. The patient has anaemia, thrombocytopenia and

leukopenia, but immature forms of white blood cells, called blasts, are present

in the blood. It is very likely that this patient has some form of acute

leukaemia. However, red bone marrow sampling is necessary to confirm and

establish a specific diagnosis. In which bones in adulthood does red bone marrow

remain and is it therefore possible to perform the necessary sampling from

them?

A 20-year-old man sustained a twisting injury to his right knee while playing football. He underwent partial medial meniscectomy. Which of the following is true for the resected tissue?

A 55-year-old former athlete develops severe

secondary knee arthritis as a result of repeated injuries and surgeries. The

condition is so severe and limits the man's normal life that he decides to

undergo total knee arthroplasty (knee replacement). All tissues are replaced,

including the menisci. Which description most closely matches the histological

composition of the meniscal tissue?