Bone Marrow Structure and Function

Bone Structure and Function

• Bones are composed of blood vessels, veins, and marrow that transport nutrients and waste in and out of bones.
• There are two types of bone marrow: red marrow (responsible for blood cell production) and yellow marrow (mostly composed of fat and found in the hollow centers of long bones).

Bone Marrow Development

• At birth, all marrow is red, producing more blood.
• In adults, red and yellow marrow are equal in proportion.
• Red marrow is found in high concentrations in the spine, sternum, ribs, and pelvis.

Fractures

• A fracture is a breakage in bone due to injury, stress, or disease.
• There are several types of fractures, including simple, compound, comminute, and incomplete fractures.

Cartilage and Joints

• Cartilage is a flexible connective tissue found in multiple organ systems, composed of chondrocytes, collagen fibers, and ground substance rich in proteoglycan and elastin fibers.
• There are three types of cartilage: hyaline cartilage (found in joints, nose, larynx, trachea, and ribs), elastic cartilage (found in the epiglottis), and fibrocartilage (found in intervertebral discs and pubic symphysis).

Joints

• A joint is a connection or union of two or more bones or cartilages.
• The study of joints is known as arthrology.
• Joints can be classified into three types: fibrous joints, cartilaginous joints, and synovial joints.

Fibrous Joints

• Fibrous joints are connected by dense fibrous connective tissue, allowing for little to no movement.
• Examples of fibrous joints include skull sutures and interosseous ligaments between forearm and leg bones.

Cartilaginous Joints

• Cartilaginous joints are connected by cartilage, allowing for limited movement.
• There are two types of cartilaginous joints: primary (found in growing bones where the shaft meets the epiphyseal plate) and secondary (found in bones whose articular surfaces are covered with a thin layer of hyaline cartilage).

Synovial Joints

• Synovial joints are freely mobile joints in which the bones are separated by a potential space called the synovial cavity.
• The synovial cavity is lined by a synovial membrane that secretes synovial fluid, which nourishes and lubricates the articulating surfaces.
• Synovial joints have a wide range of motion, defined by the joint capsule, supporting ligaments, and muscles that cross the joint.
• There are six types of synovial joints: hinge, pivot, ball and socket, ellipsoid, gliding, and saddle joints.

Muscular System

• Muscles provide several functions, including motion, maintenance of posture, production of heat, protection, and stability of joints.
• Muscle tissue constitutes about half of one's body weight and consists of specialized cells with the characteristics of excitability, contractility, and extensibility.

Muscles and Joints

• Hilton's law states that the nerve supplying the joint also supplies the muscles moving the joint and the skin covering the insertion of these muscles.
• The muscular system is responsible for all body movement, making it the "machines" of the body.

Imaging Techniques

• X-rays are a form of electromagnetic radiation with a wavelength of 10 to 0.01 nm, discovered by Röntgen in 1895.
• X-rays are used in diagnostic radiography and crystallography to take images of the inside of an object.
• Applications of X-rays include diagnosing arthritis, pneumonia, bone tumors, and fractures.

Conventional Chest X-Rays

• X-rays are used to produce high-contrast images on silver-impregnated film.
• Dense bone absorbs most of the radiation, while soft tissue and air allow more X-rays to pass through, resulting in bones appearing white, soft tissue in shades of grey, and air appearing black.

Fluoroscopy

• Fluoroscopy is an imaging technique that uses X-rays to obtain real-time moving images of internal structures and functions.
• Radiocontrast agents like Barium Sulphate and Radio-Iodine are used to describe anatomy and function of blood vessels, genitourinary system, and gastrointestinal tract.

Interventional Radiology

• Interventional radiology is a subspecialty of radiology that uses image guidance for minimally invasive procedures.
• Applications include diagnostic angiograms, treatment of peripheral vascular disease, renal artery stenosis, and gastrostomy tube placements.

Angiogram and Angioplasty

• An angiogram is a special X-ray that diagnoses blockages or narrowings in arteries.
• During an angiogram, a tube is inserted into an artery, and a radio-opaque dye is injected to visualize blood vessels.
• Angioplasty is a procedure that uses a balloon to treat narrowed or blocked arteries, often avoiding surgery.

Venogram

• A venogram is an X-ray test that visualizes blood flow through veins using a special dye.
• Venograms examine the condition of veins and valves in a specific area of the body.

Computer Tomography (CT)

• A CT scan uses a ring-shaped apparatus with an X-ray tube and detector to produce cross-sectional images.
• Coronal and sagittal images are produced by computer reconstruction, allowing for detailed images of structures like the skull bone and brain.
• Radiocontrast material enhances image clarity, and spiral multi-detector CT scans produce fine detailed images quickly.

Imaging Techniques

• X-rays are a form of electromagnetic radiation with a wavelength of 10 to 0.01 nm, discovered by Röntgen in 1895.
• X-rays are used in diagnostic radiography and crystallography to take images of the inside of an object.
• Applications of X-rays include diagnosing arthritis, pneumonia, bone tumors, and fractures.

Conventional Chest X-Rays

• X-rays are used to produce high-contrast images on silver-impregnated film.
• Dense bone absorbs most of the radiation, while soft tissue and air allow more X-rays to pass through, resulting in bones appearing white, soft tissue in shades of grey, and air appearing black.

Fluoroscopy

• Fluoroscopy is an imaging technique that uses X-rays to obtain real-time moving images of internal structures and functions.
• Radiocontrast agents like Barium Sulphate and Radio-Iodine are used to describe anatomy and function of blood vessels, genitourinary system, and gastrointestinal tract.

Interventional Radiology

• Interventional radiology is a subspecialty of radiology that uses image guidance for minimally invasive procedures.
• Applications include diagnostic angiograms, treatment of peripheral vascular disease, renal artery stenosis, and gastrostomy tube placements.

Angiogram and Angioplasty

• An angiogram is a special X-ray that diagnoses blockages or narrowings in arteries.
• During an angiogram, a tube is inserted into an artery, and a radio-opaque dye is injected to visualize blood vessels.
• Angioplasty is a procedure that uses a balloon to treat narrowed or blocked arteries, often avoiding surgery.

Venogram

• A venogram is an X-ray test that visualizes blood flow through veins using a special dye.
• Venograms examine the condition of veins and valves in a specific area of the body.

Computer Tomography (CT)

• A CT scan uses a ring-shaped apparatus with an X-ray tube and detector to produce cross-sectional images.
• Coronal and sagittal images are produced by computer reconstruction, allowing for detailed images of structures like the skull bone and brain.
• Radiocontrast material enhances image clarity, and spiral multi-detector CT scans produce fine detailed images quickly.