Anatomy & Physiology Flashcards
What are the 3 main sections of the long bone
Diaphysis
Epiphysis
Metaphysis
What is the diaphysis?
The main, mid-section of the long bone. Mostly these bones are filled with yellow marrow, composed mainly of adipose (fat) tissue in adults. This yellow, fatty marrow serves to add protection to the bone when it is subjected to the stresses of pressure, i.e., weight bearing.
What is the epiphysis?
It is found at the end of the long bones. These ends are rounded and usually have cartilage at their distal ends. The epiphysis contains red marrow, which is responsible for the production of erythrocytes (red blood cells).
What is the Metaphysis?
The portion of the long bones located in between the diaphysis and epiphysis. In children, the metaphysis contains the epiphyseal plate, or growth plate. Between 18 to 25 years of age, the plate ceases to function and becomes the remnant epiphyseal line seen in adults, a non-functional remnant of the growth plate.
Describe Haversian canals
Irregular tubes and channels that contain a blood vessel, a nerve and a lymph vessel. Haversian’s are located between the bone lamellar, and protect soft vessel tissues as they run through bone. Haversian canals help to form a communicating network between the bone cells (osteocytes), and run predominantly parallel to a long bone’s axis, but can wander.
Describe Volkmann’s canals.
Connect Haversian canals together. They are very tiny, microscopic channels in compact bone that run perpendicular to Haversian canals. Volkmann’s canals also serve to interconnect the Haversian system with the bone’s periosteum and frequently carry small arteries throughout the bone.
What are the main differences between Haversian canals and Volkmann’s canals?
Haversians canal serve to connect osteocytes and provide supportive structure, but the Volkmann’s canal serves to actually connect the Haversian canals themselves and provide a pathway and network for small arteries.
What are the 3 main cells found in bone?
Osteoblasts
Osteocytes
Osteoclasts
What are Osteoblasts?
Osteoblasts form new bone microscopically in a matrix that hardens with minerals, giving the bone its strength. Osteoblasts produce osteoid, which is a protein mixture composed mainly of Type 1 collagen material. Osteoblasts create and build new bone, important in overall bone mass. Osteoblasts are one half of the equation that is the process of maintaining bone strength.
What are Osteocytes?
Osteocytes are the most commonly found cell in bone. When osteoblast cells become trapped inside the collagen matrix, which they secrete, they cease to function as bone-building entities. Instead, they interconnect to strengthen the bone. Osteocytes form star-shaped structures called cannaliculi, which are a network of small, hollow tunnels.
What are Osteoclasts?
Osteoclasts are responsible for the breakdown of old bone material. Osteoclasts accomplish this by removing the mineralized matrix substance in the bone, literally reabsorbing it. The combined effects of the osteoblast and osteoclasts cells serve to maintain healthy, strong bones.
List the 5 major classification of bones, and give examples of where each can be found in the body.
- Long bones: The arm’s humerus and ulna, and the leg’s femur, fibula and tibia.
- Short bones: Cube-like wrist carpals, hand metacarpals, ankle tarsals and foot metatarsals.
- Flat bones: Cranium (skull) to protect the brain, and ribs, sternum and scapula (shoulder blade) to protect the heart and lungs.
- Irregular bones: The vertebrae, which protect the spinal cord; the hyoid bone, which offers supportive protection to the trachea; and the sacrum/coccyx, which protect the terminal end of the large intestine and rectum.
- Sesamoid bones: The knee cap (patella), and sesame seed-like bones embedded in tendons in the hand and foot where they pass over joints, to increase the momentum arm.
Define and describe the term fossa, and give 3 examples of where this can be found in the body.
Fossa means hollow depression.
It allows for the passage of nerves and blood vessels through bone, and also serves as an attachment point for muscles and tendons.
3 examples:
- Fossa Ovalis, located in the upper medial aspect of the thigh, just below the inguinal ligament. It is an opening into the fascia late and allows for the passage of the great saphenous vein, as well as other vessels.
- The ante cubical fossa, is found on the anterior aspect of the elbow, where blood is drawn during venipuncture. Its bony borders are the lateral and medial humeral epicondyles, and its muscle borders are the brachialis and the deep arm fascia.
- On the scapula (shoulder blades), there are three separate and distinct fossae, which are the supraspinatus, infraspinatus, and subscapularis. They provide attachment points to back muscles and allow muscle movement.
Describe the foramen magnum, its location and the function(s) it serves.
The foramen magnum is the largest of many foraminal openings in the skull, and is located at the base of the occipital bones and lies superior and central to the origin of the cervical spine. The foramen magnum leads to the medulla oblongata of the brain, the superior beginning of the spinal cord and center of autonomic function. The foramen magnum allows for passage of the posterior spinal arteries and vertebral arteries. The Occipital condyles and alar ligaments act as the “hinge points” for the attachment of the skull to the cervical spine, which are supported by many muscles and ligaments.
Chiari Malformation is a condition in which the foramen magnum is too small and pushes down onto the cerebellum, which lies below it. Cerebrospinal fluid (CSF) cannot move properly through the foramen magnum, causing dizziness, numbness, visual disturbance, headaches, and imbalance or paralysis. It is common in patients with spina bifida, spinal curvature, hydrocephalus, and syringomyelia.
Describe the occipital condyles, their location and what function(s) they serve.
The two occipital condyles are articular surfaces that are located on either side of the foramen magnum at the base of the skull. These condyles come into direct contact with the articular joint surfaces of the first cervical vertebra, or atlas. Combined with the alar ligaments, this becomes the “hinge point” for the skull’s attachment to the cervical spine and the initial point of motion between the skull and spine. Each of the two condyles is actually comprised of two facets, or small articular planes, to form a total of four (4) articular surfaces with the first cervical vertebra. This connection is the skull’s only direct attachment to the spinal column, aside from muscular and ligamentous attachments.
Define and describe bony crests, including locations and functions.
The bony crests are located in the pelvic girdle. They are the iliac and pubic crests.
The iliac crest forms the anterior and superior aspect of the ilium, which is large, winged hip basin. The iliac crest is convex and begins just slightly posterior to the superior portion of the ilium, and ends at the anterior iliac spine. In adults, the iliac crest houses a large amount of red bone marrow, and is the site of choice for bone marrow aspirations and harvesting marrow from donors for transplantation. The iliac crest also serves at an attachment point for the abdominal oblique muscles, the tensor fascia late, and the lower portions of the latissimus dorsi muscles.
The pubic crest consists of the superior pubic ramus bones that make up the superior anterior pelvic ring. These areas are attachment points for the inguinal falx, which is made up of a conjoined tendon from two abdominal muscle structures called the obliquus internus and the transversus.
Define the term foramen, and give 3 examples of where this structure can be found.
A foramen is an opening that allows for the passage of muscles, nerves, or blood vessels to various parts of the body.
- The foramen ovale is an opening in the heart of the fetus between the deoxygenated, bluish venous side and its oxygenated, scarlet arterial side. Typically closed at birth, in some cases it can remain patent (open). Venous and arterial blood mix, hence the term “ blue baby”. The foramen requires surgical closure.
- The obturator foramen is in the pelvis, between the hip joints. It’s bony borders are the inferior and superior ischial tuberosities, the symphysis pubis and the inner aspect of the acetabulum. The opening allows for passage of the obturator artery and nerve.
- The vertebral foramen is the opening formed as the “body” of a spinal vertebra meets with its posterior vertebral arch. This opening allows for the passage of the spinal cord from the upper cervical and thoracic levels to the cauda equina (lower terminal end).
Discuss the term condyles, its structural components, and give three examples of condyle locations.
A condyle is a knuckle joint, a rounded (convex), projecting articular end of a bone, usually in the thigh, elbow, jaw, hand or foot. Depending upon the joint, there may be one or more condyles present. Condyles can be weight-bearing or non weight-bearing. They can be located in virtually all quadrants of the body.
- The two condyles found at the distal end of the femur (the lateral condyle and the medial femoral condyle) comprise the superior portion of the knee joint. Each femoral condyle is coated with hyaline cartilage, or articular cartilage. These are the distal weight-bearing surfaces of the femoral portion of the knee joint.
- Lateral and medial articular condyles can also be found in the elbow. these condyles allow flexion and extension of the elbow joint.
- A third location of a condyle is in the temporomandibular (TMJ) joint of the jaw. This is called the mandibular condyle. There is one TMJ located on each side of the jaw and is where the mandible and the maxillary bones articulate.
Define trochanter, state its location(s) in the body and the function(s) it serves.
Trochanter is Greek for runner. a trochanter refers to a bony prominence located at the proximal end of the femur bone. There are two types of trochanter a found on each femur; the greater trochanter, and the lesser trochanter. The trochanters serve as attachment points for several hip and thigh muscles. The greater trochanter is the attachment for the hip abductors and rotators, and the gluteal muscles. The lesser trochanter is the attachment point for the psoas major and the iliacus, otherwise known as the Iliopsoas muscle group. The greater trochanter is located lateral and just posterior to the femoral head and neck. The lesser trochanter is located inferior to the medial aspect of the femoral neck and along the proximal medial femoral shaft. The hip trochanters are often the locus for chronic conditions such as trochanteric bursitis, and acute inner-trochanteric hip fractures in the elderly.
Describe the location of the popliteal fossa and list the main structures that it houses.
The popliteal fossa is located behind the knee ( posterior aspect) at the point where the knee bends (flexes). The bony boundaries of this fossa are the distal femur and proximal tibia. The soft tissues and muscular boundaries of the popliteal fossa are the semitendinosus and semimembranosus (which form the “hamstring” musculi-tendinous group and the gastrocnemius). Major structures of importance that pass through this fossa are the popliteal artery, popliteal vein, tibial nerve and the common peroneal nerve. Use the popliteal fossa for: Obtaining pulses in the lower extremities to determine if blood flow to the leg is adequate; to control hemorrhage through the vascular pressure point; and to draw blood if the patient has no arms, or if his/her arms are bandaged.
