E4 Vet Terms: Musculoskeletal system

Osteoblasts

Immature osteocytes that produce the bony tissue that replaces cartilage during ossification.

Rheumatoit arthritis

Immune-mediated

Acromion

Outward extension of the shoulder blade forming the point of the shoulder.

Rhabdomyolysis

Breakdown of skeletal muscle

Epiphyseal line or plate

Cartilaginous area at the ends of long bones where lengthwise growth takes place in the immature skeleton.

hyperparathyroidism

Excessive secretion of parathyroid hormone resulting in abnormally high levels of calcium in the blood.

Osteoporous

Pores in bone.

Ischium

Posterior part of the pelvis.

Styloid process

Projects downward from the temporal bone. Pole-like process extending downward from the temporal bone on each side of the skull.

Acetabulum

Socket in which the rounded proximal end of the femur fits. Rounded depression, or socket, in the pelvis, which joins the femur, forming the hip joint.

Diaphysis

Shaft or mid-portion of a long bone.

Fossa

Shallow cavity in a bone

Atrophy

Shrinkage of tissue

Cranial bones

Skull bones; ethmoid, frontal, occipital, parietal, sphenoid, and temporal

Tuberosity

Small, rounded elevation on a bone. Attachment site for muscles and tendons.

Fibula

Smaller of two lower leg bones.

Visceral muscle

Smooth muscle

Osteomalacia

Softening of the bone.

Occipital bone

forms the back and base of the skull and joins the parietal and temporal bones, forming a suture.

Arthrotomy

incision into a joint

Panosteitis

inflammation of an entire bone

Osteomyelitis

localized or generalized bone infection

Osteosarcoma

malignant bone tumor

Tarsals

Bones of the hind part of the foot.

Metatarsals

Bones of the midfoot

Osteoclasts

(-clasts mean to break) Large cells that function to reabsorb, or digest, bony tissue. These (aka phagocytes) digest bone tissue from the inner sides of bones and thus enlarge the inner bone cavity so that the bone does not become overly thick and heavy. When a bone breaks, osteoblasts lay down the mineral bone matter (calcium salts) and these remove excess bone debris (smooth out bone). These and osteoblasts work together in all bones throughout life, tearing down and rebuilding bony tissue. This allows bone to respond to mechanical stress placed on it and thus enables it to be a living tissue, constantly rebuilding and renewing itself

Synovial joint

A freely moveable joint. A joint (articulation) is a coming together of two or more bones. Some joints are immovable, such as teh suture joints between skull bones. Other joints, such as those between the vertabrae, are partially moveable. Most joints, however, allow considerable movement. The bones in these joints are surrounded by a joint capsule composed of fibrous tissue. Examples of these joints are ball-and-socket type and the hinge type.

Compact (cortical) bone

A layer of hard, dense bone that lies under the periosteum in all bones and lies chiefly around the diaphysis of long bones. Within the compact bone is a system of small canals containing blood vessels that bring oxygen and nutrients to the bone and remove waste products such as carbon dioxide.

Mastoid process

A round process of the temporal bone behind the ear.

Growth plate

Aka the epiphyseal plate, it represents an area of cartilage tissue that is constantly being replaced by new bone tissue as the bone grows. Cartilage cells at the edges of the epiphyseal plate form new bone, which is responsible for lengthening bones during growth.

Pubis

Anterior part

Articulation

Any joint, joints are places at which bones come together. Several different types of joints are found within the body. The type of joint found in any specific location is determines by the need for greater or lessef flexibility of movement.

Phalanges of the toes

Bones of the forefoot.

Osteocytes

Bone cells, mature bone cells located within lacunae. Main cells in bone tissue and maintain its daily metabolism, such as the exchange of nutrients and wastes with the blood. Do not undergo cell division. lower activity rates. help maintain matrix.

Ilium

Bone of the pelvis. Uppermost portion of the pelvis. Dorsally the two parts of this do not meet, rather they join the sacrum on either side to form the sacroiliac joints.

Sternum

Bone of the thorax, the breast bone. The lower portion is the xiphoid process and the upper is the manubrium.

Scapula

Bone of thorax, the shoulder blade.

Medullary cavity

Central, hollowed-out area in the shaft of a long bone. Contain yellow bone marrow. Yellow bone marrow is composed chiefly of fat cells.

Rotation

Circular movement around an axis (central point). Internal rotation is toward the midline and external rotation is away from the midline.

Origin of a muscle

Connection of a muscle to a stationary bone. Skeletal muscles are the muscles that move bones. When a muscle contracts, one of the bones to which it is joined remains virtually stationary as a results of other muscles that hold it in place. The point of attachment of the muscle to the stationary bone is called this. When the muscle contracts, however, another bone to which it is attached does not move. The point of junction of the muscle to the bone that moves is called the insertion of the muscle. Most often, the origin of a muscle lies proximal in the skeleton, whereas its insertion lies distal.

Insertion of a muscle

Connection of the muscle to a bone that moves

Osseous (bony) tissue

Connective tissue that comprises bones. Bones are also made of a rich supply of blood vessels and nerves. This consists of a combination of osteocytes , dense connestive tissue strands known as collagen and intercellular calcium salts.

Cartilaginous

Connective tissue that is flexible and rubbery. During fetal development, the bones of the fetus are composed of this tissue, which resembles osseous tissue but is more flexible and less dense because of a lack of calcium salts in its intercellular spaces. As the embryo develops, the process of depositing calcium salts in the soft, cartilagenous tissue occurs and continues throughout the life of the animal.

Articular

Covers the ends of long bones and the surface of any bone that meets another bone to form a joint. When two bones come together to form a joint, the bones themselves do not touch precisely. The articular cartilage that caps the end of one bone comes in contact with that of the other bone. This cartilage is a very smooth, strong and slick tissue. It cushions the joint and allows it to move smoothly and efficiently. Unlike the cartilage of the epiphyseal plate, which disappears when a bone acheives its full growth, articular cartilage is present throughout life.

Osteopenia

Decrease in bone density.

Flexion

Decreasing the angle between two bones; bending a limb

Dorsiflexion

Decreasing the angle of the joint so that the foot bends backward (upward)

Osteoarthritis

Degenerative joint disease

Collagen

Dense, connective tissue protein strands found in bone and other tissues. Collagen triple helices spontaneously form nanoscale bundles of protein, which act as a template for the crystallization of hydroxyapatite nanocrystals. The collagen matrix is also recognized by undifferentiated bone-marrow stem cells, which become bone-forming osteoblasts after signals from bone-specific proteins in the matrix.

Epiphysis

Each end of a long bone.

Bone processes

Enlarged areas that extend out from bones to serve as attachments for muscles and tendons.

Fascia

Fibrous tissue that envelopes and separates muscles. This contains the muscle's blood, lymph, and nerve supply.

Phalanges

Finger bones; each finger (except thumb) has three phalanges: a proximal, middle and distal phalanx.

Metaphysis

Flared portion of a long bone, between the diphysis (shaft) and the epiphyseal plate.

Frontal bone

Forms the forehead and the roof of the bony sockets that contain the eyes.

Sinus

Hollow air cavity within a bone.

Extension

Increasing the angle between two bones; straightening out a limb

Hematopoietic tissue

Inner core of bones, where the red bone marrow manufacture blood cells.

Vertebral body

Inner, thick, round anterior portion of the vertabra. Between the body of one vertebrae and the bodies of the vertebrae lying beneath and above is an intervertebral disk. It is a pad of cartilage that provides flexibility and shocks to the vertabral column.

Trabeculae

Interwoven fibers of cancellous bone. These are found largely in the epiphyses and metaphyses of long bones and in the middle portion of most other bones of the body as well.

Patella

Kneecap

Greater tronchanter

Large process of the femur for attachment of tendons and muscle. The lessor version of this is a smaller process. Large process at the neck of the femur.

Olecranon

Large process on the proximal end of the ulna.

Tibia

Larger of the two bones of the lower leg.

Radius

Lateral lower arm bone.

Mandibular bones

Lower jaw bones join the skull at the region of the temporal bone.

Ulna

Medial lower arm bone; the proximal bony process of the this at the elbow is called the olecranon.

Synovial membrane

Membrane lining the synovial cavity; it produces synovial fluid

Haversian canals

Minute spaces filled with blood vessels; found in compact bone.

Plantar flexion

Motion that extends the foot downward toward the ground

Abduction

Movement away from the midline of the body

Adduction

Movement toward the midline of the body

Transverse process

One of two processes that extend from each vertebra and provide the point of articulation for the ribs. The neural canal is the space between the vertebral body and the vertebral arch through which the spinal cord passes.

Foramen

Opening or passage in bones where blood vessels and nerves enter and leave. The foramen magnum is the opening of the occipital bone through which the spinal cord passes.

Malleolus

Round process on both sides of the ankle joint.

Bone head

Rounded end of a bone separated from the body of the bone by a neck; usually covered by articular cartilage. In the femur, this is called the femoral head.

Tubercle

Rounded process on many bones for attachment of tendons and muscles.

Condyle

Rounded, knuckle-like process at the joint; usually covered by articular cartilage.

Synovial cavity

Space between bones at a synovial joint; contains synovial fluid produced by the synovial membrane.

Cancellous bone

Spongy, porous, bone tissue in the inner part of a bone. The mineral matter in it is laid down in a series of separated bony fibers that make up a spongy latticework. Space in this bone contain red bone marrow. This consists of immature and mature blood cells in various stages of development.

Calcium and phosphorus

Stored in parts of the bone as minerals needed for growth. The formation of bone depends largely on a proper supply of these to the bone tissue. These minerals must be taken into the body along with a sufficient amount of vit D. Vit D helps calcium to pass through the lining of the small intestine and into the bloodstream. Once these arein the bones, osteoblasti activity produces an enzyme that forms calcium phosphate, a substance that gives bones its characteristic hard quality. It's the major calsium salt. Not only are these part of the hard structure of bone tissue, but calcium also is stored elsewhere in bones, and small quantities are present in the blood. If the proper amt of calcium is lacking in the blood, nerve fibers are unable to transmit impluses effectively to muscles, the heart muscle becomes weak, and muscles attached to bones undergo spasms. The necessary level of calcium in the blood is maintained by the parathyroid gland, which secretes a hormone that signals the release of calcium from bone storage. An excess of the hormone will raise blood calcium at the expense of the bones, which become weakened by the loss oc calcium.

Periosteum

Strong, fibrous, vascular membrane that covers the surface of long bones, except at the end of epiphyses. It has an extensive nerve supply as well.

Sphenoid bone

The "bat shaped" bone that extends behind the eyes and forms part of the base of the skull. Because it joins with the frontal, occipital, and ethmoid bones, it serves as an anchor to hold those skull bones together.

Sutures

The cranial bones join each other at joints called this. The bones of the skull, or cranium, protect the brain and structures related to it, such as the sense organs. Muscles for controlling head movements and chewing motions are connected to the cranial bones.

Fontanelles

The cranial bones of a new born are not completely joined. There are gaps of unossified tissue in the skull at birth. In these soft spots, the pulse of blood vessels can be felt.

Metacarpals

The five radiating bones in the fingers.

Ossification

The gradual replacement of cartilage and its intercellular substances by immature bone cells and calcium deposits.

Foramen magnum

The inferior portion of the occipital bone has an opening called this, through which the spinal cord passes.

Spinous process

The posterior portion of a vertabra consists of a single one of these, Single projection arising from the posterior aspect of the vertebral arch, fused laminae

Ethmoid bone

The thin, delicate bone that supports the nasal cavity (perpendicular plate) and forms part of the orbits of the eyes (orbital plate). It's composed primarily of sponging, cancellous bone, which contains numerous small holes.

Parietal bone

The two bones (one on each side of the skull) that form the roof and upper part of the sides of the cranium.

Temporal bone

The two bones that form the lower sides and base of the cranium. Each bone encloses an ear and contains a fossa for joining with the mandible (lower jaw bone). The temporomandibular joint (TMJ) is the area of connection between this bone and mandibular bones.

Intervertebral disks

The vertebral, or spinal, column is composed of vertebrae that are arranged in five divisions from the base of the skull to the tailbone (cervical, thoracic, lumber, scral, coccygeal). The bones are separated by pads of cartilage called this.

Bursae

There are closed sacs of synovial fluid lined with a synovial membrane and are located near but not with a joint. These are present wherever two types of tissue are closely opposed and need to slide past one another with as little friction as possible. They surve as layers of lubrication between tissue. Common sites of these are between tendons (connective tissue binding muscle to bone) and bones, and between skin and bones (in areas where bony anatomy is prominent).

Ligaments

These anchor one bone to another and thereby ass considerable strength to the joint capsule in critical areas. Bones at the joint are covered with smooth surface called articular cartilage. The synovial membrane lies under the joint capsule and lines the synovial cavity between the bones. The synovial cavity is filled with a special lubricating fluid produced by the synovial membrane. The synovial fluid contains water and nutrients that nourish as well as lubricate the joints so that friction on the articular cartilage in minimal.

Femur

Thigh bone; at its proximal end it has a rounded head that fits into a depression, or socket, in the pelvis.

Articular cartilage

Thin layer of cartilage surrounding the bone in the joint space.

Cardiac muscle

This muscle is striated in appearance but is like smooth muscle in its action. Its movement cannot be consciously controlled. The fibers of cardiac muscle are branching fibers and are found in the heart.

Smooth muscle

This muscle makes up the involuntary or visceral muscles that move internal organs such as the digestive tract, blood vessels and secretory ducts leading from glands. These muscles are controlled by the autonomic nervous system. They are called this because they have no dark and light fibrils in their cytoplasm. Skeletal muscle fibers are arranges in bundles, whereas this muscle forms sheets of fibers as it wraps around tubes and vessels.

Striated

This muscle makes up the voluntary or skeletal muscles that move all bones, as well as controlling facial expression and eye movement. The the central and peripheral nervous system, we have consious control over these muscles. These muscle fibers have a pattern of dark and light bands, or fibrils, in their cytoplasm.

Humerus

Upper arm bone

Synovial fluid

Viscous (sticky) fluid within the sunovial cavity. This fluid is similar in voscosity to egg white; this accounts for the origin of the term (syn-means like, ov/o means egg).

Carpals

Wrist bone

Dilated cardiomyopathy

cardiomyopathy characterized by a diffuse inflammation and rapid degeneration of myocardial fibers that results in ventricular dilation, impairment of systolic function, atrial enlargement, and stasis of blood in the left ventricle.

Arthrocentesis

removal of fluid from a joint by centesis