Big anatomy

Musculoskeletal System

Musculoskeletal System

The system in the body that allows movement and interaction with the environment.

Bones

Structural components of the musculoskeletal system that provide support, store calcium, produce blood cells, and protect organs.

Joints

Structures that facilitate movement, allow growth, and provide stability in the musculoskeletal system.

Muscles

Tissues that generate movement and heat in the body.

Compact (cortical) bone

Dense, strong, and heavy outer layer of bone.

Spongy (trabecular/cancellous) bone

More porous, weaker, and lighter inner layer of bone.

Periosteum

Fibrous connective tissue sleeve that covers the outer surface of bones, providing blood supply and innervation.

Endochondral ossification

The process in which an initial hyaline cartilage version of bone grows and turns into bone.

Shorts Bones

Cuboidal bones with strange shapes, such as carpal and tarsal bones.

Sesamoid Bones

Bones found within tendons, such as the patella.

Axial Skeleton

The part of the skeleton that includes the skull, spine, sternum, and ribs.

Appendicular Skeleton

The part of the skeleton that includes the pectoral and pelvic girdles, and the upper and lower limbs.

Vertebral Column

The series of vertebrae that make up the spine.

Intervertebral Foraminae

Openings between adjacent vertebrae through which spinal nerves emerge.

Spinal Cord

The bundle of nerves that runs through the vertebral canal and transmits signals between the brain and the body.

Spinal Nerves

Nerves that arise from the spinal cord and supply the body wall.

Cervical Vertebrae

The vertebrae in the neck region, including the atlas (C1), axis (C2), and vertebra prominens (C7).

Pelvic Girdle

The structure formed by the hip bones and the sacrum.

Pectoral Girdle

The structure formed by the scapulae and clavicles.

Cranial Vault

The bones of the skull that protect the brain.

Facial Skeleton

The bones of the face that support the facial structures.

Cardiac Muscle

Involuntary and striated muscle found in the heart.

Smooth Muscle

Involuntary and non-striated muscle found in the walls of organs and blood vessels.

Skeletal Muscle

Voluntary and striated muscle responsible for skeletal movements.

Graded Muscle Strain

A classification system for muscle strains, ranging from grade 1 (mild) to grade 3 (severe).

Striations

The striped appearance of skeletal muscle fibers due to the arrangement of actin and myosin filaments.

Fusiform Muscle

A muscle with longer fibers that allows for a greater range of shortening and movement at a joint.

Pennate Muscle

A muscle with shorter fibers that allows for a greater force production.

Flat Muscle

A muscle with a broad, flat shape and an aponeurosis attachment.

Circular Muscle

A muscle that forms a ring-like structure, such as the orbicularis oculi muscle around the eye.

Muscle Origin

The point of attachment of a muscle to a bone that remains relatively fixed during movement.

Muscle Insertion

The point of attachment of a muscle to a bone that moves during muscle contraction.

Superficial Fascia

Adipose tissue layer found above the deep fascia.

Deep Fascia

Fibrous tissue layer that covers skeletal muscles.

Epidermis

The outermost layer of the skin composed of epithelial cells.

Dermis

The layer of skin beneath the epidermis, composed of collagen and elastic fibers.

Skeletal Muscle Attachment

The points of attachment of a muscle to bone, including origins and insertions.

Muscles of Facial Expression

Muscles that attach from bone to skin and soft tissue, allowing for facial expressions and protecting entrances into the body.

Axial (transverse) section

A section that is cut perpendicular to the long axis of an object or body.

Deep fascia

A layer of connective tissue that surrounds muscles and other structures, providing support and protection.

Intermuscular septum

A thin layer of connective tissue that separates adjacent muscle groups.

Superficial fascia

A layer of connective tissue located just beneath the skin, containing fat and blood vessels.

Skin

The outermost layer of the body, providing protection and sensation.

Tibia

The larger of the two bones in the lower leg, commonly known as the shinbone.

Fibula

The smaller of the two bones in the lower leg, located on the outer side.

Fascia and Muscle Compartments

Divisions within the body that contain muscles and their associated fascia, allowing for organized movement and function.

Lower part of anal canal & anus

The terminal portion of the digestive tract, responsible for the elimination of waste.

Lower part of urinary tract

The portion of the urinary system that includes the bladder and urethra, responsible for the storage and elimination of urine.

Skeletal muscles of the proximal parts of the respiratory and alimentary tracts

Muscles involved in the movement and function of breathing and swallowing.

Approximate level of transition to smooth muscle

The point where skeletal muscle transitions to smooth muscle, such as in the trachea and middle third of the esophagus.

Approximate level of transition back to skeletal muscle

The point where smooth muscle transitions back to skeletal muscle, such as in the perineum.

Nose

The organ responsible for the sense of smell and the entrance to the respiratory system.

Tongue

A muscular organ in the mouth that is involved in taste, speech, and swallowing.

Skeletal Muscle Vs Smooth Muscle

A comparison between skeletal muscle, which is under voluntary control, and smooth muscle, which is involuntary and found in organs.

Protective reflexes

Automatic responses of the body to protect itself, such as coughing, sneezing, gagging, swallowing, and vomiting.

Diaphragm

A dome-shaped muscle located at the base of the lungs, involved in breathing.

Muscles that control micturition and defecation

Muscles involved in the voluntary control of urination and bowel movements.

Joint Classification

The categorization of joints based on their structure and function.

Fibrous Joints

Joints that are connected by fibrous tissue, allowing for limited mobility and high stability.

Syndesmoses

A type of fibrous joint that unites bones with a fibrous sheet or membrane.

Sutures

Fibrous joints found between the bones of the skull, providing high stability.

Gomphosis

A fibrous joint that connects teeth to their sockets, allowing for very little movement.

Cartilaginous Joints

Joints that are connected by cartilage, providing limited mobility and stability.

Primary cartilaginous joints (synchondroses)

Joints where bones are joined by hyaline cartilage, allowing for growth in length and eventual fusion.

Secondary cartilaginous joints (symphyses)

Joints where bones are joined by fibrocartilage, providing slight movement.

Slipped femoral epiphysis

A condition where the femoral head slips out of its normal position in relation to the growth plate.

Intervertebral discs

Fibrocartilage discs located between the vertebrae, allowing for slight movement and shock absorption.

Synovial Joints

Joints that are surrounded by a synovial membrane and filled with synovial fluid, allowing for a wide range of movement.

Synovial fluid

A lubricating fluid produced by the synovial membrane, reducing friction and acting as a shock absorber.

Ligaments

Bands of fibrous tissue that connect bone to bone, providing stability and support.

Articular disc or Meniscus

A fibrocartilage structure found in some synovial joints, providing additional support and shock absorption.

Joint cavity

The space within a synovial joint that contains synovial fluid.

Bursae

Small fluid-filled sacs located around joints, reducing friction and providing cushioning.

Articular disc in TMJ joint

A unique feature found in the temporomandibular joint, providing additional support and allowing for smooth movement.

Surface Anatomy

The study of the external features and landmarks of the body.

Epidermis

The outermost layer of the skin, providing protection and waterproofing.

Dermis

The layer of skin beneath the epidermis, containing blood vessels, nerves, and other structures.

Superficial fascia

The layer of connective tissue located just beneath the skin, containing fat and blood vessels.

Deep fascia

A layer of connective tissue that surrounds muscles and other structures, providing support and protection.

Muscles of facial expression

Muscles located in the face that are responsible for various facial movements and expressions.

Innervation

The supply of nerves to a specific area or structure.

CN V1, CN V2, CN V3

Cranial nerves responsible for the innervation of different areas of the face.

Orbicularis oris

A muscle that encircles the mouth and is involved in various movements, such as closing and puckering the lips.

Frontalis

A muscle located in the forehead that is responsible for raising the eyebrows and wrinkling the forehead.

Orbicularis oculi

A muscle that encircles the eye and is involved in blinking and closing the eyelids.

Platysma

A thin muscle located in the neck that is involved in various movements, such as lowering the jaw and pulling down the corners of the mouth.

CN VII - facial nerve

The cranial nerve responsible for the innervation of the muscles of facial expression.

Muscles of mastication

Muscles involved in the movement and function of chewing.

Medial pterygoid, lateral pterygoid, temporalis, masseter

Muscles that are responsible for the movement of the jaw during chewing.

Submandibular gland, sublingual gland, parotid gland

Salivary glands located in the mouth that produce and secrete saliva.

Arterial supply

The blood vessels that provide oxygenated blood to a specific area or structure.

Facial artery

A branch of the external carotid artery that supplies blood to the face.

Venous drainage

The system of veins that carries deoxygenated blood away from a specific area or structure.

Facial vein

A vein that drains blood from the face and empties into the internal jugular vein.

Lymphatic drainage

The system of lymphatic vessels that carries lymph fluid away from a specific area or structure.

Superficial ring of regional lymph nodes

Lymph nodes located in the scalp, face, and superficial upper neck that drain lymph fluid from these areas.

Paranasal sinuses

Air-filled spaces located within the bones of the skull, connected to the nasal cavity.

Maxillary sinuses, frontal sinus, ethmoidal cells, sphenoidal sinus

Different types of paranasal sinuses located in specific regions of the skull.

Bony orbit

The bony socket in the skull that houses the eyeball.

External layer of eyelid

The outermost layer of the eyelid, providing protection and support.