The abducens nerve or abducent nerve, also known as the sixth cranial nerve, cranial nerve VI, or simply CN VI, is a cranial nerve in humans and various other animals that controls the movement of the lateral rectus muscle, one of the extraocular muscles responsible for outward gaze. It is a somatic efferent nerve.
The radial nerve is a nerve in the human body that supplies the posterior portion of the upper limb. It innervates the medial and lateral heads of the triceps brachii muscle of the arm, as well as all 12 muscles in the posterior osteofascial compartment of the forearm and the associated joints and overlying skin.
The pectoralis major is a thick, fan-shaped or triangular convergent muscle of the human chest. It makes up the bulk of the chest muscles and lies under the breast. Beneath the pectoralis major is the pectoralis minor muscle.
An aponeurosis is a flattened tendon by which muscle attaches to bone or fascia. Aponeuroses exhibit an ordered arrangement of collagen fibres, thus attaining high tensile strength in a particular direction while being vulnerable to tensional or shear forces in other directions. They have a shiny, whitish-silvery color, are histologically similar to tendons, and are very sparingly supplied with blood vessels and nerves. When dissected, aponeuroses are papery and peel off by sections. The primary regions with thick aponeuroses are in the ventral abdominal region, the dorsal lumbar region, the ventriculus in birds, and the palmar (palms) and plantar (soles) regions.
The rectus abdominis muscle, also known as the "abdominal muscle" or simply the "abs", is a pair of segmented skeletal muscle on the ventral aspect of a person's abdomen. The paired muscle is separated at the midline by a band of dense connective tissue called the linea alba, and the connective tissue defining each lateral margin of the rectus abdominus is the linea semilunaris. The muscle extends from the pubic symphysis, pubic crest and pubic tubercle inferiorly, to the xiphoid process and costal cartilages of the 5th–7th ribs superiorly.
The superior rectus muscle is a muscle in the orbit. It is one of the extraocular muscles. It is innervated by the superior division of the oculomotor nerve (III). In the primary position, its primary function is elevation, although it also contributes to intorsion and adduction. It is associated with a number of medical conditions, and may be weak, paralysed, overreactive, or even congenitally absent in some people.
The medial rectus muscle is a muscle in the orbit near the eye. It is one of the extraocular muscles. It originates from the common tendinous ring, and inserts into the anteromedial surface of the eye. It is supplied by the inferior division of the oculomotor nerve (III). It rotates the eye medially (adduction).
The transverse abdominal muscle (TVA), also known as the transverse abdominis, transversalis muscle and transversus abdominis muscle, is a muscle layer of the anterior and lateral abdominal wall, deep to the internal oblique muscle. It is thought by most fitness instructors to be a significant component of the core.
The intermammary cleft, intermammary sulcus, or sulcus intermammarius is a surface feature of males and females that marks the division of the two breasts with the sternum (breastbone) in the middle. The International Federation of Associations of Anatomists (IFAA) uses the terms "sulcus intermammarius" or "intermammary cleft" when referring to the area between the breasts.
The subclavius is a small triangular muscle, placed between the clavicle and the first rib. Along with the pectoralis major and pectoralis minor muscles, the subclavius muscle makes up the anterior axioappendicular muscles, also known as anterior wall of the axilla.
The popliteus muscle in the leg is used for unlocking the knees when walking, by laterally rotating the femur on the tibia during the closed chain portion of the gait cycle. In open chain movements, the popliteus muscle medially rotates the tibia on the femur. It is also used when sitting down and standing up. It is the only muscle in the posterior (back) compartment of the lower leg that acts just on the knee and not on the ankle. The gastrocnemius muscle acts on both joints.
The lateral pectoral nerve arises from the lateral cord of the brachial plexus, and through it from the C5-7.
The pectoral fascia is a thin lamina, covering the surface of the pectoralis major, and sending numerous prolongations between its fasciculi: it is attached, in the middle line, to the front of the sternum; above, to the clavicle; laterally and below it is continuous with the fascia of the shoulder, axilla, and thorax.
The pectineal ligament, sometimes known as the inguinal ligament of Cooper, is an extension of the lacunar ligament. It runs on the pectineal line of the pubic bone. The pectineal ligament is the posterior border of the femoral ring.
The linea semilunaris is described by Adriaan van den Spiegel described the Linea Semilunaris as the line forming and marking the transition from muscle to aponeurosis in the transversus abdominis muscle of the abdomen. It needs to be distinguished from the lateral border of the rectus abdominis muscle sheath which is often wrongly described as semilunar line. The lateral border of the rectus sheath is part of the recently described EIT ambivium to more precisely describe this important part of the anterior abdominal wall. The EIT ambivium is formed by the Musculus Obliquus Externus (MOE), the Musculus Obliquus Internus (MOI) and the Musculus Transversus Abdominis (TA). Understanding the interrelationship between the lateral muscles and the medial compartment is of paramount importance for surgeons to understand the surgical anatomy.
An accessory muscle is a relatively rare anatomical variation where duplication of a muscle may appear anywhere in the muscular system. Treatment is not indicated unless the accessory muscle interferes with normal function.
The extensor indicis et medii communis is a rare anatomical variant in the extensor compartment of forearm. This additional muscle lies in the deep extensor layer next to the extensor indicis proprius and the extensor pollicis longus. The characteristics of this anomalous muscle resemble those of the extensor indicis proprius, with split tendons to the index and the middle finger. This muscle can also be considered as a variation of the aberrant extensor medii proprius.
The axillary arch is a variant of the latissimus dorsi muscle in humans. It is found as a slip of muscle or fascia extending between the latissimus dorsi muscle and the pectoralis major. There is considerable variation in the exact position of its origin and insertions as well as its blood and nerve supply. The arch may occur on one or both sides of the body. A meta-analysis revealed that the axillary arch had an overall prevalence of 5.3% of limbs.
An anatomical variation, anatomical variant, or anatomical variability is a presentation of body structure with morphological features different from those that are typically described in the majority of individuals. Anatomical variations are categorized into three types including morphometric, consistency, and spatial.
The myodural bridge or miodural ligament is a bridge of connective tissue that extends between the suboccipital muscles and the cervical spinal dura mater, the outer membrane that envelops the spinal cord. It provides a physical connection between the musculoskeletal and nervous systems, and the circulation of cerebrospinal fluid. Its importance has been highlighted by various authors.
