Teres major is a thick and oval-shaped muscle that lies in the upper arm. Although having similar names, Teres major is different in terms of actions and innervation when compared to the teres minor. It’s main function is to facilitate medial rotation of the arm and it also helps in maintaining static posture and arm-swinging. [...]
The right lung is split into 3 lobes: superior, middle, and inferior by 2 fissures--(a) an oblique fissure and (b) a horizontal fissure The left lung is split into 2 lobes: (a) superior and (b) inferior by an oblique fissure. Oblique Fissure: A Long Oblique Fissure Runs Obliquely Downwards And Forwards Crossing The Posterior Border [...]
The 4th ventricle is a tent-like cavity of the hindbrain lined with ependyma and filled up with cerebrospinal fluid (csf), it's situated in the posterior cranial fossa in front of the cerebellum and behind the pons and the upper part of medulla oblongata. The cavity of the ventricle seems rhomboidal (lozenge shaped) in the horizontal [...]
The pectoralis major is a large, broad, fan-shaped muscle located on the front side of the thorax. It is the biggest muscle of the pectoral region. It travels across the front of the underarm, where it stays thick, and afterwards connects to its slim, square tendon of attachment, which allows it to enter underneath the [...]
The thoracic wall is composed of skeletal parts and muscles. Posteriorly, it's created from twelve thoracic vertebrae and their intervening intervertebral discs. Laterally, the wall is composed by ribs (twelve on every side) and 3 layers of flat muscles, which span the inter costal spaces between adjacent ribs, move the ribs, and supply support for [...]
Boundaries Anterior: Anterior mediastinum. Posterior: Posterior mediastinum. Superior: Superior mediastinum. Inferior: Diaphragm. Contents 1) Heart. 2) Pericardium. 3) Arteries: Ascending aorta. Pulmonary trunk dividing into 2 pulmonary arteries. Pericardiophrenic arteries. 4) Veins: Superior vena cava (lower half). Azygos vein (terminal part). Pulmonary veins (left and right). 5) Nerves: Phrenic nerves. Deep cardiac plexus. 6) Lymph [...]
Within each intercostal space, the intercostal muscles are three flat muscles found that pass between adjacent ribs. Intercostal Muscles External Intercostal Muscles They originate superiorly to inferior margin of rib above and insert inferiorly to the superior margin of the rib below and are innervated by intercostal nerves having root value [...]
The foramen ovale is found in the fetal heart where it allows blood to go inside the left atrium from the right atrium. It is among the two fetal cardiac shunts, the ductus arteriosus is the other one which allows blood to bypass the pulmonary circulation that still discharges towards the right ventricle. The foramen [...]
Posterior and anterior intercostal arteries are responsible for the blood supply. Blood supply is abundant in the thoracic wall. 1 posterior and 2 anterior intercostal arteries (upper and lower) are included in every intercostal spaces. Posterior Intercostal Arteries There are 11 pairs of intercostal arteries, 1 in every space. They furnish the greater [...]
The heart is provided by the sympathetic and parasympathetic fibres via the superficial and deep cardiac plexuses created by the parasympathetic and sympathetic fibres. The parasympathetic fibres are originated from vagus nerves. They're cardioinhibitory, therefore, their stimulation causes slowing of the heart rate and constriction of the coronary arteries. The sympathetic fibres are originated from [...]