MALDO 1 DISCIPLINE ANAT

• Introduction to Anatomy

The Anatomical Discipline

• Anatomy is a discipline focused on the macroscopic form and structure of living beings, as well as their anatomical relationships.
• The term "anatomy" comes from the Greek "ana" (meaning "up") and "tomie" (from "temno," meaning "to cut"), signifying to cut in order to understand the structure of the body.
• Acquiring a mental image is important for comprehension.
• Example: a cardiac surgeon needs to know the morphology of the heart, visualize pathology, and interpret radiological images.

Exploration of Anatomy

• Anatomists use several tools to construct mental images.

Levels of Organization

• An organ is a grouping of tissues around a common functional objective, forming an entity.
• Example: A muscle includes muscular tissue, a fibrous envelope, and tendinous tissue.
• An anatomical system is a set of morphologically comparable organs grouped around a common functional objective.
• Example: The muscular system is the set of muscles acting in body movements.
• An anatomical apparatus is a set of structurally different organs grouped around a common functional objective.
• Example: The locomotor system includes muscles, tendons, bones, and articular surfaces.

Study of Anatomical Structures

• Organs, apparatuses, and anatomical systems are studied by anatomy.
• Cytology studies cells, and histology studies tissues.

Methods of Studying Anatomy

• Techniques for studying anatomical organization include:
• Inspection: Observing the anatomical piece or human body to identify structures.
• Palpation: Palpating structures to analyze their consistency.
• Dissection: Indispensable method providing knowledge on structures.
• Imaging: Visualizing structures without dissection.
• Inspection and palpation are important for creating a mental image and are regularly performed in medical professions.
• These methods are applied through two main approaches:
• Systemic - focusing on vascular anatomy (vessels, their form, their path).
• Regional - studying anatomical relationships between organs in a region of interest.

Fundamental Principles

• Four fundamental principles of anatomy are present in the human body.

Stratification

• Stratification is very present in the human body, and means "in layers."
• Anatomical structures are often made in layers.
• Example: At the cranial vault, from the inside out:
• Pia mater: Fine transparent meninge that adheres to the surface of the brain.
• Arachnoid: Meninge with filaments resembling spiderwebs, extending through cerebrospinal fluid to reach the pia mater.
• Dura mater: Thick meninge of two layers:

Méningeal Layer

• Enveloping the brain.

Periosteal Layer

• (Osteoperiosteal), in contact with the bone, contributing to its nutrition and growth.

Bone

• Formed of three layers with two layers of compact cortical bone (internal and external tables) framing a central layer of trabecular bone (the diploe).
• Pericranium: Periosteum of the skull comprising connective tissues, vessels, and nerves, playing a role in bone growth.
• Loose connective tissue: Structure allowing mobility.
• Epicranial aponeurosis: Fibrous and resistant connective tissue, extending from the frontal to the occipital region.
• A new layer of loose connective tissue, located under the aponeurosis.
• Dermis: Deep part of the skin, where the roots of hair and subcutaneous tissue are located.
• The superficial keratinized layer of the skin: Visible part of the epidermis.

Metamerism

• A metamere is a segment.
• The human body has retained a segmental character.
• Segmental character is defined by the repetition of structures within each segment.
• Example 1: Earthworms have segments are made of identical structures.
• Example 2: Quadrupeds (like dogs) have some segmental elements remain, like cutaneous innervation in successive bands called dermatomes.
• Segmentation in quadrupeds has vertical bands, while in bipeds (like humans) they are horizontal on the trunk and vertical on the limbs.
• In humans, metamerism is observed on the rachis (vertebral column), ribs, and medullar segments (cervical, thoracic, lumbar, sacral).
• 31 total metomeres corresponding to 31 innervated dermatomes.
• Lumbar vertebrae are more voluminous than cervical vertebrae.

Discs

• Between vertebral plates are intervertebral discs of fibrocartilage, made of collagen fibers.
• The center of each disc, called the nucleus pulposus, is less dense and has a gelatinous texture.
• Clinical application: Disc fissures cause the nucleus to exit the intervertebral disc, causing a herniated disc.
• If the nucleus goes forward, consequences are small and if it goes back, it can compress the structures.
• The intervertebral foramen is limited:
• Top and bottom: By the pedicles of the vertebrae above and below
• Behind: By the articular processes
• In front: By the vertebral body above and the intervertebral disc below
• It is the place where the spinal nerve exits that leaves the bone marrow.

Nerves

• This nerve is part of the peripheral nervous system.
• NB 1: The pedicle connects the vertebral body to the posterior elements of the rachis.
• NB 2: The spinous process is palpable under the skin along the midline.
• Clinical application: If a vertebra is examined, the intervertebral foramen is not visible. It appears when two vertebrae are present.

Antimeria

• Our body is formed of two parts are roughly symmetrical, which are called hemicorps.
• To describe two different structures on the same hemicorps, the terms "ipsilateral" or "homolateral" are used interchangeably.
• To describe two different structures on two different hemicorps, is the term "controlateral" is used.

Fundamental Cavities

• Dorsal cavity: It corresponds to the cranial cavity that extends into the rachis through the rachidian canal.
• It contains a meningeal or dural sheath that passes into the medullar canal formed by the vertebral foramen.
• Note: The succession of vertebral foramen form the medullar canal. They are distinguished from the intervertebral foramen between adjacent vertebrae and delimited by the vertebral pedicel.
• Ventral cavity: It corresponds to everything that derives from the embryonic coelomic cavity.
• Forms thoracic and abdomino-pelvic cavities.
• The thoracic cavity differentiates into the pericardial cavity and pleural cavity. The abdomino-pelvic cavity comprises the abdominal cavity and the pelvic cavity.
• Note: The pelvic cavity is the part located in the pelvis.

Branches of Anatomy

• The branch chosen depends on the approach, methods used, etc.

Descriptive Anatomy

• It is the study of a system or structure in detail.
• Example: study of vascularization focusing on the path of the aorta, its branches, diameter differences, supra-aortic branches, coronary arteries, etc.
• Descriptive anatomy has subdivisions, including:

Angiology

• study of vessels

Osteology

• study of bone structures

Myology

• study of muscles

Neuroanatomy

• study of the nervous system

Splanchnology

• study of the viscera

Topographic Anatomy

• Aims to understand how elements are combined in a region.
• Example: Simulation of anterior thigh dissection.

Skin

• Incised along the inguinal fold and lateral thigh border, revealing subcutaneous tissue with fatty and loose connective tissue.
• Muscles are apparent. Three elements form a triangle:

Inguinal Ligament

• Resistant ligament of fibrous connective tissue, from iliac crest to pubis.

Long Adductor Muscle

• Large muscle along the medial side of the thigh.

Sartorius Muscle

• That crosses the area obliquely and participates in crossing the leg.
• This triangle, called the femoral trigone, contains the femoral vein, femoral artery, and femoral nerve.
• There are also lymph nodes.
• Note: Knowing topographic anatomy is important because to puncture the artery or the vein, it is fundamental to know how to locate these elements.

Functional Anatomy

• (Not mentioned this year): Functional anatomy is concerned with function, focused on the locomotor and nervous systems.

Radiological Anatomy

• Identifies anatomical structures on radiological images, often in cross-sections.

Pathological Anatomy

• Relies on histology.
• Specialists (anatomopathologists) used to make a diagnosis from a tissue fragment obtained by biopsy, or from an anatomical piece surgically removed.

Comparative Anatomy

• Confronts the anatomical characteristics of different species.

Anatomical Language and History

• Anatomy has evolved over centuries.

Focus is on:

• 16th-19th centuries: Anatomy's rise. Vesalius wrote "De humani corporis fabrica," emphasizes parcelling body, needed for mental image gathering.
• Father if the parcelling. This period dissection improved the level of anatomical detail, also the information gathered.
• Concern: the nomenclature. Common to give structure new names to structures which could lead to confusion. The first dissections in France were practiced in Montpellier.
• 20th century: dissection and new anatomical structures continued but nomenclature was the focus.
• That used at the start of the 20th century: Basel nomenclature written in 1895. Anatomists created the Paris and Nomina Anatomica nomenclatures.
• Finally in 1998, the international anatomical community validated the Terminologia Anatomica, the grand principle of said terminology has reduced the maximum number of synonyms.
• For this, proper nouns have been suppressed.
• Updated regularly, and is published in Latin, in addition to English, thus allowing each country to translate it into its own language.

Anatomical Generalities

• In anatomy, reference planes and axes describe organs.

Reference Positions

• Exists two anatomical reference positions:

Anatomical Position Zero

• Anatomical positions were used as references, but not for physiology or movement.

The Functional Anatomical Position Zero