Dr Reeha Mahajan
Anatomy is a branch of science that deals with the structure of the body from the macroscopic (visible to the naked eye) to the microscopic level (visible under a microscope).
It is well said by Hippocrates that “Anatomy is the basis of medical discourse”. Human Anatomy is the foundation of the medical profession, including MBBS, dentistry, nursing, physiotherapy, occupational therapy, and various other allied health courses. Anatomy is the cornerstone for understanding the human body, diagnosing illnesses, and performing medical procedures.
World Anatomy Day was collectively declared by the International Federation of Associations of Anatomists (IFAA) and national anatomical societies. The IFAA Congress decided to observe World Anatomy Day on 15thOctober every year at the 19thIFAA World Congress held in London in August 2019.
World Anatomy Day is celebrated on 15th October and marks the death anniversary of Andreas Vesalius, who died in 1564 on the same day. Andreas Vesalius (AD1514-1564), a Dutch anatomist,was the greatest anatomist of his time and is now regarded as the “Father of Modern Human Anatomy”. He is also called the “Reformer of Anatomy”. Vesalius laid the foundation on which many subsequent advances in medicine and surgery occurred. He wrote a set of seven books known as De humani Corporis Fabrica Libri Septem (On the workings of the Human Body), which transformed anatomy teaching and remained a commanding text for two centuries.
World Anatomy Day is a day to commemorate the discipline of anatomy and to spread awareness of its pivotal role in educating and shaping the career of healthcare professionals globally. This day is a reminder to enhance anatomical awareness in society, promote the diversity of disciplines, change the understanding of anatomy, thank the cadaveric donor, acknowledge the kith and kin of donors, address the donor shortage, and attract young scientists into anatomy.
The Theme for World Anatomy Day 2024 is “Anatomy in Motion”
There are various subdivisions of Anatomy which include Gross anatomy/ topographical anatomy, microscopic anatomy/ histology, surface anatomy, comparative anatomy, physical anthropology, living anatomy, clinical anatomy, radiological anatomy, developmental anatomy/embryology, genetics and experimental anatomy.
Gross anatomy can be studied region-wise as well as system-wise. Locomotor system is an integral system of the human body responsible for movements and locomotion. The locomotor system of the body comprises primarily of the bones, cartilages, joints and muscles. Abnormalities in the development of these tissues can lead to skeletal deformities and malformations in the children. These deformities, if left uncorrected, can produce gait disorders and restriction of certain movements during childhood as well as in adult life,directly impacting the overall growth and productivity of the individual.
Embryology is the subdivision of Anatomy dealing with development and growth of an individual before birth. During morphogenesis i.e., growth and development of various tissues and organs of human body, the interplay of several genetic or environmental factors may interfere with the normal development of the fetus leading to congenital anomalies at birth. Thus, thorough knowledge of embryology helps us in understanding not only the formation and functions of different parts of body but also the elements responsible for causing birth defects. The understanding of these factors helps the medical practitioner in the prevention, diagnosis, and treatment of such conditions.
Overview of the development of parts of the body responsible for movements of the body: Anatomy in Motion
The appendicular skeleton is composed of upper and lower limbs and includes the shoulder and hip region. The limb buds form out pocketings that form ridges on the sides of the body wall at the end of the 4th week of pregnancy, which is genetically determined by HOX (Homeobox) genes. The forelimbs start forming first, followed by the hindlimbs 1-2 days later. The limbs attain the bud stage by the end of 5th week. The germ layer called ectoderm thickens at the end of the limb to form a ridge, the Apical Ectodermal ridge(AER) which has an inductive influence on neighbouring undifferentiated tissue which later differentiates into cartilage and muscle. The development of the arm and thigh is followed by the development of the forearm and leg and still further by the development of the hand and foot. The terminal portion of the limb buds becomes flattened to form hand and foot in 6 6-week-old embryo. The cell death in the AER separates the ridge into five parts leading to the formation of fingers and toes. During the 7th week of pregnancy, the limbs rotate in opposite directions. The upper limb rotates 90° sideways, causing the muscles involved in the extension of the limb to be placed on the back and thumbs laterally, whereas the lower limb rotates almost 90° medially, shifting the extensor muscles on the front and big toe toward the central axis of the body. The arrest of chondrogenesis (development of cartilage)at the cartilaginous condensations leads to formation of joints. The retinoic acid made in flank mesenchyme cells initiates a genetic cascade to cause differentiation of skeletal system in the arm and thigh region while the differentiation of skeletal system of forearm, leg, hand and foot regions involves various other genes including Sonic Hedgehog(SHH). Any insult to the developing tissue during the first trimester of pregnancy between the 3rd-8th week is likely to result in skeletal malformations. The mutations in HOX genes results in various congenital limb anomalies and deformities.
Congenital anomalies of the locomotor system resulting from abnormal development
The skeletal system anomalies of the limbs include short digits, brachydactyly, syndactyly, polydactyly, synpolydactyly, absent digits, absent radius (lateral bone of forearm), hypoplasia of any of the limb bones, skeletal dysplasias, clubfoot (multifactorial pattern of inheritance), achondroplasia, (common cause of dwarfism or shortness of stature caused by mutation of FGFR3 gene, leading to abnormal endochondral ossification), etc.
Other skeletal abnormalities of vertebral column(spine) include Spina bifida, which is a gap in the vertebra behind, seen more commonly in females. This could be covered by skin with no neurological symptoms (spina bifida occulta) or it could present as protrusion of meninges and spinal cord on the surface of back without skin cover(Spina bifida aperta). Some individuals with vertebral abnormalities may have half vertebra(hemivertebra) leading to scoliosis (sideways bending of spine). Some children may also present with congenital fusion of vertebrae leading to decreased range of motion and pain.
Apart from this, there may be malformations of trunk region in the form of presence of accessory ribs that is, extra cervical or lumbar ribs in the neck and trunk region respectively. The cervical rib may cause compression of nerves and vessels leading to pain and numbness in the arm.
These congenital anomalies are generally caused by the following factors:
- Genetic factors such as chromosomal abnormalities due to mutant genes, e.g., brachydactyly (short digits).
- Environmental factors such as intake of drug thalidomide during first trimester of pregnancy, leading to amelia(absence of a limb), meromelia(malformed limbs/ congenital absence of part of limbs) and phocomelia (undeveloped hands and feet directly attached to the trunk).
- Bothgenetic and environmental factors (multifactorial inheritance), e.g., congenital dislocation of the hip.
- Decreased blood supply to certain body parts(Ischaemia), e.g., reduction in size of limbs
- Radiation: High doses of X-rays during pregnancy are linked with skull defects and spina bifida.
- Fetal alcohol syndrome: Consumption of alcohol during pregnancy is associated with hypoplasia(incomplete development of parts of the body) and altered joint mobility.
- Nutritional deficiencies: Folic acid deficiency during pregnancy is related with neural tube defects such as, spina bifida(gap in the spine)
- Obesity: Recently, it has been seen that women with obesity are associated with increased possibility of neural tube defects in their babies.
- Mechanical factors: Certain birth defects such as clubfoot, congenital dislocation of hip, intrauterine amputations (removal of a part or whole limb) etc. may occur due to malformed uterus, oligohydramnios and amniotic bands formed due to rupture of amnion during early pregnancy.
The congenital anomalies of the skeletal system can be detected during pregnancy by various methods of prenatal diagnosis like ultrasonography, maternal serum screening, amniocentesis, fetoscopy, MRI, etc.
With the recent advancements in the medical field, certain skeletal anomalies like neural tube defects can be corrected in the fetus during pregnancy with the help of fetal surgery, restoring the normal anatomy and leading to proper motion in the individual immediately after birth.
Role of Physical rehabilitation in restoring the “Anatomy in Motion” to the optimal level
The treatment of Congenital skeletal and neuromuscular conditions, e.g., clubfoot, scoliosis, neural tube defects, muscular dysplasia and dystrophies, etc., requires a multidisciplinary approach tailored to each individual’s need for achieving optimal function, mobility, and quality of life. The goal of physical rehabilitation is to improve mobility and range of motion, enhance strength and flexibility, promote functional independence, and enhance cognitive and emotional well-being. The various interventions for physical rehabilitation include physical therapy(exercises, gait training, massage, joint mobilization etc.), occupational therapy, orthotics and prosthetics(customized devices for support and mobility), pain management and corrective and reconstructive surgeries. Physical rehabilitation not only aids in restoring the normal anatomy but also reduces the risk of secondary complications.
The truth is that in human movement, there are no A=B answers. Everything is unique and individual and needs addressing. This is why we teach a thought process, provide a model to follow and invite people to engage in a self-assessment and awareness of their own anatomy” – GARY WARD
(The writer is Asso Prof, Dept of Anatomy, AIIMS Jammu)
