Organisation Of The Body

INTRODUCTION The early students of anatomy and physiology were most likely concerned with treating illnesses and injuries. Early healers relied on superstitions and magic. Later, herbs were used to treat certain ailments. Eventually, after much controversy the study of medicine with standardized terms in Greek and Latin began.

ANATOMY AND PHYSIOLOGY Anatomy deals with the structure (morphology) of the body and its parts, in other words, what are things called? Physiology studies the functions of these parts or asks the question, “How do they work? The two disciplines are closely interrelated because the functional role of a part depends on how it is constructed. Anatomists rely on observation and dissection, while physiologists employ experimentation. It is more common to discover new information about physiology but anatomical discoveries are being made as well.

CHARACTERISTICS OF LIFE Fundamental characteristics of life are traits shared by all organisms. Characteristics of life include: 1. Movement (internal or gross) 2. Responsiveness (reaction to internal or external change) 3. Growth (increase in size without change in shape) 4. Reproduction (new organisms or new cells) 5. Respiration (use of oxygen; removal of CO2) 6. Digestion (breakdown of food into simpler forms) 7. Absorption (movement of substances through membranes and into fluids) 8. Circulation (movement within body fluids) 9. Assimilation (changing nutrients into chemically different forms) 10. Excretion (removal of metabolic wastes) Taken together, these 10 characteristics constitute metabolism.

REQUIREMENTS OF ORGANISMS Life depends on the availability of the following: a. Water (required for metabolic reactions, for transport of substances, for temperature regulation) b. Food (nutrients needed to supply energy and raw materials for building new living matter) c. Oxygen (used in releasing energy from nutrients) d. Heat (a byproduct of metabolism; its presence governs the rate at which reactions occur) e. Pressure (force required to facilitate movement of air or fluids) Both the quality and quantity of these factors are important.

ORGANISATION OF THE BODY OBJECTIVES After studying this paperwork you should be able to: 1) define common anatomical terms 2) use the terms that describe relative positions, body sections, and body regions 3) identify the principal bones of the axial skeleton and the appendicular skeleton 4) state the boundaries of the four body cavities 5) list the contents of the body cavities 6) state the organs located in each of the body cavities

ANATOMICAL TERMS It is a custom (usual behaviour) to use certain terms to describe the relationship of body parts, imaginary planes and sections of the body, various regions, and cavities of the body. It is essential to become accustomed to these terms before the study of anatomy and physiology begins. When these terms are used, it is assumed that the body is in the anatomical position. In this position, the body is standing erect (upright, vertical), the face is forward, and the arms are at the sides with the palms and toes directed forward.

Figure 1 the levels of structural complexity.

Relative Positions of Body Part The terms used in table 1 describe the location of a part in relation to another part of the body.

Table 1 shows the directional terms in describing human body. The terms used in figure 2, 4 & 5 describe the regional and directional terms of human body.

Figure 2 Directional terms.

Planes and Sections of the Body Planes – a 3-dimensional axis Section – a slice parallel to a plane In order to observe the internal body parts, it is necessary to section (cut open) the body in some way. It is customary to describe these sections in terms of imaginary planes that divide the body. (Fig. 3) A median (midsagittal) plane is a lengthwise cut that divides the body into right and left portions. If the section passes exactly through the midline it is called midsagittal cut. A transverse (horizontal) plane is a cut that divides the body horizontally to give a cross section. A transverse cut divides the body into superior (upper) and inferior (lower) portions. A frontal plane divides the body lengthwise into anterior and posterior portions. The terms longitudinal section and cross section are often applied to body parts that have been removed and cut either lengthwise or straight across, respectively.

Figure 3 to observe internal parts, the body may be sectioned (cut) along various imaginary planes.

Key Concept Anatomical position – hands at sides, palms forward. Supine – lying down, face up Prone – lying down, face down

Regions of the Body The human can be divided into the axial portion, which includes the head, neck, trunk, and the appendicular portion, which includes the arms and legs. The trunk, or torso, contains the thorax, abdomen, and pelvis. Each of these portions has been further divided into the specific regions mentioned.

Figure 4 Regional terms (anterior view).

Figure 5 Regional terms (posterior view).

Head Cephalic (head) Frontal (forehead) Occipital (back of head) Orbital (eye) Nasal (nose) Buccal (cheek) Oral (mouth) Neck Cervical (neck) Abdomen Sternal (breastbone) Vertebral (spinal column) Thoracic (chest) Mammary (breast) Dorsal (back) Axillary (armpit) Abdominal (abdomen) Lumbar (loin) Umbilical (navel) Inguinal (groin) Sacral (between the hips) Pubic (genital region) Gluteal (buttock) Perineal (between the anus and the external genitalia) Limbs (arms and legs) Brachial (arm) Antecubital (front of elbow) Carpal (wrist) Palmar (palm) Digital (fingers) Femoral (thigh) Patellar (front of knee) Crural (leg) Popliteal (back of knee) Tarsal (ankle) Pedal (foot) Calcaneal (heel) Hallux (great toe)

Digital (toes) Plantar (sole) Other Cutaneous (skin)

The skeleton Functions The skeleton has the following functions: 1) the skeleton, notably the large heavy bones of the legs, supports the body against the pull of gravity 2) The skeleton protects soft body parts. For example, the skull forms a protective encasement for the brain 3) Flat bones such as those of the skull, ribs, and breastbone produce red blood cells in both adults and children 4) bones are storage areas for inorganic calcium and phosphorus salts 5) bones provide sites for muscle attachment and permit flexible body movement, especially the bones of the legs and arms

Bones of the Skeleton The bones of the skeleton are not smooth; they have protuberances (swelling) called processes and indentations called depressions (dent). The skeleton is divided into the axial skeleton and the appendicular skeleton. The axial skeleton lies in the midline of the body and contains the bones of the skull, vertebral column, and thoracic cage. The appendicular skeleton contains the bones of the pectoral girdle, upper limbs (arms), pelvic girdle, and lower limbs (legs).

Figure 6 Axial skeleton and appendicular skeleton.

Figure 7 Our Skeleton.

AXIAL SKELETON The axial skeleton consists of the bones in the head and trunk of the human body. It is composed of five parts; the human skull, the ossicles of the inner ear, the hyoid bone of the throat, the chest, and the vertebral column. The axial skeleton and the appendicular skeleton together form the complete skeleton. Protective or flat bones house the brain spinal cord and other vital organs. The purpose of the axial skeleton (among other things) is to protect the body's most vital organs. All vertebrates have an axial skeleton. This article mainly deals with the axial skeletons of humans; however, it is important to understand the evolutionary lineage of the axial skeleton. The axial skeleton has 80 bones in it. In

conclusion, Professor Sherman Leung in Brisbane discovered how the axial skeleton affects a human's location or movement.

Human Skull In humans, the adult skull is normally made up of 29 bones. Except for the mandible, all of the bones of the skull are joined together by sutures, semi-rigid articulations formed by bony ossification, the presence of Sharpey's fibers permitting a little flexibility. Eight bones form the neurocranium (braincase), a protective vault of bone surrounding the brain and brain stem medulla oblongata. Fourteen bones form the splanchnocranium (facial bones), the bones supporting the face. Encased within the temporal bones are the six ear or auditory ossicles of the middle ear. The hyoid bone, supporting the larynx, is usually not considered as part of the skull, as it is the only bone that does not articulate with any other bones. The skull also contains the sinus cavities, which are air-filled cavities lined with respiratory epithelium, which also lines the large airways. The exact functions of the sinuses are debatable; they contribute to lessening the weight of the skull with a minimal reduction in strength, they contribute to resonance of the voice, and assist in the warming and moistening of air drawn in through the nasal cavities. The meninges are three layers of connective tissue, or membranes, which surround the structures of the central nervous system. They are known as the dura mater (outermost), the arachnoid mater (middle) and the pia mater (innermost). Each layer adds important protection functions. In humans, the anatomical position for the skull is the Frankfurt plane, where the lower margins of the orbits and the upper borders of the ear canals are all in a horizontal plane, or anatomical position. This is the position where the subject is standing and looking directly forward.

Skull (22) •

•

Cranial Bones (8) o Parietal (2) o Temporal (2) o Frontal (1) o Occipital (1) o Ethmoid (1) o Sphenoid (1) Facial Bones (14) o Maxilla (2) o Zygomatic (2) o Mandible (1) o Nasal (2) o Palatine (2) o Inferior nasal concha (2) o Lacrimal (2) o Vomer (1)

Ossicles The ossicles (also called auditory ossicles) are the three smallest bones in the human body. They are contained within the middle ear space and serve to transmit sounds from the air to the fluid-filled labyrinth (cochlea). The absence of the auditory ossicles would constitute a moderate-to-severe hearing loss.

Figure 8 the ossicles. Ossicles (6) • • •

Malleus (2) Incus (2) Stapes (2)

Figure 9 Anterior view of the Skull.

Figure 10 Side view of the Skull

Thoracic Cage The thoracic cavity (or chest cavity) is the chamber of the human body (and other animal bodies) that is protected by the thoracic wall (thoracic cage and associated skin, muscle, and fascia).

Components of the Thoracic Cage Structures within the thoracic cavity include: • •

• • • •

the heart, the great vessels, which include the thoracic aorta, the pulmonary artery and its branches, the superior and inferior vena cava, and the pulmonary veins other vascular structures such as the azygos vein, the trachea, bronchi and lungs the oesophagus, the thymus gland,

• •

structures of the nervous system including the paired vagus nerves, and the paired sympathetic chains, Structures of the lymphatic system, especially the thoracic duct.

It contains three potential spaces lined with mesothelium: the paired pleural cavities and the pericardial cavity. The mediastinum comprises those organs which lie in the centre of the chest between the lungs.

Fig 11 Thoracic cavity

Vertebral Column In human anatomy, the vertebral column (backbone or spine) is a column of vertebrae situated in the dorsal aspect of the torso. It houses the spinal cord in its spinal canal.

Components of the Vertebral Column Individual vertebrae named according to region and position, from superior to inferior Cervical – 7 vertebrae (C1-C7) •

Often possess bifid spinous processes

Thoracic – 12 vertebrae (T1-T12) Lumbar – 5 vertebrae (L1-L5) Sacral – 5 (fused) vertebrae (S1-S5) Coccygeal – 3-5 vertebrae (Co1-Co5)

Figure 12 the vertebral column (lateral view).

APPENDICULAR SKELETON The appendicular skeleton is the part of the skeleton that includes the pectoral girdle, the upper limbs, the pelvic girdle, and the lower limbs. The appendicular skeleton and the axial skeleton together form the complete skeleton. The appendicular skeleton, consisting of 126 bones, makes body movement possible and protects the organs of digestion, excretion, and reproduction. The word appendicular means referring to an appendage or anything attached to a major part of the body, such as the upper and lower extremities.

Components of the Appendicular Skeleton • • • • • •

Shoulder girdle Arm Hand Pelvic girdle Leg Foot

Cavities of the Body The internal organs, called the visceral organs, are located within specific cavities. The two main cavities are the dorsal cavities and the larger ventral cavity. The dorsal cavity can be subdivided into two parts: the cranial cavity within the skull contains the brain; and the spinal cavity, protected by vertebrae, contains the spinal cord. The ventral cavity is subdivided into the thoracic cavity and the abdominopelvic cavity. The lungs, heart, oesophagus, trachea, and thymus gland are located in the thoracic cavity. This cavity separated from the abdominopelvic cavity by a horizontal muscle called the diaphragm. The abdominopelvic cavity has two portions: the upper abdominal portion and the lower pelvic portion. The stomach, liver, spleen, gallbladder, and most of the small and large intestine are in the abdominal cavity. The pelvic cavity contains the rest of the large intestine, the rectum, the urinary bladder, and the internal

reproductive organs. In males, there is an external extension of the abdominal wall called the scrotum where the testes are found. Since the abdominopelvic cavity is quite large, it is sometimes divided into four sections by running a transverse plane across the midsagittal plane at the point of the navel. The abdominal cavity can also be divided into a greater number of sections as is done in figure 20.

Figure 13 Cavities of the Body. The Ventral Body Cavity – divided by the diaphragm into the thoracic cavity and the abdominopelvic cavity.

Dorsal Cavity Consists of cranial cavity, enclosed by the Skull and contains the brain, eyes, and ears and spinal canal, enclosed by the spine and contains the spinal cord.

Cranial Cavity The cranial cavity is the relatively large space formed inside the skull. The brain occupies the cranial cavity, which is lined by the meninges and which contains fluid to cushion blows.

Eight cranial bones together form the cranial cavity: the frontal and occipital bones, and two each of the parietal, temporal, sphenoid and ethmoid bones (Martini et al., 2001).

Figure 14 Bones forming the right half of the cranium and the face (viewed from the left).

Spinal Cavity The spinal canal (or vertebral canal or spinal cavity) is the space in vertebrae through which the spinal cord passes. It is a process of the dorsal human body cavity. This canal is enclosed within the vertebral foramen of the vertebrae. In the intervertebral spaces, the canal is protected by the ligamentum flavum posteriorly and the posterior longitudinal ligament anteriorly. The outermost layer of the meninges, the dura mater, is closely associated with the arachnoid which in turn is loosely connected to the innermost layer of the meninges, the pia mater. The meninges divide the spinal canal into the epidural space and the subarachnoid space. The pia mater is closely attached to the spinal cord. A subdural space is generally only present due to trauma and/or pathological situations. The subarachnoid space is filled with cerebrospinal fluid and contains the vessels that supply the spinal cord, namely the anterior spinal artery and the paired posterior spinal arteries, accompanied by corresponding spinal veins. The spinal

arteries form anastomoses known as the vasocorona of the spinal cord. The epidural space contains loose fatty tissue, and a network of large, thin-walled blood vessels called the anterior vertebral venous plexus and the posterior vertebral venous plexus.

Figure 15 Spinal cavity

Ventral Cavity The ventral cavity is a human body cavity that is in the anterior (front) aspect of the human body. It is made up of the thoracic cavity, and the abdominopelvic cavity. The abdominopelvic cavity is further separated into the abdominal cavity and pelvic cavity, but there is no physical barrier between the two. The abdominal cavity contains digestive organs; the pelvic cavity contains the urinary bladder, internal reproductive organs, and rectum.

Thoracic Cavity The thoracic cavity (or chest cavity) is the chamber of the human body (and other animal bodies) that is protected by the thoracic wall (thoracic cage and associated skin, muscle, and fascia).

Figure 16 the structures forming the walls of the thoracic cage.

Figure 17 some of the main structures in the thoracic cavity and the root of the neck.

Abdominopelvic Cavity Abdominal Cavity Abdominal cavity is the cavity of the human body (and other animal bodies) that holds the bulk of the viscera and which is located below (or inferior to) the thoracic cavity. Organs of the abdominal cavity include the stomach, liver, gallbladder, spleen, pancreas, urinary bladder, small intestine and large intestine. (The kidneys are located not in the abdominal cavity but behind it, in the retroperitoneum.)

The abdominal cavity is lined with a protective membrane termed the peritoneum. The viscera are also covered, in the front, with a fatty layer called the omentum (or omental apron).

Figure 18 Organs occupying the anterior part of the abdominal cavity and the diaphragm.

Figure 19 Organs occupying the posterior part of the abdominal and pelvic cavities. The broken line shows the position of the stomach.

Figure 20 Isolating the Organs - serous membranes consist of parietal layer and visceral layer.

Figure 21 Dividing the Cavities - thoracic cavity is divided by the mediastinum into 2 pleural cavities.

Figure 22(a, b, c) Regions of the abdominal cavity

Pelvic Cavity The pelvic cavity is a body cavity that is bounded by the bones of the pelvis and which primarily contains reproductive organs, the urinary bladder, and the rectum.

Figure 23 Female reproductive organs and other structures in the pelvic cavity.

Figure 24 the pelvic cavity and reproductive structures in the male.

CONCLUSION As a nurse, we must know certain anatomy terms and parts that lead to easiness in our practice conduct as a professional body. We need to instil all this core knowledge of human body as described as “anatomy and physiology of human being”. We, as a professional body must practise all our knowledge in making all our works done. As such, we must use anatomical terms & region to refer to the parts of client’s body. It can be area of fracture, area of aches, or signs and symptoms showed as client develop a health problem. That knowledge of human body also will be use all the times in making research conduct, filing nursing diagnosis and also for the professional jargon language between colleagues of health care paramedics. To be fully respected in not practising malpractice and negligence e.g. putting IV drip on wrong body parts, we must learn the concept and essentials of anatomy of human body to be a good and competent nurse. So that, we won’t do such destruction that will be a bad dream for the patient and also to his/her relatives member. Worst, it may affect our job only because of our unawareness of this side of knowledge as it has to be happening in conducting our nursing practice.

REFERENCES Elaine, M. N. 2006, Essentials of Human Anatomy & Physiology. 8th ed, Pearson, San Francisco. Sembulingam, K. & Sembulingam, P. 2001, Essentials of Medical Physiology 2nd ed, Jaypee Brothers, New Delhi. Shier, D., Butler, J. & Lewis, R. 2003, Hole’s Essential of Human Anatomy and Physiology. 8th ed, Mc Graw Hill : New York. Saladin, K. S. 2005. Human Anatomy, Mc Graw Hill, USA. Tortora, G. J. & Derrickson, B. 2006, Principles of Anatomy and Physiology 11th ed, John Wiley Sons, Inc. USA.