Here is the eighth lesson following on from An Elementary Herbal Course – Lesson 7 – Antispasmodics
ANATOMY AND PHYSIOLOGY
For the student of medicine a knowledge of ANATOMY and PHYSIOLOGY is indispensible.
ANATOMY is that branch of science that deals with the structure of the human body.
In PHYSIOLOGY we study the functions of the body.
In disease there is an unnatural condition of the body’s functions. In view of this, it is of paramount importance that we should know the normal functions of the body first, enabling us to see how the disease, that the patient has, alters those functions.
As a first step towards the study of the functions of the organs and systems, it is necessary for us to know their structure and position.
In these lessons, we treat only with the fundamentals of the subject, and we must emphasise, that the student should thoroughly master these. It would be of great value to the studento obtain a good anatomical atlas and to acquire some other books of Anatomy and Physiology to study.
If we look at the human body, we notice that we can divide it into a number of parts. Thesemainsub-divisions of the body we generally refer to as THE HEAD, THE TRUNK and THE LIMBS.
By HEAD we are referring to THE CRANIUM, in which is enclosed the BRAIN and also the face.
THE TRUNK is thet portion lying between THE NECK and THE LIMBS. The TRUNK is divided into two parts the upper and lower. The upper portion is termed THE THORAX or CHEST, and the lower portion is termed the ABDOMEN.
Dividing the THORAX and the ABDOMEN, there is an organ termed THE DIAPHRAGM which is in the nature of a fleshy sheet.
Looking closer at the THORAX we find enclosed the HEART, the LUNGS, the UPPER ALIMENTARY CANAL (the foodpipe), the AORTA and a number of other organs.
In the ABDOMEN are to be found the STOMACH, the LIVER, the SPLEEN, the INTESTINES, the PANCREAS, the KIDNEYS, the RECTUM, the BLADDER, and a number of other organs. Many of these other organs will be mentioned later within the Lessons.
The LIMBS are also referred to as the EXTREMITIES and are made up of the Upper and Lower extremities. The Upper Extremities are the two arms and the two hands. The Lower Extremities are the two legs and the two feet.
The body is composed of many different organs and each of these organs have their own special functions to perform. When all of the organs of the body are functioning properly, we term this condition ‘HEALTH’.
When the functions of one or more organs of the body, is or are deranged, we then call this SICKNESS, ILLNESS or DISEASE.
In the same way that each organ has a definite role to play, there are certain sets of organs that have to perform the most important functions of the body. Among these we can use as an example, the HEART and the BLOOD VESSELS that perform the function of CIRCULATION.
RESPIRATION is carried out by the NOSE, THROAT, WINDPIPE, BRONCHIAL TUBES and the LUNGS. Each of these functions is inter-dependent on the other.
In order to understand the subject more fully, I have divided it into a number of different portions and called these portions SYSTEMS.
These systems are:-
- The bony system or Skeleton
- The Muscular system
- The Digestive system
- The Circulatory system
- The Respiratory system
- The Nervous system
- The Excretory system
- The Glandular system
- The Special senses
- The Reproductive system
THE TISSUES.
When we examine any organ of the body under a microscope, we shall find that it is divided into several portions. Each of these portions will be found to be made up of similar cells. These collections of cells are called TISSUES.
In the human body we will find that there are four types of tissues. These are:-
- Muscular tissue
- Nerve tissue
- Epithelial tissue
- The Connective tissue
The MUSCULAR TISSUE is specialised for contraction and therefore, it is responsible for the continuous, and various movements of the body.
The NERVOUS TISSUE is of the greatest complexity and is the chief co-ordinating and directing agency of the body.
The EPITHELIAL TISSUE is the covering tissue and is composed of closely arranged cells, and these are considerably modified according to their position. As such they may be flattened, thickened or elongated (respectively called SQUAMOUS EPITHELIUM, CUBOIDAL EPITHELIUM, or COLUMNAR EPITHELIUM).
The CONNECTIVE TISSUE serves a supporting and binding function in the body. The commonest type of connective tissue is the FIBROUS TISSUE. The fibrous tissue is divided in to AREOLAR, FIBROUS and ELASTIC tissues.
In AREOLAR TISSUE the bundles of fibres are loosely interwoven.
In the ELASTIC TISSUE, in addition to ordinary fibres, there are a number of elastic fibres as well.
Bones and Cartilage are generally regarded as kinds of connective tissue.
CARTILAGINOUS TISSUE is a tough firm substance, and it is composed of cells lying in pairs or multiples, in an inter-cellular substance. In the BONE TISSUE there are inorganic compounds, such as, phosphates, calcium, etc..
In the MUSCULAR TISSUE there are certain contractile fibres in the cells and as such,, the power of contractability is present. Two classes of muscle tissue are generally found, and these are:-
- INVOLUNTARY or UNSTRIPED MUSCLE
- VOLUNTARY or STRIPED MUSCLE
The NERVOUS TISSUE forms the brain, Spinal cord, Nerves and ganglia. Nerve cells and their branching processes make up this tissue.
THE SKELETON.
The skeleton or bony system, consists of a cage of bones and this forms the general framework of the body. The functions of the skeleton are as follows:-
It forms a supporting framework for the body, protecting the important organs, such as, the heart, lungs, brain, spinal cord, etc..
It enables a numerous number of body movements and locomotion, by the adaptation of the bones in combination with the contractile muscular tissue.
The bones act as levers when force is exerted upon them by the attached muscles.
The skeleton is a storehouse of calcium in the system.
The blood cells are formed in the bone marrow.
When the human body has been stripped of flesh and muscle, we are left with the bare bones of the body. When all of these bones are taken together as a whole, we have left, what is called the SKELETON. As has already been stated this forms the framework of the body.
THE SKELETON.
It is a fact, that the human skeleton is composed of more than TWO HUNDRED seperate bones. These bones are united by way of joints.
Bones can be divided into three catagories. These three catagories are:-
- The flat bones
- The long bones
- The short bones
The bones of the cranium can be considered as examples of flat bones. The bones of the arms and legs are examples of long bones.
THE SKULL.
The bones of the cranium taken together with the face are called the skull.
The CRANIUM is almost a box of eight bones, in which, is securely placed the brain. Considering the importance of the brain to the human body, it is no wonder that it is so securely protected. The cranium is the SAFE of the body.
The eight bones that form the cranium are:-
One frontal bone, One Occipital bone, Two Temporal bones, Two Pariatal bones, One Sphenoid bone and One Ethmoid bone. These bones are joined together by means of serated edges, the edge of one bone interlocking with the edge of the other. This union between the bones of the head is termed a SUTURE although in reality each of these is a joint.
The FRONTAL BONE is the Forehead and it forms the roof of the head, of the sockets of the eyes and the upper portion of the nose.
The OCCIPITAL BONE forms the back of the head and to a certain extent the bottom also.
To complete the sides, there are the two PARIETAL BONES, one on each side. In each of these bones there is a narrow canal leading to the middle ear.
Behind this opening, there is a depression on each side into which the upper portion of the lower jaw fits.
In the lower part of the OCCIPITAL BONE there is a hole through which the brain is joined to the spinal cord. This hole has the name FORAMEN MAGNUM. On each side of the hole are the CONDYLES, a smooth projection. These CONDYLES move like hinges on the first vertebra and thus it allows the nodding of the head.
The face consists of fourteen bones. Of these fourteen bones only the lower jaw bone is moveable. These fourteen bones of the face are:-
THE MAXILLARY BONES. These are two in number and form the upper jaw.
THE MALAR BONES. These are reffered to as the cheek bones, two in number, uniting with a process of the temporal, called the ZYGOMATIC PROCESS.
THE PALATINES. This is a pair of bones forming the roof of the mouth.
THE LACHRYMALS. These are two small bones forming the inner wall of the orbit.
THE NASALS. This is a pair of bones forming the upper part of the bridge of the nose.
THE VOMER. This is a bone which forms the hind part of the nasal septum.
THE INTERNAL TURBINALS. These two scroll-like bones lie on the lateral walls of the nasal cavity.
THE MANDIBLE. This bone is the largest of the face and forms the lower jaw.
THE VERTEBRAL COLUMN.
The bones of the back are named the VERTEBRAL COLUMN. It consists of thirty-three irregularly shaped bones placed one upon the other and joined by strong fibrous tissues.
The backbone is called the VERTEBRAL COLUMN as the thirty-three bones are arranged in the form of a column through which the SPINAL CORD passes.
Out of the thirty -three bones, the upper twenty-four are slightly moveable, whereas the lower nine are not so moveable. The moveable portion, i.e. The first twenty-four bones, form the neck, back and loins. Each of these bones is called a VERTEBRA. The first seven forming the neck are called the CERVICAL VERTABRA. The next twelve are called the DORSAL VERTEBRA, and the portion where these bones are found is called the upper back. In these are attached the twelve pairs of RIBS which form a bony cage enclosing and giving protection to the organs inside the THORAX such as the HEART and LUNGS. The remaining five moveable vertebrae are called the LUMBAR VERTEBRAE. The last of the lumbar vertebrae is wedged with the back portion of the hip bones called the PELVIS.
The back portion of the PELVIS is called the SACRUM and to it and below it, are attached the nine non-moveable vertebrae otherwise known as the COCCYX or tail bone.
We said above, that the back portion of the hip bone is called the SACRUM. On either side of the SACRUM is attached the two sides of the hip bones and these meet in the front, thus forming a basin-shaped cavity, which is generally called the PELVIS. The two bones on either side are called the OSSA INNOMINATA, which literally means the ‘nameless bones’. The point at which these two bones meet in the front, is called the SYMPHYSIS PUBIS.