Anatomy:
Is a branch of biology and medicine that is the consideration of the structure of living things.
Physiology:
the branch of the biological sciences dealing with the functioning of organisms.
Before studying anatomy, a student should become aware of some of the vocabulary that is used to describe various aspects of the human body. If everyone uses the same terminology, then it is easier to understand what each of us is trying to say. So, before learning the particulars about the anatomy of a region, we will take a look at some of the terminology.
For the purpose of description, the body is considered as being in what is called the. "anatomical position". We will use a skeleton to describe this position. In this Anatomical Position, the body is assumed to be standing, the feet together, the arms to the side, and the head and eyes and palms of the hands facing forwards. To ensure consistency of description it is important to keep the anatomical position constantly in mind. This last point is an important one, since in a normal relaxed position of the body, the thumb points anteriorly. In anatomical parlance, the thumb is a lateral structure, not an anterior one.
FRONTAL (or coronal) separates the body into Anterior and Posterior parts.
MEDIAN (or midsagittal) separates body into Right and Left parts.
HORIZONTAL separates the body into Superior and Inferior parts.
SAGITTAL any plane parallel to the median plane.
superior (closer to the head)
inferior (closer to the feet)
posterior (dorsal) closer to the posterior surface of the body
anterior (ventral) closer to the anterior surface of the body
medial (lying closer to the midline)
lateral (lying further away from the midline)
proximal closer to the origin of a structure
distal further away from the origin of a structure
intermediate between two other structures
external internal refers to a hollow structure (external being outside and internal being inside)
supine prone face or palm up when lying on back, face or palm down when lying on anterior surface of body
cephalad caudad toward the head, toward the tail (feet)
Histology:
(compound of the Greek words: ἱστός "tissue", and -λογία -logia) is the study of the microscopic anatomy of cells and tissues of plants and animals. It is performed by examining a thin slice (section) of tissue under a light microscope or electron microscope.
Connective tissue:
Is a form of fibrous tissue. It is one of the four types of tissue in traditional classifications (the others being epithelial, muscle, and nervous tissue).
Collagen is the main protein of connective tissue in animals and the most abundant protein in mammals, making up about 25% of the total protein content.
Connective tissue is responsible for providing structural support for the tissues and organs of the body. This mechanfunction is important in maintaining the form of the body, organs and tissues. The tissue derives its name from its function in connecting or binding cells and tissues.
Connective tissue is composed of:
1. cells
2. extracellular matrix.
The extracellular material of connective tissue, which plays a major role in the functioning of the tissue, is the dominant component of the tissue. The dominance of the extracellular material is a special feature that distinguishes connective tissue from the other tissues of the body.
The extracellular matrix is composed of :
protein fibers (collagen fibers, reticular fibers, elastic fibers)
amorphous ground substance tissue fluid (not preserved in histological preparations). The amount of tissue fluid is fairly constant and there is an equilibrium between the water entering and leaving the intercellular substance of the connective tissue. In pathological conditions (traumatic injury, inflammation) fluid may accumulate in the connective tissue, a condition known as edema.
Epithelial Tissue:
Epithelial tissue covers the whole surface of the body. It is made up of cells closely packed and ranged in one or more layers. This tissue is specialised to form the covering or lining of all internal and external body surfaces. Epithelial tissue that occurs on surfaces on the interior of the body is known as endothelium. Epithelial cells are packed tightly together, with almost no intercellular spaces and only a small amount of intercellular substance. Epithelial tissue, regardless of the type, is usually separated from the underlying tissue by a thin sheet of connective tissue; basement membrane. The basement membrane provides structural support for the epithelium and also binds it to neighbouring structures.
Muscle tissue:
Muscle is a very specialized tissue that has both the ability to contract and the ability to conduct electrical impulses. Muscles are are classified both functionally as either voluntary or involuntary and structurally as either striated or smooth. From this, there emerges three types of muscles: smooth involuntary (smooth) muscle, striated voluntary (skeletal) muscle and striated involuntary (cardiac) muscle. The names in the brackets are the common names given to the particular classification of muscle.
Nervous Tissue:
All living cells have the ability to react to stimuli. Nervous tissue is specialised to react to stimuli and to conduct impulses to various organs in the body which bring about a response to the stimulus. Nerve tissue (as in the brain, spinal cord and peripheral nerves that branch throughout the body) are all made up of specialised nerve cells called neurons. Neurons are easily stimulated and transmit impulses very rapidly. A nerve is made up of many nerve cell fibres (neurons) bound together by connective tissue. A sheath of dense connective tissue, the epineurium surrounds the nerve. This sheath penetrates the nerve to form the perineurium which surrounds bundles of nerve fibres. blood vessels of various sizes can be seen in the epineurium. The endoneurium, which consists of a thin layer of loose connective tissue, surrounds the individual nerve fibres.
Organ Systems:
Although an organ has a specific function, organs also function as part of a group, called an organ system. The organ system is the organizational unit by which medicine is studied, diseases are generally categorized, and treatments are planned. This book is, in large part, organized around the concept of organ systems.
Major Organ Systems
Cardiovascular:
Heart
Blood vessels (arteries, capillaries, veins)
Respiratory:
Nose
Mouth
Pharynx
Larynx
Trachea
Bronchi
Lungs
Nervous:
Brain
Spinal cord
Nerves (both those that carry impulses to the brain and those that carry impulses from the brain to muscles and organs)
Skin:
Skin (both the surface that is generally thought of as skin and the underlying structures of connective tissue, including fat, glands, and blood vessels)
Musculoskeletal:
Muscles
Tendons and ligaments
Bones
Joints
Blood:
Blood cells and platelets
Plasma (the liquid part of blood)
Bone marrow (where blood cells are produced)
Spleen
Thymus
Digestive:
Mouth
Esophagus
Stomach
Small intestine
Large intestine
Rectum
Anus
Liver
Gallbladder
Pancreas (the part that produces enzymes)
Appendix
Endocrine:
Thyroid gland
Parathyroid gland
Adrenal glands
Pituitary gland
Pancreas (the part that produces insulin)
Stomach (the cells that produce gastrin)
Pineal gland
Ovaries
Testes
Urinary:
Kidneys
Ureters
Bladder
Urethra
Male reproductive:
Penis
Prostate gland
Seminal vesicles
Vasa deferentia
Testes
Female reproductive:
Vagina
Cervix
Uterus
Fallopian tubes
Ovaries
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