1. Chapter 2: Terms Pertaining to the Body as a Whole
Tri-State Business Institute
MD000 Medical Terminology 1
Micheal H. McCabe, EMT-P

2. Structural Organization of the Body:
The cell is the fundamental unit of all living things.
All cells have a similar structure.
Cells are everywhere in the body – every organ and tissue is composed of cells.
The study of cells is called cytology. The study of tissues is called histology.

4. Parts of the Cell:
[1] Cell Membrane – surrounds and protects the cell. Also Regulates what passes into and out of the cell.
[2] Nucleus – is the control center of the cell. Genetic material in the nucleus determines the structure and function of the cell and controls reproduction.

5. Parts of the Cell:
[3] Chromosomes are rod-like structures within the nucleus. Most human cells contain 23 paired chromosomes that comprise the human genome.
Chromosomes contain regions called genes. Each gene is built up of DNA. The DNA serves as a chemical “program” that directs the function of the cell.

6. Parts of the Cell:
[4] Cytoplasm is all the material outside the nucleus and enclosed by the cell membrane. It includes intracellular fluid as well as discrete structures like the mitochondria[a], endoplasmic reticulum[b], and ribosomes.

7. Mitochondria: Small, sausage-shaped bodies found in the cytoplasm.
Mitochondria are the “power-plants” within the cell that produce energy by combining food with oxygen.
This chemical process is called catabolism.

8. Endoplasmic Reticulum:
Is a network of canals (reticulum) within the cell.
The endoplasmic reticulum (ER) contains very small structures called ribosomes that manufacture protein.
This chemical process is called anabolism.

9. Metabolism:
Metabolism is the total of the chemical processes within the cell.
Metabolism includes catabolism and anabolism.
If a person has a “fast” metabolism, nutrients are used up quickly and energy is released.
If a person has a “slow” metabolism, nutrients are used slowly and fat accumulates in the cells.

10. Karyotype:

11. Karyotype: A karyotype is a photographic “map” of the chromosomes.
The chromosomes are treated with chemicals so that light and dark areas are visible.
An electron microscope is used to visualize and photograph the chromosomes.

12. Amniocentisis:
This procedure is undertaken to check an unborn baby for chromosomal abnormalities.
A needle is used to aspirate a quantity of cells from the amniotic sac.
A karyotype is created from the aspirated cells.
This is a prenatal test frequently used to diagnose Down’s Syndrome.

13. Study Section 1:
Anabolism – the process of building up complex materials (proteins) from simple materials.
Catabolism – the process of breaking down complex materials (foods) to form simpler substances and release energy.

14. Study Section 1:
Cell Membrane – Structure surrounding and protecting the cell. It determines what enters and leaves the cell.
Chromosomes – rod-shaped structures in the nucleus that contain regions of DNA called genes. There are 46 chromosomes (23 pairs) in most human cells.
Cytoplasm – all the material that is outside the nucleus yet contained within the cell membrane.

15. Study Section 1:
DNA – deoxyribonucleic acid; chemical found in each chromosome. Arranged like a sequence of recipes in code, it directs the activities of the cell.
Endoplasmic Reticulum – Structures (canals) within the cytoplasm. Site in which large proteins are made from smaller pieces (amino acids.)

16. Study Section 1: Genes – regions of DNA within each chromosome.
Karyotype – Picture of chromosomes in the nucleus of a cell. The chromosomes are arranged in numerical order to determine their number and structure.

17. Study Section 1:
Metabolism – The total of the chemical processes in a cell. It includes both catabolism and anabolism.
Mitochondria – Sausage-shaped structures in the cytoplasm in which foods are burned to release energy; “power plants.”

18. Study Section 1:
Nucleus – Control center of the cell. It contains chromosomes and directs the activities of the cell.

19. Differences in Cells:
Cells throughout the body are specialized to perform particular tasks.
A group of similar cells working together to do a specific job is called a tissue.
A specialist who studies tissues is called a histologist.

20. Some Types of Cells:
Muscle Cells – are long, slender, and contain contractile fibers that allow them to shorten their length.
Epithelial Cells – are specialized cells that form protective membranes like the skin.
Nerve Cells – are very long and have various fibrous extensions that aid its job of carrying impulses.
Fat Cells – contain large empty spaces for fat storage.

21. Diagrams of Cell Types:

22. Epithelial Tissue:
Epithelial Tissue – is located throughout the body and forms the lining of internal organs, makes up exocrine and endocrine glands, and forms the outer surface of the skin covering the body. The word epithelial was originally used to describe the tissue above the breast nipple. Now it is used to describe the tissues that cover the outside of the body and line the internal cavities.

23. Muscle Tissue:
Voluntary muscle is found attached to the skeleton. It allows voluntary movement under conscious control.
Involuntary muscle (smooth muscle) is found in the walls of the blood vessels, intestines, and hollow organs of the body. This movement is not under conscious control.
Cardiac Muscle is found only in the walls of the heart (myocardium) and is specialized in that it will contract automatically – independent of nervous system action. This property is called automaticity.

24. Connective Tissue:
Connective tissue is the most common and the most diverse of all body tissues.
Examples are fat (adipose tissue), bone, cartilage, and blood.
Connective tissue is characterized by relatively few cells that create non-cellular structures known as matrix.

25. Nerve Tissue: Nerve tissue conducts impulses all over the body.
Nerve cells have specialized extensions called axons and dendrites that serve as specialized communication lines.
The Axon carries messages (impulses) away from the body of the nerve cell. It serves as a transmitter. Each nerve cell has only one axon.
Dendrites carry messages (impulses) towards the body of the cells. They serve as receivers. Each nerve cell can have many dendrites.

26. Organs: Organs are structures composed of several kinds of tissue.
For example, the stomach is composed of muscle tissue, nerve tissue, glandular epithelial tissue, and connective tissue.
The medical term for internal organs is viscera (singular form: viscus)
Examples of abdominal viscera include the liver, stomach, pancreas, intestines, spleen, and gallbladder.

27. Systems:
Systems are groups of organs working together to perform complex functions.
Different books and authors group the organ systems differently.
Example: This book groups the body into ten body systems. The A&P class groups the body into 15 systems.

28. Digestive System:
Function is to digest food, absorb nutrients into the bloodstream, and eliminate solid waste.
Organs include the mouth, pharynx, esophagus, stomach, intestines, liver, gallbladder, and pancreas.

29. Urinary System: Also called the excretory system.
Function is to eliminate metabolic waste, maintain the fluid balance of the body, regulate electrolyte levels, and govern the acid/base balance.
Organs include the kidneys, ureters, bladder, and urethra.

30. Respiratory System:
Function is to bring oxygen into the bloodstream and eliminate carbon dioxide. Also helps regulate the acid/base balance.
Organs include the nose, pharynx, larynx, trachea, bronchi, bronchioles, and lungs.

31. Reproductive System:
Function is to enable reproduction of the entire organism and to help perpetuate the species.
Organs differ somewhat between males and females.
Male organs include the testes and assorted tubes, urethra, prostate gland, and penis.
Female organs include the ovaries, fallopian tubes, uterus, vagina, and mammary glands.

32. Endocrine:
Function is of a chemical communication system that regulates function and metabolism at a cellular level.
Organs include the pituitary gland, thyroid gland, sex glands (gonads), adrenal glands, parathyroid gland, thymus, and the pancreas.

33. Nervous System:
Function is complex – includes command, control, and communication throughout the entire body.
Organs include the brain, spinal cord, cranial nerves, spinal nerves, and other collections of nerve structures.

34. Circulatory System:
Functions as a transportation system – used to move oxygen, nutrients, waste products, carbon dioxide, chemicals, hormones, and immune system components throughout the body.
Organs include the heart, blood vessels, lymphatic vessels and nodes, blood, lymph, spleen, and thymus gland.
One of the more complex systems we will discuss.

35. Muscular System:
Function is to enable movement: skeletal muscles move the body itself; smooth muscles move substances within the body; cardiac muscle enables operation of the circulatory system.
Organs include more than 600 muscles and tendons.

36. Skeletal System:
Provides supporting framework for the body; also protects internal organs and provides for movement via its articulations.
Includes more than 200 bones plus ligaments, cartilage, and joint structures.

37. Skin and Sense Organs:
The skin provides an overall covering for the body.
Accessory organs of the skin include hair and nails.
General sense organs are embedded within the skin.
Special sense organs are complex independent structures.

38. Study Section 2: Adipose tissue – collection of fat cells.
Cartilage – flexible connective tissue attached to bones at joints.
Epithelial Cell – skin cells that cover the external body surfaces and line the internal surfaces of organs.
Histologist – a specialist in the study of tissues.

39. Study Section 2:
Larynx – voice box; located at the upper part of the trachea.
Pharynx – throat; The pharynx is the common passageway for food and air entering the body.
Pituitary gland – Endocrine gland located at the base of the brain.

40. Study Section 2:
Thyroid gland – endocrine gland that surrounds the trachea in the neck.
Trachea – The windpipe – a tube leading from the throat to the bronchi.
Ureter – One of two tubes leading from each kidney to the urinary bladder.

41. Study Section 2:
Urethra – Tube from the urinary bladder to the outside of the body.
Uterus – The womb. The organ that holds the embryo and fetus as it develops.
Viscera – internal organs.

42. Body Cavities:
A body cavity is a space within the body that contains internal organs (viscera.)
Ventral cavities are found in the front of the body.
Dorsal cavities are found in the back.

43. Body Cavities:

44. Ventral Cavities:
Thoracic Cavity – Located in the upper half of the torso (thorax); the diaphragm separates the thoracic cavity from the abdominal cavity.
Abdominal Cavity – located in the middle portion of the torso (abdomen)
Pelvic Cavity – located within the pelvic girdle.

45. Dorsal Cavities:
Cranial Cavity – lies within the cranial vault; the hollow, enclosed portion of the skull.
Spinal Cavity – lies within the vertebrae. Also called the vertebral canal.

46. The Cranial Cavity: Contains the brain and pituitary gland.
Is lined by the meninges surrounding the brain.
Regions of the cranial cavity (and the brain within) are named after adjacent bones (occipital, frontal, parietal, temporal, etc.)

47. The Thoracic Cavity:
Contains the heart, lungs, esophagus, trachea, bronchial tubes, thymus glad, aorta, and other large blood vessels.
Can be divided into two smaller cavities:
Pleural Cavity – space between the membranes that surround each lung.
Mediastinum – a centrally located area outside of and between the lungs. Contains the heart, aorta, trachea, esophagus, thymus gland, bronchi, and many lymph nodes.

48. Divisions of the Thoracic Cavity:

49. The Abdominal Cavity:
Contains the stomach, small intestine, large intestines, spleen, pancreas, liver, and gallbladder.
Lined by a double folded membrane called the peritoneum.
Behind the peritoneum is the retroperitoneal space where the kidneys are located.

50. The Abdominal Cavity:

51. The Pelvic Cavity: Located within the pelvic girdle.
Some authors consider this part of the abdominal cavity. May refer the collective space as the abdominopelvic cavity.
Contains portions of the large and small intestine, the rectum, urinary bladder, ureters, urethra.
In the female, also contains the uterus and vagina.
In the male, also contains the prostate gland.
Most pelvic organs not enveloped by the peritoneum.

52. The Spinal Cavity: Located within the vertebral column.
Also called the spinal canal.
Contains the spinal cord and spinal nerves.

53. Study Section 3:
Abdominal Cavity – space below the chest containing organs such as the liver, stomach, gallbladder, and intestines; also called simply the abdomen.
Cranial Cavity – space in the head containing the brain and surrounded by the skull. Cranial means “pertaining to the skull.”

54. Study Section 3:
Diaphragm – muscle separating the abdominal and thoracic cavities.
Dorsal (posterior) – pertaining to the back.
Mediastinum – Centrally located between the lungs.
Pelvic Cavity – Space below the abdomen containing portions of the intestines, rectum, urinary bladder, and reproductive organs. Pelvic means “pertaining to the hip bone,” which surrounds the pelvic cavity.

55. Study Section 3:
Pleura – a double-layered membrane surrounding each lung.
Pleural Cavity – Space between the pleural membranes and surrounding each lung.
Spinal cavity – Space within the spinal column (backbone) and containing the spinal cord. Also called the spinal canal.

56. Study Section 3:
Thoracic Cavity – Space in the chest containing the heart, lungs, bronchial tubes, trachea, esophagus, and other organs.
Ventral (Anterior) – Pertaining to the front.

57. Organs of the Abdomen and Thorax:

58. Organs of the Abdomen and Thorax (Posterior View):

59. Regions of the Abdomen:
The combined abdominal and pelvic cavities are divided into nine regions.
These regions are used by doctors to describe the location where various organs are found.
These regions are frequently used in reports describing the location of pain and surgical procedures.

60. Regions of the Abdomen:
Hypochondriac – two upper left and upper right regions below the cartilage of the ribs that extend over the abdomen.
Epigastric Region – The region above the stomach.
Lumbar Region – two middle right and middle left regions near the waist.
Umbilical Region – area of the navel (umbilicus)

61. Regions of the Abdomen:
Inguinal Regions – two lower right and left regions near the groin, where the legs join the trunk of the body. These regions are also known as the iliac regions because they are near the ilium which is the upper portion of the hip bone on each side of the body.
Hypogastric Region – lower middle region below the umbilical region.

62. Regions of the Abdomen:

63. Abdominal Quadrants:
The abdominopelvic area can be divided into four quadrants by drawing two imaginary lines – one horizontally and one vertically through the body.
Right Upper Quadrant (RUQ) contains the liver, gallbladder, part of the pancreas, and parts of the large and small intestine.

64. Abdominal Quadrants:
Left Upper Quandrant (LUQ) – contains the liver, stomach, spleen, part of the pancreas, and parts of the large and small intestine.
Right Lower Quadrant (RLQ) – contains parts of the small and large intestine, right ovary, right fallopian tube, appendix, and right ureter.

65. Abdominal Quadrants:
Left Lower Quadrant – contains part of the large and small intestines, left ovary, left fallopian tube, and left ureter.

66. Abdominal Quadrants:

67. Divisions of the Back:
The back is divided into divisions that correspond to the regions of the spinal column.
The spinal column is composed of a series of small bones that extend from the neck to the tailbone.
Each bone is called a vertebra (plural: vertebrae.)

68. Divisions of the Back:
Cervical (abbrev. C) – Neck region. There are 7 cervical vertebrae. (C1-C7)
Thoracic (abbrev. T) – Chest region. There are 12 thoracic vertebrae (T1-T12). Each vertebra is joined to a rib.
Lumbar (abbrev. L) – Loin (waist) or flank region. There are 5 lumbar vertebrae. (L1-L5)

69. Divisions of the Back:
Sacral (abbrev. S) – Joined to posterior pelvic girdle. There are five bones (S1-S5) fused into one, the sacrum.
Coccygeal – The coccyx (tailbone) is a small bone composed of four fused pieces.

70. Spinal Column V. Spinal Cord:
Do not confuse the spinal column with the spinal cord!
The spinal column is bone tissue and the spinal cord is nerve tissue.

71. Intervertebral Discs:
The spaces between the vertebrae are identified according to the two vertebrae between which they lie.
For example, L5-S1 lies between the 5th lumbar and 1st sacral vertebrae.
Within the space and between vertebrae there is a small piece of cartilage called a disc.
The disc acts as a shock absorber.
Occassionally, it moves out of place (ruptures) and puts pressure on a nerve. This is called a “slipped disc,” and can be very painful.

72. Study Section 4 – Abdominopelvic Regions:
Hypochondriac – upper right and left regions beneath the ribs.
Epigastric – upper middle region above the stomach.
Lumbar – Middle left and right regions near the waist.
Umbilical – Central region around the navel.

73. Study Section 4 – Abdominopelvic Regions:
Ingiunal – Lower right and left regions near the groin. Also called the iliac regions.
Hypogastric – Lower middle region below the umbilical region.

74. Study Section 4 – Abdominopelvic Quadrants:
RUQ – Right Upper Quadrant
LUQ – Left Upper Quadrant
RLQ – Right Lower Quadrant
LLQ – Left Lower Quadrant

75. Study Section 4 – Divisions of the Back:
Cervical – Neck region (C1-C7)
Thoracic – Chest Region (T1-T12)
Lumbar – Waist Region (L1-L5)
Sacral – Region of the sacrum (S1-S5)
Coccygeal – Region of the tailbone

76. Study Section 4 – Related Terms:
Vertebra – A single back bone
Vertebrae – Plural form of vertebra
Spinal Column – Bone tissue surrounding the spinal cavity.
Spinal Cord – Nervous tissue within the spinal cavity
Disc (disk) – A pad of Cartilage between vertebrae.

77. Positional and Directional Terms:
Anterior (Ventral) – Front side of the body. Ventral and anterior are the same in humans (we walk upright!); in an animal (on four legs), ventral refers to the belly side and anterior to the front end near the head.
Posterior (Dorsal) – The back side of the body; opposite of anterior. Also different in quadrapeds.

78. Positional and Directional Terms:
Deep – away from the surface.
Superficial – on (or near) the surface.

79. Positional and Directional Terms:
Proximal – Near the point of attachment to the trunk or near the beginning of a structure.
Distal – Far from the point of attachment

80. Positional and Directional Terms:
Inferior – Below another structure. The term caudal (pertaining to the tail) also means inferior in humans.
Superior – Above another structure. The term cephalic (pertaining to the head) is also used to mean superior.

81. Positional and Directional Terms:
Medial – In the middle or nearer the medial plane of the body.
Lateral – Pertaining to the side – farther away from the midline.

82. Positional and Directional Terms:
Supine – Lying on the back.
Prone – Lying on the belly.

83. Planes of the Body: A plane is an imaginary flat surface.
Frontal (Coronal) – a vertical plane that divides the body into anterior and posterior portions. Also called a coronal plane.
Sagittal (Lateral) – a lengthwise vertical plane that divides the body or structure into left and right sides. The midsagittal plane divides the body or structure equally in half.
Transverse – Plane running across the body parallel to the ground (horizontal.) Also called a cross-sectional plane.

84. Anatomical Directions and Planes of the Body:

85. Study Section 5:
Anterior (Ventral) – Pertaining to the front (belly side) of the body.
Deep – away from the surface
Distal – far from the trunk or far from the beginning of a structure
Frontal (Coronal) Plane – vertical plane dividing the body into anterior and posterior portions.

86. Study Section 5: Inferior (caudal) – Below another structure.
Lateral – pertaining to the side.
Medial – pertaining to the middle or near the medial plane of the body.
Posterior (dorsal) – Pertaining to the back of the body.

87. Study Section 5: Prone – lying on the belly (face down)
Proximal – Near the point of attachment to the trunk or near the beginning of a structure
Sagittal Plane – Vertical, lateral plane diving the body into left and right sides.

88. Study Section 5: Superficial – on the surface
Superior (cephalic) – above another structure
Supine – lying on the back (face up, palm up)
Transverse Plane – Horizontal plane dividing the body into upper and lower portions.