topic 1: terminology in health science

Anatomy is the study of internal and external body structures and their physical relationships among other body parts.

Physiology is the study of how living organisms perform their functions.

We study gross anatomy—the study of structures visible to the naked eye—by examining surface anatomy, regional anatomy, or systemic anatomy.

Gross anatomy (macroscopic anatomy) is the study of structures and features that are visible to the unaided (naked) eye. There are several ways to approach gross anatomy:

Surface anatomy is the study of general anatomical form, and how superficial (surface) anatomical markings relate to deeper anatomical structures.

Regional anatomy is the study of the superficial and internal features in a specific area of the body, such as the head, neck, or trunk. Advanced courses in anatomy often stress a regional approach because it emphasizes the relationships among structures. (This will be discussion in Terminology Part 2).

Systemic anatomy is the study of anatomy based upon the body’s organ systems. An organ system is a group of organs that function together to produce coordinated effects. For example, the heart, blood, and blood vessels form the cardiovascular system, which distributes oxygen and nutrients throughout the body. There are 11 organ systems in the human body, which we will introduce later in the lecture.

Microscopic anatomy—the study of structures too small to be seen by the naked eye—includes the specialties of cytology and histology.

Microscopic anatomy is the study of structures that cannot be seen without magnification. The boundaries of microscopic anatomy are established by the limits of the equipment used. A simple hand lens shows details that barely escape the naked eye, while an electron microscope shows structural details that are more than a million times smaller. Microscopic anatomy is subdivided into two specialties that consider features within a characteristic range of sizes:

Cytology analyses the internal structure of cells, the smallest units of life. Living cells are composed of complex chemicals in various combinations, and our lives depend on the chemical processes occurring in the trillions of cells that form our body.

Histology takes a broader perspective and examines tissues, groups of specialized cells and cell products that work together and perform specific functions. The human body has four basic tissue types: epithelial tissue, connective tissue, muscle tissue, and neural tissue (which will be discussed later in the course).

Tissues combine to form organs such as the heart, kidney, liver, and brain. An organ is an anatomical structure that has multiple functions. Many tissues and most organs are examined easily without a microscope, and at this point we cross the boundary from microscopic anatomy into gross anatomy.

·       Physiology is the study of how living organisms perform their functions.

·       Human physiology is the study of the functions, or workings, of the human body.

Figure 4

Physiology Categories

Note. Adapted from Seeley’s Anatomy & Physiology (p. 4), by C. VanPutte et al., 2017, McGraw-Hill Education

(https://ebookcentral.proquest.com/lib/curtin/reader.action?docID=5471248). Copyright 2017 by McGraw-Hill Education.

Physiology explanation

These functions are complex processes and much more difficult to examine than most anatomical structures. As a result, there are even more specialties in physiology than in anatomy.

Cell physiology, the study of the functions of cells, is the cornerstone of human physiology. Cell physiology looks at events involving the atoms and molecules important to life. It includes both chemical processes within cells and chemical interactions among cells.

Organ physiology is the study of the function of specific organs. An example is cardiac physiology, the study of heart function—how the heart works.

Systemic physiology includes all aspects of the functioning of specific organ systems. Cardiovascular physiology, respiratory physiology, and reproductive physiology are examples.

Pathological physiology is the study of the effects of diseases on organ functions or system functions. Modern medicine depends on an understanding of both normal physiology and pathological physiology.

Physicians normally use a combination of anatomical, physiological, chemical, and psychological information when they evaluate patients. When a patient presents signs (an objective disease indication like a fever) and symptoms (a subjective disease indication, such as tiredness) to a physician, the physician will look at the structures affected (gross anatomy), perhaps collect a fluid or tissue sample (microscopic anatomy) for analysis, and ask questions to find out what changes from normal functioning the patient is experiencing.

Characteristics of Life

•       Organisation refers to the specific interrelationships among the parts of an organism and how those parts interact to perform specific functions.

•       Metabolism refers to all of the chemical reactions taking place in an organism.

•       Responsiveness is an organism’s ability to sense changes in its external or internal environment and adjust to those changes.

•       Growth refers to an increase in the size or number of cells, which produces an overall enlargement of all or part of an organism.

•       Development includes the changes an organism undergoes through time, beginning with fertilization and ending at death.

•       Reproduction is the formation of new cells or new organisms.

Content & Explanation

Humans are organisms, sharing characteristics with other organisms. The most important common feature of all organisms is life. This slide is to recognise six essential characteristics of life:

1. Organisation refers to the specific interrelationships among the parts of an organism and how those parts interact to perform specific functions. Living things are highly organized. All organisms are composed of one or more cells. Cells in turn are composed of highly specialized organelles, which depend on the precise organisation of large molecules. Disruption of this organized state can result in loss of functions, or even death.

2. Metabolism refers to all of the chemical reactions taking place in an organism. It includes an organism’s ability to break down food molecules, which the organism uses as a source of energy and raw materials to synthesize its own molecules. Energy is also used when one part of a molecule moves relative to another part, changing the shape of the molecule. Changes in molecular shape can lead to changes in cellular shape, which can produce movement of the organism. Metabolism is necessary for vital functions, such as responsiveness, growth, development, and reproduction.

3. Responsiveness is an organism’s ability to sense changes in its external or internal environment and adjust to those changes. Responses include such actions as moving toward food or water and moving away from danger or poor environmental conditions. Organisms can also make adjustments that maintain their internal environment. For example, if the external environment causes the body temperature to rise, sweat glands produce sweat, which can lower body temperature back toward its normal range.

4. Growth refers to an increase in the size or number of cells, which produces an overall enlargement of all or part of an organism. For example, a muscle enlarged by exercise is composed of larger muscle cells than those of an untrained muscle, and the skin of an adult has more cells than the skin of an infant. An increase in the materials surrounding cells can also contribute to growth. For instance, bone grows because of an increase in cell number and the deposition of mineralized materials around the cells.

5. Development includes the changes an organism undergoes through time, beginning with fertilization and ending at death. The greatest developmental changes occur before birth, but many changes continue after birth, and some go on throughout life. For example, following fertilization, generalized cells specialize to become specific cell types, such as skin, bone, muscle, or nerve cells. These differentiated cells form the tissues and organs.

6. Reproduction is the formation of new cells or new organisms. Without reproduction of cells, growth and development are not possible. Without reproduction of organisms, species become extinct.

Levels of Organisation for the human body

Figure 5

Levels of Organisation for the Human Body

Note. From Seeley’s Anatomy & Physiology (p. 4), by C. VanPutte et al., 2017, McGraw-Hill Education

(https://ebookcentral.proquest.com/lib/curtin/reader.action?docID=5471248). Copyright 2017 by McGraw-Hill Education.

Content & Explanation

The three most basic (chemical, cellular, and tissue) levels of organisation of the human body. They interact with more complex structures and vital processes. The levels of organisation of the human body include:

The Chemical Level. Atoms are the smallest stable units of matter. They can combine to form molecules with complex shapes. The atomic components and unique three dimensional shape of a particular molecule determine its function. For example, complex protein molecules form filaments that produce the contractions of muscle cells in the heart.

The Cellular Level. Cells are the smallest living units in the body. Complex molecules can form various types of larger structures called organelles. Each organelle has a specific function in a cell. Energy-producing organelles provide the energy needed for heart muscle cell contractions.

The Tissue Level. A tissue is a group of cells working together to perform one or more specific functions. Heart muscle cells, also called cardiac muscle cells (cardium, heart), interact with other types of cells and with materials outside the cell to form cardiac muscle tissue.

The Organ Level. Organs are made of two or more tissues working together to perform specific functions. Layers of cardiac muscle tissue, in combination with another type of tissue called connective tissue, form the bulk of the wall of the heart, which is a hollow, three-dimensional organ.

The Organ System Level. A group of organs interacting to perform a particular function forms an organ system. Each time it contracts, the heart pushes blood into a network of blood vessels. Together, the heart, blood, and blood vessels make up the cardiovascular system, one of 11 organ systems in the body. This system functions to distribute oxygen and nutrients throughout the body.

The Organism Level. An organism—in this case, an individual human—is the highest level of organisation that we consider. All of the body’s organ systems must work together to maintain the life and health of the organism.

Organ Systems of the Body

Note. From Seeley’s Anatomy & Physiology (p. 4), by C. VanPutte et al., 2017, McGraw-Hill Education

(https://ebookcentral.proquest.com/lib/curtin/reader.action?docID=5471248). Copyright 2017 by McGraw-Hill Education.

Content & Explanation

Integumentary System: major organs are skin, hair, sweat glands and nails; Functions: Protects against Environmental hazards; helps regulate body Temperature; provides sensory information

Skeletal System: Major Organs Bones; Cartilages; Associated ligaments; Bone marrow; Functions: Provides support and protection for other Tissues; Stores calcium and other minerals; Forms blood cells

Muscular System: Major Organs: Skeletal muscles and associated tendons; Functions: Provides movement; Provides protection and support for other Tissues; Generates heat that maintains body temperature

Lymphatic System: Major Organs: Spleen; Thymus; Lymphatic vessels; Lymph nodes; Tonsils; Functions: Defends against infection and Disease; Returns tissue fluids to the bloodstream

Respiratory System: Major Organs: Nasal cavities, Sinuses, Larynx, Trachea, Bronchi, Lungs, Alveoli; Functions: Delivers air to alveoli (sites in lungs where gas exchange occurs); Provides oxygen to Bloodstream; Removes carbon dioxide from Bloodstream; Produces sounds for communication

Digestive System: Major Organs: Teeth, Tongue, Pharynx, Oesophagus, Stomach, Small intestine, Large intestine, Liver, Gallbladder, Pancreas; Functions: Processes and digests Food; Absorbs and conserves water; Absorbs nutrients; Stores energy reserves

Nervous System: Major Organs: Brain, Spinal cord, Peripheral nerves, Sense organs; Functions: Directs immediate responses to stimuli; Coordinates or moderates activities of other organ systems; Provides and interprets sensory information about external conditions

Endocrine System: Major Organs: Pituitary gland, Thyroid gland, Pancreas, Adrenal glands, Gonads, Endocrine tissues in other systems; Functions: Directs long-term changes in the activities of other organ systems; Adjusts metabolic activity and energy use by the body; Controls many structural and functional changes during development

Cardiovascular System: Major Organs: Heart, Blood, Blood vessels; Functions: Distributes blood cells, water and dissolved materials including nutrients, waste products, oxygen, and carbon Dioxide; Distributes heat and assists in control of body temperature

Urinary System: Major Organs: Kidneys, Ureters, Urinary bladder, Urethra; Functions: Excretes waste products from the blood; Controls water balance by regulating volume of urine produced; Stores urine prior to voluntary elimination; Regulates blood ion concentrations and pH

Female Reproductive System: Major Organs: Ovaries, Uterine tubes, Uterus, Vagina, Labia, Clitoris, Mammary glands; Functions: Produces female sex cells (oocytes) and Hormones; Supports developing embryo from conception to delivery; Provides milk to nourish newborn Infant; Sexual intercourse

Male Reproductive System: Major Organs: Testes, Seminal vesicles, Prostate gland, Penis, Scrotum; Functions: Produces male sex cells (sperm), seminal fluids, and Hormones; Sexual intercourse

Anatomy is about studying the body's structures, both inside and outside, and how these parts relate to one another. Physiology focuses on how organisms function. In anatomy, we look at gross anatomy, which is about studying parts of the body that we can see without any tools. There are three main ways to study it:

• Surface anatomy: This looks at how the body's outer features connect to deeper structures.

• Regional anatomy: This focuses on specific areas of the body, like the head or chest, and how features in those areas work together.

• Systemic anatomy: This method studies the body's systems, like how the heart and blood vessels work together in the cardiovascular system. There are 11 major organ systems in the human body that we'll explore later.

Anatomy and Physiology

Anatomy

Anatomy studies the body's structures, both inside and outside, and how they relate to each other.

Gross Anatomy

• What is it?: Focuses on body parts visible without tools.

• How to study it:

  • Surface Anatomy: Looks at how outside features connect to deeper structures.

  • Regional Anatomy: Focuses on specific areas, like the head or chest.

  • Systemic Anatomy: Studies organ systems, like how the heart and blood vessels work together.

Physiology

Physiology focuses on how living things function.

Types of Physiology

• Cell Physiology: Studies how cells work.

• Organ Physiology: Looks at how specific organs function (e.g., the heart).

• Systemic Physiology: Examines how entire organ systems work together.

• Pathological Physiology: Studies how diseases affect organ functions.

Key Points

• Anatomy is about structures; physiology is about their functions.

• There are 11 major organ systems in the human body that will be discussed later.

Anatomy and Physiology

Anatomy

Anatomy studies the body's structures, both inside and outside, and how they relate to each other.

Gross Anatomy

• What is it?: Focuses on body parts visible without tools.

• How to study it:

  • Surface Anatomy: Examining the relationship between the skin and underlying muscles. For example, observing how the biceps muscle can be felt when the arm is flexed.

  • Regional Anatomy: Studying the structures within the abdominal region, such as the stomach, liver, and intestines, to understand how they interact in digestion.

  • Systemic Anatomy: Analyzing the cardiovascular system by tracing the path of blood circulation from the heart through arteries to capillaries and back to the heart.

Physiology

Physiology focuses on how living things function.

Types of Physiology

• Cell Physiology: Studies how individual cardiac muscle cells generate electrical signals to initiate heartbeats.

• Organ Physiology: Investigates how lungs facilitate gas exchange during breathing.

• Systemic Physiology: Examines how the renal system maintains electrolyte balance and regulates blood pressure.

• Pathological Physiology: Looks at how diabetes affects insulin regulation and glucose metabolism in the body.

Key Points

• Anatomy is about structures; physiology is about their functions.

• There are 11 major organ systems in the human body that will be discussed later.

Microscopic Anatomy

What is Microscopic Anatomy?

• Microscopic anatomy is the study of tiny structures that we cannot see with our eyes.

• It requires tools like microscopes to look at these small details.

Specialties of Microscopic Anatomy

1. Cytology:

   • This is the study of cells, which are the smallest units of life.

   • Cells are made of complex chemicals, and many processes happen inside them.

2. Histology:

   • This field looks at tissues, which are groups of specialized cells that work together.

   • The human body has four main types of tissues:

     • Epithelial tissue

     • Connective tissue

     • Muscle tissue

     • Neural tissue

How Tissues and Organs Work

• Tissues combine to form organs like the heart, kidneys, liver, and brain.

• Organs have multiple functions.

• While many tissues and organs can be seen without a microscope, that's when we move from microscopic anatomy to gross anatomy.