BIO 252 Anatomy and Physiology Module 1
AP 1– Introduction to the Human Body
1.1 – Overview of Anatomy and Physiology
Human Anatomy
● Human anatomy is the scientific study of the body’s structures
● The word “anatomy” comes from a Greek root that means “to cut apart”
○ First studied by observing the exterior of the body and observing the wounds of
soldiers and other injuries → later, physicians would use dissections to augment
knowledge
○ Dissection involves cutting the body apart in order to observe its physical attributes and
their relationships to one another
○ To observe structures in living people, a multitude of imaging techniques have been
developed
● Branches of Anatomy – Areas of Specialization
○ Gross Anatomy – the study of larger structures in the body, visible without
magnification ■ Also referred to as “Macro-Anatomy”
○ Microscopic Anatomy – the study of structures that can only be observed with the use of a
microscope or other magnification devices
■ E.g. Cytology – the study of cells
■ E.g. Histology – the study of
tissues ● Approaches to the study of the body’s
structure
○ Regional anatomy – the study of the interrelationships of all the structures in a specific
body region, such as the abdomen
■ This approach helps us appreciate the interrelationships of these body structures;
such as how muscles, nerves, blood vessels, and other structures work together
to serve a particular region
○ Systemic Anatomy – the study of structures that make up a discrete body system; that is, a
group of structures that work together to perform a unique body function
■ E.g. a systematic anatomical study of the muscular system would consider all of
the skeletal muscles of the body
Human Physiology
● Human physiology is the scientific study of the chemistry and physics of the structures of the
body and the ways in which they work together to support the functions of life
○ Similar to anatomy, physiology can be observed by both the naked eye and microscopes,
as well as manipulations and measurements
, ■ Note that most advances in physiology are studied in carefully designed laboratory
experiments that help to reveal the many structures and chemical compounds
that make up the human body
○ Much of the study of physiology centers on the body’s tendency toward homeostasis
○ Homeostasis – the state of steady internal conditions maintained by living things
● Branches of Physiology – Areas of Specialization
○ Organ Level – e.g. exploring what different parts of the brain can do
■ Neurophysiology – study of the brain, spinal cord, and nerves and how these work
together to perform functions like vision, movement, and thinking
○ Molecular Level – e.g. exploring how an electrochemical signal travels along nerves
1.2 – Structural Organization of the Human Body
Structures of the Body in Terms of Fundamental Levels of Organization
(Increasing in Complexity) ● Subatomic particles
● Atoms
● Molecules
● Organelles
● Cells
● Tissues
● Organs
● Organ systems
● Organisms
● Biosphere
Levels of Structural Organization of the Human Body (Increasing in Complexity)
● Chemical Level
● Cellular Level
● Tissue Level
● Organ Level
● Organ System Level
● Organism Level
Levels of Organization
Chemical Level – atoms and molecules
● E.g. Hydrogen and Oxygen atoms bonding to form water molecules
● Simplest building blocks of matter – subatomic particles, atoms, and molecules
, ● All matter in the universe is composed of one or more unique pure substances called elements,
familiar examples include hydrogen, oxygen, carbon, nitrogen, calcium, and iron
● Atoms – the smallest unit of any of these pure substances that maintains its chemical properties
○ Atoms are made up of subatomic particles such as protons, electrons, and neutrons
● Two or more atoms combine to form a molecule, such as water molecules, proteins, and sugars
all found in living things
● Molecules are considered the chemical building blocks of all body structures
Cellular Level – variety of molecules combine to form the fluid and organelles of a body cell
● E.g. cell fluid or smooth muscle cell
● Cell – the smallest independently functioning unit of a living organism
● Human cells typically consist of flexible membranes that enclose cytoplasm, a water-based
cellular fluid, together with a variety of tiny functioning units called organelles
● Cells perform all functions of life
Tissue Level – community of similar cells forming body tissue
● E.g. smooth muscle tissue
● Tissue – a group of many similar cells (sometimes composed of a few related types) that work
together to perform a specific function
Organ Level – two or more different tissues combine to form an organ
● E.g. smooth muscle and skeletal muscle combine to form the bladder
● Organ – an anatomically distinct structure of the body composed of two or more tissue types
○ Each organ performs one or more specific physiological functions
Organ System Level – two or more organs work closely together to perform the functions
of a body system ● E.g. urinary tract system
● Organ System – a group of organs that work together to perform major functions or meet
physiological needs of the body
Distinct Organ Systems in the Human Body
● Integumentary System
○ Encloses internal body structures
○ Site of many sensory receptors
○ E.g. hair, skin, nails
● Skeletal System
○ Supports the body
○ Enables movement (with muscular system)
○ E.g. cartilage, bones, joints
AP 1– Introduction to the Human Body
1.1 – Overview of Anatomy and Physiology
Human Anatomy
● Human anatomy is the scientific study of the body’s structures
● The word “anatomy” comes from a Greek root that means “to cut apart”
○ First studied by observing the exterior of the body and observing the wounds of
soldiers and other injuries → later, physicians would use dissections to augment
knowledge
○ Dissection involves cutting the body apart in order to observe its physical attributes and
their relationships to one another
○ To observe structures in living people, a multitude of imaging techniques have been
developed
● Branches of Anatomy – Areas of Specialization
○ Gross Anatomy – the study of larger structures in the body, visible without
magnification ■ Also referred to as “Macro-Anatomy”
○ Microscopic Anatomy – the study of structures that can only be observed with the use of a
microscope or other magnification devices
■ E.g. Cytology – the study of cells
■ E.g. Histology – the study of
tissues ● Approaches to the study of the body’s
structure
○ Regional anatomy – the study of the interrelationships of all the structures in a specific
body region, such as the abdomen
■ This approach helps us appreciate the interrelationships of these body structures;
such as how muscles, nerves, blood vessels, and other structures work together
to serve a particular region
○ Systemic Anatomy – the study of structures that make up a discrete body system; that is, a
group of structures that work together to perform a unique body function
■ E.g. a systematic anatomical study of the muscular system would consider all of
the skeletal muscles of the body
Human Physiology
● Human physiology is the scientific study of the chemistry and physics of the structures of the
body and the ways in which they work together to support the functions of life
○ Similar to anatomy, physiology can be observed by both the naked eye and microscopes,
as well as manipulations and measurements
, ■ Note that most advances in physiology are studied in carefully designed laboratory
experiments that help to reveal the many structures and chemical compounds
that make up the human body
○ Much of the study of physiology centers on the body’s tendency toward homeostasis
○ Homeostasis – the state of steady internal conditions maintained by living things
● Branches of Physiology – Areas of Specialization
○ Organ Level – e.g. exploring what different parts of the brain can do
■ Neurophysiology – study of the brain, spinal cord, and nerves and how these work
together to perform functions like vision, movement, and thinking
○ Molecular Level – e.g. exploring how an electrochemical signal travels along nerves
1.2 – Structural Organization of the Human Body
Structures of the Body in Terms of Fundamental Levels of Organization
(Increasing in Complexity) ● Subatomic particles
● Atoms
● Molecules
● Organelles
● Cells
● Tissues
● Organs
● Organ systems
● Organisms
● Biosphere
Levels of Structural Organization of the Human Body (Increasing in Complexity)
● Chemical Level
● Cellular Level
● Tissue Level
● Organ Level
● Organ System Level
● Organism Level
Levels of Organization
Chemical Level – atoms and molecules
● E.g. Hydrogen and Oxygen atoms bonding to form water molecules
● Simplest building blocks of matter – subatomic particles, atoms, and molecules
, ● All matter in the universe is composed of one or more unique pure substances called elements,
familiar examples include hydrogen, oxygen, carbon, nitrogen, calcium, and iron
● Atoms – the smallest unit of any of these pure substances that maintains its chemical properties
○ Atoms are made up of subatomic particles such as protons, electrons, and neutrons
● Two or more atoms combine to form a molecule, such as water molecules, proteins, and sugars
all found in living things
● Molecules are considered the chemical building blocks of all body structures
Cellular Level – variety of molecules combine to form the fluid and organelles of a body cell
● E.g. cell fluid or smooth muscle cell
● Cell – the smallest independently functioning unit of a living organism
● Human cells typically consist of flexible membranes that enclose cytoplasm, a water-based
cellular fluid, together with a variety of tiny functioning units called organelles
● Cells perform all functions of life
Tissue Level – community of similar cells forming body tissue
● E.g. smooth muscle tissue
● Tissue – a group of many similar cells (sometimes composed of a few related types) that work
together to perform a specific function
Organ Level – two or more different tissues combine to form an organ
● E.g. smooth muscle and skeletal muscle combine to form the bladder
● Organ – an anatomically distinct structure of the body composed of two or more tissue types
○ Each organ performs one or more specific physiological functions
Organ System Level – two or more organs work closely together to perform the functions
of a body system ● E.g. urinary tract system
● Organ System – a group of organs that work together to perform major functions or meet
physiological needs of the body
Distinct Organ Systems in the Human Body
● Integumentary System
○ Encloses internal body structures
○ Site of many sensory receptors
○ E.g. hair, skin, nails
● Skeletal System
○ Supports the body
○ Enables movement (with muscular system)
○ E.g. cartilage, bones, joints
