Chapter 1 The Human Chapter 1 The Human Body: Body:

Chapter 1 The Human Chapter 1 The Human

Body:

Body: An Orientation An Orientation

Be Able To Be Able To

• Define anatomy and physiology.

• Explain how anatomy and physiology are related.

• Name the levels of structural organization and explain their relationships.

• List and describe the functions of the organ systems of the body.

Key Terms

Key Terms: anatomy, physiology, atoms, cells, tissues, organ, organ system, organism, systems of the body;

integumentary, skeletal, muscular, nervous, endocrine, cardiovascular, lymphatic, respiratory, digestive,

urinary, and reproductive.

An Overview of Anatomy and An Overview of Anatomy and

Physiology Physiology

• Anatomy is the study of Anatomy the structure of the body.

– Gross anatomy deals with Gross anatomy large or easily observable structures, e.g. bones

– Microscopic anatomy Microscopic anatomy involves much smaller structures, e.g. cells

• Physiology is the study of Physiology the function of body

structures.

• Structure determines

function.

Levels of Structural Organization Levels of Structural Organization

1) 1) Atomic- chemical level, Atomic smallest level.

2) 2) Cellular – smallest unit of Cellular life

3) 3) Tissue – groups of similar Tissue cells with same function.

4) 4) Organ – similar tissue Organ types that perform

specific function.

5) 5) Organ system – group of Organ system organs that perform

similar function.

6) 6) Organism – composed of Organism

organ systems, highest

level.

Organ System Overview Organ System Overview

• Integumentary system Integumentary system

consists of skin that functions to waterproof, protect external surfaces, excrete salts and urea, and contains

temperature, pain, and pressure receptors.

• Skeletal system consists of Skeletal system bones, cartilages, ligaments, and joints that functions to

support the body and produce blood cells.

• Muscular system performs Muscular system

one function to contract or

shorten skeletal muscle.

Organ System Overview Organ System Overview

• Nervous system consists of Nervous system the brain, spinal cord,

nerves, and sensory

receptors which functions in assessing incoming stimuli and in response.

• Endocrine system controls Endocrine system body activities through the release of hormones.

• Cardiovascular system, Cardiovascular system

including the heart and blood vessels, transports blood

which carries oxygen, carbon dioxide, nutrients, wastes,

and hormones throughout

the body.

Organ System Overview Organ System Overview

• Lymphatic system, including Lymphatic system lymphatic vessels, lymph

nodes, and other lymphoid

organs, function to cleanse the blood and house the cells of the immune system.

• Respiratory system, including Respiratory system the lungs, bronchi, and trachea, functions to constantly supply oxygen to and remove carbon dioxide from blood.

• Digestive system, including

the esophagus, stomach, and

the large and small intestines,

functions to break down food

and deliver the products to the

blood.

Organ System Overview Organ System Overview

• Urinary system, including Urinary system the kidneys, ureters, and bladder, functions to

remove nitrogen containing wastes from the blood and maintain salt balance.

• Reproductive system Reproductive system functions to produce

offspring in both the male

system of scrotum, penis,

and accessory glands and

female system of ovaries,

ova, and uterus.

Chapter 1 The Human Body: An Chapter 1 The Human Body: An

Orientation Orientation

Continued

Be Able To Be Able To

• Define homeostasis and explain the role of negative and positive feedback mechanisms to homeostasis.

• Use proper anatomical terminology to describe body directions, surfaces, and body planes.

• List the survivals needs of humans ant the functions that humans must perform to maintain life processes.

• Locate and identify the chief organs in the major body cavities.

Key Terms

Key Terms : movement, responsiveness, digestion, metabolism, excretion, reproduction, growth, nutrients,

homeostasis, receptor, effector, negative feedback, positive feedback, homeostatic imbalance, sagittal section, midsagittal section, frontal section, coronal section, transverse section, cross section, dorsal body cavity, spinal cavity, ventral body cavity,

thoracic cavity, and abdominopelvic cavity.

Maintaining Life Maintaining Life

• Organ systems work together to promote the well being of the body.

• From cells to the skin, living organisms maintain maintain

boundaries

boundaries from the internal and external environments.

• Movement includes all the Movement activities promoted by the muscular system, such as in swimming, biking, and running.

• The nervous system has the main responsibility of

responding to stimuli, e.g. pain

stimulus, breathing stimulus.

Maintaining Life Maintaining Life

• In the complex human body, food must be broken down into macromolecules for transport into cells.

• Metabolism or the sum of all chemical reactions in the body is chiefly regulated by the

endocrine system.

• Several organ systems

participate in the removal of

nonuseful substances known as excretion

excretion.

• All cells grow and multiply in number and the production of offspring happens at the cell

level and at the organismal level.

Survival Needs Survival Needs

• Nutrients taken in by the diet Nutrients contain the chemical building blocks required for life, e.g.

proteins, lipids, minerals.

• Oxygen is required for survival as Oxygen it is needed to release energy

from foods.

• Water accounts for 60 to 80% of Water body weight provides a fluid base for excretion and secretion.

• A body temperature body temperature of 37

C is maintained for an efficient

metabolism and is generated mostly from the skeletal system.

• Breathing and the exchange of O

and CO

depend on atmospheric atmospheric pressure.

pressure.

Homeostasis Homeostasis

• Homeostasis is a state of body Homeostasis equilibrium or stable internal environment of the body.

• The body is in homeostasis when its needs are being adequately met and its functions run

smoothly.

• All homeostatic control

mechanisms have at least 3 components: receptor, control receptor, control

center, and effector.

center, and effector.

• Negative feedback Negative feedback mechanisms

mechanisms cause the stimulus to decline or end, e.g. blood

pressure

• Positive feedback mechanisms Positive feedback mechanisms enhances the stimulus, e.g. birth

• Homeostatic imbalance occurs Homeostatic imbalance

when homeostasis is disturbed.

The Language of Anatomy The Language of Anatomy

• To prevent misunderstanding, anatomists have accepted a set of terms that allow body

structures to be located and identified clearly with few words.

• The body is in correct anatomical position

anatomical position when the body is erect with feet parallel and the arms hang at the sides with the palms facing forward.

• Directional terms allow medical Directional terms personnel to explain exactly

where one body structure is in relation to another.

• When a cut or section section is made through the body wall or organ it can be done in 3 types of

imaginary lines or planes that lie planes at right angles to each other:

– sagittal, frontal or coronal,

transverse or cross section.

Body Cavities

Body Cavities • The human body has two sets of body cavities that protect the organs within them.

• Dorsal cavity is comprised of the Dorsal cavity cranial and spinal cavity.

• Ventral body cavity contains all of Ventral body the structures in the chest and

abdomen.

• The ventral body cavity is divided into the thoracic cavity and the thoracic cavity abdominopelvic

abdominopelvic cavity by the diaphragm.

– The abdominopelvic cavity is

often divided into 4 equal regions called quadrants for study. Fig quadrants 1.8a

• The abdominopelvic cavity can be further subdivided into the

abdominal

abdominal and pelvic cavity. pelvic cavity

• Anatomists also divide the

abdominal cavity into 9 regions by 4 regions

planes. Fig. 1.8b