Pgs. 5-25

Anatomy (ana-”up” tomos – “cutting”)

- the study of the structure of an organism and the relationship of its parts

Physiology (physis–“nature” logos – “study of”)

-the study of the functions of the body

Studying both the body parts(anatomy) and how they function(physiology) with each other are important when trying to understand the body as a living and integrated whole.

For example; see how the anatomy and physiology of the heart pump your blood to the rest of your body

Although all living things share a common set of characteristics the following are specific to the human body.

However, simply put, all living things are self-organizing and self-maintaining where as non-living things are not.

1. Responsiveness- sensing, monitoring, and responding to changes in environment

2. Conductivity- capacity conduct electricity or heat

3. Growth – increase in size or number of cells

4. Respiration – absorption, utilization, or exchange of gasses (O2 and CO2)

5. Digestion – breaking down complex food into simpler substances that can be utilized by the body

6. Absorption – movement of nutrients to cells

7. Secretion – production and delivery of certain substances like hormones to the rest of the body

8. Excretion – removal of wastes

9. Circulation – movement of body fluids with in the body

10. Reproduction – formation of a new individual or new cells

Smallest to Largest

Atoms Molecules Organelle

Cell Tissue Organ Organ System

Organism

There are 11 main organ systems that make up the human body.

Although we will study each individual system in detail later, it is important to understand they all ultimately work together as the human body.

Integumentary

System

• Main Organ – Skin

• Function- protection, temperature regulation, sensation

Skeletal System

• Organs – Bones/ Ligaments

• Function – support, protection, movement, fat storage, blood production

Muscular System

Organs- Muscles/ Tendons

Function – movement, posture, heat production

Nervous System

Organs – Brain, Spinal cord, Nerves, sensory organs

Function – Control, regulation and coordination of other sensations, memory

Endocrine System

Organs- pituitary gland, adrenals, pancreas, thyroid, other glands

Function- control and regulation of other systems

Cardiovascular

system

Organs – Heart, arteries, veins, capillaries

Function- Exchange and transport of materials

Lymphatic System

Organs- Lymph nodes, lymphatic vessels, spleen, tonsils, thymus

Function- Immunity, fluid balance

Respiratory System

Organs- Lungs, bronchial tree, trachea, larynx, nasal cavity

Function- gas exchange, acid-base balance

Digestive System

Organs - Stomach, small and large intestine, esophagus, liver, mouth, pancreas

Function – Breakdown and absorption of nutrients, elimination of wastes

Urinary System

Organs - Kidneys, ureters, bladder, urethra

Function – Excretion of waste, fluid and electrolyte balance, acid-base balance

Reproductive System

Organs –

Female- Ovaries, fallopian tubes, uterus, vagina, breasts

Males- Testes, vas deferens, prostate, seminal vesicles, penis

Function – reproductions, continuation of genetic information, nurturing of offspring

Anatomical Position

When discussing the body or the relating of one part to another, we always assume to body is in a specific position known as anatomical position

In this position the body is in standing posture, arms to the side, palms turned forward, and both head and feet are pointed forward.

Bilateral symmetry refers to any organism that the right and left sides are mirror images of each other.

An important feature of organisms with bilateral symmetry is balanced proportions

Body Cavities

Ventral – composed of the thoracic cavity and the abdominopelvic cavity

Dorsal- composed of the cranial and spinal cavities

The thoracic cavity or chest cavity houses the following organs

Lungs

Heart

Trachea

Bronchi

Esophagus

Thymus gland

It is separated from the abdominopelivc cavity by the diaphragm

The following organs are contained in the abdominopelvic cavity:

Liver Gallbladder Stomach Pancreas Intestines Spleen Kidneys Ureters Bladder Reproductive organs

BODY REGIONS

The body as a whole can be subdivided into two major portions:

Axial – along the middle (or axis of the body)

Appendicular – arms, legs and appendages

Superior – toward the head “upper” Inferior – toward the feet “lower”

Anterior – Front Posterior – Back

Medial – toward the middle Lateral – toward the side (away from the middle)

Proximal – toward the closest trunk of the body Distal – away from the trunk of the body

Superficial – near the surface Deep – Far from the surface

Body Planes divide the body into sections along an invisible axis called a plane.

The three main planes are:

Sagittal – lengthwise from front to back. Divides body into right and left

Coronal – lengthwise from side to side. Divides front from back

Transverse – crosswise; divides body from upper and lower parts

Homeostasis – homoios – “the same” stasis – “standing”

The relative constancy of the normal body’s internal environment.

It is the maintenance of relative constant internal conditions despite changes in either internal or external environment.

This is the body’s ability to “self-regulate”

Homeostasis is maintained by the body by two main mechanisms; positive and negative feedback

Signals are sent to and from different parts of the body to regulate these system

Afferent signals – are signals traveling toward a particular point of reference

Efferent signals - are signals moving away from a particular point of reference

This is a system that inhibits or opposes a change in homeostasis.

These loops are responsible for stabilization and maintaining a constant internal environment.

They oppose a change (like a drop in external temp.) by creating a response ( producing heat by shivereing)

Does not operate to help maintain homeostasis, can sometimes be harmful to the body.

These loops amplify or reinforce the change that is occurring.

Positive feedback loops stimulate the body to increase the change.

They will continue to accelerate the process until something stops it.

Examples of “good” positive feedback loops are blood clotting, birth of a baby, or an immune response to infection