Necessities for Lifeand

Body Regions

The 8 necessary life functions for all organisms:

1. Maintaining Boundaries2. Movement3. Responsiveness4. Digestion 5. Metabolism6. Excretion 7. Reproduction8. Growth

Maintaining Boundaries

• Why do we need to maintain boundaries?

• What organ system allows us to maintain boundaries?

Movement

• Why is movement important?

• What body systems allow us to have movement?

Responsiveness

• Explain why responsiveness helps us stay alive.

• What systems are involved in responsiveness?

Digestion

• What does digesting food provide our bodies?

• Note: Cells are “digestion factories” that further digest absorbed nutrients.

Metabolism

• Once food is ingested (taken in) what does metabolism do for us?

• What two organ systems are involved in metabolism?

Excretion

• Why is excretion useful?

• Why do we want to get rid of waste?

• What organ systems are involved?

Reproduction

• Why do we want to reproduce at the organismal level?

• Why do we want to reproduce at the cellular level?

Growth

• What is necessary for growth to occur?

Survival Needs

• Nutrients: Used for energy and cell building– Carbohydrates = energy– Proteins and fats= building cell structures– Fats= cushion organs and are fuel storages– Vitamins and minerals= for chemical reactions

• Oxygen: chemical reactions require oxygen to occur. Human cells cannot survive without oxygen.

Survival Needs Cont…

• Water (universal solvent): ~60-80% of body weight. Necessary for chemical reactions to occur.

• Body Temperature: Must be maintained around 98F. If body temp. decreases too low metabolic reactions get slower. If body temp. too high proteins denature (unravel).

At both extremes death can occur!!

Survival Needs Cont….

• Atmospheric Pressure: Allows for even exchange between oxygen (O2) and carbon dioxide (CO2) in lungs.

– At high atmospheric pressures (high altitudes) air becomes too thin and adequate gas exchange may not be possible.

Homeostasis

• 3 Control Factors– Receptor

– Control Center (hypothalamus)

– Effector

How do they work together?

2 types of Feedback Mechanisms

Negative Feedback• Most Common type• Response of receptor is to

do the opposite of the original stimulus.

• Used in regulating heart rate, glucose (sugar) blood levels, oxygen, carbon dioxide, minerals, body temperature, etc.

Positive Feedback• Least Common Type• Response of receptor is to

amplify original stimulus.

• Used mainly during pregnancy (contractions) and blood clotting.

Anatomical Position

• Body erect, feet slightly apart, palms facing forward, thumbs point away from body

Figure 1.7a

Anterior (ventral)*

Toward or at the front of the body; in front of

The breastbone is anterior to the spine

Posterior (dorsal)*

Toward or at the back of the body; behind

The heart is posterior to the breastbone

Orientation and Directional Terms

Superior vs. Inferior

• Superior: Towards the head– The shoulder is superior to the stomach

• Inferior: Away from head– The ankle is inferior to the knee.

*Whereas the terms ventral and anterior are synonymous in humans, this is not the case in four-legged animals. Ventral specifically refers to the "belly" of a vertebrate animal and thus is the inferior surface of four-legged animals. Likewise, although the dorsal and posterior surfaces are the same in humans, the term dorsal specifically refers to an animal's back. Thus, the dorsal surface of four-legged animals is their superior surface.

dorsal

ventral

anterior(cranial) posterior

(caudal)

Medial Toward or at the midline of the body; on the inner side of

The heart is medial to the arm

Lateral Away from the midline of the body; on the outer side of

The arms are lateral to the chest

Intermediate Between a more medial and a more lateral structure

The collarbone is intermediate between the breastbone and shoulder

Proximal Closer to the origin of the body part or the point of attachment of a limb to the body trunk

The elbow is proximal to the wrist

Distal Farther from the origin of a body part or the point of attachment of a limb to the body trunk

The knee is distal to the thigh

Used For Appendages!!

Superficial (external)

Toward or at the body surface

The skin is superficial to the skeletal muscles

Deep (internal)

Away from the body surface; more internal

The lungs are deep to the skin

Body Cavities

Labeled Body Cavities

Abdominopelvic Regions

Abdominopelvic Quadrants

Terms to Memorize