A&P Lecture Topic 1

The human body, food, and meds are all composed of

Chemicals

Anatomical structures are

Chemicals

Physiological processes are based on

Chemical reactions

The 4 most common elements in the body:

CHON: Carbon, hydrogen, oxygen, nitrogen

Atoms composed of:

Protons, neutrons, elections

A proton carries a single:

Positive charge

Neutrons carries;

No electrical charge

Electron carries a single

Negative charge

Nucleus is

Central part of an atom composed of protons & neutrons

Electrons move

Around the nucleus

Chemical bonds form when

Atoms combine with other atoms

What are the rules for atoms with atomic numbers of 18 or less?

1st shell holds up to 2 electrons , The 2nd shell holds up to 8 electrons as well as the 3rd shell

What is an ion?

An atom that gains or loses electrons to become stable ( electrically charged atom)

Cation

Formed when atom loses electrons and is positively charged

Anion

Formed when atom loses electron and is negatively charged

Ionic bonds

Formed when an atom accepts or donates 1 or more of its electrons

Covalent bonds

Created when atoms shares an electron

Hydrogen bond

Attraction between a slight positive charge on hydrogen atom of a polar covalent bond and a slight negative charge on oxygen, nitrogen, or fluorine atom of another polar covalent bond (these bonds are two weak to create molecules but can change shape or pull molecules close together)

Pure covalent (non-polar bond)

Elections are shared equally and are common with 2 same electrons due to similar electronegativity and atom charge is equal on both sides

Polar covalent

Unequal sharing of electrons, one atom stronger has a stronger pull leading to the electron spending more time with said atom

Surface tension

Acts as a barrier that keeps from small objects entering water

The 4 properties of water

Solubility, reactivity, high heat capacity, lubrication

Hydrophilic

Reacts with water

Hydrophobic

Does not react with water

Electrolytes

Releases ions in water. Solutions can conduct an electric current and is inorganic

Acids

Electrolytes that dissociates to release hydrogens in water

Bases

Substances that releases ions that can combine with hydrogen ions

pH

The concentration of hydrogen ions h+ in a solution

Neutral pH

Balance of h+ and OH-, pure water in neutral and has pH of 7.0

Acid pH level

Lower than 7,0 and has high h+ and low OH-

Base pl level

PH higher than 7 and has low h+ and high OH-

Acidosis

Excess h+ in body fluid

Alkalosis

Excess OH- in body fluid

pH of blood

7.35 - 7.45

Anatomy

Structure of the body

Physiology

Function of the Body

6 Levels of organizations from smallest to largest

Chemical, Cellular, Tissue, Organ, Organ system, Organism

Anabolism

Synthesis of new molecules within the body’s cells or tissue

Catabolism

decomposition of complex molecules withon the body’s cells or tissues

Negative feedback (homeostasis)

shuts off original stimulus or reduces its intensity balance in body is reached

positive feedback

amplifies the original stimulus farther until it stops

Homeostasis

is the maintaining of a stable environment

Homeostasis mechanism

monitor aspects of the internal environment and correct them as needed

Receptor

detects and provides information about the stimuli

Control Center

decision-maker that maintains the set point

effector

muscle or gland that responds to the control center, and causes the necessary change in the internal environment

Intrinsic regulation

is a local, automatic adjustment of organs to an environmental change

Extrinsic regulation

nervous and endocrine systems act to regulate organism homeostasis