Doom and Despair A&P

Six levels of structural organization in the human body (simplest to most complex)

Chemical → Cellular → Tissue → Organ → Organ system → Organismal

Chemical level of organization

Atoms, molecules, and organelles

Structures that make up the integumentary system

Hair, skin, and nails

Vitamin synthesized by the integumentary system

Vitamin D

Receptors housed in the integumentary system

Cutaneous receptors, such as receptors for pain and pressure

Structures that make up the skeletal system

Cartilage, bones, and joints

Major functions of the skeletal system

Protects and supports body organs and provides a framework that muscles use to cause movement

Structures that make up the muscular system

Skeletal muscles and tendons

Major functions of the muscular system

Allows manipulation of the environment, locomotion, and facial expression; maintains posture; produces heat

Structures that make up the nervous system

Brain, spinal cord, and peripheral nerves

How the nervous system responds to changes

Responds to internal and external changes by activating appropriate muscles and glands

Major organs/glands of the endocrine system

Pituitary gland, thyroid gland, pancreas, adrenal glands, testes, and ovaries

Processes regulated by endocrine hormones

Growth, reproduction, and nutrient use (metabolism) by body cells

Structures that make up the cardiovascular system

Heart and blood vessels

Substances transported by blood

Oxygen, carbon dioxide, nutrients, wastes, and other substances

Structures that make up the lymphatic system

Thymus, lymph nodes, spleen, and lymphatic vessels

Fate of fluid leaking from blood vessels

Picked up by the lymphatic system and returned to the blood

Structures that make up the respiratory system

Nasal passage, trachea, and lungs

Major functions of the respiratory system

Keeps blood supplied with oxygen and removes carbon dioxide

Location of gaseous exchange

Through the walls of the air sacs of the lungs

Structures that make up the digestive system

Stomach, liver, gallbladder, large intestine, and small intestine

Main function of the digestive system

Breaks down food into absorbable units that enter the blood for distribution to body cells

Structures that make up the urinary system

Kidneys and urinary bladder

Waste eliminated by the urinary system

Nitrogenous wastes

Three parameters regulated in the blood by the urinary system

Water, electrolyte, and acid-base balance

Structures of the male reproductive system

Epididymis and testes

Structures of the female reproductive system

Mammary glands, ovaries, and uterus

Six necessary life functions

Organization, metabolism, responsiveness, movement, growth, and reproduction

Meaning of organization as a life function

Separation between internal and external environments

Structure separating cells from their external environment

Plasma membrane

Structure separating an organism from its external environment

Skin

Metabolism

All chemical reactions that occur in body cells

Catabolism

Breakdown of molecules

Anabolism

Synthesis/building of molecules

Responsiveness

Ability to sense and respond to stimuli

Five survival needs

Nutrients, water, oxygen, normal body temperature, and appropriate atmospheric pressure

Function of the sensor/receptor in homeostasis

Monitors a physiological value and reports homeostatic imbalance to the control center

Function of the control center in homeostasis

Receives input from the sensor, processes the information, and sends output to the effector

Function of the effector in homeostasis

Receives instructions from the control center and acts to return the value to the normal range

Sequence of a homeostatic control mechanism

Sensor detects → Control center processes → Effector responds

Negative feedback

Mechanism that reverses a change in the body's physiological condition

Positive feedback

Mechanism that intensifies a change in the body's physiological condition

Two examples of positive feedback

Blood clotting and labor contractions

Catabolism vs. Anabolism

Catabolism = breakdown of molecules; Anabolism = building/synthesis of molecules

Sensor vs. Control center vs. Effector

Sensor detects; Control center processes; Effector responds

Skeletal vs. Cardiac vs. Smooth muscle in movement

Skeletal = body parts; Cardiac = blood; Smooth = digestion/urination

Structural organization sequence

Chemical → Cellular → Tissue → Organ → Organ system → Organismal

Matter

Anything that has mass and occupies space

Mass

Amount of matter contained in an object

Weight

Mass plus the effects of gravity

Element

A substance that cannot be broken down into simpler substances by ordinary chemical methods

Composition of matter

Elements

Four elements making up $96\%$ of human body mass

Oxygen, carbon, hydrogen, and nitrogen

Percentage of body mass made up of oxygen

$$65\%$$

Percentage of body mass made up of carbon

$$18.5\%$$

Percentage of body mass made up of hydrogen

$$9.5\%$$

Percentage of body mass made up of nitrogen

$$3\%$$

Atom

Smallest particle of an element that retains the unique properties of that element

Three subatomic particles

Protons, neutrons, and electrons

Charge of a proton

Positive ($+$)

Mass of a proton

$$1\,\text{amu}$$

Charge of a neutron

No charge ($0$)

Mass of a neutron

$$1\,\text{amu}$$

Charge of an electron

Negative ($-$)

Approximate mass of an electron

$$0\,\text{amu}$$

Location of protons and neutrons

In the nucleus

Location of electrons

Orbiting around the nucleus

Subatomic particle composition of hydrogen

$1$ proton, $0$ neutrons, $1$ electron

Subatomic particle composition of helium

$2$ protons, $2$ neutrons, $2$ electrons

Subatomic particle composition of lithium

$3$ protons, $4$ neutrons, $3$ electrons

Atomic number

The number of protons in the nucleus

Information provided by atomic number in a neutral atom

The number of protons and electrons

Reason why atoms are electrically neutral

Equal numbers of positive protons and negative electrons

Mass number

The number of protons $+$ neutrons in the nucleus

What mass number represents

Total mass of the atom

Contents of the periodic table

All known elements

Isotopes

Structural variations of the same element containing different numbers of neutrons

Difference between isotopes of the same element

Same number of protons, different numbers of neutrons

Atomic number comparison among isotopes

They have the same atomic number

Mass number comparison among isotopes

They have different mass numbers

Electron shells

Areas around the nucleus where electrons are located

Maximum electron capacity for most electron shells

$8$ electrons

Maximum electron capacity of the first electron shell

$2$ electrons

Factor determining the precise number of electron shells

Number of electrons in the atom

Valence shell

Outermost electron shell

Primary determinant of an atom's reactivity

Number of electrons in its valence shell

Octet rule

Atoms tend to desire $8$ electrons in their valence shell

Exceptions to the octet rule

Smaller atoms such as hydrogen and helium (need only $2$ electrons in the first shell)

Reason atoms gain, lose, or share electrons

To achieve a stable valence shell (generally with $8$ electrons)

Result of chemical combination of most atoms

Formation of molecules and compounds

Molecule

General term for $2$ or more atoms bonded together

Possibility of a molecule containing only one type of atom

Yes (e.g., $H_2$, $O_2$)

Compound

Specific molecule containing $2$ or more different kinds of atoms

Is $H_2$ a compound?

No, because it contains only one type of atom

Is $C_6H_{12}O_6$ a compound?

Yes, because it contains multiple types of atoms

Ion

An atom that has gained or lost electrons and possesses an electrical charge

Difference between an ion and a neutral atom

An ion has an unequal number of protons and electrons

Event occurring during ionic bonding

Valence electrons are transferred from one atom to another

Anion

Negatively charged ion formed when an atom gains electrons

Cation

Positively charged ion formed when an atom loses electrons