General Anatomy and Physiology Chs 1, 2, & 3

Freshman Nursing Semester 1

Anatomy

focuses on structure; what body parts and where they are located

Physiology

focuses on function; how body parts work to sustain life

Anatomy and Physiology

structure determines function, and function demands influence on structure

Gross (Macroscopic) Anatomy

study of structures visible to the naked eye

G(M)A: Surface Anatomy

external landmarks

G(M)A: Regional Anatomy

specific body area (thorax, abdomen)

G(M)A: Systemic Anatomy

organ systems (skeletal, muscular)

Microscopic Anatomy

study of structures not visible to the naked eye

MA: Cytology

cells

MA: Histology

tissues

Developmental Anatomy

structural changes from fertilization to adulthood

DA: Embryology

first 8 weeks post-fertilization (most critical period for development)

Specialized Branches

anatomy of specific subjects

SB: Pathological Anatomy

disease-related structural changes

SB: Radiographic Anatomy

imaging (X-ray, CT, MRI)

Cell Physiology

functions of cells

Systemic Physiology

functions of organ systems

SP: Neurophysiology

functions of the nervous system

SP: Cardiovascular Physiology

functions of the cardiovascular system

SP: Respiratory Physiology

functions of the respiratory system

Pathophysiology

functional changes due to disease

Exercise Physiology

responses to physical activity

Comparative Physiology

comparisons across species

Structural Organization: 1. Chemical Level

atoms and molecules (water, proteins, DNA)

Structural Organization: 2. Cellular Level

cells—smallest living units

Structural Organization: 3. Tissue Level

groups of similar cells with common functions

Structural Organization: 4. Organ Level

two or more tissues working together

Structural Organization: 5. Organ System Level

related organs with major functions

Structural Organization: 6. Organismal Level

the complete human body

Structural Organization hierarchy

disruption at a lower level affects all higher levels

Homeostasis

the body’s ability to maintain a stable internal conditions within narrow limits despite external changes

Homeostasis is Maintained

1. Maintained by coordinated cellular and organ system activity

2. Essential for survival

Set Point

1. The normal target value for a physiological variable

2. body temperature around 37 C (98.6 F)

Receptor (sensor)

detects changes (stimuli)

Control Center

compares value to set point and determines response (often the brain or endocrine gland)

Effector

produces a response to restore balance

Negative Feedback (Most Common)

1. response reverses the original stimulus

2. maintains stability

Positive Feedback

1. response amplifies stimulus

2. pushes system away from homeostasis temporarily

3. always self-limiting and ends with a specific event

3 Examples of Positive Feedback

1. Childbirth

2. Blood clotting

3. Breastfeeding (milk ejaculated from breasts)

Ionizing Radiation

higher risk, high structural detail

Non-Ionizing

safer for repeated use

X-Ray

Mechanism: differential absorption of electromagnetic radiation

Best for: bone fractures, chest imaging

Limitations: poor soft-tissue contrast; radiation exposure

CT (Computed Tomography)

Mechanism: rotating X-ray source creates cross-sectional images reconstructed volumes

Best for: trauma, internal bleeding, complex fractures

Limitations: higher radiation dose

MRI (Magnetic Resonance Imaging)

Mechanism: magnetic alignment of hydrogen nuclei

Best for: brain, spinal cord, ligaments, soft tissues

Limitations: time-consuming, expensive, contraindicated with some implants

Ultrasound

Mechanism: reflection of high frequency sound waves

Best for: fetal monitoring, cardiac imaging, abdominal organs

Limitations: poor imaging through bone or air

PET (Positron Emission Tomography)

Mechanism: detection of metabolically active tissues using radioactive tracers

Best for: cancer detection, brain metabolism studies

Limitations: radiation exposure; limited anatomical detains (often paired with CT)

Scientific Method

structured, logical process used to investigate natural phenomena and solve biological problems

SM: 1. Observation

identify a question or phenomena

SM: 2. Hypothesis

form a testable explanation

SM: 3. Experimentation

Design controlled experiments

SM: Data Collection & Analysis

measure, analyze, and interpret results

SM: Conclusion

support or refute hypothesis

SM: Communication

share findings through reports or publications

Science is iterative, meaning

new evidence can refine or overturn conclusions

Medical science depends on

accurate evidence-based information (use good sources)

Trustworthy Sources

1. Peer reviewed

2. reputable organizations

3. written by qualified experts

4. citations provided

blogs with no evidence = red flags

Human Body =

chemical system

Physiological processes depend on …

atomic and molecular interactions

Protons

positive charge, nucleus

Neutrons

neutral, nucleus

Electrons

negative charge, orbit nucleus

Molecule

two or more atoms bonded together (O2)

Compound

molecule composed of different elements (H2O, and O2)

Cations

positive charge

Anions

negative charge

Electrolytes

1. nerve impulse conduction

2. muscle contraction

3. fluid balance

Synthesis

A+B=AB (building)

Decomposition

AB=A+B (breaking down)

Exchange

AB + CD = AD + CB

Properties of Water

1. polar molecule with hydrogen bonding'

2. universal solvent'

3. high heat capacity

4. high heat of vaporization

Biological Roles of Water

1. makes up ~ 70% of adult body weight

2. lubricates joints and organs

3. cushions organs (brain, fetus)

4. regulates body temperatures

water’s properties make life possible

Dehydration Synthesis

builds up polymers by removing water

Hydrolysis

breaks polymers by adding water

Synthesis Reactions

control digestion, macromolecule formation, and metabolism

pH

measure of hydrogen ion concentration

Acids

release H+

Bases

accept H+ or release OH-

Buffers

1. resist changes in pH

2. maintain blood pH between 7.35-7.45

Acidosis

pH < 7.35 (respiratory failure, metabolic disorders)

Alkalosis

pH> 7.45 (excessive vomiting, hyperventilation)

Homeostatic Imbalances

even small pH changes can be life-threatening

Organic Molecules

1. carbohydrates

2. lipids

3. proteins

4. nucleic acids

Inorganic Molecules

-water, salts, acids, bases

-many contain either hydrogen or carbon, not both

Metabolism

sum of all chemical reactions in the body

Anabolism

builds molecules; requires energy

Catabolism

breaks down molecules; releases energy

Metabolic Balance

essential for growth, repair, and surivival

Chemical

energy stored in bonds (ATP)

Electrical

nerve impulses

Mechanical

muscle movement

Radiant

UV light (vitamin D synthesis)

Energy transformations

maintain homeostasis and life

Plasma Membrane Barrier

selective barrier (selectively permeable)

Plasma Membrane Major Components

1. Phospholipid bilayer (hydrophilic head face outwards; hydrophobic tail face inwards)

2. Membrane proteins (integral and peripheral; transport, receptors, enzymes)

3. Cholesterol (stabilizes membrane and maintains fluidity)

4. Carbohydrates/glycocalyx (cell recognition and immune signaling)

Selectively Permeable

allowing controlled exchange of substances

Passive Transport (No ATP Needed)

movement occurs down the concentration gradient

PT: Simple Diffusion

• small, nonpolar, lipid-soluble molecules

• ex: O2, CO2

PT: Facilitated Diffusion

• large, polar, or charged substances

• requires channel or carrier proteins

• ex: glucose transporters, ion channels

PT: Osmosis

• diffusion of water across a semipermeable membrane

• often occurs through aquaporins

• water moves toward the area with higher solute concentration

Osmosis and Tonicity: Isotonic

equal solute concentration; cell maintains normal shape