HUBS 1403 Biomedical Science Part 1 Notes

Introduction to Biomedical Science

• HUBS 1403: Biomedical Science Part 1, focusing on the whole person.
• Principles of Anatomy and Physiology: Using the 2nd Asia-Pacific Edition by Tortora et al.

Levels of Organisation

• Molecular Level:
  • Atoms: Basic units of matter (e.g., C, H, O, N, P).
  • Molecules: Combinations of atoms (e.g., DNA).
• Cellular Level:
  • Cells: The basic structural and functional units of an organism (e.g., Smooth muscle cell).
  • Cell Biology.
• Tissue Level:
  • Tissues: Groups of similar cells performing specific functions (e.g., Smooth muscle tissue).
• Organ Level:
  • Organs: Structures composed of two or more different tissues with specific functions (e.g., Stomach).
    • Examples: Epithelial tissue, connective tissues, smooth muscle tissue layers.
• System Level:
  • Organ Systems: Groups of organs working together (e.g., Digestive system).
    • Examples of Digestive System Components: Mouth, salivary glands, pharynx, esophagus, stomach, small intestine, large intestine, liver, gallbladder, pancreas.
• Organismal Level:
  • Organism: An individual living being.
• Ecological Levels:
  • Populations: Groups of one species.
  • Ecosystems: Communities of different species.
  • Biosphere: All ecosystems combined.

Human Body Systems

• Integumentary System
• Skeletal System
• Muscular System
• Nervous System
• Endocrine System
• Circulatory System
• Lymphatic System
• Respiratory System
• Digestive System
• Urinary System
• Reproductive System

Integration of Body Systems

• Body systems are interconnected and work together
• Examples of Interacting Systems:
  • Integumentary, Circulatory, Digestive, Respiratory, Nervous, Endocrine, Urinary, Musculo-skeletal, and Reproductive systems.
• Hollow organs' interiors (e.g., digestive tract) are part of the external environment.

Themes in Physiology

• Structure and function are closely related.
• Molecular interactions are crucial.
• Compartmentation is important for organization.
• Energy transfer, storage, and use are fundamental.
• Information flow coordinates body functions.
• Homeostasis maintains internal stability.

Course Information

• Course Coordinator: A/Prof Phil Jobling (phillip.Jobling@newcastle.edu.au).
• Other Lecturers: Dr Melissa Tadros and Dr Daniel Beard.
• Teaching Support Unit: 49212058.
• Course Code: HUBS1403 – Biomedical Science I.

Recommended Core Reading

• Principles of Anatomy & Physiology, 3rd Asia Pacific Edition.

Additional Resources

• Fundamentals of Anatomy & Physiology: https://usq.pressbooks.pub/anatomy/
• Library databases for free textbooks and resources.
• Recommended Database: https://www-clinicalkey-com-au.ezproxy.newcastle.edu.au/
  • Suggested textbooks: Berne and Levy Physiology (7th ed.), Guyton and Hall Textbook of Medical Physiology (14th ed.), Banes Medical Biochemistry (6th ed.).

Canvas

• Canvas URL: https://canvas.newcastle.edu.au
• Course Materials:
  • Course outline (timetable, assessment, contacts).
  • Lecture notes and recordings.
  • Online assessments.
  • Practice tests.
  • Announcements.
  • Discussion Board.
• Ensuring access to Canvas is crucial.

Assessment

• Assessment dates are in the Course Outline.
• Reminders: Add assessment dates to your diary or calendar.

Workload

• Expected workload: 140 hours/semester = 10 hours/week per course.
• University policy: 120-140 hours of effort (contact and non-contact) per 10-unit course.
• Full-time study: 4 courses = 40 hours per week total study time.
• Seek advice: If external commitments hinder study time, contact the program convenor.
• Success: Possible for everyone with sufficient time for reading, note-taking, and practice questions.
• Caution: Avoid binge-watching lectures and cramming.

Adverse Circumstances

• Mid-semester & formal exams: use the online system.
• Documentation: Ensure medical certificates match impacted dates.
• Outside work: Generally not a sufficient reason to miss a test; communicate exam timetable to employer.
• Elite athletes: Must be registered with the University's elite athlete program for allowances.

Extra Help

• Help link on Canvas: https://canvas.newcastle.edu.au/courses/18359/pages/help
• Student Support Services: Assistance and encouragement, including free counseling.
• Disability support: Support for students with special needs; recommendations to course coordinator.
• Academic difficulties: Inform the course coordinator promptly.

Progress Feedback

• Practice Quizzes
• Mid-semester exam(s)
  • Score; Review of difficult questions
• Individual feedback appointments are available

Homeostasis and Terminology

• Introduction to Homeostasis and Terminology
• Using Principles of Anatomy & Physiology, 2nd Asia-Pacific Edition by Tortora et al.

A New Language

• Learning new words in a first-year science/physiology course is like learning a foreign language.
• Many terms are based on standard language rules (stem words).

Terminology

• Understanding nomenclature in physiology aids in understanding new terminology.
• Learn basic phrases in the local language.

Terminology Building Blocks

• Prefixes, root words, and suffixes are used to build and understand terminology.

Terminology Examples

• Unicyclist: Prefix (uni-), root word (cycle), suffix (-ist).
• Cardiology: Combining form (cardi/o), suffix (-logy).
• Polyneuropathy: Prefix (poly-), combining form (neur/o), suffix (-pathy).
• Gastroenterologist: Combining form #1 (gastr/o), combining form #2 (enter/o), suffix (-ologist).
• Hematology.
• Intravenous.
• Hyperthyroidism.

Medical Dictionary

• Recommended: Oxford Concise Medical Dictionary (10th ed.).
• Available as ebooks through the library.

Terminology Table

• Prefixes and Suffixes (examples):
  • hypo- (Meaning: below)
  • hyper- (Meaning: above)
  • -cyte (Meaning: cell)
  • -phobic (Meaning: fear)
  • -philic (Meaning: attraction)
  • -pathy (Meaning: disease)
  • glyc- (Meaning: sugar)
  • -lysis (Meaning: breakdown)
  • macro- (Meaning: large)
  • -megaly (Meaning: enlargement)
  • inter- (Meaning: between)
  • -itis (Meaning: inflammation)
  • intra- (Meaning: within)
  • -ium (Meaning: structure)
  • poly- (Meaning: many)
  • -genesis (Meaning: origin)

Homeostasis

• Using Human Anatomy & Physiology by Marieb & Hoehn (Pearson International Edition).

Homeostasis Objectives

• Define homeostasis.
• Understand the relationship between internal and external environments.
• Describe components of a feedback system.
• Contrast negative and positive feedback systems.
• Understand consequences of homeostatic failure.

Defining Homeostasis

• Homeostasis: Maintaining a stable internal environment.
• Achieved by balancing inputs and outputs.
• Homeo: like or similar, stasis: condition.

Body Fluids

• Intracellular fluid (ICF): Within cells.
• Extracellular fluid (ECF): Outside body cells; the internal environment.
• Precise regulation is essential.

Fluid Compartments

• Locations of intracellular fluid and extracellular fluid (interstitial & plasma).

Composition of ECF Regulated Variable

• Normal Ranges or Values
  • Core Body Temperature: $37^{\circ}C$
  • [H+] or pH: 7.35-7.45
  • [K+]: 3.5-5.0 mmol/L
  • [Ca+]: 2.2-2.7 mmol/L
  • [Blood glucose]: 70-110 mg/dl
  • Blood volume: 5 L
  • Mean arterial pressure: 93 mmHg
  • Arterial O2 levels: 75-100 mmHg
  • Arterial CO2 levels: 34-45 mmHg
  • [ ] denotes concentration

Homeostatic Regulation

• Involves the nervous system and endocrine system.
• Regulation through negative feedback.

Components of a Homeostatic Feedback System

• Receptor (sensor): Monitors a physiological variable and detects changes.
• Control center: Integrates information from the receptor, comparing the monitored value with the acceptable range.
• Effector: Returns the monitored value within limits of normal range.

Temperature Regulation

• An example of negative feedback
• Receptors: Temperature-sensitive cells in the skin and brain
• Control Center: Thermoregulatory center in the brain
• Effectors: Sweat glands
• Process:
  • Stimulus: Body temperature rises
  • Information sent along the afferent pathway to the control center
  • Information sent along the efferent pathway to effectors
  • Sweat glands activated
  • Response: Evaporation of sweat causes body temperature to fall; stimulus ends

Regulation of Blood Pressure

• Negative Feedback Loop:
  • Stimulus: Produces change in variable (Imbalance)
  • Receptor (sensor): Detects change
  • Input: Information sent along afferent pathway to control center
  • Output: Information sent along efferent pathway to activate effector
  • Response of the effector feeds back to influence magnitude of stimulus and returns variable to homeostasis.

Feedback Control

• Negative feedback: Reverses the effect of the original stimulus; maintains conditions that require frequent monitoring; long term.
• Positive feedback: Amplifies effect of original stimulus; associated with infrequent, short-term processes; minor role in maintenance of homeostasis.

Negative Feedback Control - Regulated Variables

• Values and Ranges
  • Core Body Temperature: $37^{\circ}C$
  • [H+] or pH: 7.35-7.45
  • [K+]: 3.5-5.0 mmol/L
  • [Ca+]: 2.2-2.7 mmol/L
  • [Blood glucose]: 70-110 mg/dl
  • Blood volume: 5 L
  • Mean arterial pressure: 93 mmHg
  • Arterial O2 levels: 75-100 mmHg
  • Arterial CO2 levels: 34-45 mmHg
  • Note: [ ] denotes concentration

Blood Clotting

• Example of positive feedback
  1. Break or tear occurs in blood vessel wall.
  2. Damaged cells release chemicals. Positive feedback cycle is initiated.
  3. Platelets adhere to site and release chemicals.
  4. Released chemicals attract more platelets. Positive feedback loop.
  5. Platelet plug forms.
  6. Feedback cycle ends when plug is formed.

Consequences of Homeostatic Failure

• Physiological parameters drift outside normal ranges.
• Disease may affect a tissue, organ, or system.
• Changes occur throughout the body (processes integrated).
• Death.

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Building Blocks of Life

• What is matter?
• Using Principles of Anatomy & Physiology, 2nd Asia-Pacific Edition by Tortora et al.

Let's Build a Person

• Physiology (HUBS1403/1404), Population health.

Atoms

• Smallest component of an element that retains its properties.
• Unique properties due to number of protons, neutrons, and electrons.

Atoms Interaction

• Hydrogen and oxygen atoms have unique properties that shape all life on earth.
• Oxygen atoms possess 8 positive protons and 8 negative electrons.
• Electrons exist at various distances from the nucleus.
• The electrons in the outer shell give each atom specific properties.
• Individual oxygen atoms are unstable and try to gain an electron in their outer shell.
• Usually, they share electrons with another atom.
• Hydrogen atoms possess 1 proton and electron.
• Hydrogen behaves opposite to oxygen. It is more stable if it can lose or donate its electron to another atom.

Water

• Electrons are shared unequally spending more time closer to oxygen. This gives the whole water molecule a “polarity” where the oxygen side is partially negative, and the hydrogen side is partially positive.
• This gives water properties like no other liquid. It also has implications for whole-body water balance as water and things dissolved in water need to move from the gut to the blood to the tissues to the cells.

Water Properties

• Unequal sharing of electrons.
• Electrons spend more time orbiting the oxygen nucleus – Small –ve charge.
• Electrons spend less time orbiting the hydrogen nucleus – Small +ve charge.

Polar Covalent Bonds Facilitate Hydrogen Bonds

• Hydrogen bond: The attraction between a small +ve charge on the H atom of a polar covalent bond and a small -ve charge on a neighboring atom of another polar covalent bond.

Hydrogen Bonds

• The attraction between a small +ve charge on the H atom of a polar covalent bond and a small -ve charge on a neighboring atom (usually O or N) of another polar covalent bond. This is really important in setting the “3d shape” of a molecule.
• Weak attractive force – Between adjacent molecules
• Properties of water e.g. surface tension – Too weak create molecules – Can be within the same molecule

Other Atoms

• Main Chemical Elements in the Body
  • Oxygen (O): 65.0% - Part of water and many organic molecules; used to generate ATP.
  • Carbon (C): 18.5% - Forms backbone chains and rings of all organic molecules.
  • Hydrogen (H): 9.5% - Constituent of water and most organic molecules; ionized form (H+) makes body fluids more acidic.
  • Nitrogen (N): 3.2% - Component of all proteins and nucleic acids.
  • Calcium (Ca): 1.5% - Contributes to hardness of bones and teeth; ionized form (Ca2+) needed for blood clotting, hormone release, muscle contraction.
  • Phosphorus (P): 1.0% - Component of nucleic acids and ATP; required for normal bone and tooth structure.
  • Potassium (K): 0.35% - Ionized form (K+) is the most plentiful cation in intracellular fluid; needed to generate action potentials.
  • Sulfur (S): 0.25% - Component of some vitamins and many proteins.
  • Sodium (Na): 0.2% - Ionized form (Na+) is the most plentiful cation in extracellular fluid; essential for maintaining water balance; needed to generate action potentials.
  • Chlorine (Cl): 0.2% - Ionized form (Cl) is the most plentiful anion in extracellular fluid; essential for maintaining water balance
  • Magnesium (Mg): 0.1% - Ionized form (Mg2+) needed for action of many enzymes.

Anions and Cations

• Atoms that lose electrons:
  • Are electron donors
  • Become cations
  • possess a net positive charge
  • e.g Na+
• Atoms that gain electrons
  • Are electron acceptors
  • become anions
  • possess a net negative charge
  • e.g Cl-
• Electrical attraction b/n cations & anions = ionic bonds

Organic and Inorganic Compounds

• Organic Compounds contain carbon
  • many polymers, including all plastics
  • carbohydrates, lipids, nucleic acids and proteins.
  • characteristic of living organisms.
• Inorganic Compounds Not of biological origin
  • Do not contain carbon atoms but exceptions:
    • Oxides of carbon e.g CO2, CO
    • Carbonates & bicarbonates e.g H2CO3
    • Cyanide & cyanates e.g. NaCN
  • Include water, oxygen, nitrogen, carbon dioxide, salts, acids, bases
  • essential for life

Key Points

• We introduced an important concept of how atoms interact to form molecules through their outer shell electrons. We will build on this when we talk about more complex molecules (carbohydrates, proteins, fats, bone)
• We introduced a very important concept of how hydrogen atoms through “hydrogen bonds” can determine the shape of a larger molecule. You will need this to understand how drugs, hormones and neurotransmitters work. We will revisit hydrogen bonds when we talk about proteins and DNA
• We introduced some of the other atoms that make a person
• We talked about anions and cations. We will talk a lot more about those later. Especially when we talk about the various components of your plasma.