Human Physiology - PSL223 Quiz

Course Information

• Course title and code: Human Physiology - PSL223
• Credit hours: 3 hours (2+1)
• Offered in: Public Health and Nursing
• Prerequisites:
  • 1st year (Basic Foundation course)
  • Biology course in first year II semester

Course Objectives

• Identify physiological terminology
• Understand human body structure (chemical, cellular, tissue, organ, system levels)
• Demonstrate understanding of homeostasis mechanisms
• Plan, perform, and interpret physiological functions
• Explain pathophysiological bases of common diseases

Course Assessment

• Quiz (MCQs): 5% (any week before 1st midterm)
• 1st Midterm Theory Exam (MCQs): 15% (7th week)
• 1st Midterm Theory Exam (Spotting, True/False, Fill in the blanks): 15% (8th week)
• 2nd Midterm Theory Exam (MCQs): 15% (11th week)
• Assignment: 10% (12th week)
• Final Practical Exam (Spotting, True/False, Fill in the blanks): 15% (after 15th week)
• Final Theory Exam (MCQs, TF, Fill in the blanks, essay): 25% (after 15th week)

Learning Resources

• Ross and Wilson's "Anatomy and Physiology in Health and Illness" 12th Edition; ISBN 978-0-7020-5325-2, International ISBN 978-0-7020-5326-9. (Pages 4-7)
• Arthur C. Guyton, update, Textbook of Medical Physiology, W.B. Saunders Company. 2010.
• List of Essential References Materials (Journals, Reports, etc.):
  • John B., Respiratory physiology, The William & Wilkins Company
  • Cecil Gray John Nunn and J.E. Uttering, General Anesthesia, Butterwirths (pages 32-45)

What is Physiology?

• The scientific study of normal functions of living organisms

Branches of Physiology

• Human physiology
• Cellular physiology
• Cardiovascular physiology
• Renal physiology
• Respiratory physiology
• Gastrointestinal physiology
• Neurophysiology
• Muscular physiology
• Endocrine physiology

Levels of Organization of the Body

• Chemical
• Cellular
• Tissue
• Organ
• System
• Human

Organ Systems

• Lists organ systems with their roles
  • Endocrine
  • Nervous
  • Musculoskeletal
  • Cardiovascular
  • Respiratory
  • Urinary
  • Gastrointestinal
  • Reproduction
  • Immune
  • Integumentary

Organization of the Body: The Cell

• Cell: The smallest structural and functional unit of living organisms
• Cytology: The science of cells as fundamental units of living things

Organization of the Body: The Cell - Plasma Membrane

• Outer boundary that separates intracellular from external environment
• Selective barrier for passage of substances
• Role in cellular communication

Functions of Membrane Proteins

• Ion channels
• Transporters (Carrier proteins): transport molecules through the membrane
• Receptors: cellular recognition (ligand binds)
• Enzymes: catalyze chemical reactions
• Cell Identity markers

Cytoplasm - Components

• Cytosol: Fluid portion (mostly water) in the cell
• Organelles: Subcellular structures with specific functions

Organelles: Nucleus

• Spherical/oval structure (usually prominent)
• Nuclear envelope: double membrane separating nucleus from cytoplasm
• Nuclear pores: control movement between nucleus and cytoplasm
• Nucleolus: produces ribosomoes
• Chromosomes: contain hereditary units (genes)

Organelles: Mitochondria

• Known as "powerhouses" of the cell
• Double membrane (inner and outer mitochondrial membranes)
• Cristae: folds of inner membrane
• Matrix: central fluid-filled cavity
• Responsible for ATP generation through cellular respiration

Organelles: Ribosomes

• Sites for protein synthesis
• Tiny granules composed of RNA and protein
• Synthesize proteins from amino acids

Organelles: Endoplasmic Reticulum

• Network of membranes (flattened sacs or tubules)
  • Rough ER: connected membrane system, studded with ribosomes, involved in protein synthesis
  • Smooth ER: a continuous network, not studded with ribosomes, synthesizes lipids and steroids

Organelles: Golgi Complex

• Sacs called cisternae
• Packages and processes proteins for transport to different destinations
• Proteins are transported in vesicles
• Important in cells that synthesize and export proteins

Organelles: Lysosomes

• Vesicles formed from Golgi complex
• Contain digestive enzymes
• Break down fragments of organelles and large molecules (e.g., RNA, DNA, carbohydrates, proteins)

Organelles: Cytoskeleton

• Extensive network of protein fibers
• Microfilaments: smallest fibers (e.g., actin in muscle cells)
• Microtubules: larger, maintain cell shape, involved in organelle and chromosome movement

Tissue

• Tissues: Group of cells similar in structure and function
• Histology: Branch of science that studies structure and functions of body tissues

Types of Tissues

• Epithelial (covers and lines body surfaces)
• Connective (supports and connects organs)
• Muscle (contraction and movement)
• Nervous (initiates and transmits nerve impulses)

Development of Tissues

• Tissues develop from three primary germ layers: Ectoderm, Endoderm, and Mesoderm

Epithelial Tissues

• Cells arranged in continuous sheets
• Covering and lining of body parts
• Classified by arrangement and cell shape (e.g., simple squamous, simple cuboidal, simple columnar, stratified squamous)
  • Major functions: Protection, secretion, absorption

Glandular Epithelium

• Formed from epithelium Categorized into:
  • Exocrine glands: produce secretion into ducts (e.g., sweat, oil, saliva)
  • Endocrine glands: produce hormones released into blood

Muscular Tissue

• Elongated cells (muscle fibers, myocytes)
• Classified into three types
  • Skeletal muscle
  • Cardiac muscle
  • Smooth muscle

Nervous Tissue

• Two types of cells are found in the nervous system:
  • Exitable cells (neurons): Initiate, conduct, receive, and transmit information
  • Non-excitable cells (glial cells): support neurons

Connective Tissue

• The most diverse tissue type
• Characterized by extracellular matrix
• Examples: Bone, Tendons, Fat, Blood

Body Fluid Compartments

• Internal environment: fluid surrounding cells (Extracellular Fluid - ECF)
• 70-kg man: Total body water (42 liters); with intracellular fluid (ICF) and extracellular fluid (28 L), with plasma (3 liters) and interstitial fluid (11 liters).

Homeostasis

• Ability to maintain relatively constant internal environment
• Conditions regulated include temperature, volume, composition
• Negative feedback loop (variable changes in one direction, causing a response to correct change).

Homeostasis: Terms

• Set point: The expected value of a regulated variable (e.g., body temperature, blood glucose level, blood pH)
• Error signal: Difference between the current value and the set point of the regulated variable, that triggers a reaction.
• Important homeostatic parameters which are controlled by negative feedback: Temperature, Volume, and Composition

Homeostasis: Components

• Receptors: detect changes in the environment (e.g., thermoreceptors, chemoreceptors, baroreceptors)
• Integrating centers: process information from receptors to effectors to maintain homeostatic balance (e.g., brain).
• Effectors: carry out actions that restore homeostasis (e.g., muscles and glands)
• Signals: Allow components to communicate (e.g., chemical signals such as hormones, or nerve signals)

Homeostasis: Thermoregulation

• Mechanisms of heat transfer between the body and environment: Radiation, Conduction, Evaporation, Convection

Thermoregulation: Components

• Receptors: thermoreceptors (central and peripheral)
• Effectors: sweat glands, skeletal muscles, smooth muscles of vessels.
• Integrating center: thermoregulatory center in the hypothalamus.
• Signals: nerve impulses via neurons and chemicals via hormones

Thermoneutral Zone

• Range of outside temperatures where body temperature is regulated by blood flow alone (25-30°C)

Fever

• Rise in core body temperature that accompanies infection
• White blood cells secrete pyrogens; resulting in body temperature set point increase
• Enhanced immune response

Test your understanding of key concepts in Human Physiology covered in the PSL223 course. This quiz will assess your knowledge on physiological terminology, body structure, and homeostasis mechanisms. Prepare to explain common pathophysiological bases of diseases.