Principle Structures and Processes

• Presenter: Cky Davies

• Course Code: HP401

• Institution: Prifysgol Wrecsam

• Contact: ky.davies@wrexham.ac.uk

Learning Outcomes

• Recognise medical terminology and life science principles related to healthcare

• Identify anatomical structures and components of the human body

• Describe physiological functions and mechanisms of the human body

• Summarise the human growth process and changes throughout the lifespan

• Explain pathophysiological changes due to common illnesses, diseases, injuries across life

Session Overview

• Key Structures: Cells, Tissues, Fluid compartments, Genetic material

• Functions and Processes: Homeostasis, Energy metabolism, Cell cycle

Cell Structure

• Organelles include:

  • Rough Endoplasmic Reticulum

  • Smooth Endoplasmic Reticulum

  • Mitochondria

  • Ribosomes

  • Golgi Apparatus

  • Nucleus, including the nucleolus and chromatin

  • Lysosomes

  • Cytoplasm

  • Plasma Membrane

  • Centrosome and Centrioles

Cell Activity

• Key Structures and Functions:

  • Nucleus: Control center of the cell

  • Mitochondria: Powerhouse of the cell

  • Ribosomes: Protein synthesis

  • Endoplasmic Reticulum: Protein and lipid synthesis

  • Golgi Apparatus: Modifies and packages proteins

  • Lysosomes: Breakdown of waste materials

  • Cytoskeleton: Provides structure to the cell

  • Plasma Membrane: Protects cell and regulates entry/exit of substances

Tissues

• Defined as a group of similar cells working together

• Major Types of Tissues:

  • Epithelium: Covers body surfaces, variety of shapes

  • Connective Tissue: Most abundant, provides support and binding

  • Muscle Tissue: Facilitates movement

  • Nervous Tissue: Conducts impulses and supports neurons

Epithelium

• Functions:

  • Covers body surfaces, organs, cavities

  • Protects underlying structures

  • Types based on cell shape: Squamous, Cuboidal, Columnar

  • Organization: Simple (single layer) vs. Stratified (multiple layers)

Connective Tissue

• Characteristics:

  • Most diverse and abundant tissue type

  • Functions: Binding, support, transportation, insulation

  • Types: Loose tissue, Adipose, Lymphoid, Blood, Cartilage, Bone

Blood

• Function: Circulates throughout the body

• Composed of: Plasma, blood cells, platelets

  • Delivers oxygen, nutrients, removes waste

Blood Composition

• Plasma (55% of blood volume): Contains majority of liquid substances

• Cell Types:

  • Erythrocytes: Red Blood Cells, transport oxygen

  • Leukocytes: White Blood Cells, immune defense

  • Platelets: Involved in clotting

Muscle Tissue

• Characteristics: Contracts and relaxes for movement

• Types:

  • Skeletal Muscle: Voluntary control

  • Smooth Muscle: Involuntary, found in walls of hollow organs

  • Cardiac Muscle: Involuntary, heart muscle

Nervous Tissue

• Neurons: Conduct impulses, respond to stimuli

• Neuroglia: Support and protect neurons

Fluid Compartments

• Types:

  • Intracellular Fluid (ICF): Fluid inside cells

  • Extracellular Fluid (ECF): Includes interstitial fluid and plasma

Genetic Material: DNA

• Deoxyribonucleic Acid, contains genetic instructions

• Composed of: Bases Adenine, Thymine, Guanine, Cytosine

Chromosomes

• Located in cell nucleus, tightly coiled structures

• Human cells usually have 23 pairs (46 chromosomes total)

• Chromatin condenses into chromosomes during cell division

Genes

• Segments of DNA that carry genetic information for proteins

• A gene influences a specific trait or characteristic

Homeostasis

• Definition: Maintenance of stable internal conditions despite external changes

• Examples: Temperature regulation, pH balance

Negative Feedback System

• Mechanism by which the body counteracts changes to maintain homeostasis

• Involves:

  • Stimulus: Conditions change

  • Sensor: Detects changes

  • Control Center: Processes information and initiates response

  • Effector: Carries out actions to restore balance

Energy Production

• Macromolecules: Proteins, Carbohydrates, Fats yield energy

• Key Processes: Kreb’s cycle, Oxidative phosphorylation for ATP production

Cell Division

• Two Types:

  • Mitosis (2 identical daughter cells) occurs in somatic cells

  • Meiosis (4 non-identical gametes) occurs in sex cells

Gene Expression

• Process of how genes are used to produce proteins

• Influenced by environmental factors

Cellular Aging

• Factors impacting aging:

  • Cellular clock, DNA damage, oxidative stress

  • Results in deterioration and apoptosis (programmed cell death)

Summary

• Understanding genetic material, organelles, tissues and their functions is critical in life sciences

• The metabolism of nutrients and cellular processes are governed by gene expression

Reading Recommendations

• McArdle, W. D., Katch, F. I., & Katch, V. L. (2015)

• Waugh, A. & Grant, A. (2022)