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Human Physiology Overview

Course Details

  • Instructor: Dr. Ripley

  • Grading: Exams, quizzes, class participation with iClicker

  • Attendance required

  • Course materials available on eCampus including syllabus, PowerPoint slides, quizzes, and exams

Introduction to Physiology

  • Physiology defined: study of body functions

  • Involves processes from molecular level within cells to organs and systems

  • Examines how the body works

Functions During Reading

  • Comprehensive list of physiological activities during reading:

    • Eye transformation of images into nerve impulses

    • Heart pumps 5 liters of blood to lungs and body per minute

    • 150 million red blood cells die and are replaced

    • Kidneys process blood, producing 1 ml of urine

    • Digestive system processes meals for nutrient delivery

    • Brain processes visual inputs and delivers outputs to maintain posture and movement

    • Breathing rate: 12 breaths, exchanging 6 liters of air

    • Cells consume 250 ml of oxygen and produce 200 ml of carbon dioxide

Levels of Organization:

  1. Chemical Level:

    • Molecules forming cell membranes

  2. Cellular Level:

    • Cells like stomach lining

  3. Tissue Level:

    • Layers of tissue in stomach wall

  4. Organ Level:

    • Example: Stomach

  5. Body System Level:

    • Example: Digestive system

  6. Organism Level:

    • Entire body

Tissue Types

Overview of Major Tissue Types

  • Four main tissue types in the body:

    1. Muscle

    2. Nerve

    3. Epithelial

    4. Connective

Muscle Tissue

  • Muscle contraction is key:

    • Skeletal: Attached to bones, voluntary movement, striated

    • Cardiac: Found in heart, involuntary, unique contraction

    • Smooth: Involuntary, non-striated, in digestive and vascular systems

Nervous Tissue

  • Function: Create and transmit electrical signals

  • Key components: Neurons and neuroglial cells

Epithelial Tissue

  • Functions: Create boundaries, line cavities, form glands

  • Characteristics: Avascular, high cellularity

  • Classifications based on layers and shapes:

    • Simple: Single layer (varying functions)

    • Stratified: Multiple layers, protective roles

    • Examples include simple squamous, cuboidal, and columnar

Connective Tissue

  • Features: Lower cellularity, separated by extracellular matrix (ECM)

  • Types include adipose, cartilage, blood, etc.

Organ Systems

  • Body contains 11 inter-related organ systems

  • Examples: Digestive, Circulatory, Respiratory, Endocrine, Urinary, Muscular

Homeostasis

Definition

  • Homeostasis: Maintenance of a stable internal environment

  • Extracellular fluid (ECF) is the internal environment

Mechanisms

  • Typically achieved through negative feedback loops

  • Example: Calcium regulation via parathyroid glands

Feedback Loops

  • Communication and feedback among organs/systems is crucial

  • Maintains levels near set points through sensors and effectors

Feedback Types

Negative Feedback

  • Action reduces the output/effect of the system

  • Example: Calcium levels regulation

Positive Feedback

  • Enhances or promotes a response

  • Example: Oxytocin release during childbirth