BE 202- Chapter 1

Introduction to Physiology and Homeostasis

Physiology

the study of the functions of living thing

Levels of Organization in the Body

Chemical, Cellular, Tissue, Organ, Body system, Organism

Chemical Level

Various atoms and molecules make up the body

Cellular Level

• Cells are the basic units of life

• tissues, organs, body systems and the whole body body

Basic Cell Functions

• Obtaining nutrients and O2

• Performing chemical reactions

• Elimination wastes

• Synthesizing proteins and cell components

• Moving materials throughout the cell

• Responding to the environment

• Reproducing

  • except nerve cells and muscle cells

Specialized Cell Functions: Digestive System

Gland cells secrete enzymes that break down ingested food

Specialized Cell Function: Kidneys

Epithelial cells selectively retain or eliminate substances

Specialized Cell Function: Muscle cell

produce muscle movement

Specialized Cell Function: Nerve cells

Generate and transmit electrical impulses that relay information

Tissue

groups of cells with similar structure and specialized function

4 types of Tissue

Muscle tissue, skeletal, cardiac, and smooth muscle

Muscle tissue

skeletal, cardiac and smooth muscle

Nervous tissue

initiate and transmit electrical impulses

Epithelial tissue

selective transfer material s between the cell and environment

Connective tissue

connects, supports, anchors various body parts

Two Types of Epithelial tissue

epithelial sheets and secretory glands

Two categories of secretory glands

exocrine and endocrine

Gland Formation

Example of Exocrine gland

Sweat gland, Salivary gland

Example of endocrine gland

Pancreas

Organ Level

made up of several tissue types; consists of two or more primary tissue types organized to perform particular functions

Body System

a collection of organs that performs related functions

11 body systems

Circulatory, Digestive, Respiratory, Urinary, Skeletal, Muscular, Integumentary, Immune, Nervous, Endocrine, Reproductive

Circulatory System

• heart, blood vessels, and blood

• Transports nutrients, O2, CO2, waste, electrolytes and hormones throughout the body

Digestive System

• mouth, pharynx, esophagus, stomach, intestines

• breaks down food into small nutrient molecules and transfers them into the blood plasma

Respiratory System

• Lungs and major airways

• Receives O2 and eliminates CO2

Urinary System

• Kidneys and associated structures

• Kidneys filter wastes and extra water from blood and make urine

• Urine travels from the kidneys through the ureters and fills the bladder

Muscular system and Skeletal system

• Support and protect organs

• allow body movement

Muscular System

generate heat and are important in maintaining body temperature

Skeletal Systems

storage reservoirs for calcium

Integumentary System

• skin and related structures

• the outer protective barrier

• regulated body temperature

Immune System

• white blood cell and lymphoid organs

• defend Bacteria, Viruses

• Help replace injured or worn-out cells

Nervous system

• Brain, spinal cord, nerves and sense organs

• controls and coordinates body activities

• pathway for communication

Endocrine System

• All hormone-secreting glands

• Regulated activities that require duration rather than speed

Reproductive System

• essential for perpetuating the species

• not essential for homeostasis

Homeostasis

dynamic steady state in the internal environment

Intracellular Fluid (ICF)

fluid contained within cells

Extracellular Fluid (ECF)

fluid outside the cells

Plasma

the fluid portion of blood

Interstitial fluid

surrounds the cells

Factors to maintain homeostasis

• Concentration of nutrients

• Concentration of O2 and (acid forming) CO2

• Concentration of waste products