Download The Study of Body Function

The Study of Body Function
Chapter 1
Overview
Introduction to physiology – scientific method
Homeostasis and feedback control
The primary tissues
Organs and systems
Introduction
Physiology is the study of function of body or body parts.
Emphasis is on cause and effect mechanisms
These mechanisms were improved over time by using scientific method.
Most of the times these mechanisms are based on homeostasis.
Homeostasis is maintaining internal conditions within limits different from ambient (immediate)
environment.
Scientific Method
Scientific Method: Science develops by
1) discovering new things, processes, and phenomena
2) asking right question/s
3) developing explanations = hypotheses and testing them repeatedly until all wrong ones are
eliminated.
Main steps include:
Observation, Question, Hypothesis, Predictions, Experiment,
Control – (similar to experiment but lacks variables; helps to eliminate other hypotheses),
Conclusions and Theory.
Conclusions result from supported or rejected hypotheses.
Different hypotheses tested by many workers can lead to a general principle of science = Theory.
Experimental group and control group, peer reviewed journals
Development of pharmaceutical drugs
Experiments on cells or tissues in vitro.
Testing on animal models (rats or mice)
Clinical testing is done on humans
Phase 1 – healthy humans to know toxicity
Phase 2 – target group with disease, to know effectiveness
Phase 3 – at large scale in many centers wide population groups; seek approval of FDA
Phase 4 – drug tested for other uses
Homeostasis-a defining feature of physiology
Homeostasis are dynamic mechanisms
Homeostasis operates by self-regulatory feedback mechanisms
Components of Homeostatic mechanism
A. Reflex – neural and chemical
pathways
Receptors, 2. Integrating Center and 3. Effectors
Physiological Variable, stimulus, Set point, balance of inputs and outputs
B. Local Homeostatic Responses
Organization levels
Organization Levels: Body parts range from cells  tissues
 organs organ
-systems
 Body
Intercellular Chemical Messengers
Intercellular communication is essential to reflexes and local responses.
Neurotransmitters, hormones, and paracrine or autocrine agents act as chemical messengers
Internal Conditions
3 Important Body Fluid Compartments representing internal conditions
ICF = Intracellular Fluid is present inside cells
Tissue fluid = IST = Interstitial Fluid surrounds cells in tissues and organs
Plasma is the fluid part of blood and runs through arteries, veins and capillaries
Chapter 1 Recap 1
1. Intracellular fluid occurs in spaces ---------------------.
2. Interstial fluid occurs in spaces ------------ ---------3. ------------ is the liquid part of blood.
4. Molecules  --------  tissues  ---------  organ-system  ------5. Homeostasis maintains ----------- --------- within limits.
6. Most abundant fluid in body (28L) is -----------7. 2nd most abundant fluid in body (11L) is ------------8. The component that restores set point value is --------------9. The component that observes the change in variable is ------------10. The component that compares the value to set point --------- --------11. In homeostasis absolute values do not matter but the balance of ------------ and ------------.
12. In scientific method ---------- leads to a question and ----------- possible explanation to find
general principle.
The primary tissues
Epithelial Tissues – surface forming - membranes
Connective tissues – anchor and support
Muscular tissues – contraction, movements
Nervous tissues – excitation, rapid communication
11 Organ-Systems of Body
Learn the parts and main functions of each system.
Integumentary System
Skeletal System
Muscular System
Nervous System
Endocrine System
Cardiovascular System
Lymphatic System
Respiratory System
Digestive System
Urinary System
Reproductive System – male and female
Organ-Systems 1
Integumentary System has Skin, hair and nails
Protection, thermoregulation, and sensation
Skeletal System has bones, cartilages, joints and ligaments
Support, protection, movements and forms new blood cells
Muscular System has skeletal muscles and tendons
Movements, posture, heat generation
Nervous System has brain, spinal cord and nerves
Fast acting Control system, rapid internal communication, coordination, motor control, sensation
Endocrine System has ductless glands - pituitary, thyroid, thymus, adrenal, testes and ovaries
Secrete hormones to regulate metabolism, growth and reproduction
Cardiovascular System has heart, arteries, veins and capillaries
Distribution of nutrients, oxygen, hormones, antibodies and heat
Organ-Systems 2
Lymphatic System has thymus, spleen, lymph nodes and vessels
Returns leaked fluid from blood vessels, production of immune cells
Respiratory System has nose, pharynx, larynx, trachea, bronchi, lungs
Procures oxygen, discharge of CO2, and speech
Digestive System has mouth, pharynx, esophagus, stomach, large intestine and small intestine,
anus; liver and pancreas
Breakdown and absorption of nutrients
Urinary System has kidneys, ureters, urinary bladder, and urethra
Elimination of urea, maintain balance of water, pH and electrolyte
Reproductive System - Male has testes, vas deferens, prostate gland, penis; production and
delivery of sperm, production of hormones
Reproductive System - Female has ovaries, uterine tubes, uterus, and vagina
Production of eggs, development of fetus, production of hormones
Recap 2 Chapter 1
1. ---- system is responsible for rapid communication and coordination.
2. ----anchors and support other tissues.
3. Epithelial tissue forms surface covering --------, and ----by infolding.
4. ----system returns leaked blood from capillaries.
5. ----tissue has tightly packed cells with little intercellular spaces.
6. ----tissue has lot of formless intercellular matter with fibers.
7. We classify connective tissues on the basis of density of ------.
8. Local acting chemical messenger include ---- and ---- messengers.
9. Hormones are secretions of -----glands and always travel through ---.
10. Distribution of nutrients and oxygen is done by ---- system.