Human Body Physiology Quiz

Introduction to Human Physiology

• Professor Mitat KOZ is the instructor
• Room: SBF132
• Email: [email protected]
• Course Title: Introduction to Human Physiology
• Course Code: HLTS103

What is Physiology?

• Physiology is the study of how living organisms function
• It examines how the human body works
• Physiology is the study of life
• Physiologists investigate the function and integration of organisms, organ systems, organs, cells, and biomolecules within a living system.

Course Schedule

• Dates and corresponding content covered in the course
• Includes introduction to general principles in medical physiology, cellular physiology, cell membranes, blood physiology, immunity, peripheral nerve, skeletal muscle, cardiovascular, pulmonary physiology etc
• Covers topics like midterm exam weeks, and exam dates

Recommended Resources

• Ganong's Review of Medical Physiology, McGraw-Hill
• Guyton, Arthur C. Textbook of medical physiology, Elsevier Inc.
• Vander's Human Physiology: The Mechanisms Of Body Function, McGraw-Hill
• Koz M., Gelir E., Ersöz G. Fizyoloji Ders Kitabı. Nobel Yayıncılık

Evaluation

• Evaluation is 50% midterm exam grade + 50% final exam grade

Physiology is related with basic sciences

• Physiology is directly associated with biology, chemistry, physics and mathematics

The Body Organized as "Solutions"

• Cells in the body exist within an extracellular fluid (ECF).
• ECF contains necessary materials for cell survival (e.g., O2 and nutrients).
• The ECF's composition is similar to seawater.
• Inside the cells is intracellular fluid (ICF).

Water, Electrolytes, & Acid/Base

• Water (H2O) is an ideal solvent for physiological reactions
• It interacts with other H2O molecules via hydrogen bonds.
• It works as an excellent biological fluid and solute
• Electrolytes are important in body fluids
• Electrolytes in water play a significant role in health

Units for Measuring Concentration of Solutes

• Concentrations of solutes can be expressed in different ways (moles, equivalents, osmoles).
• The number of molecules, electrical charges, and particles per unit volume can be more meaningful.
• Physiologic concentrations are often expressed in moles, equivalents, or osmoles.
• % concentration is used to express the amount of solute in the solvent (grams/100ml)

Physiological Saline or Serum Physiologic

• A sterile sodium chloride solution is considered isotonic.
• Isotonic solutions have equal solute concentration to body fluids.
• These solutions are used as solvents for parenterally administered drugs

Moles

• A mole is the gram molecular weight of a substance (g/mol).
• Millimoles (mmol) represent 1/1000 of a mole.
• The molecular weight of NaCl is 58.5 g

Equivalents

• An equivalent is 1 mol of an ionized substance divided by its valence.
• The general number of equivalents formula is E = MW/charge number.

pH & Buffering

• Maintaining stable hydrogen ion concentration (H+) is crucial for life.
• pH measures the concentration of H+
• The pH of pure water at 25°C is 7.0.
• The normal pH range of blood plasma is 7.35-7.45 (slightly alkaline)

pH & Buffering (molecules)

• H+ donors are acids and H+ acceptors are bases.
• Strong acids dissociate completely in water.
• Most acids and bases in physiology are weak.
• The body's pH is stabilized by buffers.

pH & Buffering (buffers)

• Buffers are substances that can bind or release H+ to maintain stable pH.
• Biologic fluids have multiple buffers.

How Is The Body Organized? (General)

• Understanding the components of the body and their organization is crucial
• Structural (anatomy) and Functional organization should be considered

Biological Organization Levels

• The six organization levels in the human body are: chemical, cell, tissue, organ, system, and organism.

How Is The Body Organized? (Chemical Level)

• The chemical level of organization is the simplest level containing elements and molecules
• Elements are chemical substances that cannot be broken down.
• Molecules are formed when two or more atoms combine.

Major Elements in the Human Body

• Major elements in the human body include hydrogen (H), carbon (C), oxygen (O), nitrogen (N), phosphorus (P), calcium (Ca), sodium (Na), potassium (K), and chlorine (Cl).

Inorganic Compounds

• Inorganic compounds are small and simple compounds in the human body, crucial for establishing water and electrolyte balance and for membrane transport. (e.g., water, salt, HCl, ammonia).

Organic Compounds

• There are four major categories of organic compounds in the human body: carbohydrates, lipids, proteins, and nucleic acids.

Cell Organization

• Cell are the fundamental building block.
• Cells and molecules combine in different ways forming an organism.
• Each cell in an organism has particular features that aid in its specific function.

Tissues

• Tissues form by similar cells
• Different tissues combines to form organs
• Four types of tissue include muscle, nervous, epithelial, and connective tissue.

Epithelial Tissue

• Composed of epithelial cells
• Key roles of epithelial tissue include protection, secretion, absorption, and sensory functions

Epithelial Tissue: Endocrine Glands

• Endocrine glands release hormones directly into the bloodstream to affect the body.
• E.g., adrenal glands

Epithelial Tissue: Exocrine Glands

• Exocrine glands have a channel that secrete material to release material
• E.g.-sweat, saliva glands

Epithelial Tissue: Absorption

• Epithelial cells in kidney tubules reabsorb water
• Another example is absorption tissues in intestine

Epithelial Tissue: Sensory Function

• Specialized epithelial cells in taste buds and the olfactory region of the nose detect tastes and smells

Muscle Tissue

• Muscle tissue is composed of cells specialized for contraction.
• Three types of muscle tissue include skeletal muscle, cardiac muscle, and smooth muscle

Connective Tissue

• Connective tissue supports, protects, stores, and repairs structures of the body.
• Fibroblast cells play role in repairing and regeneration
• Includes Bone, cartilage, blood and lymphatic tissue

Nervous Tissue

• Makes up the nervous system
• Functions to generate and transmit electrical signals throughout the body.
• Neurons and glial cells are part of the nervous tissue

Organs

• An organ is formed when different tissues work together to perform a particular function.
• Organs in the body form systems

Systems

• Systems are composed of different organs to perform a particular task
• Organs work together to form systems (e.g. circulatory, digestive, nervous, musculoskeletal, reproductive, lymphatic & immune, respiratory, urinary)

The Organism

• An organism is the highest level of biological organization.
• It is formed when the systems work together to carry out functions.

Body Fluids (Summary)

• 60% of the human body is fluid.
• This fluid is dilute solutions found in and around cells.
• The majority of the fluid is in ICF, and ECF
• ECF is sub-categorised in Plasma and Interstitial fluid
• Extracellular fluid helps maintain stable internal body conditions

Properties of Extracellular Fluid

• Ions and nutrients in extracellular fluid are essential for cell survival
• Extracellular fluid (ECF) creates a stable internal environment.
• Cells can function as long as proper concentrations of molecules, ions, etc. are maintained

Extracellular Fluid as The Cell's Environment

• Fluid around cells is essential to maintain stable internal conditions (homeostasis)
• Cells depend on this environment for proper function

Importance of Homeostasis

• Homeostasis is crucial for proper function
• Body systems maintain internal stability in response to changes in the internal or external environment
• Homeostasis is maintained via feedback loops

How is Homeostasis Maintained & Controlled?

• Homeostasis is controlled via feedback loops, which are cycles of events to regulate an aspect of the internal environment (e.g., temperature or blood pressure)
• Physiological parameter are monitored and regulated via input, processing and output via feedback mechanism

What is a Feedback Loop?

• Receptors detect changes in a physiological variable
• The control center compares the monitored variable to a set point
• The effector produces a response
• Maintaining homeostasis requires a continual cycle of monitoring, feedback, and response.

Let's use an Air Conditioner as an Example

• Air conditioners use negative feedback loops to maintain a consistent room temperature
• The thermostat acts as the receptor and control center
• The air conditioning unit acts as the effector

Feedback Loops - types (Negative/positive)

• Negative feedback loops counteract a change to maintain an internal equilibrium such as blood pressure
• Positive feedback loops amplify or enhance a change such as contractions during labor or blood clot formation

Negative Feedback Loops in The Body

• Negative feedback loops are common in the body.
• They are essential for maintaining homeostasis in various physiological conditions, like blood pressure, glucose regulation, oxygen regulation etc
• Each system has a particular role

Blood pressure (BP)

• Blood pressure (BP) is regulated by negative feedback loops
• Receptors monitor BP, input to the brain, output back to the blood vessels to regulate

Temperature Regulation

• Body temperature is regulated by negative feedback loops
• Receptors monitor temperature, input to the brain, output (response mechanism) to regulate temp.

When Does a Negative Feedback Loop End?

• Negative feedback processes end when a stimulus or variable is back within its normal range

Positive Feedback Loops in the Body

• Positive feedback loops amplify a change to cause a significant change such as childbirth and blood clotting

What about Positive Feedback?

• Positive feedback loops are less common in maintaining homeostasis
• Positive feedback involves amplifying a change or response beyond baseline

Positive Feedback in Childbirth

• Oxytocin release during childbirth is an example of a positive feedback loop.
• Amplification of the feedback loop pushes labor towards completion

Positive Feedback in Blood Clotting

• Platelets release chemicals during blood clotting
• The chemicals cause more platelets to adhere, thus amplifying the clotting response

Dangerous Positive Feedback

• A dangerous positive feedback loop can occur when the body loses control of a variable, like unregulated body temperature increase which can cause a negative effect such as death/injury

What stops a Positive feedback loop?

• External stimuli that stop the feedback loop