Zhikal O. Khudhur/Assist lecturer _____________________________________________ Human physiology– 2 nd Stage /1 st Semester [email protected] https://tiu.edu.iq/ 2021 - 2022 TIU - Faculty of Science Medical Analysis Department Lec.1: Human Physiology
Welcome message from author
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
Zhikal O. Khudhur/Assist lecturer_____________________________________________Human physiology– 2nd Stage /1st Semester
https://tiu.edu.iq/
2021 - 2022
TIU - Faculty of ScienceMedical Analysis Department
Lec.1: Human
Physiology
Introduction
Introduction to Physiology
Levels of Organization
Characteristics of Life
Homeostasis Model
Structure and Function
Anatomy
Investigates the structures of the body
What they are made of
Where they are located
Associated structures
Physiology
Investigation of the processes or functions of living things
Functions of anatomical structures
Individual and cooperative functions
4What is Physiology?
• Physiology: biological sciences
• dealing with the normal life phenomena
exhibited by all living organisms.
• Human physiology: basic sciences
• dealing with normal life phenomena of the
human body.
• Goal of physiology:
• explain the physical and chemical factors
that are responsible for the origin,
development and progression of life.
II. Levels of Organization
The Chemical (or Molecular) Level
Atoms are the smallest chemical units
Atoms combine to form molecules
Molc. form organelles
The Cellular Level
Smallest functional unit of an organism
All cells are similar in some ways
Cells are a group of atoms, molecules, and organelles
working together
II. Levels of Organization
The Tissue Level
Tissues are a groups of similar cells working together
to produce a common function
Four types:
Epithelial tissue-covers the surface of the body and lines
cavities
Muscle tissue-provides movement
Connective tissue- connects tissues, supports and protects
body organs
Nervous tissues-rapid communication throughout body
II. Levels of Organization
The Organ Level
An organ is a group of different tissues working
together composed of at least 2 tissue types usu. 4
though
The Organ System Level
Organ systems are a group of organs working
together to perform a certain function
Humans have 11 organ systems
The Organism Level
Comprised of all structural levels working together to
keep us alive
© 2013 Pearson Education, Inc.Figure 1.1 Levels of structural organization.
Slide 7
Atoms Molecule Organelle
Smooth muscle cell
Chemical levelAtoms combine toform molecules.
Cellular levelCells are made upof molecules.
Smooth muscle tissue
Cardiovascular system
Heart
Bloodvessels
Tissue levelTissues consist ofsimilar types of cells.
Blood vessel (organ)
Smooth muscle tissue
Connective tissue
Organ levelOrgans are made up of different typesof tissues.
Organismal levelThe human organism is madeup of many organ systems.
Organ system levelOrgan systems consist of differentorgans that work together closely.
Epithelialtissue
III. Characteristics of Life
Maintain Boundaries
Inside/outside
Integument & cell membranes
Movement
Muscles & circ. of body fluids
Responsiveness
Sense changes in environment & respond
Withdrawal reflex or homeostatic
feedback mechanism (CO2)
Digestion
Breakdown & absorb nutrients from GI tract blood
III. Characteristics of Life
Metabolism
All chemical reactions that occur
in our cells
Catabolism-breaking down
reactants to smaller products
(sucrose glu + fru)
Anabolism-adding reactants to
build up a larger product
(enzyme)
Cellular Respiration/Metabolism-
production of ATP for work
Regulated by hormones
III. Characteristics of Life
Excretion
Excrete waste products such as CO2,
urea, and fiber
Reproduction
Cellular repro.-cell divides into two
identical daughter cells for growth and
repair
Organismal repro.-produces a new
individual through sexual reproduction
Growth
Increase in size of cell and/or number of
cells
III. Characteristics of Life
Factors required for
our survival:
Nutrients
Oxygen
Water
Normal body temp.
Appropriate
atmospheric
pressure
Internal Environment and Homeostasis
Interstitial fluid
Blood Plasma
Intracellular fluid
Total body water = 60 % BW
= 40 % BW
Extracellular fluid
2/3
1/3
1/5
4/5
1
4 Internal environment
Extracellular fluid directly baths body cells
Internal environment = Extracellular fluid
Plasma
Interstitial fluid
Intracellular
fluid
Extracellular fluids
Intracellular
fluid
2. Plasma
1. Interstitial fluid
3. Fluid of special compartments:
pericardial fluid, pleural fluid, cerebrospinal fluid
Homeostasis
Homeostasis
“Unchanging”
Maintaining a relatively stable internal
environment, regardless of external
conditions.
Allows changes within narrow limits.
“Dynamic Equilibrium”
Homeostasis & Controls
•Successful compensation
•Homeostasis reestablished
•Failure to compensate
•Pathophysiology
•Illness
•Death
Homeostasis
Mechanisms of Regulation
Autoregulation/ Intrinsic Regulation
Automatic response in a cell, tissue, or organ to
some environmental change
Extrinsic regulation
Responses controlled by nervous and endocrine
systems
1
9 Regulation of the Body Functions
Regulation- the ability of an organism to
maintain a stable internal conditions in a
constantly changing environment
Three types:
1. Chemical (hormonal) Regulation
2. Nervous Regulation
3. Autoregulation
2
0 Chemical (hormonal) Regulation
a regulatory process performed by hormone or active chemical substance in blood or tissue. response slowly
acts extensively
lasts for a long time.
2
1 Nervous Regulation
a process in which body functions are
controlled by nerve system Pathway: nerve reflex
Types: unconditioned reflex and conditioned
reflex
Example: baroreceptor reflex of arterial
blood pressure
Characteristics:
response fast
acts exactly or locally
last for a short time
2
2 Autoregulation
a tissue or an organ can directly
respond to environmental changes
independent of nervous and hormonal
control
Characteristics：
Amplitude of the regulation is smaller than
other two types.
Extension of the effects is smaller than
other two types.
2
3 Control System in the Human Body
Feedback Control
Feedback: Output (feedback signal) from
controlled organ returns to affect or modify
the action of the control system.
Feedback control mechanism consists of
two forms:
Negative feedback control.
Positive feedback control
Stimulus
Sensor
Integrator
Effector
Response
Result
All homeostatic feedback loops
have the same steps:
Regulation of Homeostasis
Negative Feedback System
Common
Reverses Change
Results in Fluctuations about Set Point
Examples?
Positive Feedback System
Rare
Change is amplified
Examples?Feed forward System
Neg. Feedback Homeostatic Mechs
Set point: the ideal normal value of a
variable What is your body temperature set point?
Error: values that are still normal values
that are not the “set point” There is a normal range of values OR
“ERROR” for any homeostatic feedback
system in the body
What are some error values for our body
temperature?
Stimulus
Sensor
Integrator
Effector
Response
Result
Deviation from the set point. This
error is measured by the sensor
Receptor that senses change in
stimulus
Compares signal coming in to “set
point” —usually a part of the brain
Usually an organ or tissue
Change that occurs
Result due to change
Homeostatic Feedback Loops
Stimulus
Sensor
Integrator
Effector
Response
Result
Increase in body temperature
thermoreceptors in the skin &
hypothalamus
Hypothalamus
Skin blood vessels and sweat glands
Blood vessels in skin vasodilate release
heat from surface
Sweat glands in skin release heat as sweat
Decrease in body temperature
Body Temperature Homeostasis
Negative feedback
The feedback signals from controlled
system produces effect opposite to the
action of the control system.
The opposite effect is mainly “inhibitory
action”.
Negative Feedback: Inhibitory.
Stimulus triggers response to counteract further change in the
same direction.
Negative-feedback mechanisms prevent small changes from
becoming too large.
Disturbance of Homeostasis
Physiological systems work to restore
balance
Disturbance-failure to maintain
homeostasis (balance) that results in
disease or death.
Can you think of a disturbance for body
temperature?
Blood glucose
http://jazdb2b.files.wordpress.com/2009/07/blood-testtube-inline.jpg
• 70-110 mg/dl blood
• Cellular respiration ATP
• Brain function
• Pancreas (Islet of Langerhans)
http://www.theholisticcare.com/cure%20diseases/Images/Pancreas.jpg
www.histol.chuvashia.com/im
ages/digestive/pancreas
blood glucose (120 mg/dl)
b-cells of Isl. of Lang.
Body cells, adipose, liver and
skeletal muscle
Liver and skeletal muscle uptake
glucose glycogen
Blood Glucose Homeostasis
Insulin in blood
blood glucose (110 mg/dl)
www.histol.chuvashia.com/im
ages
Stimulus
Sensor
Integrator
Effector
Response
Result
Blood Glucose Homeostasis
Disturbance
(i.e. Diabetes
melitus)
Positive feedback
The feedback signal or output from the
controlled system increases the action of the
control system
Examples:
Blood clotting
Micturition
Defecation
Na+ inflow in genesis of nerve signals
Contraction of the uterus during childbirth
(parturition)
3
6 Positive Feedback: Stimulatory.Stimulus trigger mechanisms that amplify the response and reinforces the stimulus.
Example 3:
Is this a negative
feedback system or
positive feedback
system?
How do you know?
3
8 Importance:
Enhance the action of original
stimulus or amplify or reinforce
change
promote an activity to finish
can lead to instability or even death
3
9 Feed-forward control
Concept: Direct effect of stimulus on the
control system before the action of
feedback signal occurs.
Disturb signal or interfere signal.
Example: Shivering before diving into the
cold water
4
0 Feed-forward control
Significance of Feedback-forward :
adaptive feedback control.
makes the human body to foresee and
adapt the environment promptly and
exactly
(prepare the body for the change).
Related Documents
