Basic anatomy and physiology

1. Nutritional Physiology
Unit 1
Unit of Life
Introduction to Human Anatomy &Physiology
&Structural organization of body
Dr. Sweta Patel

2. Anatomy and Physiology
Anatomy: is the science of body structures and the
relationships among them. It was first studied by
dissection .
Physiology: is the science of body functions—how the
body parts work

3. Level of organization
Molecules combine
to form cells
epithelial tissue,
connective
tissue, muscular
tissue, and
nervous tissue
organs are structures that are
composed of two or more
different types of tissues; they
have
specific functions and usually
have recognizable shapes
consists
of related organs
with a common
function
All the parts of
the human body
functioning
together constitute
the total organism
This very basic
level can be
compared to the
letters of the
alphabet and
includes atoms

4. Characteristics of Life
•Metabolism : is the sum of all the chemical processes that occur in the body.
[Catabolism+ Anabolism]
•Responsiveness: is the body’s ability to detect and respond to changes
Nerve cells respond by generating electrical signals known as nerve impulses
Muscle cells respond by contracting
•Movement : motion of the whole body, individual organs, single cells, and even
tiny structures inside cells
The coordinated action of leg muscles moves
Gallbladder contracts and squirts bile into the gastrointestinal tract
•Growth: is an increase in body size that results from an increase in the size of
existing cells, an increase in the number of cells, or both.
Growing bone
1-6

5. • Differentiation: is the development of a cell from an unspecialized to a
specialized state
red blood cells and several types of white blood cells all arise from the same
unspecialized precursor cells in red bone marrow
Stem cells: precursor cells, which can divide and give rise to cells that undergo
differentiation
• Reproduction: refers either to the formation of new cells for tissue growth,
repair, or replacement, or to the production of a new individual.

8. Organ Systems Are Inter -related
Respiratory
system
Cardiovascular
system
Digestive
system
Blood
Internal
environment
External
environment
Organic waste,
excess salts, water
Unabsorbed
matter
Nutrients,
salts, water
Cell Extracellular
fluid
O2 in
Urinary
system
CO2 out
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

9. Requirements of Organisms
Water: most abundant substance in body
➢ metabolism
➢ transport
➢ regulates body temperature
Food
➢energy
➢building blocks
Oxygen - ~20% of air
➢releases energy from nutrients
Heat
➢helps control rate of metabolic reactions
Pressure
➢ atmospheric pressure – breathing
➢hydrostatic pressure – blood flow 1-8

10. Superior
Inferior
Medial
Lateral
Midline
Right Left
Proximal
Distal
Proximal
Distal
Anterior
(Ventral)
Posterior
(Dorsal)

11. Body Cavities
Body cavities are spaces within the body that help protect,
separate, and support internal organs
Bones, muscles, ligaments, and other structures separate the
various body cavities from one another.

12. Orbital cavities
Nasal cavity
Oral cavity
Middle ear
cavity
Cranial
Cavity

13. Thoracic
Cavity

14. Body Membranes
• Serous membranes
– lines organ surfaces in thoracic and abdominal
cavities
– thin, double layered, watery secretions
– reduces friction
• Mucous membrane
– lines hollow organs that lead to exterior of body
(ex. GI, respiratory, genito-urinary)
– thick secretions
– protective

15. •Each serous membrane composed of 2 layers:
•visceral layer – directly covers an organ
•parietal layer – lines a cavity or body wall
•small cavity between layers is filled with serous fluid

16. 4 Serous Membranes
The serous membrane of the pleural cavities
Pleura
• The visceral pleura clings to the surface of the lungs
• The anterior part of the parietal pleura lines the chest wall, covering the superior surface of the
diaphragm
• In between is the pleural cavity
The serous membrane of the pericardial cavity
Pericardium
• Visceral pericardium covers the surface of the heart
• Parietal pericardium lines the chest wall.
• Between them is the pericardial cavity
is the serous membrane of the abdominal cavity.
Peritoneum
• Visceral peritoneum covers the abdominal viscera
• parietal peritoneum lines the abdominal wall
• Between them is the peritoneal cavity.
The abdominopelvic cavity
• boundary between the abdominal and pelvic cavities

17. Homeostasis
External environment – keeps changing
Internal environment - remains stable.
How?
Body has “Homeostatic Mechanisms”
Imagine one day is very cold out, while the next day
is very hot.
What effect does that have on your body
temperature?

18. ◼ Homeostasis in the human body is
continually being disturbed
◼ The body has many regulating
systems that can usually bring the
internal environment back into
balance
◼ The nervous system and the
endocrine system, working
together or independently, provide
the needed corrective measure
Control of homeostasis
Feedback Loop

19. Internal Environments: Body Fluids
◼ An important aspect of homeostasis is maintaining the volume
and composition of body fluids [dilute, watery solutions
containing dissolved chemicals that are found inside cells as
well as surrounding them]
◼ Intracellular and Extracellular Fluid
◼ Blood plasma : Extracellular Fluid withing blood vessels
◼ Lymph: Extracellular Fluid withing lymphatic vessels
◼ Cerebrospinal fluid : Extracellular Fluid around the brain and
spinal cord
◼ Synovial fluid : in joints
◼ Aqueous humor and vitreous body: Extracellular Fluid of eyes

20. The proper functioning of body cells depends
on precise regulation of the composition of the
interstitial fluid surrounding them. Because of
this, interstitial fluid is often called the body’s
internal environment.

21. Feedback loop/Feedback Systems
◼ It is a cycle of events in which the status of a
body condition is monitored, evaluated,
changed, re-monitored, reevaluated, and so on.
◼ Controlled conditions: each monitored
variable, such as body temperature, blood
pressure, or blood glucose level, is termed a
controlled condition.
◼ Simulus: Any disruption that changes a
controlled condition is called a stimulus.
◼ Three basic components—a receptor, a
control center, and an effector

22. 1. Receptor is a body structure that monitors changes
in a controlled condition and sends input to a control
center.
Typically, the input is in the form of nerve impulses or
chemical signals.
e.g, certain nerve endings in the skin sense temperature
and can detect changes
2. Control center: evaluates the input it receives from
receptors, and generates output commands when they
are needed
e.g: the brain, sets the range of values within
which a controlled condition should be maintained,.
Output from the control center typically occurs as nerve
impulses, or hormones or other chemical signals.
e.g skin temperature example, the brain acts as the
control center, receiving nerve impulses

23. 3. Effector is a body structure that receives output
from the control center and produces a response or
effect that changes the controlled condition.
Nearly every organ or tissue in the body can
behave as an effector.
When your body temperature drops sharply,
your brain (control center) sends nerve impulses
(output) to your skeletal muscles (effectors). The
result is shivering, which generates heat and raises your
body temperature.
A group of receptors and effectors communicating with
their control center forms a feedback system that can
regulate a controlled condition in the body’s internal
environment.

24. Types of Regulation
◼ Negative feedback
❑ most common!
❑ Reverses a change in a controlled condition
◼ ex. maintaining body temperature; release of
most hormones, etc.
◼ Positive feedback
❑ strengthen or reinforce a change in one of the
body’s controlled conditions
❑ blood clotting
❑ labor

26. Characteristics of Life Organ Systems
•Movement
•Responsiveness
•Growth
•Reproduction
•Respiration
•Digestion
•Defense
•Assimilation
•Circulation
•Excretion
•structure 1-6
Which organ
system(s)
contribute to
each of the
characteristics
listed on the
left?