Anatomy is the study of the shape and structure of
the body and all of its parts as well as their
relationships to each other. The word anatomy is
derived from the Greek words tomy, which means to
cut, and ana, which means apart.
Physiology is the study of how the body and all its
parts function. Physiology consists of the words
physio, which means nature, and logy, which means
the study of.
CHARACTERISTICS OF LIVING
Composed of cells (one or more)
Different levels of organization
Respond to stimuli
The study of anatomy and physiology teaches
that the human body is organized into different
systems. These systems are the integumentary
system, the skeletal system, the muscular
system, the nervous system, the endocrine
system, the cardiovascular system, lymphatic
system, respiratory system, digestive system,
urinary system and the male and female
The heart is a (an) ___________ that belongs in
the _____________ system.
a) Tissue; cardiovascular
b) Organ; respiratory
c) Organism; cardiovascular
d) Cell; respiratory
e) Organ; cardiovascular
f) System; digestive
A condition in which the internal
environment of the body remains relatively
constant despite changes in the external
Homeostatic mechanisms are designed to reestablish
homeostasis when there is an imbalance.
The Home Heating System
1. When the temperature of a room decreases below a set point, the
thermostat electrically starts the furnace.
2. As the temperature of the room rises to the set point, the thermostat
shuts down the furnace.
3. As the room cools, step one is repeated.
There are three components to this system:
1. The Sensor which detects the stress.
2. The Control Center which receives information from the sensor and
sends a message to the Effector.
3. The Effector which receives the message from the control center
and produces the response which reestablishes homeostasis.
There are three components to a homeostatic system:
1. The Sensor which detects the stress.
2. The Control Center which receives information from the sensor and sends
a message to adjust the stress.
3. The Effector which receives the message from the control center and
produces the response which reestablishes homeostasis
It should be noticed that
1. the heat produced by the furnace shuts the furnace down through the
2. the original stress is reduced, i.e., the room warms up.
Homeostatic mechanisms that show these two
characteristics are operating by negative feedback
Homeostatic Regulation of Body Temperature through Negative
Heat receptors in
Stress is reduced
of sweat glands
flow to the skin
Homeostasis Using a Neural Pathway
mechanisms use a nerve
pathway in which to
produce their effects.
These pathways involve an
afferent path which brings
sensory messages into the
brain and an efferent path
which carries outgoing
nerve messages to
Positive Feedback Mechanisms
Homeostatic systems utilizing positive feedback exhibit two primary
1. Time limitation – Processes in the body that must be completed within a
constrained time frame are usually modified by positive feedback.
2. Intensification of stress – During a positive feedback process, the initial
imbalance or stress is intensified rather than reduced as it is in negative
Typical Positive Feedback Process
Homeostatic Regulation of Child Birth through Positive
Pressure of Fetus on the
Nerve endings in the uterine wall
carry afferent messages to the
Increasing strength of
Production and Release of
Oxytocin into the Blood
The birth of the child will bring this process to a close. Other examples of
positive feedback regulation occur during milk letdown and blood clotting.
The feedback in which the output quantity or
signal increases the input quantity or signal is
called negative feedback.
The body is assumed to be standing, the feet
together, the arms to the side, and the head and
eyes and palms of the hands facing forwards.
To ensure consistency of description it is
important to keep the anatomical position
constantly in mind.
A nurse is administering an IV medication on the
anterior area of the elbow. What is the correct
anatomic terminology for this area?
a) Facial area
b) Cervical area
c) Antecubital area
d) Lumbar area
e) Umbilical area
f) Elbow area
The lungs are located in the thoracic cavity and
surrounded by the pericardium.
The liver is located in the __________ cavity and
surrounded by the ____________.
a) Thoracic cavity; peritoneum
b) Abdominal cavity; peritoneum
c) Abdominal cavity; pleura
d) Thoracic cavity; pleura