Transcript divides the body or an organ into front

Anatomy & Physiology = study of characteristics
Common Characteristics Of Living Things:
1. Organization: pattern that differs from environment, involves
regulation of internal conditions within limits
2. Responsiveness: (irritability), responding to changes in
environment. Adaptation = long term response
3. Growth and Differentiation Growth = increase in size/cell
number Differentiation = specialization of cells to perform
particular functions
4. Reproduction
5. Movement Internal Transport substances in body External
move around environment
6. Metabolism and Excretion Metabolism = all chemical processes
in the body (building and breaking molecules)
Form Follows Function: the shape of a structure is related to its
use
Anatomy = study of internal and external structures of body and
their relationships to each other: Form
Gross Anatomy = macroscopic, see by eye
Microscopic Anatomy = cell and molecule level, need
microscope
Cytology = study of cells
Histology = study of tissues (groups of specialized cells that
work together to perform functions)
Physiology = study of how organism perform functions: (Function)
Human Anatomy and Physiology = the study of the form and
function of the human body
-understanding physiology requires a knowledge of
anatomy and physics (chemistry), to explain how the
heart works, how we breathe, how we regulate blood
glucose…
The pattern of organization at the lower levels determines both
the characteristics and functions at the higher levels.
Principle of Complementarity
•The anatomy of a part of the body reflects the
physiology of that part
-form
determines function
-all the parts of the body are designed to create an
extremely efficient and effective machine
Homeostasis
Homeostasis is the ability to maintain a relatively
constant internal environment = unchanging sameness
•For the body to work as efficiently as possible, there
are hundreds of variables that must remain relatively
constant (at a set point) - essential to life
–body temperature, blood glucose levels, blood
pressure, body CO2 levels, body pH…
–these variables are constantly changing
•The body uses control systems (loops) to maintain
these variables at their respective setpoint after a
stimulus causes it to deviate from the setpoint
Homeostatic Regulation (keeping within set limits)
1. Autoregulation (Intrinsic Regulation) - activities of a
cell/tissue/organ/system adjust automatically in response to
environmental change.
2. Extrinsic Regulation - results from activities of nervous or
endocrine systems
-Nervous system: directs rapid, short term, specific responses
-Endocrine system: works through hormones, slow to act but long
lasting effects
Homeostatic Control Mechanisms
Homeostasis use requires coordinated efforts of multiple organ
systems: human body integrated to support life
•There are three interdependent components of a
control system:
–Receptor
•monitors the variable and responds to changes
(stimuli). The receptor sends information
regarding the changed variable to the…
–Control center
•determines the set point at which the variable
is maintained. Then the control center sends
information to the…
–Effector
•provides the means to respond to the stimulus
(creates an effect) to bring the variable back to
the set point
- essentially a muscle or a gland
Homeostatic Control Systems
Homeostatic Control Systems (Loops)
There are 2 different types of control systems
•Most (over 99%) of them are referred to as negative
feedback loops where the output of the system
(effector) causes a change in the variable which
opposes the original stimulus
–If the original stimulus caused a increase in a
variable, the effector will cause the variable to
decrease back to the set point
–Function like the heating/cooling system in a
house to maintain a constant room
temperature
Negative Feedback
Negative Feedback
The setpoint for body temperature is 37ºC
•If body temperature increases:
–blood vessels dilate increasing blood flow to
the skin
–sweating occurs
•If body temperature decreases
–blood vessels constrict reducing blood to the
skin
–skeletal muscles contract vigorously (shiver)
Homeostatic Control Systems (Loops)
•The minority (less than 1%) of the systems are
referred to as positive feedback systems where the
output of the system causes a change in the variable
which reinforces the original stimulus
–If the original stimulus caused a increase in a
variable, the effector will cause the variable to
further increase
Positive Feedback
Anatomical Position
• The anatomical position is a
standardized method of observing or
imaging the body that allows precise
and consistent anatomical references.
• When in the anatomical position, the
subject stands.
–
–
–
–
–
–
standing upright
facing the observer, head level
eyes facing forward
feet flat on the floor
arms at the sides
palms turned forward (ventral)
Reclining Position
• If the body is lying face down, it is in the
prone position.
• If the body is lying face up, it is in the
supine position.
Common Regional
Names
cranial (skull),
thoracic (chest),
brachial (arm),
patellar (knee),
cephalic (head), and
gluteal (buttock) as
seen in Figure
• Clinical
terminology is
based on a Greek
or Latin root word.
-Lumbar region = lower back
-Gluteal region = butt
-Pelvic region = hips
-Pubic region = anterior pelvis
-Inguinal region = groin
-Femoral region= thigh
-Crural region= front of leg
-Sural region=calf
-Tarsal region= ankle
-Pedal region= top of foot
-Plantar region= sole of foot
Anatomical Terms - contd.
-Carpal region = wrist
-Manual region = hand
-Abdominal region = belly
Directional Terms
• Directional terms are used to precisely
locate one part of the body relative to
another and to reduce length of
explanations.
• Commonly used directional terms:
– dorsal, superior, medial, and distal
• Superior
-towards the head
– The eyes are
superior to the
mouth.
• Inferior
– away from the head
– The stomach is
inferior to the heart.
Dorsal or Ventral
• Dorsal or Posterior
– at the back of the body
– The brain is posterior to
the forehead.
• Ventral or Anterior
– at the front of the body
– The sternum is anterior to
the heart.
Medial or Lateral
• Medial
– nearer to the midline of
the body
– The heart lies medial to
the lungs.
• Lateral
– farther from the midline
of the body
– The thumb is on the
lateral side of the hand.
Proximal or Distal
• Proximal
– nearer to the attachment of the
limb to the trunk
– The knee is proximal to the
ankle.
• Distal
– farther from the attachment of
the limb to the trunk
– The wrist is distal to the elbow.
Superficial - towards the surface
Deep - towards the interior
Body Cavities
• Body cavities are spaces within the body
that help protect, separate, and support
internal organs.
Dorsal Body Cavity
• The dorsal body cavity is located near the dorsal
surface of the body and has two subdivisions, the
cranial cavity and the vertebral canal.
• The cranial cavity is formed by the cranial bones
and contains the brain.
• The vertebral (spinal) canal is formed by the bones
of the vertebral column and contains the spinal
cord.
• Three layers of protective tissue, called meninges,
line the dorsal body cavity.
Dorsal Body Cavity
Ventral Body Cavity
• Near ventral surface of
body
• 2 subdivisions
– thoracic cavity above
diaphragm
– abdominopelvic cavity
below diaphragm
• Diaphragm = large,
dome-shaped muscle
• Organs called viscera
• Organs covered with
serous membrane
Serous Membranes
• Thin slippery membrane lines body cavities
not open to the outside
– parietal layer lines walls of cavities
– visceral layer covers viscera within the cavities
• Serous fluid reduces friction
Ventral Body Cavity
• The thoracic cavity contains two pleural cavities,
and the mediastinum, which includes the
pericardial cavity.
– The pleural cavities enclose the lungs.
– The pericardial cavity surrounds the heart.
• The abdominopelvic cavity is divided into a
superior abdominal and an inferior pelvic cavity.
– Viscera of the abdominal cavity include the stomach,
spleen, pancreas, liver, gallbladder, small intestine, and
most of the large intestine.
– Viscera of the pelvic cavity include the urinary bladder,
portions of the large intestine and internal female and
male reproductive structures.
Mediastinum
• The mediastinum is a broad, median partition between the
lungs that extends from the sternum to the vertebral
column, it contains all contents of the thoracic cavity
except the lungs.
– heart and great vessels, esophagus, trachea, thymus.
Thoracic Cavity
• Encircled by ribs, sternum, vertebral column and muscle
• Divided into 2 pleural cavities by mediastinum
• Mediastinum contains all thoracic organs except lungs
Abdominopelvic Cavity
• Inferior portion of ventral body cavity below diaphragm
• Encircled by abdominal wall, bones & muscles of pelvis
Abdominopelvic Regions and
Quadrants
• To describe the location of organs or
abdominopelvic abnormalities easily, the
abdominopelvic cavity may be divided into
– nine regions by drawing four imaginary lines
as shown in.
– quadrants by passing imaginary horizontal and
vertical lines through the umbilicus.
Abdominopelvic
Regions & Quadrants
• Describe locations of organs or source of pain
• Tic-tac-toe grid or intersecting lines through navel
Clinical Application: Autopsy
• An autopsy is a postmortem examination of
the body and dissection of the internal
organs to confirm or determine the cause of
death.
• An autopsy supplies information relating to
the deceased individual.
Planes and Sections
• Planes are imaginary flat surfaces that are used to
divide the body or organs into definite areas
• Principal planes include:
– midsagittal (medial) and parasagittal
– frontal (coronal)
– transverse (cross-sectional or horizontal)
– oblique
• Sections
– flat surfaces resulting from cuts through body
structures, named according to the plane on which
the cut is made (transverse, frontal, and midsagittal
sections)
Sagittal Plane
• Sagittal plane
– divides the body or an
organ into left and
right sides
• Midsagittal plane
– produces equal halves
• Parasagittal plane
– produces unequal
halves
Other Planes and Sections
• Frontal or coronal plane
– divides the body or an organ into front
(anterior) and back (posterior) portions
• Transverse(cross-sectional) or
horizontal plane
– divides the body or an organ into upper
(superior) or lower (inferior) portions
• Oblique plane
– some combination of 2 other planes