Download The Human Body: Anatomical Regions, Directions, and Body Cavities

The Human Body: Anatomical
Regions, Directions, Body
Cavities, and Homeostasis
Credit: Carlos J Bidot Author 2006
Revised 2010
Overview of Anatomy and Physiology
• Anatomy – the study of the structure of
body parts and their relationships to one
another
– Gross or macroscopic
– Microscopic
– Developmental
• Physiology – the study of the function of
the body’s structural machinery
Gross Anatomy
• Regional – all structures in one part of
the body (such as the abdomen or
leg)
• Systemic – gross anatomy of the body
studied by system
• Surface – study of internal structures as
they relate to the overlying skin
Microscopic Anatomy
• Cytology – study of the cell
• Histology – study of tissues
Developmental Anatomy
• Traces structural changes throughout
life
• Embryology – study of developmental
changes of the body before birth
Specialized Branches of
Anatomy
• Pathological anatomy – study of
structural changes caused by disease
• Radiographic anatomy – study of
internal structures visualized by X ray
• Molecular biology – study of
anatomical structures at a sub-cellular
level
Physiology
• Considers the operation of specific
organ systems
– Renal – kidney function
– Neurophysiology – workings of the nervous
system
– Cardiovascular – operation of the heart
and blood vessels
• Focuses on the functions of the body,
often at the cellular or molecular level
Levels of Structural Organization
Smooth muscle cell
Molecules
2 Cellular level
Cells are made up of molecules
Smooth
muscle
tissue
3 Tissue level
Tissues consist of
similar types of
cells
Cardiovascular
system
Epithelial
tissue
Smooth
muscle
tissue
Connective
tissue
4 Organ level
Organs are made up of
different types of tissues
Atoms
1 Chemical level
Atoms combine to
form molecules
Heart
Blood
vessels
Blood
vessel
(organ
)
6 Organismal level
The human organism is
made up of many organ
systems
5 Organ system level
Organ systems consist of different organs
that work together closely
Figure 1.1
Levels of Structural Organization
(*VERY important*)
• Chemical – atoms combined to form
molecules
• Cellular – cells are made of molecules
• Tissue – consists of similar types of cells
• Organ – made up of different types of
tissues
• Organ system – consists of different organs
that work closely together
• Organism – made up of the organ systems
Homeostasis
Imagine one day is very cold out, while the
next day is very hot.
What effect does that have on your body
temperature?
External environment – keeps changing
Internal environment - remains stable.
How?
Body has “Homeostatic Mechanisms”
Homeostasis
• Homeostasis is the ability to maintain a
relatively stable internal environment in
an ever-changing outside world
• The internal environment of the body is
in a dynamic state of equilibrium
• Chemical, thermal, and neural factors
interact to maintain homeostasis
Feedback Loops
• The beginning of a reflex pathway is a
disturbance in a controlled parameter called a
stimulus
• The stimulus is detected by a sensor (receptor)
– continuously monitoring the environment
– when a change is detected, it sends out a
signal
• The signal travels from the receptor to the control
(integrating) center
Feedback Loops
• The control center evaluates the incoming
signal, compares it to the homeostatic
setpoint, and decides on the appropriate
response
• The control center sends out a signal to the
effector
• The effector is a cell or tissue that carries out
the appropriate response to bring the
parameter back to within normal limits
(setpoint)
Types of Feedback
• Negative feedback
– Most common
– The effector removes the cause of
imbalance
– Ex. Body temperature, blood pH
• Positive feedback
– The effector reinforces the stimulus
(does not stop it)
– Ex. Blood clotting, labor
Anatomical Position
• Body erect
• Feet slightly apart
• Palms facing forward
• Thumbs point away
from body
Figure 1.7a
Directional Terms
• Superior and inferior – toward and
away from the head, respectively
• Anterior and posterior – toward the
front and back of the body
• Medial, lateral, and intermediate –
toward the midline, away from the
midline, and between a more medial
and lateral structure
Directional Terms
• Proximal and distal – closer to and
farther from the origin of the body
• Superficial and deep – toward and
away from the body surface
Directional Terms
Table 1.1
Directional Terms
Table 1.1
Regional Terms: Anterior View
• Axial – head,
neck, and
trunk
• Appendicular
–
appendages
or limbs
• Specific
regional
terminology
Figure 1.7a
Regional Terms: Posterior View
Figure 1.7b
Activity!
• https://www.wisconline.com/learn/natural-science/lifescience/ap15305/anatomicalterminology-relative-position
Anatomical Locations
•
•
•
•
•
•
•
•
•
•
Abdominal: abdominal region
Acromial: the point of the shoulder
Antebrachial: forearm
Antecubital: anterior surface of the elbow
Axillary: armpit
Brachial: upper arm
Buccal: cheek of the face
Calcaneal: heel of the foot
Carpal: wrist
Cephalic: head
24
Anatomical Locations
•
•
•
•
•
•
•
•
•
•
•
Cervical: neck
Deltoid: round part of the shoulder
Digital: fingers and toes
Dorsum: back
Femoral: thigh
Frontal: forehead
Gluteal: buttocks
Hallux: big toe
Inguinal: groin
Lumbar: lower back
Mammary: breast
25
Anatomical Locations
•
•
•
•
•
•
•
•
•
•
Mental: chin
Nasal: Nose
Occipital: base of the skull
Olecranal: elbow
Oral: mouth
Orbital: bony eye socket
Otic: ear
Palmar: palm of hand
Patellar: Kneecap
Pedal: Foot
26
Anatomical Locations
• Pelvic: pelvis region
• Perineal: area between anus and external
genitals
• Plantar: sole of foot
• Pollex: thumb
• Popliteal: behind the knee
• Pubic: genital region
• Sacral: lower back between the hips
• Scapular: shoulder blade
• Tarsal: ankle
• Thoracic: chest
• Vertebral: spine
27
Body Planes
• Sagittal – divides the body into right
and left parts
• Midsagittal or medial – sagittal plane
that lies on the midline
• Frontal or coronal – divides the body
into anterior and posterior parts
• Transverse or horizontal (cross section)
– divides the body into superior and
inferior parts
• Oblique section – cuts made
diagonally
Body Planes
Figure 1.8
Anatomical Variability
• Humans vary slightly in both external
and internal anatomy
• Over 90% of all anatomical structures
match textbook descriptions, but:
– Nerves or blood vessels may be
somewhat out of place
– Small muscles may be missing
• Extreme anatomical variations are
seldom seen
Body Cavities
Figure 1.9a
Body Cavities
• Dorsal cavity protects the nervous system,
and is divided into two subdivisions
– Cranial cavity is within the skull and
encases the brain
– Vertebral cavity runs within the vertebral
column and encases the spinal cord
• Ventral cavity houses the internal organs
(viscera), and is divided into two
subdivisions: - Thoracic and
Abdominopelvic cavities
Body Cavities
Figure 1.9b
Body Cavities
• Thoracic cavity is subdivided into
pleural cavities, the mediastinum, and
the pericardial cavity
– Pleural cavities – each houses a lung
– Mediastinum – contains the
pericardial cavity, and surrounds the
remaining thoracic organs
– Pericardial cavity – encloses the
heart
Body Cavities
• The abdominopelvic cavity is
separated from the superior thoracic
cavity by the dome-shaped
diaphragm
• It is composed of two subdivisions
– Abdominal cavity – contains the
stomach, intestines, spleen, liver, and
other organs
– Pelvic cavity – lies within the pelvis
and contains the bladder,
reproductive organs, and rectum
Ventral Body Cavity Membranes
• Parietal serosa lines internal body walls
• Visceral serosa covers the internal organs
• Serous fluid separates the serosae (A
serous membrane, especially one that
lines the pericardial, pleural, and
peritoneal cavities, enclosing their
contents)
Ventral Body Cavity Membranes
Figure 1.10a
Ventral Body Cavity Membranes
Figure 1.10b
Other Body Cavities
• Oral and digestive – mouth and
cavities of the digestive organs
• Nasal –located within and posterior to
the nose
• Orbital – house the eyes
• Middle ear – contain bones (ossicles)
that transmit sound vibrations
• Synovial – joint cavities
Abdominopelvic Regions
• Umbilical
• Epigastric
• Hypogastric
• Right and left iliac
or inguinal
• Right and left
lumbar
• Right and left
hypochondriac
Figure 1.11a
Organs of the Abdominopelvic Regions
Figure 1.11b
Abdominopelvic Quadrants
• Right upper
(RUQ)
• Left upper (LUQ)
• Right lower (RLQ)
• Left lower (LLQ)
Figure 1.12