Download Chapter 1: The Human Body An Orientation

Chapter 1: The Human Body
An Orientation
Science as a Process:
1.) Observations & Previous Experiments
2.) Propose hypothesis (educated guess)
3.) Design experiment (w/experimental & control
group)
4.) Collect data & analyze it
- data is biased - redesign experiment
- not - continue
5.) Refine hypothesis - broad to specific
6.) Repeat experiment - (100s of times)
- results are not consistent - new hypothesis
- results are - accept as theory - could become
a law
Anatomy
- the study of the
structure of an
organism & the
relationship of its
parts
- learn through
dissection
- subdivisions are:
a.) gross anatomy
b.) microscopic
c.) developmental
d.) pathological
e.) systemic
Physiology
- the study of the
functions of living
organisms & their
parts
- subdivided into:
a.) type of organism
involved
b.) organizational level
studied
c.) systemic function
being studied
Characteristics of Life:
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Responsiveness
Conductivity
Growth
Respiration
Digestion
Absorption
Secretion
Excretion
Circulation
Reproduction
***These 10 characteristics maintain
metabolism
***Other criteria have been used to
determine life on other planets such as the
presence of ATP (adenosine triphosphate)
Levels of Organization
1.) Chemical Level - atoms
molecules
macromolecules
cytoplasm
2.) Organelle Level - structures made of molecules organized to
perform a specific function
3.) Cellular Level - smallest “living” unit of structure & function
in the body - made of many organelles
4.) Tissue Level - organization of many similar cells that act
together to perform a common function
5.) Organ Level - group of several different kinds of tissues
arranged to perform a special function
- each organ has a unique shape, size, appearance &
placement in the body - “Form Fits Function”
6.) System Level - organization of varying # & kinds of organs
arranged to perform complex functions
7.) Organism Level - any living entity considered as a whole contains the characteristics of life
Anatomical Position
• The body is in an erect or standing posture
w/ the arms at the sides & palms turned
forward - head & feet also turned forward
• Humans are bilaterally symmetrical -
rht & left sides of the body are
mirror images of each other
• only 1 plane can divide the body
• terms:
– ipsilateral - on the same side
– contralateral - on opposite sides
Body Cavities
- 2 major cavities
I. Ventral Cavity - made of:
A. Thoracic Cavity
(chest)
1.) left & rht pleural
cavity - lungs
2.) mediastinum heart, trachea,
bronchi, esophagus,
thymus, blood &
lymph vessels,
lymph nodes,
nerves
Is this person in the anatomical position?
Justify your answer in 3 or more ways.
B. Abdominopelvic Cavity
(stomach & groin)
1.) Abdominal Cavity liver, gall bladder,
stomach, pancreas,
intestines, spleen,
kidneys, ureters
2.) Pelvic Cavity bladder, certain
repro. organs, part
of large intestines
***The thoracic & abdominal cavities
are separated by a white band called
the diaphragm, used for breathing
II. Dorsal Cavity made of:
A.) Cranial Cavity brain
B.) Spinal Cavity spinal cord
***Membranes that line or cover body
cavities are:
a.) parietal - actual wall of the body
cavity or the lining membranes
that cover its surface
b.) visceral - thin membranes that
cover organs w/in a cavity
Body Regions - 2 of them
A. Axial - consists of the head, neck,
torso (trunk)
B. Appendicular - consists of the upper
& lower extremities
- each portion is then divided further
Directional Terms
1.) Left
(subject’s)
2.) Dorsal
(vertebral side)
3.) Caudad
(toward tail)
4.) Medullary
(inner region)
5.) Superior
(toward head; upper;
above)
vs
vs
vs
vs
vs
Right
(subject’s)
Ventral
(belly side)
Cephalad
(toward head)
Cortical
(outer region)
Inferior
(toward feet;
lower; below)
6.) Anterior
vs
(front; in front of;
ventral)
7.) Medial
vs
(toward body’s midline)
8.) Proximal
vs
(toward or nearest trunk
or pt of origin)
Posterior
(back; in back
of; dorsal)
Lateral
(toward side
of body; away
from midline)
Distal
(away from or
farthest from
trunk or pt of
origin)
9.) Superficial
(nearer the surface)
vs
10.) Supine
(lying face upward)
vs
Deep
(farther away
from surface)
Prone
(lying face
downward)
Body Planes & Sections
1.) Sagittal - lengthwise plane runing from front to
back
- divides the body into left & rht sides
- divided into 2 equal halves - midsagittal plane
2.) Coronal (Frontal) - lengthwise plane running from
side to side
- divides the body into anterior & posterior (front
& back) portions
3.) Transverse (Horizontal) - crosswise plane
- divides the body into upper & lower portions
Abdominopelvic Regions
4 Quadrants
****Body planes are used in medical
imaging like radiography, CT Scans,
MRIs & ultrasonography
Body Types - Somatotypes
1.) Endomorphs - heavy, rounded physique charac. by
large accumulations of fat in trunk & thighs - 2
types
a.) apple shaped - higher health risk such as
heart disease, stroke, hypertension,
diabetes, breast cancer
b.) pear shaped
***Determined by waist-to-hip ratio
2.) Mesomorph - muscular
3.) Ectomorph - thin, fragile physique charac. by
little body fat
Homeostatic Control Mechanisms:
- have at least 3 components
a.) receptor – the sensor
b.) control center – deter the set point at
which a variable is to be maintained,
analyzes the received info, & deter
the appropriate response
c.) effector – how the control center
responds to the stimuli - feedback
- feedback can be either:
a.) negative feedback – effect either shuts
off or decreases the stimuli’s
intensity – mostly used in the body –
ex) body temperature
b.) positive feedback – effect enhances the
stimuli’s intensity – rare – ex) blood
clotting & giving birth
Feed Forward – info may flow ahead to another
process to trigger a change in anticipation of an
event that will follow – ex.) digestion
Fake!!!!