Introduction to Anatomy & Physiology Mrs. Yanac

Introduction to Anatomy
& Physiology
Mrs. Yanac
• Study of the STRUCTURE of organisms &
their relationship to each other.
• “What are the structures of the body?”
• Study of body FUNCTION.
• “How do parts work?”
Relationship between A & P
• Anatomy & physiology are closely related as to
the function depends on how it is put
Levels of organization
• Chemical
- Atoms & molecules
• Cellular
- Basic structural & functional unit of all living things
- Smallest unit of life
• Tissue
- Cells with similar structure & function
• Organ
- 2 or more tissue types that work together to perform 1
or more functions
• Organ systems
- A group of organs working together
• Organism
- Many systems that work together to maintain life
- Highest level of structural organization
Structural Organization
Necessary Life Functions
Maintaining boundaries
– Cell membranes and integumentary system
– Muscular and skeletal systems
– Sensing changes in the environment (nervous system)
– Breaking down food to get energy
– All chemical reactions within the body (endocrine system)
– Removal of wastes (urinary/excretory system)
– Ensures continuation of the species
Growth & Development
– Increase in size
Human Organ Systems
1. Integumentary – skin, hair, and nails for protection and regulation
2. Skeletal – support and protection
3. Muscular – movement
4. Nervous – control system
5. Endocrine – communication within the body
6. Cardiovascular – transport and delivery (circulatory)
7. Lymphatic - body’s defense system (immune)
8. Respiratory – gas exchange
9. Digestive – breakdown of food & waste excretion
10. Urinary – removes wastes from the blood (excretory)
11. Reproductive – production of offspring
Figure 1.2a–c
Figure 1.2d–f
Figure 1.2g–i
Figure 1.2j–l
Survival Needs
• Nutrients
– Contain chemicals used for energy & cell building
• Oxygen
– Needed to carry out cellular respiration
• Water
– 60-80% of body weight
– Fluid base for the body
• Body Temperature
– Needs to be maintained at 37oC (98oF)
• Atmospheric Pressure
– Breathing & gas exchange depend on proper pressure
• Maintaining a constant (stable) internal
• Depends on a constant state of
– Chemical composition
– Temperature
– Pressure & Volume
• All body systems work together to maintain
homeostasis, but it is mainly controlled by the
nervous & endocrine systems.
• Internal conditions may change & vary, but
always within narrow limits…equilibrium is
Homeostatic Regulation
• Autoregulation (intrinsic)
– Adjust automatically in response to environmental
• When O2 levels decline in tissue, cells release chemicals that
dilate local blood vessels to increase rate of blood flow
which provides more O2
• Extrinsic regulation
– Results from activities from nervous or endocrine
• We you set your hand on a hot stove, the heat produces a
painful, localized disturbance & the nervous system orders
your muscles to pull your hand away from the stove
Regulatory Mechanism
• Receptor
– Sensor that is sensitive to a particular
environmental change or stimulus
• Control Center
– Area that receives & processes the info
• Effector
– Cell or organ that responds to the commands of
the control center
– Action either opposes or enhances the stimulus
Negative Feedback
Stimulus produces a response that OPPOSES the
original stimulus (does the opposite)
Example: Temperature control
• If body temp exceeds 37oC (98.6oF),
hypothalamus acts as a thermostat & heat
loss is increased through enhanced blood flow
to skin & increased sweating
Positive Feedback Mechanisms
Stimulus produces a response that ENHANCES or
SPEEDS UP the original stimulus (domino
Example: Blood Clotting
• Break in blood vessel wall causes bleeding.
Damaged cells release chemicals that attract
platelets to which will block the break and
stop the bleeding.
Anatomical Position
• Standing, feet apart,
with palms forward
and thumbs facing
Directional Terms
Anterior and Posterior, which describe structures at the front (anterior) and back
(posterior) of the body.
Superior and Inferior, which describe a position above (superior) or below
(inferior) another part of the body.
Proximal and Distal, which describe a position that is closer (proximal) or further
(distal) from the trunk of the body.
Superficial and Deep, which describe structures that are closer to (superficial) or
further from (deep) the surface of the body. Sometimes profound is used
synonymously with deep.
Medial and Lateral, which describe a position that is closer to (medial) or further
from (lateral) the midline of the body.
Ventral and Dorsal, which describe structures derived from the front (ventral) and
back (dorsal)
Cranial and Caudal, which describe structures close to the top of the skull (cranial),
and towards the bottom of the body (caudal).
Occasionally, sinister for left, and dexter for right are used
Body Planes
Anatomical Landmarks
Body Cavities
• CRASH COURSE: Intro to Anatomy & Physiology
• BOZEMAN SCIENCE: Anatomy & Physiology
• BOZEMAN SCIENCE: Positive & Negative
Feedback Loop
• DRAWN & DEFINED - Anatomical Terms
• PENGUIN PROF - Anatomical Directions & Planes
See Mr. Ford’s video series on my website under