1. Human Anatomy and Physiology I
INTRODUCTION
Chapter 1

2. Chapter 1 Outline Levels of Structural Organization Maintaining Life
Overview of Anatomy and Physiology
Levels of Structural Organization
Maintaining Life
Homeostasis
The Language of Anatomy

3. Overview of Anatomy and Physiology
Anatomy: Structure
Major Subdivisions:
Gross or macroscopic anatomy
regional, surface, and systemic
Microscopic anatomy
cytology and histology
Developmental anatomy
embryology

4. Overview of Anatomy and Physiology
Physiology: Function
Subdivisions are based on organ systems
Examples: renal or cardiovascular physiology

5. Principle of Complementarity
Anatomy and Physiology are inseparable
Always be thinking Structure and Function when you study!

6. Levels of Structural Organization
Chemical: atoms and molecules (Chapter 2)
Cellular: cells and their organelles (Chapter 3)
Tissue: groups of similar cells (Chapter 4)
Organ: contains two or more types of tissues
Organ system: organs that work closely together
Organismal: all organ systems together

7. Levels of Structural Organization
Organelle
Molecule
Atoms
Chemical level Atoms combine to form molecules.
Cellular level Cells are made up of molecules.
Tissue level Tissues consist of similar types of cells.
Organ level Organs are made up of different types of tissues.
Organ system level Organ systems consist of different organs that work together closely.
Organismal level The human organism is made up of many organ systems.
Smooth muscle cell
Smooth muscle tissue
Blood vessel (organ)
Heart
Blood vessels
Epithelial tissue 2 1
Cardiovascular system
Cardiovascular system 3
Connective tissue 4 6 5

8. Overview of Organ Systems
Integumentary System
Forms the external body covering
Protects deeper tissues from injury
Synthesizes vitamin D
Houses cutaneous receptors
and sweat and oil glands
(pain, pressure)
Nails
Skin
Hair

9. Overview of Organ Systems
Skeletal System
Protects and supports body organs
Provides framework for muscles to cause movement
Blood cells are formed
within bones
Bones store minerals
Bones
Joint

10. Overview of Organ Systems
Muscular System
Allows manipulation of the environment
locomotion, and facial expression
Maintains posture
Produces heat
Skeletal
muscles

11. Overview of Organ Systems
Nervous System
Fast-acting control system of the body
Responds to internal and external changes
by activating appropriate
muscles and glands
Brain
Nerves
Spinal
cord

12. Overview of Organ Systems
Endocrine System
Glands secrete hormones
Regulate body processes
growth, reproduction and
nutrient use (metabolism)
Pineal gland
Pituitary
gland
Thyroid
Thymus
Adrenal
Pancreas
Testis
Ovary

13. Overview of Organ Systems
Cardiovascular System
The heart pumps blood
Blood vessels transport
blood
Blood carries oxygen,
carbon dioxide, nutrients,
and wastes
Heart
Blood
vessels

14. Overview of Organ Systems
Lymphatic System/Immunity
Picks up fluid leaked from blood vessels
and returns it to blood
Disposes of debris in the
lymphatic stream
Houses white blood cells
(lymphocytes) involved in
immunity
Mounts immune response
against foreign substances
within the body
Lymphatic
vessels
Red bone
marrow
Thoracic
duct
Thymus
Spleen
Lymph
nodes

15. Overview of Organ Systems
Respiratory System
Keeps blood constantly supplied with oxygen
Removes carbon dioxide
Gaseous exchanges
occur through the walls
of the air sacs of the lungs
Nasal
cavity
Bronchus
Pharynx
Larynx
Trachea
Lung

16. Overview of Organ Systems
Digestive System
Breaks down food into absorbable units
Absorbable foodstuffs
enter the blood for
distribution to body cells
Indigestible foodstuffs
are eliminated as feces
Liver
Oral cavity
Esophagus
Large
intestine
Stomach
Small
Rectum
Anus

17. Overview of Organ Systems
Urinary System
Eliminates nitrogenous wastes from the body
Regulates water,
electrolyte and acid-base
balance of the blood
Kidney
Ureter
Urinary
bladder
Urethra

18. Overview of Organ Systems
Reproductive System
Production of gametes, hormones and ultimately
offspring
Prostate
gland
Ductus
deferens
Penis
Testis
Scrotum
Ovary
Uterine
tube
Mammary
glands (in
breasts)
Uterus
Vagina
Male Reproductive System
Female Reproductive System

19. Organ System Interrelationships
Digestive system
Takes in nutrients, breaks them
down, and eliminates unabsorbed
matter (feces)
Respiratory system
Takes in oxygen and
eliminates carbon dioxide
Food O2
CO2
Cardiovascular system
Via the blood, distributes oxygen
and nutrients to all body cells and
delivers wastes and carbon
dioxide to disposal organs
Interstitial fluid
Nutrients
Urinary
system
Eliminates
nitrogenous
wastes and
excess ions
Nutrients and wastes pass
between blood and cells
via the interstitial fluid
Integumentary system
Protects the body as a whole
from the external environment
Blood
Heart
Feces
Urine
Cells and organs work
cooperatively in the
body to maintain well
being

20. Homeostasis
Maintenance of a relatively stable internal environment despite continuous outside changes
A dynamic state of equilibrium

21. Homeostatic Control Mechanisms
Involve continuous monitoring and regulation of many factors
Nervous and Endocrine systems accomplish the communication via nerve impulses and hormones

22. Components of a Control Mechanism
Receptor (sensor)
Monitors the environment
Responds to stimuli (changes in controlled variables)
Control center
Determines the set point at which the variable is maintained
Receives input from receptor
Determines appropriate response

23. Components of a Control Mechanism
Effector
Receives output from control center
Provides the means to respond
Response acts to reduce or enhance the stimulus (feedback)

24. Components of a Control Mechanism
Stimulus produces change in variable.
BALANCE
IMBALANCE 1

25. Components of a Control Mechanism
Stimulus produces change in variable.
Receptor detects change.
Receptor
BALANCE
IMBALANCE 1 2

26. Components of a Control Mechanism
Stimulus produces change in variable.
Receptor detects change.
Input: Information sent along afferent pathway to control center.
Receptor
Control Center
BALANCE
Afferent pathway
IMBALANCE 1 2 3

27. Components of a Control Mechanism
Stimulus produces change in variable.
Receptor detects change.
Input: Information sent along afferent pathway to control center.
Output: Information sent along efferent pathway to effector.
Receptor
Effector
Control Center
BALANCE
Afferent pathway
Efferent pathway
IMBALANCE 1 2 3 4

28. Components of a Control Mechanism
Stimulus produces change in variable.
Receptor detects change.
Input: Information sent along afferent pathway to control center.
Output: Information sent along efferent pathway to effector.
Response of effector feeds back to reduce the effect of stimulus and returns variable to homeostatic level.
Receptor
Effector
Control Center
BALANCE
Afferent pathway
Efferent pathway
IMBALANCE 1 2 3 4 5

29. Negative Feedback
The response reduces or shuts off the original stimulus
Example:
Regulation of body temperature (a nervous mechanism)

30. Negative Feedback Stimulus Sweat glands activated Shivering begins
Body temperature
rises
BALANCE
Information sent
along the afferent
pathway to control
center
Afferent
pathway
Efferent
along the efferent
pathway to
effectors
pathway to effectors
Body temperature falls
Receptors
Temperature-sensitive
cells in skin and brain
Effectors
Sweat glands
Skeletal muscles
Control Center
(thermoregulatory
center in brain)
Response
Evaporation of sweat
Body temperature falls;
stimulus ends
Body temperature rises;

31. Positive Feedback
The response enhances or exaggerates the original stimulus
May exhibit a cascade or amplifying effect
Usually controls infrequent events
Enhancement of labor contractions by oxytocin
Platelet plug formation and blood clotting

32. Positive Feedback 1 Break or tear occurs in blood vessel wall.
Positive feedback cycle is initiated.
Break or tear occurs in blood vessel wall. 1

33. Positive Feedback 1 2 Break or tear occurs in blood vessel wall.
Positive feedback cycle is initiated.
Break or tear occurs in blood vessel wall.
Platelets adhere to site and release chemicals. 1 2

34. Positive Feedback 1 3 2 Break or tear occurs in blood vessel wall.
Positive feedback cycle is initiated.
Positive feedback loop
Break or tear occurs in blood vessel wall.
Platelets adhere to site and release chemicals.
Released chemicals attract more platelets. 1 2 3

35. Positive Feedback 1 3 2 4 Break or tear occurs in blood vessel wall.
Feedback cycle ends when plug is formed.
Positive feedback cycle is initiated.
Positive feedback loop
Break or tear occurs in blood vessel wall.
Platelets adhere to site and release chemicals.
Released chemicals attract more platelets.
Platelet plug forms. 1 2 3 4

36. Homeostatic Imbalance
Disturbance of homeostasis
Increases risk of disease
Contributes to changes associated with aging
May allow destructive positive feedback mechanisms to take over (heart failure)

37. The Language of Anatomy
Anatomical Position
Body Landmarks
Directional Terms
Regional Terms
Body Planes and Sections
Body Cavities and Membranes

38. Body Landmarks Cervical Anterior/Ventral Pubic (genital) Cephalic
Frontal
Orbital
Nasal
Oral
Mental
Thoracic
Axillary
Mammary
Sternal
Abdominal
Umbilical
Pelvic
Inguinal
(groin)
Upper limb
Acromial
Brachial (arm)
Antecubital
Antebrachial
(forearm)
Carpal (wrist)
Manus (hand)
Palmar
Pollex
Digital
Lower limb
Coxal (hip)
Femoral (thigh)
Patellar
Crural (leg)
Fibular or peroneal
Pedal (foot)
Tarsal (ankle)
Metatarsal
Hallux
Thorax
Abdomen
Back (Dorsum)

39. Body Landmarks Cervical Back (dorsal) Posterior/Dorsal Scapular
Vertebral
Lumbar
Sacral
Gluteal
Perineal (between
anus and external
genitalia)
Upper limb
Acromial
Brachial (arm)
Olecranal
Antebrachial
(forearm)
Manus (hand)
Metacarpal
Digital
Lower limb
Femoral (thigh)
Popliteal
Sural (calf)
Fibular or peroneal
Pedal (foot)
Calcaneal
Plantar
Cephalic
Otic
Occipital (back
of head)
Thorax
Abdomen
Back (Dorsum)

40. Body Planes and Sections
Transverse plane
Median (midsagittal) plane
Frontal plane
Liver
Spleen
Pancreas
Aorta
Vertebral
column
Spinal cord
Subcutaneous fat layer
Body wall
Rectum
Intestines
Left and
right lungs
Heart
Stomach
Arm
(a) Frontal section
(through torso)
(b) Transverse section
(through torso,
inferior view)
(c) Median section
(midsagittal)

41. Body Cavities Cranial cavity (contains brain) Dorsal body Vertebral
spinal
cord)
Superior
mediastinum
Pericardial
cavity within
the mediastinum
Pleural
Abdomino-
pelvic
Ventral body
(thoracic and
abdominopelvic
cavities)
Abdominal cavity
(contains digestive
viscera)
Diaphragm
Pelvic cavity
(contains urinary
bladder, reproductive
organs, and rectum)
Thoracic
heart and
lungs)
Lateral view
Anterior view
Dorsal body cavity
Ventral body cavity