1. An Introduction to the Human Body
Chapter 1
An Introduction to the Human Body

2. Definitions of A & P: Anatomy Physiology
science of structure
relationships revealed by dissection (cutting apart)
imaging techniques
Physiology
science of body functions
normal adult physiology studied in this text
some genetic variations described
Subdivisions of A & P = Table 1.1 (pg 3)

3. Levels of Organization
Chemical
atoms
molecules
Cellular
Tissue
Organs
System Level
Organismic Level

4. Levels of Structural Organization
Chemical Level
atomic and molecular level
Cellular level
smallest living unit of the body
Tissue level
group of cells and the materials surrounding them that work together on one task
4 basic tissue types
epithelium, muscle, connective tissue, and nerve

5. Levels of Structural Organization
Organ level
grouping of 2 or more tissue types into a recognizable structure with a specific function.
Organ system
collection of related organs with a common function
sometimes an organ is part of more than one system
Organismic level
one living individual.

6. Clinical Observational Techniques (Non-invasive Techniques)
Palpation
feel body surface with hands
pulses and breathing rates
Can detect enlarged organs
Auscultation
listen to body sounds with stethoscope
abnormal fluid in lungs
Percussion
tap on body surface and listen to echo
air in intestines, Fluid in lungs

7. Interaction of Organ Systems
All major body systems will be examined
Interaction of different systems of the body
skin produces vitamin D needed for calcium absorption and bone growth
bone marrow produces cells which help the skin resist infection.

8. Life Processes Metabolism = sum of all chemical processes
breakdown of large molecules into small
building new structural components (proteins)
providing chemical energy for cells
Responsiveness
detect & respond to changes in internal or external environment
some typical responses
muscle contraction, electrical signals, hormone or glandular secretion

9. Life Processes Movement at any structural level Growth Differentiation
the body, an organ, a cell or cell component
Growth
increase in number or size of cells or the material found between cells
Differentiation
specialization of cells for a specific function
stem cells give rise to cells that specialize
Reproduction
formation of new cells or new individuals

10. Autopsy Postmortem examination of body by dissection Purpose
confirm or determine cause of death
support findings of other tests
provide information on effects of drug usage
educate healthcare students
reveal congenital defects

11. “Autopsy is a Slice of Real -Life CSI”
Video

12. Homeostatis
Maintaining the internal environment within physiological limits
First described by French physiologist,
Process named by Walter Cannon,
Example
blood glucose level is kept within narrow range /100ml

13. Homeostasis of Body Fluids
Maintaining volume and composition
Delineation of fluid compartments
intracellular fluid (ICF) = within cells
extracellular fluid (ECF) = outside cells
intercellular fluid = tissue fluid = interstitial fluid
plasma = fluid portion of blood
Composition of fluids change as substances move between compartments
nutrients, oxygen, ions and wastes move in both directions across capillary walls

14. Control of Homeostasis
Homeostasis is continually being disrupted by
external stimuli or
intense heat, cold , and lack of oxygen
internal stimuli
psychological stresses
exercise
Disruptions are usually mild & temporary
If homeostasis is not maintained, death may result

15. Neural and Endocrine Controls
Process of maintaining a controlled condition
sensory receptors detect change in a monitored
variable
nervous system and/or endocrine system responds
Example of control of blood gas level
exercise increases blood CO2 levels
sensory receptors detect change
nervous system increases heart and breathing rates to remove excess CO2
adrenal gland releases epinephrine to increase heart and breathing rates

16. Components of Feedback Loop
Receptor
monitors a controlled condition
Control center
determines next action
Effector
receives directions from the control center
produces a response that changes the controlled condition

17. Negative & Positive Feedback Loops
Negative feedback loop
original stimulus reversed
most feedback systems in the body are negative
used for conditions that need frequent adjustment
body temperature, blood sugar levels, blood pressure
Positive feedback loop
original stimulus intensified
seen during normal childbirth

18. Homeostasis of Blood Pressure
Pressure receptors in walls of certain arteries detect an increase in BP
blood Pressure = force of blood on walls of vessels
Brain receives input and signals heart and blood vessels
Heart rate slows and arterioles dilate (increase in diameter)
BP returns to normal

19. Positive Feedback during Childbirth
Stretch receptors in walls of uterus send signals to the brain
Brain releases hormone (oxytocin) into bloodstream
Uterine smooth muscle contracts more forcefully
More stretch, more hormone, more contraction etc.
Cycle ends with birth of the baby & decrease in stretch

20. Homeostatic Imbalances
Disorder = abnormality of structure or function
Disease = homeostatic imbalance with distinct
symptoms---changes in body function felt by the patient such as nausea and anxiety
signs----changes in body function that can be observed by the doctor such as rash or fever
Epidemiology----how disease is transmitted
Pharmacology --- how drugs used to treat disease
Diagnosis---skill of distinguishing one disease from another

21. Basic Anatomical Terminology
Anatomical position
Regions of the body
Anatomical planes, sections and directional terms

22. Anatomical Position
Standardized position from which to describe directional terms
standing upright
facing the observer, head level
eyes facing forward
feet flat on the floor
arms at the sides
palms turned forward
A reclining body?
Prone position = lying face down
Supine position = lying face up

23. Clinical terminology based on a Greek or Latin root word.

24. Planes and Sections
A plane is an imaginary flat surface that passes through the body.
A section is one of the 2 surfaces (pieces) that results when the body is cut by a plane passing through it.

25. Sagittal Plane Sagittal plane Midsagittal plane Parasagittal plane
divides the body or an organ into left and right sides
Midsagittal plane
produces equal halves
Parasagittal plane
produces unequal halves

26. 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

27. Planes and Sections of the Brain (3-D anatomical relationships revealed)
Horizontal Plane
Frontal Plane
Midsagittal Plane

28. Major Directional Terms
See Definitions page 14

29. Superior or Inferior Superior Inferior towards the head
The eyes are superior to the mouth.
Inferior
away from the head
The stomach is inferior to the heart.

30. Dorsal or Ventral Dorsal or Posterior Ventral or Anterior
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.

31. Medial or Lateral Medial Lateral 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.

32. Proximal or Distal Proximal Distal
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.

33. Body Cavities Spaces within the body
Help protect, separate, and support internal organs
Separates by bones, ligaments, and muscles

34. Dorsal Body Cavity Near dorsal surface of body 2 subdivisions
cranial cavity
holds the brain
formed by skull
vertebral or spinal canal
contains the spinal cord
formed by vertebral column
Meninges line the cranial cavity and the vertebral canal

35. Ventral Body Cavity Near ventral surface of body trunk 2 subdivisions
thoracic cavity above diaphragm
abdominopelvic cavity below diaphragm
Diaphragm = large, dome-shaped muscle
Organs called viscera
Organs covered with serous membrane

36. Abdominopelvic Cavity
Inferior portion of ventral body cavity below diaphragm
Encircled by abdominal wall, bones & muscles of pelvis
Subdivided into Abdominal and pelvic cavities

37. Abdominopelvic Cavity
Abdominal Cavity: stomach, spleen, liver, gallbladder, small intestine, most of the large intestine.
Pelvic Cavity: urinary bladder, portions of the large intestine, and internal organs of reproduction

38. Thoracic Cavity A.K.A. – Chest Cavity
Encircled by ribs, sternum, vertebral column and muscle
Divided into 2 pleural cavities by mediastinum
Mediastinum contains all thoracic organs except lungs

39. Mediastinum
Midline wall of tissue that contains heart and great vessels, esophagus, trachea and thymus.

40. 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

41. Pleural & Pericardial Cavities
Visceral pleura clings to surface of lungs --- Parietal pleura lines chest wall
Visceral pericardium covers heart --- Parietal pericardium lines pericardial sac

42. Peritoneum
Visceral peritoneum --- serous membrane that covers the abdominal viscera
Parietal peritoneum --- serous membrane that lines the abdominal wall

43. Abdominopelvic Regions & Quadrants
Describe locations of organs or source of pain
Tic-tac-toe grid or intersecting lines through navel

44. Medical Imaging Allows visualization of structures without surgery
Useful for confirmation of diagnosis
Examples: radiography, MRI, CT, Ultrasound, PET, Radionuclide scanning, & Endoscopy

45. Conventional Radiography
A.K.A – X-ray
A single burst of xrays
Produces 2-D image on film
Inexpensive, quick, and simple to perform
Bones appear white
Hollow structures are black
Skin, fat, and muscle appear varying shades of gray

46. Other types of Radiography
Mammography
Bone Densitometry
Angiography
Intravenous urography
Barium contrast x-ray
Breast
Bone density
Blood vessels
Urinary system
Gastrointestinal tract

47. Computed Tomography (CT Scan)
Moving x-ray beam
Image produced on a video monitor of a cross-section through body
Computer generated image reveals more soft tissue detail
kidney & gallstones
Multiple scans used to build 3D views
Most beneficial in screening for lung cancer, coronary artery disease, and kidney cancer

48. Digital Subtraction Angiography(DSA)
Radiopaque material injected into blood vessels
Before and after images compared with a computer program
Image of blood vessel is shown on a monitor
Can locate blocked blood vessels

49. Ultrasound (US) High-frequency sound waves emitted by hand-held device
Safe, noninvasive & painless
Image or sonogram is displayed on video monitor
Used for fetal ultrasound and examination of pelvic & abdominal organs, heart and blood flow through blood vessels
Also to observe the size, location, and actions of organs and blood flow through blood vessels

50. Magnetic Resonance Imaging (MRI)
Body exposed to high-energy magnetic field
Protons align themselves relative to magnetic field
Pulse of radiowaves used to generate an image on video monitor
Can not use on patient with metal in their body
Reveals fine detail within soft tissues
Used to detect tumors, fatty plaques, brain abnormalities, measuring blood flow, and musculoskeletal, liver, and kidney disorders

51. Positron Emission Tomography(PET)
Substance that emits positively charged particles is injected into body
Collision with negatively charged electrons in tissues releases gamma rays
Camera detects gamma rays & computer generates image displayed on monitor
Used to study physiology of body structures, such as metabolism in the brain or heart

52. YouTube - RADIOLOGY