Anatomy & Physiology

An Introduction to Anatomy & Physiology

Chapter 1

pp. 2-27

Characteristics of Living Organisms

1) Responsiveness: respond to changes in the environment

• irritability – immediate environment• adaptability – over a long period

2) Growth – in size or # of cells

3) Reproduction

4) Movement – internal and external

5) Metabolism: series of complex chemical reactions that provide energy for all the other characteristics

Anatomy vs. Physiology

Anatomy: study of internal and external structures and their relationships

Physiology: study of how living organisms perform their vital functions

What is the Anatomy and Physiology of an automobile?

AnatomyTwo divisions:

1) Microscopic – structures that cannot be seen without magnification

• Cytology: study of individual cells• Histology: study of tissues, or groups of specialized cells working

together

2) Macroscopic (Gross) – structures that are visible to the naked eye

• Surface anatomy: study of general form and superficial markings• Regional anatomy: study of all the superficial and internal features

in a specific region of the body

Physiology

• Many different specialties (human, cell, individual organs)

• Pathological Physiology (Pathology): study of the effects of diseases on organ system functions

Levels of Organization

Have you ever heard of“nesting dolls?”

Levels of Organization

Question: Why should we study activity at the cellular level?

Answer: Damage at any of the levels can affect those levels above

and/or below. They are interconnected.

Example: Genetic Heart Defect

Homeostasis

Definition: existence of a stable internal

environment

NECESSARY FOR SURVIVAL!!

Homeostatic Regulation: physiological

adjustments systems make to maintain

homeostasis

Question: What happens when homeostatic regulation breaks down?

Answer: DISEASE

Process of Homeostatic Regulation

Step 1: Receptor (ex. nerve ending) responds to a stimulus and sends info to control center

Step 2: Control center (ex. brain) processes the information from the receptor and coordinates response

Step 3: Effector (ex. gland) responds to the commands of the control center to oppose or enhance the stimulus

Example: Regulating Room Temperature

Weymouth High School

Feedback: A Method ofHomeostatic Regulation

Negative feedback: a variation outside normal limits (set point) triggers an automatic response that corrects the situation (within normal limits) – MOST COMMON IN BODY

Example: Thermoregulation, glucose regulation (Teeter-totter)

Positive feedback: initial stimulus produces a response that reinforces the stimulus – ONLY A FEW EXAMPLES IN BODY

Example: Blood clotting, Birth (Dominos)

Anatomical Landmarks

• Helps in remembering the names of multiple structures

• Provides the location for multiple structures

Anatomical Landmarks

The Language of Anatomy

Anatomical Position: human form standing with hands at sides and the palms facing forward

Supine: lying face up in the anatomical position

Prone: lying face down in the anatomical position

The Language of AnatomyAnatomical DirectionsAnterior/Ventral: the front or belly side of the

body

Posterior/Dorsal: the back of the human body

Remember, LEFT and RIGHT refer to the body of the subject and not the observer.

The Language of Anatomy

Anatomical DirectionsCranial/Cephalic: toward the head

Caudal: toward the tailbone (coccyx)

Superior: above, or toward the head

Inferior: below, or toward the feet

The Language of Anatomy

Anatomical DirectionsMedial: toward the center of the body

Lateral: away from the center of the body

Proximal: toward the attached base (typically used for limbs)

Distal: away from the attached base (typically used for limbs)

The Language of Anatomy

Anatomical DirectionsSuperficial: at or near the body surface

Deep: farther from the body surface

Anatomical Directions

The Language of Anatomy

Anatomical RegionsBody is divided into 4 regions by lines that intersect

at the bellybutton (umbilicus)

1) Right Upper Quadrant (RUQ)2) Right Lower Quadrant (RLQ)3) Left Lower Quadrant (LLQ)4) Left Upper Quadrant (LUQ)

Clinicians use even more specific distinctions, including 9 abdominopelvic regions. (Thank goodness!)

Anatomical Regions

The Language of AnatomyPlanes and SectionsDefinition: slice through a 3-dimensional object divides the body into

sections (important in non-invasive diagnostic testing procedures)

Transverse: perpendicular to the head-foot axis of the body (parallel to the floor while standing; divides the body into superior and inferior sections

Frontal/Coronal: parallel to the head-foot axis and extends side to side; divides the body into anterior and posterior sections

Sagittal: parallel to the head-foot axis and extends front to back; divides the body into left and right sections **Mid-sagittal refers to a midline division creating equal left and right halves.**

Anatomical Planes

Planes and Sections

Which planes create these “slices”?

The Language of AnatomyBody CavitiesFunctions:1) Protect delicate organs, by cushioning them

during movement (fluid sacs)2) Permit for size/shape changes of organs without

disrupting the activities of surrounding organs

Dorsal: surrounds the brain and spinal cord

Ventral: much larger, surrounds organs of the respiratory, cardiovascular, digestive, urinary, and reproductive systems (viscera)

The Language of Anatomy

Dorsal Cavity in Detail1) Cranial Cavity (Skull)2) Spinal Cavity (Spine)

The Language of Anatomy

Ventral Body Cavity in Detail1) Thoracic Cavity

A. Pericardial Cavity (heart)B. Two Pleural Cavities (lungs)

2) Abdominopelvic Cavity (Peritoneal Cavity)

A. Abdominal Cavity (stomach, liver)B. Pelvic Cavity (reproductive organs)

Body Cavities

Introduction to Organ Systems

Integumentary

• Forms the external body covering

• Protects deeper tissue from injury

• Synthesizes vitamin D

• Location of cutaneous nerve receptors and glands

• Major Components: Skin, Hair, Nails

Skeletal

• Protects and supports body organs

• Provides muscle attachment for movement

• Site of blood cell formation

• Stores minerals

• Major Components: Bone, Cartilage, and Ligaments

Muscular

• Allows locomotion

• Maintains posture

• Produces heat

• Major Components: Muscles and Tendons

Nervous

• Fast-acting control system

• Responds to internal and external changes (stimuli)

• Directs activities of other organ systems by activating muscles and glands

• Major Components: Brain, Spinal Cord, and Peripheral Nerves

Endocrine

• Slow-acting control system

• Secretes regulatory hormones which direct activities of other organ systems

• Growth

• Reproduction

• Metabolism

• Major Components: Glands, Kidneys, Pancreas, Gonads

Cardiovascular

• Transports materials in body via blood pumped by heart including:

• Oxygen

• Carbon dioxide

• Nutrients

• Wastes

• Major Components: Heart, Blood Vessels, Blood

Lymphatic

• Returns fluids to blood vessels

• Disposes of debris

• Involved in immunity

• Major components: Tonsils, Lymph Vessels, Lymph Nodes, Spleen and Thymus

Respiratory

• Keeps blood supplied with oxygen

• Removes carbon dioxide

• Major Components: Air passageways, Lungs

Digestive

• Breaks down food

• Allows for nutrient absorption into blood

• Eliminates indigestible material

• Major Components: Food passageways, Stomach, Intestines, Liver, Pancreas

Urinary

• Eliminates nitrogenous wastes

• Maintains acid – base balance

• Regulation of water and electrolytes

• Major Components: Kidneys, Bladder, Urine passageways

Reproductive

• Production of sex cells and sex hormones

• Production of offspring

• Major Components: Testes and Penis (Male)/Ovaries, Uterus, Vagina (Female)

Interrelatedness of Organ Systems

Just as one level of organization is dependent on another, organs of different systems rely on the function

of the others!

1) Nutrients

• Chemicals for energy and cell building

• Includes carbohydrates, proteins, lipids, vitamins, and minerals

2) Oxygen

• Required for chemical reactions

3) Water (60-80% of body weight)

4) Stable body temperature

5) Appropriate atmospheric pressure

Essential Requirements for Survival

Radiological Procedures

X-ray: high-energy radiation is sent through body tissues to a photographic plate

• “radiodense” tissues such as bone appear white, while air appears black

Barium-contrast: dense liquid is used to see tissues that are normally difficult to see with x-ray, such as stomach and intestine

X-ray

X-ray

Barium-Contrast

Radiological Procedures

CAT Scan: x-ray source rotates around the body to show three-dimensional relationships between body tissues

MRI: body is surrounded by a magnetic field, atoms of different tissues release different amounts of energy forming an image; more detailed than a CAT Scan

Ultrasound: sound waves are sent through the skin, the echoes that are reflected by internal structures form an image

CT Scan

CT Scan

CT Scan

PET Scan

MRI

MRI

MRI

MRI

Ultrasound

Ultrasound