CHAPTER 1 Introduction to Human Anatomy and Physiology

CHAPTER 1 Introduction to Human Anatomy and Physiology

Anatomy and Physiology Anatomy -- deals with the structure of the body and its parts Physiology -- studies the functions of these parts or asks the question, “how do they work? ” Structure and function closely related Which field is most likely to have new discoveries? Why?

Anatomy or Physiology? To send a nerve impulse, sodium and potassium ions must switch places in the cell. The human tailbone is a fusion of multiple vertebrae. When the bicep muscle contracts, it pulls on tendons and ligaments which move the lower arm toward the upper arm.

Copyright The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display. Levels of Organization:

Characteristics of the human organism 1. 2. 3. 4. 5. 6. 7. 8. 9. Movement (either gross or movement of internal organ) Response to stimuli Growth Reproduction Respiration (take in oxygen, out with carbon dioxide) Digestion Absorption (nutrients taken into bloodstream) Circulation (movement of substances in bodily fluids) Assimilation (changing absorbed substances into chemically different forms) 10. Excretion Metabolism: all chemical reactions at work to maintain/allow for these

. Life depends on the availability of: a. Water b. Food c. Oxygen d. Heat (a by-product of metabolism; affects reaction rates) e. Pressure (force required for movement of air and fluids)

Homeostasis Dynamic process of self-regulating controls which create a stable internal environment External conditions are always changing To survive, internal conditions must remain relatively stable…How? ? ?

Homeostasis Maintaining a stable internal environment Organ systems function to maintain homeostasis Examples?

Homeostasis 1. Body has a set point (normal, balanced) 2. Receptors in the body detect deviations away from set point 3. Brain interprets information 4. Triggers a set of events (using effectors) to bring the situation back to normal

Homeostasis – Negative Feedback NEGATIVE FEEDBACK – Correction occurs opposite direction of stimulus Examples: Body temp rises; cooling mechanisms activated Body temp drops; heating mechanisms activated Other examples? Blood sugar levels, blood oxygen levels

Blood Sugar Regulation

Homeostasis – Positive Feedback POSITIVE FEEDBACK - Stimulus amplifies response in the same direction Why?

Homeostasis – Positive Feedback Examples: Chemicals present in a blood clot lead to more clotting A baby drinking mother’s milk causes more milk production Pressure in the uterus during childbirth leads to stronger contractions Positive Feedback responses are typically short-term… why?

Homeostasis VITAL SIGNS A measure of homeostasis Indicate that someone is alive What is measured in a test of vital signs?

Vital Signs Monitored to determine level of health: Vital Sign What is it? Normal Body Temp 97 o-100 o. F Blood Pressure 100/60 - 140/90 Heart Rate 60 -100 beats/min Resp Rate 12 -20 breaths/min Pupils Dilate and contract Blood O 2 level >90% Reflexes Responsive

Anatomical Terminology Lots of vocabulary to describe the body Why? Allows doctors/health professionals to communicate as clearly as possible Which would you rather hear as a surgeon? “It hurts in the left upper side of my chest. ” “I’m having pain in the left lateral pleural cavity, superior to the heart. ”

Organization of Body - Body Cavities AXIAL (head, neck, trunk) vs. APPENDICULAR (upper and lower limbs) Ventral Cavity: Front (anterior) -thoracic cavity -diaphragm -abdominopelvic cavity Dorsal Cavity: Back (posterior) -cranial cavity -vertebral (spinal) cavity

Organization of Body Membranes PARIETAL – lines body cavity VISCERAL – covers organ

Organization of Body - Ventral Cavity Thoracic Cavity contains pleural (lung) pericardial (heart) cavities

Organization of Body - Cranial Cavity

Anatomical Terminology Always refer to body in ANATOMICAL POSITION Face forward Palms forward Note: Right and left refer to the patient

. Anatomical Terminology Relative Positions: Terms used to describe the location of a body part relative to another part. Terms include: superior (closer to the head), inferior anterior (towards the front), posterior medial (closer to midline), lateral proximal (closer to trunk), distal superficial (towards the surface), deep ipsilateral (on same side), contralateral

. Anatomical Terminology - Body Sections 1. A sagittal (median) section divides the body into right and left portions. 2. A transverse (cross) section divides the body into superior and inferior portions. 3. A coronal (frontal) section divides the body into anterior and posterior sections.

Copyright The Mc. Graw-Hill Companies, Inc. Permission required for reproduction or display.

What does this mean? The lesion is located in the right thoracic cavity just lateral to the mid-sagittal plane.