Presentation on theme: "The Human Body: An Orientation. Overview of Anatomy and Physiology Anatomy – the study of the structure of body parts and their relationships to one another."— Presentation transcript:
The Human Body: An Orientation
Overview of Anatomy and Physiology Anatomy – the study of the structure of body parts and their relationships to one another How is it constructed?
Physiology Physiology – the study of the function of the bodys structural machinery or organ systems How does it work?
Levels of Structural Organization Chemical – atoms combined to form molecules Cellular – cells are made of molecules Tissue – consists of similar types of cells
Organ – made up of different types of tissues Organ system – consists of different organs that work closely together Organismal – made up of the organ systems
Chemical level Atoms combine to form molecules Cellular level Cells are made up of molecules Tissue level Tissues consist of similar types of cells 5 Organ system level Organ systems consist of different organs that work together closely Organ level Organs are made up of different types of tissues 6 Organismal level The human organism is made up of many organ systems Atoms Molecules Smooth muscle cell Smooth muscle tissue Connective tissue Smooth muscle tissue Epithelial tissue Blood vessel (organ) Heart Blood vessels Cardiovascular system Levels of Structural Organization Figure 1.1
Orientation Orientation is the position of something relative to some point. The human body is oriented into –Directions –Landmarks –Planes –Cavities –Quadrants –Regions –Systems
Superior or cranial toward the head end of the body; upper (example, the hand is part of the superior extremity). Inferior or caudal away from the head; lower (example, the foot is part of the inferior extremity). Directional Terms
Anterior or ventral front (example, the kneecap is located on the anterior side of the leg). Posterior or dorsal back (example, the shoulder blades are located on the posterior side of the body).
Medial toward the midline of the body (example, the middle toe is located at the medial side of the foot). Lateral away from the midline of the body (example, the little toe is located at the lateral side of the foot).
Proximal toward or nearest the trunk or the point of origin of a part (example, the proximal end of the femur joins with the pelvic bone). Distal away from or farthest from the trunk or the point or origin of a part (example, the hand is located at the distal end of the forearm).
Superficial toward the surface Deep away from the surface Cephalad toward the head Caudal toward the tailbone
Anatomical Landmarks See page 4 for anterior and posterior landmarks. Record those landmarks on the handout provided.
Body cavities are internal chambers holding vital organs –Cavities protect vital organs –Cavities allow organs to change in shape and size Body Cavities
Two body cavities –Dorsal body cavity includes the cranial cavity and the spinal cavity –Ventral body cavity includes the thoracic cavity and the abdominopelvic cavity
The abdominopelvic cavity is lined by the peritoneum –The abdominal cavity extends from the diaphragm to the superior margins of the pelvis liver, stomach, spleen and most of the large intestine Abdominopelvic Cavity
–The pelvic cavity is bordered by the pelvis, with a floor of muscle reproductive organs, urinary bladder and the final portion of the large intestine Abdominopelvic Cavity
Prefixes, Suffixes, and Roots epi- upon, above hypo – below gastric – stomach iliac – superior part of the hip bone chondro – cartilage lumbus – loin umbilicus - navel Decipher the following words: 1.Hypochondriac 2.Epigastric 3.Hypogastric
Body Systems See the handout that describes the 11 body systems. Learn the function and organs found in each system.
Organ Systems Interrelationships Organ systems work together to carry necessary life functions. For example –Digestive and respiratory systems, in contact with the external environment, take in nutrients and oxygen
Necessary Life Functions Maintaining boundaries – the internal environment remains distinct from the external –Cellular level – accomplished by plasma membranes –Organismal level – accomplished by the skin
Movement – locomotion, propulsion (peristalsis), and contractility Responsiveness – ability to sense changes in the environment and respond to them Digestion – breakdown of ingested foodstuffs
Metabolism – all the chemical reactions that occur in the body Excretion – removal of wastes from the body Reproduction – cellular and organismal levels –Cellular – an original cell divides and produces two identical daughter cells –Organismal – sperm and egg unite to make a whole new person
Growth – increase in size of a body part or of the organism
Homeostasis Homeostasis is the ability to maintain a relatively stable internal environment in an ever-changing outside world The internal environment of the body is in a dynamic state of equilibrium
The nervous system and the endocrine system work together to maintain homeostasis.
Homeostatic Control Mechanisms The variable produces a change in the body The three interdependent components of control mechanisms are:
–Receptor – monitors the environments and responds to changes (stimuli) –Control center – determines the set point at which the variable is maintained –Effector – provides the means to respond to the stimulus
Stimulus: Produces change in variable Change detected by receptor Input: Information sent along afferent pathway to 5 Response of effector feeds back to influence magnitude of stimulus and returns variable to homeostasis Variable (in homeostasis) Imbalance Receptor (sensor) Control center 4 Output: Information sent along efferent pathway to Effector Homeostatic Control Mechanisms Figure 1.4
Negative Feedback In negative feedback systems, the output shuts off the original stimulus Example: Regulation of blood glucose levels
Negative Feedback Figure 1.5
Positive Feedback In positive feedback systems, the output enhances or exaggerates the original stimulus Example: Regulation of blood clotting Figure 1.6
Homeostatic Imbalance Disturbance of homeostasis or the bodys normal equilibrium Overwhelming of negative feedback mechanisms allowing destructive positive feedback mechanisms to take over