Intro to Medical Science Unit 1: Objectives

• 1. Review the basic functions of living organisms • 2. Define and Physiology and gain an understanding of the relationship between the two • 3. Identify major levels of organization in living organisms • 4. Understand the basic functions of the various systems in the body • 5. Explain the significance of Homeostasis • 6. Use anatomical terms to describe body orientation • 7. Identify major cavities of and their multiple subdivisions Characteristics of Life

• Six common characteristics of living things Characteristics of Life

• 1. Cellular organization- The ‘cell’ is the smallest unit that can be alive. The cells within a multicellular organism are arranged into tissues and systems • 2. Energy requirement- living organisms carry out cellular respiration which converts energy in food to a form that is useable by cells for life processes Characteristics of Life

• 3. Interaction with the environment- living organisms depend on the environment for food and nutrients. Organisms must maintain a stable internal environment through homeostasis • 4. Reproduction- living organisms have the ability to reproduce more of their own kind Characteristics of Life

• 5. Adaptation- Populations of living organisms are able to adapt to changing environmental conditions • 6. Growth and Development- Organisms grow from a single cell as an egg, to an adult with millions (or more) cells. Anatomy and Physiology

• anatomy (n.)-The study of internal and external structures and the physical relationship between body parts. • physiology (n.)-The study of how living organisms perform their functions. Major Levels of Organization

Atom Molecule Cells Tissue Organ Organ system Organism Major Levels of Organization

• Atom and Molecule- chemical level of organization • Cells- smallest unit of life • Tissue- similar cells working together • Organ- two or more different tissues work together to perform specific functions • Organ system- multiple organs work together to perform specific functions • Organism- organ systems working in sync to create homeostasis Major Systems of the Body • Integumentary- skin, nails, hair – Protects and regulates temperature Major Systems of the Body • Skeletal- bones and cartilage – Support, protection, blood cell formation Major Systems of the Body • Muscular- muscle – Movement, support, creates heat Major Systems of the Body • Nervous system- , , nerves – Responds to stimuli, coordinates organ systems Major systems of the body • Endocrine system- glands – Directs long term changes in organ systems Major systems of the body • Cardiovascular system- , blood vessels – Transportation of materials through body Major systems of the body • Lymphatic system- lymph nodes, – Immune system Major systems of the body

• - – Delivers air to gas exchange sites Major systems of the body • Digestive system- , intestines, – Processes food and absorbs materials Major systems of the body • Urinary system- kidneys – Eliminates water, wastes, etc. Major systems of the body • – Creates sex cells and hormones Homeostasis

• The existence of a stable internal environment. • Is it constant? – NO!! Unless you are dead. – It is constantly fluctuating Homeostasis • 3 Components to this regulation – 1. Receptor/Sensor- detects the change (body is getting too warm) – 2. Control center- receives and processes the signal from the receptor/sensor (usually the brain) and sends message to effector – 3. Effectors- responds to the commands of the control center and reverses the initial change (skin pores begin to perspire and blood vessels dilate) Homeostasis

• Response can be either – opposition to stimulus or a Negative feedback loop – Reinforcement of stimulus or a Positive feedback loop Example: Household Thermostat

Temperature Set point 68 degrees increases (stimulus)

Temperature Thermometer senses decreases change (receptor)

Thermostat turns AC on (control center) Set point 98.6 Outside temperature Degrees Decreases (stimulus)

Detected by temperature Body temp stays receptors in skin constant (receptor)

Muscle fibers contract Brain processes info generate heat and sends signal to (effectors) Body (control center) Homeostasis

• Positive feedback loop- intensifies stimulus – Severe cut: signals more clotting factors – Labor: signals more contractions Homeostasis

• Negative feedback loop- opposes the initial stimulus – Regulation of body temp. – Regulation of blood glucose levels – Regulation of CO2 levels in blood The Language of Anatomy

Anterior front side The navel is on the anterior surface of the trunk. Ventral belly side The legs are located on the ventral side of the mink. Posterior back side The shoulder blade is located posterior to the . Dorsal back side The breathing hole in dolphins is located on the dorsal side. The Language of Anatomy

Cephalic the head The cephalic border of the is superior to the thigh. Superior above; toward The nose is superior to the chin. the head Caudal Tail The hips are caudal to the waist.

Inferior Below The knees are inferior to the hips. The Language of Anatomy

Medial Toward the The medial surfaces of the thighs may be midline of the in contact. Moving medially from the arm body across the chest brings you to the sternum. Lateral Away from the Moving laterally from the nose brings you midline of the to the eyes. body

Proximal Toward an The thigh is proximal to the foot. attached base

Distal Away from an The fingers are distal to the wrist attached base

PLANES OF THE BODY • Three different sectional planes – 1. Transverse plane- divides body into superior and inferior sections

Transverse Plane PLANES OF THE BODY

• 2. Frontal plane/Coronal Plane- divides body into anterior and posterior sections PLANES OF THE BODY

• 3. Sagittal plane- divides the body into left and right sections Fun WebSite Quadrants of

• Abdominopelvic quadrants- four segments that intersect at umbilicus – Right upper quadrant – Right lower quadrant – Left upper quadrant – Left lower quadrant

Quadrants of abdomen

• For more precise regional distinctions, there are nine abdominopelvic regions used to describe the location of internal organs

Body Cavities

• Serve two functions – 1. Protect organs from accidental shocks and cushion them during walking, running, jumping, etc. – 2. Permit significant changes in size and shape of visceral organs Body Cavities

• Two main body cavities formed during embryological development…each has various sub cavities Body Cavities

• 1. Dorsal – - encloses the brain – Spinal cavity- surrounds the spinal cord

Body Cavities

• 2. Ventral body cavity – • (lungs) • Pericardial cavity (heart) – • • Body Cavities

• - not considered body cavity, yet houses pericardial cavity, thymus gland, trachea, and esophagus