Unit 1: Intro to Physiology

Anatomy The branch of science that studies body parts.

Physiology The branch of science that describes HOW the body works, or functions. Example - how the heart pumps blood and why it is essential for life

Structure and Function Anatomy (structure) and physiology (function) are closely related. When you look at a hand, how does its structure relate to its function? A hand needs to grasp things, so how does the structure allow for that?

The Body’s Levels of Organization

Note the progression from simple to complex: Atoms – building blocks of all matter Molecules – made up of many atoms Cells – the basic units of life Tissues – specialized groups of cells Organs – tissues are arranged into organs, each with its own function Organ systems – groups of organs working together

Organs and Organ Systems Organ – group of tissues arranged to accomplish a particular function Organ system – group of organs that help each other to perform a particular function

Major Organ Systems (There are 11 total!) Integumentary – skin/protection Skeletal – support Muscular – movement Nervous – sensory Endocrine – hormones/biochemical control Circulatory – transports blood/nutrients

Lymphatic – immunity Respiratory – obtaining O2/ridding of CO2 Digestive – ingest/digest food Urinary system – excrete waste product Reproductive – reproduction Now…let’s take a tour of the organ systems!

Homeostasis Literally means staying (-stasis) the same (homeo-) The body’s ability to maintain a stable internal environment despite changing external conditions Ex – maintaining your body temperature of 370C even though the room temp increases to 1000C. Ex – the amount of water in your cells stays the same whether your drink 2,3, or 4 liters of water per day

Homeostasis – the body has a way of staying the same even when external conditions change Mechanisms that help maintain homeostasis are called homeostatic mechanisms Temperature control Blood sugar control Water balance Blood pressure regulation Plasma sodium levels

Anatomical Terms: Talking About the Body Anatomical position (at right) refers to a person standing erect with face forward, upper limbs hanging to the sides, and palms of the hands facing forward, thumbs out.

Directional Terminology Describe the position of one body part in relation to another body part Similar to north, south, east, west Terms come in pairs that are opposites

Common Directional Terms Superior : toward the head Inferior: away from the head Anterior : toward the front of the body Posterior : toward the backside of the body Dorsal : toward the spine Ventral : toward the belly

Medial: toward the midline of the body Lateral: away from the midline Intermediate: between medial & lateral Proximal: closer to the point of attachment Distal: away from the point of attachment Used when talking about limbs! Superficial: toward the body surface Deep: away from the body surface

Planes and Sections of the Body Each plane divides the body with an imaginary line in one direction… Sagittal plane – divides the body lengthwise into right and left portions Frontal plane – divides the body into anterior (ventral) and posterior (dorsal) portions

Transverse plane – divides the body horizontally, creating an upper (superior) and a lower (inferior) body

Regional Terms List of terms to know on Intro to Physiology Vocab handout.

Cavities of the Body Organs, called viscera, are located within the cavities of the body. Cavities are large internal spaces.

The body contains two major cavities: Dorsal cavity – located toward the back of the body and has two divisions: cranial cavity – within the skull and contains the brain spinal (vertebral) cavity – contains the spinal cord Ventral Cavity – located toward the front of the body and has two divisions: thoracic cavity – surrounded by the rib cage abdominopelvic cavity – cavity below the diaphram

A further breakdown of the abdominopelvic cavity: The upper portion is the abdominal cavity, it contains: Stomach Most of intestine Liver Gallbladder Pancreas Spleen kidneys

The lower portion of the abdominopelvic cavity is called the pelvic cavity, and it contains: Rectum Urinary bladder Internal parts of the reproductive system Because the abdominopelvic cavity is so large, it is subdivided into smaller quadrants and regions: