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 BodyEach 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: