HANGERS Decide between you and your table partner who will bring in a hanger for Friday’s activity.

LECTURE 28: CIRCULATORY AND RESPIRATORY

CIRCULATORY SYSTEM Function Transports nutrients and waste throughout the body

STRUCTURES 1.Heart : muscular organ that pumps blood Divided into right and left by septum Each side has an upper section (atrium) and lower section (ventricle).

STRUCTURES, CONT. 2. Vessels: smooth muscle surrounded by connective tissue

STRUCTURES, CONT. arteries – carries blood AWAY from the heart veins –carries blood to the heart

STRUCTURES, CONT. capillaries – narrow blood vessels that allow for gas exchange to occur

STRUCTURES, CONT. 3. Blood  PLASMA: liquid medium  made of 90% water, sugar, salts, amino acids, vitamins, minerals  RED BLOOD CELLS (erythrocytes):  transport CO 2 and O 2 gas  Contains hemoglobin (O2 binds here)  Lacks nucleus to increase space

STRUCTURES, CONT.  WHITE BLOOD CELLS (leukocytes): fight pathogens  PLATELETS: form blood clots

MOVEMENT OF BLOOD Two Circuits (Pathways) 1. Pulmonary (deoxygenated) right side of heart sends blood to the LUNGS

MOVEMENT OF BLOOD 2. Systemic (oxygenated) left side of heart sends blood to BODY

RESPIRATORY SYSTEM

External Function Exchange of gases between atmosphere and blood Pathway mouth/nose  pharynx  epiglottis  trachea  bronchi  lungs

MECHANISM Diaphragm contracts and pulls the thoracic cavity down causing the lungs to fill with air

INTERNAL FUNCTION Exchange of gases between blood and other body cells Gases diffuse across due to concentration gradients….. DIFFUSSION!