BIOL 199 Study Guide - Final Guide: Blood Sugar, Atrioventricular Node, Cardiac Muscle
Anatomy
Heart
• Muscular pump made up of cardiac muscle (involuntary) that pumps blood
through the veins and throughout the body
o Cardiac muscle has special discs between cells which allow impulses to
be passed quickly
• The heart has a three-layered wall
o Epithelial tissue
o Membrane
o Muscle
Sinoatrial node – internal pacemaker
Sinoatrial node – cells discharge periodically, sending impulses to atrial muscle cells to
Sinoatrial node – contract in unison
Atrioventricular node – impulse travels to ventricles
Atrioventricular node – slows down the signal to allow ventricles to fill
Vein System
Artery – taking blood away from the heart
Artery – most oxygenated, nutrient-rich blood
Artery – thick, elastic walls
Capillaries – branch off an arteriole (small arteries)
Capillaries – one cell thick to allow for diffusion for nutrient and waste exchange
Vein – connected to capillaries by venules
Vein – larger blood vessel that returns oxygen-depleted blood to the heart
Vein – lower speed and pressure, so veins have valves to keep the blood moving
Functions
• The lymphatic system runs alongside the circulatory system and picks up fluid
from capillaries and returns it to the blood
• Valves are responsible for opening and closing valves
o Creates a heart beat
o Allows blood to flow in the correct rhythm
• Circulate blood
o Oxygen/hemoglobin
o White and red blood cells
o Carbon dioxide and other waste
o Plasma (blood glucose and nutrients)
• Circulate body heat