Cardiac System
Define Diastole and Systole.
Diastole: Relaxation
Systole: Contraction
Which ventricle is the thickest?
Left Ventricle
The action potential in excitable cells relies on which two ions moving into and out of the cell membrane?
Sodium and Potassium
What is the resting potential?
-70 mV
T/ F: Action potentials are all or nothing.
True
Define the following: Veins, arteries, and capillaries.
Veins: Carry deoxygenated blood to the heart, Not as strong as arteries.
Arteries: Carry oxygenated blood from the heart to body tissues. Have thicker walls & elastic fibers to withstand pressure.
Capillaries: Where blood diffusion occurs. Capillaries have the thinnest walls to help with diffusion into tissues. Connects veins and arteries.
What makes AV and Semilunar Valves open and close?
AV Nodes: Opens when ventricles are relaxed. Close when the ventricles contract
Semilunar Valves: Opens when the ventricles contract. Close when ventricles relax.
Parasympathetic stimulation of cardiac muscle would ________ activity. (heart rate)
Decrease
What does a leak channel do?
It allows some potassium to move out of the neuron membrane which creates a change in charge.
What are the different orders of the reflex center?
1st Order: Just spinal cord (knee Jerk)
2nd Order: Brain Stem (breathing, sweating)
3rd Order: Cerebral Cortex (tie shoes)
How does the heart get blood for its self?
Through the coronary circulation. It is the most oxygenated.
What is a refractory period? What are the 2 parts?
- When a cell will not respond to any stimulus
* Relative Refractory Period: On repolarization downslope, Stronger than normal impulse allows AP
*Supernormal Period: Impulse weaker than normal
Repolarization of a nerve fiber is accomplished by ...
K+ diffusion from inside the cell to outside the cell
What is the difference between the two matters of the spinal cord?
Grey: Contains neural cell bodies, unmyelinated axons, and dendrites, Talking site,
White: Covers grey matter, Contain axons that form ascending and descending tracts, Highway for sensory and motor fibers, Transition site
1. Excitatory chemically gated channels move ______ the membrane potential threshold (encouraging the all or nothing process). It uses Na to move towards the threshold.
Whereas
2. Inhibitory chemically gated channels move ______ from the membrane potential threshold (discourage the all or nothing process). It uses K to move away from the threshold.
1. Towards
2. Away
Define the following: AV Node, SA Node, AV Bundle of HIS, Authorythmic Cells.
AV Node: Located in the atrial septum, it transmits a signal to the Bundle of HIS
SA Node: Cluster of cells in the wall of the right atria. It begins heart activity that spreads to both atria.
AV Bundle of HIS: Connection between atria and ventricles. It divides into bundle branches and purkinje fibers.
Authorythmic Cells: Cells that fire sponateously, the cell acts as a pacemaker and forms the conduction system for the heart.
What are the steps of electrical conduction in the heart?
Which features of the heart allow for cell-to-cell propagation of neural impulses to cause a heartbeat?
Intercalated Discs
What are the 5 components of a reflex arc?
1. Receptor (skin)
2. Sensory Neuron (sends message to spinal cord)
3. Integrating Center (interneuron)
4. Motor Neuron (sends message to muscle)
5. Effector (skeletal muscle)
The spinal cord contains 2 different types of fibers enclosed in connective tissue. What are those fibers and describe them?
Efferent Fibers: Motor, Carries motor information away from the CNS by sending messages out of the spinal cord through the ventral root to muscles and glands in the body
Afferent Fibers: Sensory, Carries information from sensory receptors of the skin and other organs and enters the spinal cord through the dorsal root
List the steps to heart circulation? (HINT: Systemic and Pulmonary Circulation)
Deoxygenated blood flows into the right atrium through the tricuspid valve and into the right ventricle. It is pumped through the pulmonary semilunar valve into the pulmonary trunk and the pulmonary arteries carry blood to the lungs for the exchange of gases. Oxygenated blood is brought back to the heart through the pulmonary veins and deposited into the left atrium. It flows through the bicuspid valve into the left ventricle. It gets pumped through the aortic semilunar valve into the aorta and pumped to the rest of the body through the aortic arteries.
What is the cardiac cycle and what are the steps?
Steps:
The area of modified cardiac muscle cells in the cell wall of the right atrium that initiates the heartbeat is _____.
Sinoatrial Node
What is the purpose of Cranial Nerve 1, 2, 3, 7, 8, 9?
1: Olfactory (Smell)
2: Optic (Vision)
3: Oculomotor (Muscles of the eye)
7: Facial
8: Vestibulocochlear
9: Vagus (Sensations & Secretions of viscera)
What are the structural classifications of neurons?
Multipolar: Several dendrites & one axon (Most Common)
Bipolar: One main dendrite & One axon
Unipolar: One process only (sensory neurons)