Lecture Exam 1 Study Flashcards
What sequence does blood flow through the heart?
Watch more videos on it!!!!!!!!! don’t be dumb.
How does contraction occur in cardiac contractile cells?
hint: describe actions of actin/myosin
the binding of the myosin head to ATP, pulls the actin filaments to the center of the sarcomere, the mechanical force of contraction.
What occurs at the sarcolemma?
Site where calcium enters and leaves a cell
What occurs during mid-late diastole
the ventricles become fully dilated, the atria begin to contract, pumping blood to the ventricles.
What occurs during early ventricular diastole
during ventricular diastole–early, the heart relaxes and expands while receiving blood into both ventricles through both atria
Explain the extrinsic innervation of the heart
sympathetic/parasympathetic
The extrinsic supply is from parasympathetic (from the vagus nerve) and sympathetic nerves from both the superficial and deep cardiac plexuses, which provide post-ganglionic fibers to the (SA) and (AV) nodes
What are the characteristics of elastic arteries?
contain larger numbers of collagen and elastin filaments in their tunica media than muscular arteries do, giving them the ability to stretch in response to each pulse
What are the characteristics of muscular arteries?
the tunica media is composed almost entirely of smooth muscle
What are the characteristics of arterioles?
have muscular walls (usually only one to two layers of smooth muscle cells) and are the primary site of vascular resistance.
What are the characteristics of continuous capillaries?
Continuous capillaries are generally found in the nervous system, as well as in fat and muscle tissue
What are the characteristics of fenestrated capillaries?
can be found in tissues where a large amount of molecular exchange occurs, such as the kidneys, endocrine glands, and small intestine.
What are the characteristics of sinusoidal capillaries?
found in the liver, spleen, lymph nodes, bone marrow and some endocrine glands
What are venules?
Very small branches that collect the blood from the various organs and parts to return to the heart
What are veins?
blood vessels that carry blood low in oxygen from the body back to the heart
Describe blood pressure regulation
blood pressure is regulated by baroreceptors which act via the brain to influence the nervous and the endocrine systems.
How are RBC’s produced?
are formed in the red bone marrow of bones through a process called Erythropoiesis.
What is meant by antigens in reference to RBC’s?
any substance to which the immune system can respond
What is meant by antibodies in reference to RBC’s?
proteins made by your body to attack foreign substances such as viruses and bacteria.
Describe what causes hemolytic disease of newborns
when the immune system of the mother sees a baby’s RBCs as foreign. Antibodies then develop against the baby’s RBCs. These antibodies attack the RBCs in the baby’s blood and cause them to break down too early. HDN may develop when a mother and her unborn baby have different blood types
How are systemic and pulmonary circuits similar?
They both move blood from the heart to another system
What does auto rhythmic mean?
the heart produces its own pulses through electrochemical stimuli originating from a small group of cells in the wall of the right atrium, known as the sinoatrial node (or SA node).
What is an ECG?
means of measuring heart membrane potential during the cardiac cycle by measuring the electric current conducted through body fluid to the skin
What does the P wave represent?
depolarization of the atria
What does the QRS wave represent?
depolarization of the ventricles
What does the T wave represent?
repolarization of the ventricles
What things are measured in an ECG?
heart rate (intervals between cycles) contraction force (amplitude of waves) rhythm (intervals between waves)
What does abnormally long P-Q interval indicate?
AV conduction problem
What do ectopic beats indicate?
an AP is being generated independently of the SA node
What is pulmonary circulation?
movement of blood between the heart and lungs
What is systemic circulation?
Movement of blood from the heart to the rest of the body
What causes the first heart sound?
The first heart sound represents closure of the atrioventricular (mitral and tricuspid) valves
What occurs during an action potential in cardiac autorythmic cells?
slow influx of sodium ions until the threshold is reached followed by a rapid depolarization and repolarization. The prepotential accounts for the membrane reaching threshold and initiates the spontaneous depolarization and contraction of the cell.
The _____ supply is from _______ (from the vagus nerve) and sympathetic nerves from both the superficial and deep cardiac plexuses, which provide post-ganglionic fibers to the (SA) and (AV) nodes
Extrinsic
Parasympathetic
