06/06/2023 Notes Flashcards
What spinal nerves for the lumbar nerve plexus?
Spinal nerves L1-L4
What does the femoral nerve innervate?
Quadriceps femoris and sartorius
What does the obturator nerve innervate?
Gracilis
What spinal nerves form the sacral nerve plexus?
Spinal nerves L4-S4
What is the largest nerve in the body? what two nerves compose it?
Sciatic nerve is the largest nerve in the body and is formed by both the tibial and common fibular nerve
What does the tibial nerve innervate?
Hamstring, gastrocnemius, and soleus
What does the common fibular nerve innervate?
Peroneus longus and tibialis anterior
Where does the CNS primarily develop from in the embryo?
Within the neural tube
What does the cranial part of the neural tube form?
Brain
What part of the neural tube forms the spinal cord?
Caudal part
What forms the central canal of the spinal cord?
hollow neural tube
Where does the spinal cord extend to in a newborn?
L3
Where does the spinal cord extend to in a child?
L2
Where does the spinal cord extend to in an adult?
L1
Trauma to the spinal cord above C3 leads to what?
Death by asphyxiation since innervation of the diaphragm and intercostal walls are lost
Trauma to spinal nerves C3-C7 leads to what?
Quadripledia
Trauma to spinal nerves T1-L1 may result in what?
Paraplegia
What is paraplegia?
Paralysis of both lower extremeties
What is necessary for maintaining homeostasis?
Continuous circulation of blood
What happens if the heart fails to pump blood?
Cells are deprived of oxygen and nutrients, waste products build up, and death occurs
What is the average heart beat?
75bpm
What is cardiac output?
Amount of blood pumped from one ventricle in a minute
Cardiac output can increase _____ times when the body is active since cells need nutrients and oxygens at a faster pace
5-6
What is the cardiovascular system composed of?
Heart and blood vessels
What are the two basic types of blood vessels?
Arteries and Veins
What are arteries?
Blood vessels that carry blood away from the heart that is usually high in oxygen except for pulmonary arteries
What are veins?
Blood vessels that carry blood to the heart that are lower in oxygen except for pulmonary veins
What are the great vessels?
Blood vessels that enter/leave the heart that have a large diameter
What are the 3 characteristics and functions of the heart?
Heart’s anatomy ensures unidirectional flow of blood, acts like 2 side-by-side pumps, and develops blood pressure
How is backflow of blood prevent in the heart to ensure unidirectional flow of blood?
Valves
Where does blood on the right side of the heart travel to?
The lungs for gas exchange
Where does blood from the left side of the body travel to?
Body tissues to deliver nutrients and gas exchange
What is pulmonary circulation?
Movement of deoxygenated blood from the right atrium to the right ventricle to the lungs via pulmonary arteries and returns to the left atrium via pulmonary veins
What is systemic circulation?
Movement of oxygenated blood from the left atrium to the left ventricle to the rest of the body
What is the largest systemic artery?
Aorta
Where does gas exchange occur?
Capillaries
What are systemic veins?
Veins that carry deoxygenated blood high in carbon dioxide and waste products
Most veins merge where and where does that venous blood drain into?
Most veins merge into superior/inferior vena cava and drain into the right atrium
Where is the heart located?
In the mediastinum left of the body’s midline and posterior to the sternum
What is the base of the heart?
Posterosuperior surface of the heart (formed by left atrium) that has the entrance for pulmonary veins
What is the apex of the heart?
Inferior, conical end of the heart
What is the pericardium?
A double-layered serous membrane with a fibrous sac that covers the heart
What is the function of the pericardium?
Restrict movement of the heart so it doesn’t bounce and move around in the thoracic cavity, and prevents the heart from overfilling with blood
What are the two parts of the pericardium?
Fibrous pericardium and serous pericardium
What is the fibrous pericardium?
outer, tough dense connective tissue layer of the pericardium
What is the serous pericardium?
the inner, thin, double-layered serous membrane of the pericardium composed of the parietal layer (lines inner surface of fibrous pericardium) and visceral layer/epicardium (fuses to outer surface of heart)
What is the pericardial cavity?
A potential space that exists between the parietal and visceral layers of the pericardium that contains serous fluid to lubricate membranes and prevent friction
What is cardiac tamponade?
inflammation or bleeding in the pericardial cavity that can be identified by pulsus paradoxus, jugular vein distention (JVD) and falling blood pressure
What is the size of the heart?
Roughly the size of a person’s fist
What three layers form the heart wall?
Epicardium, myocardium, and endocardium
What is the epicardium?
“visceral layer”; Outermost layer of the heart wall where fat is deposited with age
What is the myocardium?
Middle layer of the heart wall composed of cardiac muscle tissue
What is the thickest layer of heart wall?
Myocardium
Where do myocardial infarction (heart attacks) occur in the heart?
Within the myocardium
What is the endocardium?
Innermost layer of the heart wall that covers the internal heart and external surface of heart valves and is continuous with the endothelium (inner lining of blood vessels)
What 4 chambers compose the heart?
Right atrium, right ventricle, left atrium, left ventricle
What are atria (atrium)?
thin-walled chambers located superiorly on the heart
What are the wrinkled, flap-like extensions located on the anterior parts of each atria?
Auricles
Where does blood from the systemic circle travel to?
Right atrium
What circuit does the left atrium receive blood from?
Left atrium
What are ventricles?
Inferior chambers of the heart
What two large arteries exit the heart at the basal surface?
Pulmonary trunk and aorta
Where does the pulmonary trunk deliver blood?
From the right ventricle into the pulmonary circuit
Where does the aorta deliver blood?
From the left ventricle into the systemic circuit
