Bio 116 Test 2

Why is it beneficial for capillary pressure to be very low?

Because it allows time for diffusion between the blood and the surrounding interstitial fluid.

Where are chemoreceptors located?

Carotid bodies, aortic bodies, and on the ventrolateral surfaces of the medulla oblongata.

Name the arterial structure in the neck region that contains baroreceptors.

Carotid sinus

List the unpaired branches of the abdominal aorta that supply blood to the visceral organs.

Celiac trunk, superior mesenteric artery, and inferior mesenteric artery.

Define respiratory defense system.

A series of filtration mechanisms that prevent airway contamination by debris and pathogens.

Describe a Capillary:

A small blood vessel located between an arteriole and a venule. The thin walls permit exchange between blood and interstitial fluid by diffusion.

Define bronchopulmonary segment.

A specific region of a lung supplied by a segmental bronchus.

What are blood islands and form which cells do they form?

Aggregations of embryonic cells scattered within the yolk sac that form blood vessels and blood cells. During embryonic development, these islands give rise to hematopoietic stem cells and hemangioblasts.

Define external respiration:

All the processes involved in the exchange of oxygen and carbon dioxide between the blood, lungs, and the external environment.

What function do the C-shaped tracheal cartilages allow?

Allow room for the esophagus to expand when food or liquids are swallowed.

Where does gas exchange between the air and lungs occur?

Alveoli

Define edema.

An abnormal accumulation of interstitial fluid in peripheral tissues.

Identify the compensatory mechanisms that respond to blood loss.

An increase in cardiac output, a mobilization of venous blood reservoir, peripheral vasoconstriction, and the release of hormones that promote the retention of fluids and the maturation of erythrocytes,

Describe the structure and the function of the blood air barrier.

It is made up of the fused basement membranes of the alveolar epithelium and capillary endothelium. Because it is very thin and oxygen and carbon dioxide are lipid soluble, diffusion occurs rapidly across the membrane.

Explain the 1/r4 equation.

States that resistance (R) is inversely proportional to the fourth power of the vessel radius (r). This means that a small change in vessel diameter results in a large change in resistance.

What pressures determine the direction of airflow within the respiratory tract?

The intrapulmonary pressure and the atmospheric pressure. Air moves from the area with higher pressure to the area with lower pressure.

Identify two veins that carry blood away from the stomach.

The left and right gastroepiploic veins.

Describe the location of the lungs within the thoracic cavity.

The left and right lungs are surrounded by the left and right pleural cavities.

Define gas diffusion:

The movement of oxygen and carbon dioxide across the blood air barrier between alveolar air spaces and alveolar capillaries and across the capillary walls between blood and other tissues.

What physical changes affect the volume of the lungs?

The movements of the diaphragm and rib cage.

Define pulmonary lobule.

The smallest subdivisions of the lungs; branches of the pulmonary arteries, pulmonary veins, and segmental bronchi supply each lobule.

Grace is in an automobile accident and her celiac trunk is ruptured. Which organs will be affected most directly by this injury?

The stomach, inferior portion of the esophagus, spleen, liver, gallbladder, and proximal portion of the small intestine.

Describe the distribution of total blood volume in the body.

The systemic venous system and systemic arterial system contain 64 and 13 percent of the total blood volume. The remaining volume is contained in the heart (7%), pulmonary circulation (9%), and systemic capillaries (7%).

Define blood flow and describe its relationship to blood pressure and peripheral resistance.

The volume of blood flowing per unit of time through a vessel or group of vessels; it is directly proportional to arterial pressure (increased pressure results in increased blood flow) and inversely proportional to peripheral resistance (increased resistance results in decreased blood flow).

What factors are involved in the formation of varicose veins?

These veins are sagging, swollen superficial veins in the thighs and legs. They result from the pooling of blood due to gravity and the failure of venous valves.

Which vessel collects most of the venous blood inferior to the diaphragm?

The inferior vena cava.

Name the first two branches of the common iliac artery.

The internal iliac artery and the external iliac artery.

Identify the veins that combine to form the brachiocephalic vein.

External jugular, internal jugular, vertebral, and subclavian veins.

Describe the structures of the glottis.

"voice box" of the larynx. It is made up of vocal folds and the rima glottidis.

Briefly describe general patterns of blood vessel organization.

(1) peripheral distributions of arteries and veins on the body's left and right sides are identical, except near the heart, where the largest vessels connect to the atria or ventricles (2) a single vessel may have several names as it crosses specific anatomical boundaries, making accurate anatomical descriptions possible (3) tissues and organs are serviced by several arteries and veins.

Describe the structure and function of the cerebral arterial circle.

(circle of Willis) a ring shaped anastomosis that encircles the infundibulum of the pituitary gland. Its arrangement creates alternate pathways in the cerebral circulation, so that if blood flow is interrupted in one area, other blood vessels can continue to perfuse the entire brain with blood.

Under what general conditions would fluid move into a capillary?

(reabsorption) Whenever blood colloid osmotic pressure (BCOP) is greater than capillary hydrostatic pressure (CHP).

Calculate the mean arterial pressure for a person whose blood pressure is 125/70.

(use the formula MAP) diastolic pressure + pulse pressure/3. Therefore, 70+ (125-70)/3 = 70+18.3 or 88.3 mm Hg.

Describe irreversible shock.

Fatal stage that occurs if the positive feedback loops initiated during progressive shock are not broken.

List the factors that contribute to total peripheral resistance.

A combination of vascular resistance, vessel length, vessel luminal diameter, blood viscosity, and turbulence.

Which would reduce the peripheral resistance: an increase in vessel length or an increase in vessel diameter?

An increase in vessel diameter.

The plantar venous arch carries blood to which three veins?

Anterior tibial, posterior tibial, and fibular (peroneal) veins.

Identify the conditions that would shift the balance between hydrostatic and osmotic forces.

Any condition that affects either blood pressure or osmotic pressures in the blood or tissues will shift the balance between hydrostatic and osmotic forces.

Identify the largest artery of the body.

Aorta

Which is greater: arterial pressure or venous pressure?

Arterial pressure is much higher than venous pressure because it must push blood a greater distance and through progressively smaller and thinner vessels.

List the 5 classes of blood vessels:

Arteries, Arterioles, Capillaries, Venules, and Veins.

Describe the changes in cardiac output and blood flow during exercise.

Blood flow to skeletal muscles increases at the expense of blood flow to skeletal muscles increases at the expense of blood flow to less essential organs.

Define tissue perfusion.

Blood flow to tissues that is sufficient to deliver adequate oxygen and nutrients.

Describe circulatory shock.

Blood loss exceeds about 35% of the total blood volume. Involves a series of positive feedback loops that are initiated after homeostasis has been disrupted.

Distinguish between the conducting portion and respiratory portion of the respiratory tract.

Conducting: begins at the nasal cavity and extends through the pharynx, larynx, trachea, bronchi, and larger bronchioles. Respiratory: respiratory bronchioles and alveoli.

Identify the two types of capillaries with a complete endothelium:

Continuous and Fenestrated Capillaries.

Describe the pattern of fetal blood flow to and from the placenta.

Deoxygenated blood flows from the fetus to the placenta through a pair of umbilical arteries, and oxygenated blood returns from the placenta in a single umbilical vein. The umbilical vein then drains into the ductus venosus within the fetal liver.

Distinguish among efferent and afferent vessels:

Efferent vessels (arteries): carry blood AWAY from the heart. Afferent vessels (veins): carry blood to the heart, and exchange vessels (capillaries) exchange nutrients, dissolved gases, and wastes between the blood and interstitial fluid.

Identify the hormones responsible for short term regulation of decreasing blood pressure and volume.

Epinephrine and norepinephrine.

Whenever Thor gets angry, a large vein bulges in the lateral region of his neck. Which vein is this?

External jugular vein

How are hypoxia and anoxia different?

Hypoxia is low tissue oxygen levels and anoxia is the complete cutoff of oxygen supply.

Name the immediate and long-term problems related to hemorrhage.

Immediate, short-term: to maintain adequate blood pressure and peripheral blood flow. Long-term: to restore normal blood volume.

Neural and endocrine regulatory mechanisms influence which factors?

Influence heart rate, stroke volume, peripheral resistance, and venous pressure.

A blood clot that blocks the popliteal vein would interfere with blood flow in which other veins?

Interfere with blood flow in the tibial and fibular (peroneal) veins (which form the popliteal vein) and the small saphenous vein (which joins the popliteal vein).

Describe auto-regulation as it relates to cardiovascular function.

Involves local factors changing the pattern of blood flow within capillary beds in response to chemical changes in interstitial fluids.

Why can cystic fibrosis become lethal?

It causes production of dense mucus that restricts respiratory passages and accumulates in the lungs. Harmful bacterial infection of the lungs may also develop, leading to death.

A blockage of which branch of the aortic arch would interfere with the blood flow to the left arm?

Left subclavian artery

Trace the path of a drop of blood from the left ventricle to the right hip joint.

Left ventricle -> ascending aorta -> aortic arch -> thoracic aorta -> abdominal aorta -> right common iliac -? right external iliac -> right femoral -> right deep femoral -> right hip joint

Name the lobes and fissures of each lung.

Left: divided into 2 lobes - superior and inferior - by the oblique fissure. Right: horizontal fissure separates the superior and middle lobe, while the oblique fissure separates the superior and middle lobes from the inferior lobe.

Identify the major branches of the inferior vena cava.

Lumbar, gonadal, hepatic, renal, adrenal, and phrenic veins.

Describe the respiratory pump.

Mechanism by which a reduction of pressure in the thoracic cavity during inhalation assists venous return to the heart.

Describe progressive shock.

Next stage after circulatory shock. A series of positive feedback loops that accelerate tissue damage.

List the structures of the upper respiratory system.

Nose, nasal cavity, paranasal sinuses, and pharynx.

Trace the pathway of air through the upper respiratory system.

Nostrils -> nasal vestibule (guarded by hairs that screen out large particles) -> superior, middle, and inferior meatuses (air bounces off the conchal surfaces) -> choanae (openings between the nasal cavity and nasopharynx) -> nasopharynx -> oropharynx -> laryngopharynx -> larynx

Name the three branches of the internal carotid artery.

Ophthalmic, anterior cerebral, and middle cerebral arteries.

Identify the paired and unpaired cartilages that compose the larynx.

Paired: arytenoid, corniculate, and cuneiform. Unpaired: thyroid cartilage, cricoid cartilage, and epiglottis.

Distinguish between phonation and articulation.

Phonation: production of sound and is one component of speech. Articulation: modification of sound by the tongue, teeth, and lips for clear speech.

Describe the Pulmonary Circuit:

Pulmonary Circuit: transports blood from the right ventricle through the pulmonary arteries, capillaries in the lungs, and pulmonary veins and returns it to the left atrium.

Compare the oxygen content in the tow circulatory outlets.

Pulmonary: carries deoxygenated blood from right ventricle to lungs and returns oxygenated blood to left atrium. Systemic: carries oxygenated blood to the organs and tissues and returns deoxygenated blood to right atrium.

Why is the vascularization of the nasal cavity important?

Radiates body heat so inhaled air is warmed before it leaves the nasal cavity. The heat also evaporates moisture from the epithelium to humidify the incoming air.

What effect does an increase in the respiratory rate have on CO2 levels?

Reduces CO2 levels.

What is the function of hemangioblasts?

Remodel blood islands first into capillary networks and then into larger arterial and venous networks.

What membrane lines the conducting portion of the respiratory tract?

Respiratory mucosa

Define Boyle's law.

States that at a constant temperature, the pressure of a gas is inversely proportional to its volume.

What is the function of chemoreceptor reflexes?

Respond to decreasing pH and oxygen levels and to increasing CO2 levels in the blood and cerebrospinal fluid (CSF) by adjusting cardiovascular and respiratory activity. These reflexes stimulate responses by the cardiovascular centers to increase blood pressure through vasoconstriction and increased cardiac output and stimulate responses by the respiratory centers to increase the respiratory rate, which increases pH and oxygen levels and decreases CO2 levels.

Explain the function of baroreceptor reflexes.

Responds to changes in blood pressure. Located in the walls of the carotid sinuses and aortic arch. Monitors the degree of stretch at those sites.

Name the two arteries formed by the division of the brachiocephalic trunk.

Right common carotid artery and the right subclavian artery.

Trace the path of a drop of blood from the right forearm to the right atrium.

Right forearm -> right brachial -> right axillary -> right subclavian -> right brachiocephalic -> superior vena cava -> right atrium

Trace a drop of blood through the lungs, beginning at the right ventricle and ending at the left atrium.

Right ventricle -> pulmonary trunk -> right and left pulmonary arteries -> pulmonary arterioles -> alveoli -> pulmonary venules -> pulmonary veins -> left atrium

Compare the two main bronchi.

Right: larger in diameter than the left and it descends toward the lung at a steeper angle.

Name the veins that drain dural sinuses of the brain.

The internal jugular veins.

Identify the branches of the external carotid artery.

Superficial temporal, maxillary, occipital, facial, lingual, and external carotid.

Identify the three veins that merge to form the hepatic portal vein.

Superior mesenteric, inferior mesenteric, and splenic veins.

Name the two large veins that collect blood from the systemic circuit.

Superior vena cava and inferior vena cava.

Describe the Systemic Circuit:

Systemic Circuit: transports blood through the arteries, capillaries, and veins of the body from left ventricle to right atrium.

Define internal respiration:

The absorption of oxygen from blood and the release of carbon dioxide by tissue cells.

What would happen if the alveoli surfactant were not produced?

The alveoli would collapse because of the normally high surface tension in the thin layer of water coating the alveolar surfaces.

In a healthy person, where is blood pressure greater: the aorta or inferior vena cava?

The aorta. If pressure was higher in the inferior vena cava, blood would flow in the reverse direction.

How is blood pressure mainlined in the veins against the force of gravity?

The contraction of the surrounding skeletal muscles squeezes venous blood toward the heart.

Describe the lung borders and landmarks.

The curving anterior and inferior borders of each lung follow the coutours of the rib cage. The apex of each lung extends superiorly to the first rib, and the base of each lung rests on the superior surface of the diaphragm.

Besides containing valves, cite another major difference between the arterial and venous systems.

The existence of dual (superficial and deep) venous drainage in the neck and limbs.

Which chamber of the heart receives blood from the systemic circuit?

The right atrium.

Describe the role of natriuretic peptides.

This is released at excessive stretching of the right atrium during diastole causes the release of atrial natriuretic peptide (ANP). Excessive stretching of the ventricles during diastole causes the release of brain natriuretic peptide (BNP). The roles of these peptides are to trigger responses whose combined effects act to decrease blood volume and blood pressure. As blood volume and blood pressure decrease, natriuretic peptide production ceases.

Describe the function of the hepatic portal system, and name its primary vessel.

To carry blood with absorbed nutrients from the digestive organs to the liver for processing. The primary vessel is the hepatic portal vein.

Why are valves located in the veins but not arteries?

To prevent blood from flowing backwards whenever the venous pressure drops.

Tract the pathway of airflow along the passages of the lower respiratory tract.

Trachea -> main bronchi -> lobar bronchi -> segmental bronchi -> terminal bronchioles -> pulmonary lobule

Identify the 6 structures that are vital to fetal circulation but cease to function at birth, and describe what becomes of these structures.

Two umbilical arteries, one umbilical vein, the ductus venosus, the foramen ovale, and the ductus arteriosus. After birth, the foramen ovale closes and persists as the fossa ovalis, a shallow depression; the ductus arteriosis persists as the ligamentum arteriosum, a fibrous cord; and the umbilical vessels and ductus venosus persist throughout life as fibrous cords.

Compare a ventricular septal defect with tetralogy of Fallout.

Ventricular septal defects are abnormal openings between the left and right ventricles. Tetralogy of Fallout includes a ventricular septal defect plus three other heart defects: a narrowing of the pulmonary trunk, a displaced aorta, and an enlarged right ventricle with corresponding thickened right and left ventricles.

At what sites of the body are fenestrated capillaries located?

Where solutes as large as small peptides move freely into and out of the blood. Sites include endocrine glands, the choroid plexus of the brain, absorptive areas of the intestines, and filtration areas of the kidneys.

How does the kidney respond to vasoconstriction of the renal artery?

Would decrease both blood flow and blood pressure at the kidney. In response, the kidney would release EPO and renin. EPO increases the rate of RBC formation, which leads to an increase in blood volume. Renin leads to an increase in the level of angiotensin II. Angiotensin II leads to increased blood pressure and increased blood volume.