CVA Circulation🫀🩸

These flashcards cover the anatomy and functions of vertebrate circulation, focusing on blood vessels, hearts, and the lymphatic system.

What are the two systems of vertebrate circulation?

Lymphatic system and cardiovascular system.

What does the lymphatic system transport?

Lymph, which is not pumped by the heart.

How do blood and lymph move in the body?

Through tubes (blood vessels and lymph vessels) and pumps (heart).

What role does fluid movement play aside from transporting materials?

Regulates temperature and pressure.

What are arteries responsible for?

Carrying blood away from the heart.

What type of blood do most arteries carry?

Oxygen-rich blood.

What are arterioles?

Very small arteries.

What do veins do?

Carry blood toward the heart.

What type of blood do most veins carry?

Oxygen-poor blood.

What is the function of one-way valves in veins?

Control the flow of blood.

What are venules?

Very small veins.

What are capillaries?

Tiny vessels between arteries and veins; sites of exchange.

What can smooth muscles control in blood vessels?

The size of vessels through vasoconstriction and vasodilation.

What are the two patterns of circulation in most vertebrates?

Single circuit and double circuit.

What is the single circuit plan?

Blood passes through the heart once per circuit, typical in most fishes.

Describe the double circuit plan.

Blood passes through the heart twice per circuit, including pulmonary and systemic circuits.

Which vertebrates have intermediate-type circulatory systems?

Lungfishes, amphibians, and some reptiles.

What are aortic arches?

Paired arteries immediately after the heart and ventral aorta.

How many aortic arches are most commonly found?

Six.

What happens to the first aortic arch?

It is almost always lost.

Which arteries supply the gills in fish?

Afferent branchial arteries enter the gills.

What is the function of efferent branchial arteries?

They exit the gills.

Which arch supplies the internal carotid artery in sharks?

Arch II.

What do arches III-VI supply in sharks?

The rest of the body.

What happens to arches I and II in amphibians?

They are lost.

In salamanders, what arteries carry external gills?

Arches III-V.

What does arch VI form in amphibians?

Pulmonary artery.

What do arches III and IV form in amphibians?

Common carotid artery to the head.

How do frog arteries differ from those of salamanders?

Frogs lose gills in larvae; arches III-VI are utilized differently.

What is the difference in aortic arches between reptiles and amphibians?

Reptiles have asymmetric arches whereas amphibians do not.

What happens to the ventral aorta in reptiles?

It splits into left and right systemic arches.

What is the general heart structure in birds?

Like reptiles, birds have a right systemic arch predominating.

What do mammals retain of the aortic arches from embryo?

Only three arches are retained in adults.

What do pulmonary veins drain?

The lungs.

Which veins are associated with draining viscera to the liver?

Hepatic portal veins.

What do renal portal veins drain?

The kidneys.

What is a portal system?

Carries blood from one set of capillaries to another without passing through the heart.

What does the hepatic portal system drain?

Digestive organs to the liver.

What type of heart did vertebrates likely originate from?

A contractile blood vessel like in lancelets.

What is a typical characteristic of vertebrate hearts?

A basic pattern has four chambers in series.

What is the sinus venosus?

The first chamber in a primitive heart structure.

What is the bulbus cordis in embryos?

It develops into the conus arteriosus or bulbus arteriosus in adults.

What specialized structure does the hagfish heart lack?

Bulbus/conus arteriosus.

What is unique about the heart of a lamprey?

It is innervated and follows a basic four-chamber plan.

What does the interatrial and interventricular septum do in lungfish?

Partially separates oxygenated and deoxygenated blood.

How do amphibian hearts vary?

They depend on the mode of respiration.

What occurs in the ventricle of most amphibian hearts?

Oxygen-rich and oxygen-poor blood are separated by trabeculae.

What differentiates turtles and squamates reptilian heart structure?

They have five chambers with interconnected compartments.

How do crocodilian hearts differ from those of turtles?

They have four chambers and valves to control blood flow.

What connects the left and right systemic arches in crocodilians?

Foramen of Panizza.

What unique feature do turtle and crocodilian hearts have when diving?

A right-to-left shunt.

What are countercurrent exchanges?

Methods to maximize heat transfer in animals.

What is the role of carotid rete in heat regulation?

It regulates brain temperature by cooling incoming blood.

What does the lymphatic system collect?

Tissue fluids and water returning it to the bloodstream as lymph.

What does lymph contain?

No red blood cells (RBCs).

What drives the movement of lymph?

Hydrostatic pressure, skeletal muscles, and arterial pulsing.

What type of valves are present in the lymphatic system?

One-way valves to keep lymph moving in the right direction.

What do lymph vessels absorb from the digestive tract?

Lipids.

How does lymph drain to the heart?

Via sinus venosus or subclavian veins.

What does the movement of lymph depend on besides pressure?

The action of skeletal muscles.

What is the main function of lymph nodes?

To monitor for infections.

What role does skeletal muscle play in the lymphatic system?

It helps drive the movement of lymph.

Where does the lymphatic system drain to in cardio-vacular systems?

Into the bloodstream.

What does lymphatic tissue contain to assist immune functions?

White blood cells (WBCs).

How can blood vessels act in thermoregulation?

As heat blocks or radiators.

What occurs in peripheral vasodilation?

Blood vessels widen to increase blood flow to skin.

What is trapped in the artery-vein networks in cetaceans?

Body heat.

What is evaporative cooling of venous blood involved with?

Cooling blood coming from the nasal cavity.

What is the characteristic of heat conservation systems in marine mammals?

They possess countercurrent exchange systems.