Exam 4 Nguyen UF

Identify which half of the heart is associated with the pulmonary circuit vs. which half is associated with the systemic circuit.

The right side of the heart pumps blood to the pulmonary circuit, the left pumps to the systemic circuit.

Describe the orientation, location, and surface anatomy of the heart in the thorax.

The heart is tilted slightly to the left and is anterior to the spinal cord; the base is superior to the apex which is tilted up and to the left.

Describe the layers of the pericardium and tissue layers of the heart wall, including identification of the layer shared by the heart wall and the pericardium.

Layers of the pericardium from superficial to deep: fibrous, parietal, visceral. The layer shared by the heart wall and the pericardium is the visceral pericardium (epicardium).

Layers of the heart from superficial to deep: epicardium, myocardium, endocardium (also called endothelium because it is continuous with the simple squamous epithelium lining the blood vessels).

The epicardium and endocardium are made of simple squamous epithelium, the myocardium is made of cardiac muscle tissue.

Explain the functional relevance of myocardial thickness in the chambers (atria vs. ventricles; right vs. left ventricle).

Ventricles have thicker myocardial layers because they need to pump blood against gravity; the left ventricle is thicker than the right because it pumps to the whole body against a higher pressure.

Identify (and explain related functions if relevant) the important structural features of each heart chamber.

Atria:

Crista terminalis: c shaped ridge that runs between the openings of the superior and inferior vena cava on the posterior wall of the atrium.

Pectinate muscles: horizontal ridges on anterior surface of the atria.

Fossa ovalis: remnant of the fossa ovale present in fetuses because they don't use their lungs.

Ventricles:

Trabeculae carnae: columns of tissue

Papillary muscles: projections of TC

Chordae tendinae: anchor valves

AV valves: right tricuspid and left mitral allow blood flow from atria to ventricles, unidirectional.

Semilunar valves: 3 cusps

Identify blood vessels carrying blood to the atria and away from the ventricles.

Superior and inferior vena cavae bring blood to the right auricle. From there: right atrium --> right ventricles --> pulmonary trunk --> to lungs back to the heart --> pulmonary veins --> left atrium --> left ventricle --> aorta

Name and identify the heart valves. Describe how they facilitate unidirectional blood flow.

Atrioventricular valves: regulate blood flow between the atria and the ventricles, prevents back flow when the ventricles contract. Chordae tendinae anchor cusps to stop backflow

The semilunar valves are forced open when the ventricles contract and push blood into the vessels and close when blood flows back into them to prevent backflow.

Left mitral controls blood between left atrium and ventricle, right tricuspid controls flow between right atrium and ventricle.

Name the components of the conducting system of the heart and describe electrical conduction through the heart.

The senoatrial (SA) node aka pacemaker generates impulses, the impulses pause at the AV node which allows for time between the atria contraction and ventricle contraction, preventing back flow into the atria. The AV bundle connects the atria to the ventricles, the branches of the bundle conduct the impulses through the intraventricular septum. Finally, the purkinje fibers stimulate contractile cells of both ventricles.

Describe the locations of the coronary arteries and veins on the heart's surface.

Right coronary artery runs along right atrium. Left coronary artery next to right atrium. Marginal artery fourth from the top of the right arteries. Circumflex artery wraps around ventricle.

Great cardiac vein runs with both branches of left coronary artery, dumps into coronary sinus.

Middle cardiac vein- runs beside posterior interventricular sulcus, dumps into coronary sinus

Small cardiac vein- runs beside right marginal artery turns and runs alongside right main coronary artery on posterior side, dumps into coronary sinus

Coronary sulcus dumps into right atrium.

Describe the three tunics that form the wall of an artery or vein. Compare and contrast arteries, veins, and capillaries—structurally and functionally.

Blood vessels are hollow organs.

The tunica intima lines the vessels, is made of simple squamous epithelium, and is continuous with the endocardium of the heart.

The tunica media is made of smooth muscle fibers that lie between elastin and collagen fibers. It functions to vasoconstrict and vasodilate. Arteries have a thicker tunica media than veins to allow for enhanced vasoconstriction.

The tunica externa is made of connective tissue and functions to anchor the vessels, provide structure and protection. Larger in veins. So is the lumen.

Define vasa vasorum.

the vasa vasorum supply the smooth muscle wall (outer layers) of the blood vessels.

Explain the role of smooth muscle in vasodilation, vasoconstriction, and regulation of blood flow into a capillary bed.

Smooth muscle contracts to decrease the diameter of the vessel (vasoconstriction) Relaxation of the smooth muscle cells is called vasodilation. These two processes are regulated by the sympathetic ANS (increased ANS response = increased vasoconstriction).

Blood enters the capillary beds via a terminal arteriole and then goes through a metarteriole, whose branches from the beds. The metarteriole is connected to precapillary sphincters which close to regulate flow.

Name the vessels on either side of a capillary bed.

Blood enters the capillary beds via a terminal arteriole, then --> metarteriole --> capillary bed --> converge into the thoroughfare channel --> dump into the post capillary venule

Explain the structural basis of capillary permeability.

direct diffusion - exchange of CO2 and oxygen

intercellular clefts - have leaky gap junctions that let small molecules pass through

fenestrations - pores in the endothelial cells that allow passage of small molecules

pinocytotic vesicles - invaginate from the plasma membrane and migrate across the endothelial cells, transporting dissolved gases, nutrients, and waste products into the capillary

The Blood Brain Barrier permeability:

consists of only tight junctions. no fenestractions/clefts, no leakiness. glucose is "ushered" across the walls.

Describe the differences between continuous capillaries, fenestrated capillaries, and sinusoids; describe where each type of vessels would be located and why.

Continuous capillaries are the least permeable and most common (found in muscles and skin). They have clefts; no fenestrations.

Fenestrated capillaries are more permeable, they have both clefts and fenestrations. Found in areas where fast exchange is necessary i.e. kidney (glomerulus), small intestine, areas where filtration/absorption happens.

Sinusoidal capillaries are the most permeable, they have large fenestrations and clefts. They are found in areas where large materials (cells, proteins) are exchanged i.e. liver, bone marrow, spleen.

Identify the specific veins that do and do not contain valves.

The veins that do not contain valves are in the head/thorax/abdomen/neck. Valves are commonly found in limbs.

Explain the two ways veins work against gravity.

Valves in limbs: tunica intima forms cusps that prevent backflow.

Skeletal muscle pump: contracting skeletal muscles press against the veins, forcing valves proximal to the area of contraction to open and propel blood toward the heart

Describe vascular anastomoses and list common locations.

Anastomoses is the cross connection/overlap of veins (more commonly than arteries). This happens around joints because they are commonly compressed. Arterial anastomoses found in the brain + digestive system.

Name the major vessels (arteries, veins, types of capillaries) of the pulmonary circuit + systemic circuit.

See sarah's diagram.

Explain the blood flow through the hepatic portal system, including named vessels, types of capillaries, and number of capillary beds.

Arterial blood comes into the first capillary bed in the stomach and intestine where nutrients and toxins are absorbed. The hepatic portal vein carries them into the second capillary bed in the liver where the nutrients and toxins are digested by hepatocytes. The blood flows into the hepatic vein and enters the heart as venous blood through the inferior vena cava.

Predict areas of the body supplied by specific vessels based on location.

See lecture.

External iliac supplies the lower limbs, interal supplies the pelvis, butt,

Identify the respiratory passageways, in order, from the nose to the alveoli.

Nose → pharynx → larynx → trachea → carina → primary bronchus → bronchioles → alveoli

Distinguish the structures of the conducting zone from those of the respiratory zone.

Conducting zones: resp passageways that carry air to sites of gas exchange (nose, larynx, pharynx etc)

Respiratory zones: sites of gas exchange in the lungs (key difference is this zone contains alveoli)

Identify structures of the external nose, including specific tissues involved.

Septal (hyaline) cartilage, bone (nasal and maxilla), external nares.

Identify structures and functions of the internal nasal cavity.

nasal conchae (humidify air) and meatus, internal nares, vestibule, etc.

Distinguish between olfactory and respiratory mucosa, including locations, tissues, and specialized cells/functions.

Olfactory mucosa: form CN 1, roof of nasal cavity, sense of smell.

Respiratory mucosa: rest of nasal cavity, pseudostratified ciliated columnar epithelium, have goblet cells that secrete mucus and serous cells that secrete digestive enzymes

Identify the boundaries of the three regions of the pharynx and the structures and tissues located in each region.

Nasopharynx: vestibule, external/internal nares, conchae and meatus, uvula, pharyngeal tonsils, pseudostratified ciliated columnar epithelium

Oropharynx: uvula to epiglottis, lined with non-keratinized stratified squamous epithelium (highly protective), palatine tonsils in fauces, lingual tonsil

Laryngopharynx: epiglottis to esophagus, lined with non-keratinized stratified squamous epithelium.

The last two need toucher tissue because they have to move food and liquid down, not just air.

Describe the structure and functions of the larynx, including specific tissues.

The larynx is a set of 9 cartilages connected by ligaments/membranes. It is anchored to the hyoid bone superiorly and the trachea inferiorly and it functions in vocalization, opening the airway, and moving food into the proper passageway. Most superior cartilage is the epiglottis and largest is the thyroid cartilage.

Distinguish between the true and false vocal cords/folds and explain the difference between vocal cords/folds and the glottis/rima glottis.

False vocal cord: vestibular fold, no sound function just used for sensory. Enhance high frequency sounds.

True vocal cord- vocal fold, can open/close/stretch to change sounds, arytenoid cartilage connects to move them (have skeletal muscle)

Laryngeal ventricle: space between the 2 folds; voice resonance

Glottis: 2 structures, hole between them.

Rimaglottis: slit formed between the two vocal cords when the arytenoid cartilage changes positions

Identify and describe the structures of the trachea and tissues of the tracheal wall, including the trachealis.

the trachea is a continuation of the larynx and consists of C shaped rings of hylaine cartilage. It has a sensitive epithelium around the carina that will make you cough if irritated. The trachealis muscle helps the esophagus descend anteriorly and it decreases the size of the lumen when coughing.

Describe the branching of the trachea into primary, secondary, and tertiary bronchi.

Trachea --> primary bronchus --> lobar (secondary) bronchus --> segemental (tertiary) bronchus --> bronchioles

Describe the basic shape and organization of the lungs into lobes and differentiate right from left.

left lung has a superior and inferior lobe, right lung has a superior, middle, and inferior lobe.

Describe how alveoli are organized into sacs with a central duct.

Alveoli are bulbs of simple squamous epithelium that form a sac. Sac-->alveolar duct--> resp bronchioles --> terminal bronchioles

Describe the cellular/tissue structures of an individual alveolus and the respiratory membrane, including blood vessels and elastic fibers.

Elastic fibers: in ECM, stretch and recoil

Connected via pores which allow the sacs to be continuous.

Blanket of blood around cluster. Highly vascular via capillaries.

Alveolar walls consist of Type I cells. Type II cells create surfactant which stops the alveoli from sticking together.

Macrophages digest things that shouldnt be there and then become mucous.

Resp membrane: alveolar membrane and capillary membrane are both simple squamous epithelium, in between is fused basement membrane.

Describe the gross anatomy of the lungs, including lobes, bronchopulmonary segments, and lobules.

Each lung has 10 bronchopulmonary segments served by CT supplied by tertiary bronchi. There is an apex at the bottom and a base at the top. Each lobule is supplied by a bronchiole and arteriole.

Distinguish the lung hilum/hilus from the root. Name structures of the lung root.

Hilum: region of lung where structures pass through

Root: space where blood vessels, nerves, airways pass through into the lung

Describe the layers and tissues of the pleura.

Right and left lobes each have their own pleura.

Visceral pleura is right outside the organ, parietal pleura faces the body wall. Pleural space is between them, has serous fluid and lets them be continuous with each other.

Predict symptoms that would arise if specific regions of the respiratory system were damaged.

The pneumothorax equilibrates pressure between outside and inside environment, if this is damaged the lung collapses.