Thirdmidquarterstudy Flashcards
What are the parts of the cardiovascular system?
The pump (heart) the container (vessels) the contents (blood)
Heart ( pump function) = damage to the heart by disease by injury decreases the ability of the heart to properly function as a pump. Therefore, it cannot move enough blood through the body to support perfusion. Blood vessels (container function)= if all the blood vessels dilate rapidly, the normal amount of blood volume is not enough to fill the system and provide adequate perfusion to the body. Blood (content function)= if there is enough blood or plasma loss, the volume of fluid in the container is not enough to support the perfusion needs of the body.
What is required for perfusion to be adequate?
Cells require oxygen, water, and glucose to carry out cellular processes to produce energy in the form of adenosine triphosphate. When the cells do not receive these requirements via the bloodstream, the cells cannot create energy and are categorized as hypoperfused. If cells are hypoper-fused, tissues and organs are also hypoperfused. In the early stages of shock, the body will attempt to compensate by maintaining homeostasis (a balance of all systems of the body);
Perfusion is the circulation of blood to the tissues in adequate amounts to meet the cells needs.
Define anaphylactic shock
Anaphylaxis, or anaphylactic shock, occurs when a person reacts quickly to a substance to which he or she has been sensitized. Sensitization means becoming sensitive to a substance that did not initially cause a reaction. Do not be misled by a patient who reports no history of allergic reaction to a substance on first or second exposure. Each subsequent exposure after sensitization tends to produce a more severe reaction.
Instances that cause severe allergic reactions commonly fall into the following four categories of exposure:
• Injections (tetanus antitoxin, penicillin) -
• Stings (wasps, bees, hornets, ants) 1
• Ingestion (fish, shellfish, nuts, eggs, medication) ~
• Inhalation (dust, pollen, mold) ~
Anaphylactic reactions can develop within minutes after contact with the substance to which the patient is allergic. The signs of such allergic reactions are distinct and not seen with other forms of shock. TABLE 13-2 lists the signs of anaphylactic shock in the order in which they typically occur.
Note that cyanosis (blue discoloration of the skin) is a late sign of anaphylactic shock. Although pale-ness, or a decrease in blood flow, can be difficult to detect in dark-skinned people, it may be observed by examining mucous membranes inside the inner lower eyelid and capillary refill. On general observa-tion, the patient may appear ashen or gray.
In anaphylactic shock, there is no loss of blood or vascular damage. Instead, there is widespread vascular dilation, increased permeability, and bron-choconstriction. The combination of poor oxygenation and poor perfusion in anaphylactic shock may easily prove fatal.
For more information on allergic reactions and anaphylaxis, see Chapter 21, Allergy and Anaphylaxis.
Define psychogenic shock
A patient in psychogenic shock has had a sudden reaction of the nervous system that produces a tem-porary, generalized vasodilation, resulting in fainting, or syncope. The fainting episode is temporary, and the patient rouses soon after. Syncope occurs when blood pools in the dilated vessels, reducing the blood supply to the brain; as a result, the brain temporarily ceases to function normally, and the patient faints.
There are many causes of syncope, and it is important to realize that some are serious. Syncope that is potentially life threatening may be caused by events such as an irregular heartbeat or a brain aneurysm. Non-life-threatening events that cause syncope include receiving bad news, experiencing fear, or encountering an unpleasant sight, such as blood. Those experiencing syncope should receive a full assessment.
What does the systolic and diastolic parts of the blood pressure measure?
Remember, blood pressure is the pressure of blood within the vessels at any moment in time. The systolic pressure is the peak arterial pressure, or pressure generated when the heart contracts; the diastolic pressure is the pressure maintained within the arteries while the heart is at rest, or between beats. Pulse pressure is the difference between the systolic and
diastolic pressures (Systolic - Diastolic = Pulse pressure). It signifies the amount of force the heart generates with each
contraction.
How much blood can a person donate at one time
500 ml. One unit,
Describe linear skull fractures
Linear skull fractures (nondisplaced skull fractures) account for approximately 80% of all fractures to the skull (FIGURE 29-11A). Radiographs are required to diagnose a linear skull fracture because there are often no physical signs such as deformity. If the brain is uninjured and there are no scalp lacerations, then linear fractures are not life threatening. However, if there is a scalp laceration with the linear fracture-making it an open fracture —there is a risk of infection and bleeding inside the brain.
Describe basilar skull fracture
Basilar skull fractures are also associated with high-energy trauma, but they usually occur following diffuse impact to the head (eg, falls, motor vehicle crashes). These injuries generally result from extension of a linear fracture to the base of the skull and are usually diagnosed with a CT scan of the head (FIGURE 29-11C))
Signs of a basilar skull fracture include CSF drainage from the nose or the ears, which indicates rupture of the tympanic membrane in the ear, and freely flowing CS through the ear. Patients with leaking CS from either the nose or the ear are at risk for bacterial meningitis.
Other signs of a basilar skull fracture include raccoon eyes or Battle sign. Depending on the extent of the damage, raccoon eyes and Battle sign may appear relatively quickly, but in many patients, they may not appear until up to 24 hours following the injury, so their absence in the field does not rule out a basilar skull fracture.
Depressed skull fracture
Depressed skull fractures result from high-energy direct trauma to the head with a blunt object (such as a baseball bat to the head) (FIGURE 29-11B). The frontal and parietal bones of the skull are most susceptible to these types of fractures because the bones in these areas are relatively thin. As a consequence, bony fragments may be driven into the brain, resulting in injury. The scalp may or may not be lacerated. Patients with depressed skull fractures often present with signs of neurologic injury (such as loss of consciousness).
Raccoon eyes and Battle sign stuff
Other signs of a basilar skull fracture include raccoon eyes or Battle sign. Depending on the extent of the damage, raccoon eyes and Battle sign may appear relatively quickly, but in many patients, they may not appear until up to 24 hours following the injury, so their absence in the field does not rule out a basilar skull fracture.
Coup-countercoup injury
The third collision in a typical impact is that of the passenger’s internal organs against the solid structures of the body. A coup-contrecoup injury occurs when the brain continues its forward motion and strikes the inside of the skull (the coup), resulting in a compression injury to the anterior portion of the brain and a tension injury (stretching) of the posterior portion (the contrecoup).
Traumatic asphyxia
Sometimes a patient will experience a sudden, severe compression of the chest, which produces a rapid increase in pressure within the chest. This may occur in a pedestrian who is compressed between a vehicle and a wall, or a patient who is pinned under a vehicle. The sudden increase in intrathoracic pressure results in a characteristic appearance, including distended neck veins, cyanosis in the face and neck, and hemorrhage into the sclera of the eye, signaling the bursting of small blood vessels (FIGURE 30-16). This is called traumatic asphyxia. These findings suggest an underlying injury to the heart and possibly a pulmonary contusion. Provide ventilatory support with supplemental oxygen and monitor the patient’s vital signs as you provide immediate transport.
Commotio cordis
Commotio cordis is a blunt chest injury caused by a sudden, direct blow to the chest (over the heart) that occurs during a critical portion of a person’s heartbeat. The result may be immediate cardiac arrest. This phenomenon has occurred after patients were struck with softballs, baseballs, bats, snowballs, fists, and even kicks during kickboxing. The force of the blow to the chest is commonly at speeds of 35 to 40 miles per hour. The blunt force, at a single specific point in the cardiac cycle, causes a lethal abnormal heart rhythm called ventricular fibrillation. The ventricular fibrillation is often responsive to defibrillation and early initiation of CPR. Commotio cordis is more commonly associated with sports-related injuries, although it should be suspected in all cases in which the person is unconscious and unresponsive after a blow to the chest. These patients present in cardiac arrest and should be managed as any other cardiac arrest, understanding that they may be particularly responsive to early defibrillation.
Cardiac tamponade
Cardiac tamponade (pericardial tamponade) occurs when the pericardial sac, the space between the protective membrane around the heart (pericardium) and the heart, fills with blood or fluid, perhaps from a ruptured, torn, or lacerated coronary artery or vein (FIGURE 30-14). The pericardial sac can also fill with fluid as a result of cancer or an autoimmune disease such as lupus. As the amount of blood or fluid increases, the heart is less able to fill with blood during each relaxation phase. As a result, the heart cannot pump an adequate amount of blood and the patient experiences a decrease in systemic blood flow, or cardiac output. The signs of this condition are often subtle until the situation is dire. The signs and symptoms, referred to as the Beck triad, include distended or engorged jugular veins seen on both sides of the trachea, a narrowing pulse pressure (the difference between the systolic and diastolic blood pressure numbers), and muffled heart sounds. Because the heart cannot pump sufficiently, the jugular veins fill with blood and, thus, blood backs up. The narrowing pulse pressure occurs as the diastolic pressure increases but the systolic pressure cannot, because the heart cannot stretch to contract harder. An associated and more commonly noticed sign is a decrease in mental status as blood flow decreases to the brain. The heart muscle is unique in that it needs to be stretched to create a good contraction to pump blood out of the ventricles. This mechanism can fail because of tamponade and can be directly related to a decrease in blood returning to the heart.
Pulmonary contusion
In addition to fracturing ribs, any severe blunt trauma to the chest can injure or bruise the lung. The pulmonary alveoli become filled with blood, and fluid accumulates in the injured area, leaving the patient hypoxic. Severe pulmonary contusion should always be suspected in patients with a flail chest and usually develops over a period of hours following the injury. If you believe that a patient may have a pulmonary contusion, provide supplemental oxygen and positive-pressure ventilation as needed to ensure adequate oxygenation and ventilation.
Blunt myocardial injury
Blunt trauma to the chest may injure the heart itself, making it unable to maintain adequate blood pressure. There is much debate in the medical literature about how to assess myocardial contusion, or bruising of the heart muscle. Often the pulse is irregular, but dangerous rhythms such as ventricular tachycardia and ventricular fibrillation are uncommon. Currently, there is no specific diagnostic test in the prehospital setting, and there is no prehospital treatment for the condition. Still, you should suspect myocardial contusion in all cases of severe blunt injury to the chest. Carefully check the patient’s pulse and note any irregularities. Also note any change in blood pressure because this can be a direct result of the injury to the myocardium.
Often the patient’s signs and symptoms can mimic a heart attack in which the patient may report chest pain or discomfort that is similar in nature to cardiac symptoms. Provide supplemental oxygen, and transport immediately.
What are the parts of the nervous system
The nervous system is divided into two anatomic parts: the central nervous system (CNS) and the peripheral nervous system (PNS) (FIGURE 29-1). The CNS is composed of the brain and the spinal cord, including the nuclei and cell bodies of most nerve cells. Long nerve fibers link these cells to the body’s various organs through openings in the spinal column.
These nerve fibers constitute the PNS.
The__, the other major portion of the CNS, is mostly made up of fibers that extend from the brain’s nerve cells.
The spinal cord carries messages between the brain and the body via the gray and white matter of the spinal cord. Gray matter is composed of neural cell bodies and synapses, which are connections between nerve cells. White matter consists of fiber pathways.
spinal cord
The__ has two anatomic parts: 31 pairs of spinal nerves and 12 pairs of cranial nerves
PNS
The__ pairs of spinal nerves conduct sensory impulses from the skin and other organs to the spinal cord. They also conduct motor impulses from the spinal cord to the muscles. Because the arms and legs have so many muscles, the spina nerves serving the extremities are arranged in complex networks. The brachial plexus controls the arms, and the lumbosacral plexus controls the legs.
Cranial nerves are the 12 pairs of nerves that emerge from the brainstem and transmit information directly to or from the brain. For the most part, they perform special functions in the head and face, including sight, smell, taste, hearing, and facial expressions.
There are two major types of peripheral nerves. The sensory nerves, with endings that perceive only one type of information, carry that information from the body to the brain via the spinal cord. The motor nerves, one for each muscle carry information from the CNS to the muscles. The connecting nerves, found only in the brain and spinal cord, connect the sensory and motor nerves with short fibers, which allow the cells on either end to exchange simple messages.
31
The___ controls virtually all of the body’s activities, including reflex, voluntary, and involuntary activities In connecting the sensory and motor nerves of the limbs, the connecting nerves in the spinal cord form a reflex arc. If a sensory nerve in this arc detects an irritating stimulus, such as heat, it will bypass the brain and send a message directly to a motor nerve, causing a response such as pulling away from the heat
nervous system
__structures, whose bony enclosures protect them quite well, are also very fragile. Protecting them from further damage is vital to the patient’s future ability to live a normal life. Lean toward caution and overprotection in assessing and treating possible brain and spinal cord injuries.
CNS
The part of the ___that regulates or controls our voluntary activities, including almost all coordinated muscular activities, is called the somatic (voluntary) nervous system. The mechanism of the somatic nervous system is simple. The brain interprets the sensory information that it receives from the peripheral and cranial nerves and responds by sending signals to the voluntary muscles
The body functions that occur without conscious effort are regulated by the much more primitive autonomic (involuntary) nervous system. The autonomic nervous system controls the functions of many of the body’s vital organs, over which the brain has no voluntary control.
The autonomic nervous system is divided into two sections: the sympathetic nervous system and the parasympathetic nervous system. When confronted with a threatening situation, the sympathetic nervous system reacts to the stress with the fight-or-flight response. This response causes the pupils to dilate, smooth muscle in the lungs to dilate, heart rate to increase, and blood pressure to rise. This response also causes the body to shunt blood to vital organs and to skeletal muscle. During this time of stress, a hormone called epinephrine (also known as adrenaline) is released, which is responsible for much of these activities inside the body. The parasympathetic nervous system has the opposite effect on the body, causing blood vessels to dilate, slowing the heart rate, and relaxing the muscle sphincters. When this portion of the autonomic nervous system is activated, the body shunts blood to the organs of digestion. As the body attempts to maintain homeostasis (balance), these two divisions of the autonomic nervous system tend to balance each other so that basic body functions remain stable and effective.
nervous system
Which part of the brain controls voluntary motor functions
Cerebrum
