CNA Anatomy and Physiology Basics 2 — Questions and Answers
Question 1: An elderly resident with a history of cardiovascular disease is in a facility without air conditioning during a heatwave. Which age-related physiological change puts them at the GREATEST risk for hyperthermia?
- Increased metabolic rate leading to excess heat production.
- A blunted thirst mechanism, leading to severe dehydration.
- Reduced sweat gland function and decreased skin blood flow. (Correct answer)
- Thickening of the subcutaneous fat layer, trapping heat.
Correct answer: Reduced sweat gland function and decreased skin blood flow.
Aging impairs thermoregulation by reducing the efficiency of sweat glands and decreasing cutaneous vasodilation (skin blood flow). These are the body's primary mechanisms for dissipating heat. A blunted thirst mechanism contributes to dehydration, which worsens the situation, but the core problem is the reduced ability to cool down through sweating and increased skin blood flow.
Question 2: A CNA is assisting a resident with dysphagia (difficulty swallowing) during a meal. The resident begins to cough forcefully after taking a drink of water. Which structure is designed to prevent this from happening by covering the larynx?
- The uvula
- The trachea
- The epiglottis (Correct answer)
- The esophagus
Correct answer: The epiglottis
The epiglottis is a leaf-shaped flap of cartilage located at the base of the tongue. During swallowing, it reflexively folds down to cover the opening of the larynx (voice box) and trachea (windpipe), directing food and liquid into the esophagus. When this mechanism is impaired, aspiration (entry of foreign material into the lungs) can occur, leading to coughing or choking.
Question 3: A resident has developed pitting edema in their lower legs. Which of the following best describes the role of the lymphatic system in preventing this condition?
- It produces white blood cells to fight infection in the tissues.
- It delivers oxygen and nutrients to the cells in the legs.
- It transports hormones that regulate fluid and electrolyte balance.
- It collects excess interstitial fluid and returns it to the bloodstream. (Correct answer)
Correct answer: It collects excess interstitial fluid and returns it to the bloodstream.
The lymphatic system's key function in fluid balance is to collect excess fluid, proteins, and other substances from the interstitial (tissue) spaces. This fluid, called lymph, is then transported through lymphatic vessels and eventually returned to the bloodstream. When this system is overwhelmed or impaired, fluid accumulates in the tissues, leading to edema.
Question 4: A resident experiences a sudden, frightening fall but is not physically injured. A CNA observes that the resident's heart is racing and they are breathing rapidly. This immediate "fight-or-flight" response is primarily triggered by hormones from which gland?
- Thyroid gland
- Pancreas
- Pituitary gland
- Adrenal glands (Correct answer)
Correct answer: Adrenal glands
The adrenal glands, specifically the adrenal medulla, are responsible for releasing epinephrine (adrenaline) and norepinephrine in response to acute stress. These hormones trigger the "fight-or-flight" response, causing increased heart rate, rapid breathing, and redirection of blood flow to major muscle groups to prepare the body for perceived danger.
Question 5: In an adult, what is the primary physiological function of yellow bone marrow, which is more abundant than red bone marrow in the shaft of long bones?
- Production of all new red and white blood cells.
- Storage of fat for energy reserves. (Correct answer)
- Filtering of old and damaged blood cells from circulation.
- Production of calcium to strengthen the bone matrix.
Correct answer: Storage of fat for energy reserves.
While red bone marrow is the primary site of hematopoiesis (blood cell production), yellow bone marrow consists mainly of fat cells (adipocytes). Its primary function is to store fat, which can be used as an energy reserve. In cases of severe blood loss, the body can convert yellow bone marrow back into red bone marrow to increase blood cell production.
Question 6: Which of the following is a normal physiological change in the urinary system due to aging, which a CNA should anticipate when providing care for elderly residents?
- The bladder becomes more elastic and can hold more urine.
- Kidney function and filtration rate significantly increase.
- The bladder muscles weaken and its capacity decreases. (Correct answer)
- The sensation of thirst becomes more acute and reliable.
Correct answer: The bladder muscles weaken and its capacity decreases.
As part of the normal aging process, the bladder wall becomes less elastic and the muscles weaken. This leads to a decreased capacity to hold urine and can result in more frequent urination (frequency) and sometimes incomplete emptying. This is a key reason why issues like nocturia (waking at night to urinate) and incontinence are more common in the elderly.
CNA Anatomy and Physiology Basics 2
An elderly resident with a history of cardiovascular disease is in a facility without air conditioning during a heatwave.
Which age-related physiological change puts them at the GREATEST risk for hyperthermia?