how does a sagittal section divide the body

HESI A2

Anatomy HESI A2

1. How does a sagittal section divide the body?

A. Into right and left regions
B. Into upper and lower regions
C. Into front and back regions
D. Between the dorsal and ventral cavities

Correct answer: A

Rationale: A sagittal section divides the body into right and left regions. This type of section runs longitudinally from front to back, separating the body into right and left halves. Sagittal sections are crucial for understanding the anatomical structure and orientation of various body parts. Choices B, C, and D are incorrect because a sagittal section specifically divides the body into right and left portions, not upper and lower regions, front and back regions, or between the dorsal and ventral cavities.

2. What is the most visible part of the ear called?

A. Cochlea
B. Pinna
C. Ear canal
D. Organ of Corti

Correct answer: B

Rationale: The pinna, also known as the auricle, is the most visible part of the ear. It is responsible for capturing sound waves and directing them into the ear canal, where the process of hearing begins. The other structures mentioned, such as the cochlea, ear canal, and organ of Corti, play crucial roles in the auditory system but are not the most visible parts of the ear. The cochlea is a spiral-shaped cavity responsible for converting sound vibrations into neural signals. The ear canal is a tube that connects the outer ear to the eardrum. The organ of Corti is the actual sensory organ of hearing located in the cochlea.

3. How does the integumentary system interact with the nervous system?

A. The integumentary system removes heat from the neurons in the nervous system.
B. The nervous system circulates nutrients outward to the integumentary system.
C. Touch input via the integumentary system sends messages to the nervous system.
D. Messages from the nervous system affect the color and texture of the skin.

Correct answer: C

Rationale: Touch input via the integumentary system sends messages to the nervous system. The integumentary system, comprising the skin, hair, and nails, functions as a sensory organ and a protective barrier against external threats. Specialized receptors in the skin detect stimuli like pressure, temperature, and pain, transmitting signals to the nervous system for interpretation. This communication enables the perception of touch and is vital for sensory processes, showcasing the interconnectedness between the integumentary and nervous systems. Choices A, B, and D are incorrect because the integumentary system primarily interacts with the nervous system through sensory input and communication of stimuli, rather than heat removal, nutrient circulation, or affecting skin color and texture based on nervous system messages.

4. What is the primary function of the heart in the circulatory system?

A. To filter blood
B. To pump blood throughout the body
C. To absorb oxygen
D. To remove carbon dioxide

Correct answer: B

Rationale: The correct answer is B: 'To pump blood throughout the body.' The primary function of the heart in the circulatory system is to pump blood, which carries oxygen and nutrients, throughout the body. Choice A, 'To filter blood,' is incorrect as the heart does not filter blood; that is primarily done by the kidneys. Choice C, 'To absorb oxygen,' is incorrect as the lungs are responsible for oxygen absorption. Choice D, 'To remove carbon dioxide,' is incorrect as the lungs facilitate the removal of carbon dioxide from the body.

5. How many bones are found in the human skull?

A. Approximately 5
B. Approximately 30
C. Approximately 60
D. Approximately 210

Correct answer: B

Rationale: The correct answer is B: Approximately 30. The human skull is composed of 22 bones that are fused together. These 22 bones consist of 8 cranial bones and 14 facial bones, totaling approximately 30 bones in total. Choices A, C, and D are incorrect because the human skull does not have as few as 5 bones, as many as 60 bones, or as many as 210 bones. Understanding the basic anatomy of the skull helps in identifying the correct number of bones it comprises.