13.1 Flashcards
The embryonic nervous system begins as a very complex structure that simplifies over time.
True
False
False
Explanation: The embryonic nervous system begins as a very simple structure, essentially just a straight line, and becomes increasingly complex.
The endoderm gives rise to the _______ of the digestive and respiratory systems.
A) Muscle
B) Connective tissues
C) Lining tissues
D) Skin
C) Lining tissues
Explanation: The endoderm, or inner tissue, is responsible for generating the lining tissues of various spaces within the body.
Which germ layer develops into the nervous system?
A) Endoderm
B) Mesoderm
C) Ectoderm
D) None of the above
C) Ectoderm
Explanation: The ectoderm develops into the integumentary system (skin) and the nervous system.
The neural tube develops from the mesoderm.
True
False
False
Explanation: The neural tube develops from the ectoderm.
A specialized region of _______ differentiates into the neuroectoderm.
A) Endoderm
B) Mesoderm
C) Ectoderm
D) None of the above
C) Ectoderm
Explanation: As the embryo develops, a portion of the ectoderm differentiates into a specialized region of neuroectoderm.
The neural plate forms as a result of differentiation in which germ layer?
A) Endoderm
B) Mesoderm
C) Ectoderm
D) None of the above
C) Ectoderm
Explanation: Molecular signals induce cells in this region to differentiate into the neuroepithelium, forming a neural plate.
The primary vesicles are formed at the first stage of brain development and consist of three parts: prosencephalon, mesencephalon, and rhombencephalon.
True
False
True
Explanation: These vesicles are given names based on Greek words and correspond to their positions along the developing nervous system.
The _______ runs lateral to the neural tube and migrates away to form parts of the peripheral nervous system.
A) Neural fold
B) Neural crest
C) Neural groove
D) Neural plate
B) Neural crest
Explanation: The neural crest runs lateral to the neural tube and forms parts of the peripheral nervous system, including the enteric nervous tissue.
At what point does the basic arrangement of the nervous system, with a hollow tube from the anterior to the posterior end, begin?
A) 16 days
B) 25 days
C) 4 weeks
D) 8 weeks
B) 25 days
Explanation: Beginning at 25 days, the anterior end develops into the brain, and the posterior portion becomes the spinal cord.
The rhombencephalon is also known as the forebrain.
True
False
False
Explanation: The rhombencephalon is referred to as the hindbrain.
The prosencephalon enlarges into two new vesicles called the _______ and the _______.
A) Telencephalon, Diencephalon
B) Mesencephalon, Metencephalon
C) Myelencephalon, Metencephalon
D) Cerebellum, Medulla
A) Telencephalon, Diencephalon
Explanation: The prosencephalon (forebrain) enlarges into the telencephalon, which will become the cerebrum, and the diencephalon, which gives rise to several structures including the thalamus and hypothalamus.
The mesencephalon differentiates into two finer divisions during development.
True
False
False
Explanation: The mesencephalon (midbrain) does not differentiate into any finer divisions and remains an established region.
The rhombencephalon develops into which of the following structures?
A) Telencephalon, Diencephalon
B) Metencephalon, Myelencephalon
C) Cerebellum, Medulla
D) Pons, Cerebellum
B) Metencephalon, Myelencephalon
Explanation: The rhombencephalon (hindbrain) develops into the metencephalon, which gives rise to the pons and cerebellum, and the myelencephalon, which corresponds to the medulla oblongata.
The structures that come from the mesencephalon and rhombencephalon, except for the cerebellum, are collectively considered the _______.
A) Cerebrum
B) Brain stem
C) Cortex
D) Spinal cord
B) Brain stem
Explanation: The brain stem includes the midbrain (mesencephalon), pons, and medulla oblongata (from the myelencephalon).
The spinal cord develops from the anterior neural tube.
True
False
False
Explanation: The spinal cord develops from the posterior neural tube.
The neural tube is defined in terms of its _______ versus _______ portions.
A) Dorsal, Ventral
B) Anterior, Posterior
C) Superior, Inferior
D) Medial, Lateral
B) Anterior, Posterior
Explanation: The neural tube is defined in terms of its anterior (front) versus posterior (back) portions, but it also has a dorsal (top) – ventral (bottom) dimension.
The dorsal tissues of the spinal cord are associated with _______, and the ventral tissues are associated with _______.
A) Motor functions, Sensory functions
B) Sensory functions, Motor functions
C) Reflexes, Conscious movements
D) Voluntary actions, Involuntary actions
B) Sensory functions, Motor functions
Explanation: The dorsal tissues are associated with sensory functions, and the ventral tissues with motor functions.
The anterior-posterior dimension of the nervous system is established by the neural tube and is called the _______.
A) Neuroepithelium
B) Neuraxis
C) Neural plate
D) Neural crest
B) Neuraxis
Explanation: The neuraxis establishes the anterior-posterior dimension of the nervous system.
Mnemonic: “Axis for direction, Neuraxis for nervous system.”
The cephalic flexure is a major curve between the brain stem and forebrain.
True
False
True
Explanation: The cephalic flexure is a major curve between the brain stem and forebrain, which helps in the arrangement of the brain’s structures.
The myelencephalon corresponds to the adult structure known as the _______.
A) Pons
B) Cerebellum
C) Medulla oblongata
D) Cerebrum
C) Medulla oblongata
Explanation: The myelencephalon develops into the medulla oblongata, which is part of the brain stem.