Structure And Development Of NS Flashcards
What are the primary functions of the nervous system?
Stimulus processing, decision making, and movement control
What type of nervous system do sponges and jellyfish (Invertebrates) possess?
Nerve net
They have a ventral nerve cord compared to dorsal nerve cords (nerve cord in the back) in vertebrates
List the brain divisions common to all vertebrates.
- Olfactory bulb
- Cerebral hemispheres
- Cerebellum
- Optic tectum
- Medulla oblongata
What is the small central collection of neuronal control circuits in Amphioxus called?
Primitive brain
What are the two main parts of the forebrain?
- Diencephalon - thalamus and hypothalamus
- Telencephalon - cortex and olfactory bulb
What does the central nervous system (CNS) develop from?
The walls of the neural tube
The neural plate folds and fuses to form the neural tube
What is spina bifida?
Failure of the posterior neural tube to close
This forms a gap in the vertebral column and portion of the spinal cord pokes out of the back = paralysis down to legs
How can the incidence of neural tube defects be reduced?
Supplementing diet with folic acid in early pregnancy
What are the three layers of cells in the developing nervous system?
- Endoderm (lining of organs; viscera)
- Mesoderm (bones and muscles)
- Ectoderm (nervous system and skin)
What do the dorsal roots of the spinal cord contain?
Sensory, afferent neurons
Sensory information enters the spinal cord through these
Located at the back
What do the ventral roots of the spinal cord contain?
Motor, efferent neurons
Motor information leaves the spinal cord through these
What is the primary channel for messages between the brain and the body?
Spinal cord
Messages from skin, joints and muscles to the brain and from the brain to the periphery
What are the two types of matter in the spinal cord?
- Grey matter = neuron cell bodies
- White matter = myelinated axons
Which part of the brainstem is important for controlling blood pressure and respiration?
Medulla = important in ANS
What role does the pons play in the brain?
Important relay between cortex and cerebellum
Swells out from ventral surface of brain stem
What is the function of the thalamus and hypothalamus?
In the Diencephalon (located above midbrain)
Thalamus = Relay and gating roles in sleep and conscious movement
Hypothalamus = homeostasis and reproduction
What is the function of the Midbrain?
Located above brain stem
Linkages between components of motor systems, eye movement, sleep and temperature regulation
What is the cerebellum primarily responsible for?
Movement control centre
Extensive connections to cerebrum and spinal cord
Disease includes ataxias = aberrant movement coordination (drunk-like movement)
What structure separates the two halves of the cerebral cortex?
Sagittal fissure
What is the neocortex?
The more complex 6-layer structure of the cortex in mammals
List the cortical lobes of the cerebral cortex in clockwise order from the front.
- Frontal = voluntary actions, motor actions, speech control & emotions
- Parietal = sensory information & language
- Occipital = processes visual information
- Temporal = involved in memory, sensory and language functions
What anatomical feature increases the processing power of the brain?
Cortical neurons
True or False: The cerebellum contains at least as many neurons as both cerebral hemispheres combined.
True
Fill in the blank: The brain is hollow and bathed in _______.
Cerebrospinal fluid (CSF)
