Week 2 - Anatomy and Physiology of the Central Nervous System (Theory) Flashcards
(25 cards)
What are the 2 parts of the nervous system
- Central nervous system (CNS)
- Peripheral nervous system (PNS)
What is the central nervous system (CNS)
The control center, responsible for processing and interpreting information.
What are the components of the central nervous system (CNS)
- Brain - controls thought, memory, emotions and body functions
- Spinal cord - transmits signals between the brain and the body, also responsible for reflex actions
What is the peripheral nervous system
Connects the CNS to the rest of the body, transmitting signals between them
What are the functions of the peripheral nervous system
Motor: Somatic and autonomic - conscious and unconscious response to stimuli
Sensory - stimulus detection
Together - role in homeostasis and co-ordination
What are spinal nerves
Spinal nerves are a part of the Peripheral Nervous System and plays a key role in transmitting signals between the central nervous system and the rest of the body
What are roots
- Dorsal roots contain sensory (afferent) nerves
- terminate in the posterior grey horn
- Ventral roots contain motor (efferent) nerves
- Somatic motor nerves extend from the anterior grey horn
- Autonomic motor nerves extend from the lateral grey horn
What is a spinal nerve
The roots then combine together to form a spinal nerve which would contain both sensory and motor nerves.
What is a ramus (Rami)
Spinal nerve splits into two ramus (rami) where both rami contain both sensory and motor nerves
- Dorsal ramus (rami) - supplies muscles and skin of the back
- Ventral ramus (rami) - supplies the front and sides of the body as well as the limbs
What are cranial nerves
nerves that emerge directly from the brain (instead of the spinal cord) and primarily serve the head, neck and some internal organs. They are but of the peripheral nervous system (PNS).
how many cranial nerves are there
12
What are the different cell types of the brain
- neuron
- Gilia
- Astrocytes
- Neuroglia (astroycutes, oligodendrocytes, microglia, ependymal cells)
What are neurons
- Main unit of the nervous system
- function to fire action potential/ impulses to communicate signals
What are glia cells (glue)
- support cells
- provide nutrients, support, immune functions, myelination
- 5-25 times more glia than neurons
What are astrocytes
- Star shaped glial cells found in the CNS (brain and spinal cord)
- support neurons
- have processes in contact with most aspects of neurons
- secrete growth factors, influence neurotransmission (associated with synapses)
- provide structural support by holding neurons in place
- helps maintain the blood brain barrier
How do astrocytes contribute to the blood brain barrier
The endfeet wrap around blood vessels in the brain. These endfeet help reinforce the tight junctions between endothelial cells, which are essential for the selective permeability of the brain blood barrier
What are neuroglia (glial) cells
- non neural cells that support protect and nourish neurons
- They do not transmit signals but play crucial roles in nervous system function
What is the function of astrocytes
support and regulate the environment
What is the function of oligodendrocytes
form myelin sheaths for CNS
What is the function of microglia cells
immune defense cells
What is the function of ependymal cells
produce cerebrospinal fluid (CSF)
What happens during the 4th week of development of the brain
- rapid growth of neural tissue in the cranial area
- forms two main flexures - cephalic and cervical
What happens during the 5th week of brain development
further (secondary) brain vesicles form resulting in (from rostral):
- Telencephalon: cerebrum
- Diencephalon: thalamus, hypothalamus and epithalamus
- Mesencephalon: Midbrain
- Metencephalon and myelencephalon: Hindbrain (Pons, cerebellum and medulla oblongata)
How does the ventricular system develop and what is its function
The ventricular system development parallels that of the brain
Essentially it is the lumen of the neural tube
