Functional Anatomy of the Nervous System Flashcards
What are the 4 main regions of the brain?
- Cerebrum
- Thalamus
- Hypothalamus
- Cerebellum
What does the brain develop from?
The embryonic neural tube
What are the primary functions of the cerebrum?
- Initiation of voluntary movement
- Sensory perception
- Memory, integration and planning
- Personality
(Movement, memory, sense, self)
What are the main functions of the thalamus?
Sensory input and outgoing commands
Regulation of consciousness, sleep and alertness.
What is the primary function of the hypothalamus?
Controls homeostatic functions
What is the function of the medulla oblongata?
To help with breathing, circulation and vomiting.
What is the function of the midbrain?
To help coordinate reflex responses to sight and sound.
What is the function of the cerebellum?
Helps with proprioception, posture and coordination (+ balance)
How many cranial nerves are there?
12
How do the spinal nerves exit the vertebral column?
They exit in between the vertebrae in intervertebral foramen.
What is the cauda equina?
The point at which the vertebral column stops and the spinal cord keeps going.
Why do we see enlargements in the cervical and lumbar spinal cord?
- This is where nerves to the limbs arise
- From the brachial plexus and lumbosacral plexus.
How are the nerves named in relation to the vertebrae?
Nerves exit cranial to their corresponding vertebrae until you reach the thoracic region at which point the nerves enter caudally to their corresponding vertebrae.
What are bundles of neurones called in the CNS?
Tracts
What are bundles of neurones called in the PNS?
Nerves
What is the difference in myelination between nerves in the CNS and in the PNS?
- Axons in the PNS are myelinated by separate Schwann cells.
- Axons in the CNS have arms of myelin-forming oligodendrocytes
What is grey matter made of?
Neuronal cell bodies
What is white matter made of?
Myelinated axons of neurones
What is the name for clusters of cell bodies within white matter?
Nuclei
What is the difference between tracts and nerves?
- Nerves are bundles of axons outside the spinal cord
- Tracts are bundles of axons inside the spinal cord
What is the function of astrocytes?
- Provide structural and functional support for the nervous system
- Absorb excess neurotransmitters
- Help to form the blood-brain barrier.
What are microglia and what is their function?
- They are specialised macrophages
- They help to clear up foreign agents in the nervous system
What are the 3 meninges helping to protect the brain?
- Dura mater
- Arachnoid mater
- Pia mater
How does the blood-brain barrier protect the brain?
Tight junctions between the cells stop substances from passing between cells.
What are the 3 main functions of the cerebrospinal fluid?
1) Cushioning impact
2) Buoyancy
3) Some nourishment
What is the ventricular system?
The system of cavities within the CNS.
Where is CSF secreted from?
Secreted by ependymal cells and choroid plexus.
Where does the CSF circulate through?
- Circulates through brain ventricles, central canal of spinal cord and subarachnoid space.
- CSF is eventually reabsorbed into the blood.
How does the brain get its blood supply?
Blood is pooled into the cerebral arterial circle (circle of Willis) before distribution to the brain
What is different about dogs and horses in terms of their blood supply to the brain?
Dogs and horses supply their cerebral arterial circle via the carotid artery but in other species it comes from the external carotid - maxillary artery.
What does the CNS consist of?
The brain and spinal cord
What does the PNS consist of?
Cranial nerve, spinal nerves and ganglia.
What are the alternative names for afferent and efferent nerves?
- Afferents can be called sensory neurones or ascending neurones (when they run through the spinal cord)
- Efferents can be called motor neurones or descending neurones (in spinal cord).
What are special afferents associated with?
Special senses such as vision, hearing and balance.
What is the difference between the somatic and visceral nervous system?
Somatic is the voluntary nervous system
Visceral is the involuntary nervous system
