Structures of the Central Nervous System Flashcards
What makes up the Nervous System?
2
- Peripheral NS
2. Central NS
What makes up the Peripheral NS?
2
- Autonomic NS
2. Somatic NS
What are the functions of Parasympathetic and Sympathetic Systems in the Autonomic NS?
(3)
Creating homeostasis in the body
- Parasympathetic decreases/ slows down processes
- Sympathetic increases/ Speeds up processes
What is the basal organisation function of the PNS and CNS?
13
- Afferent (in)
Stimuli => Detected by peripheral NS => sensory information sent through the Spinal Cord in the Central Nervous System => Recognised by Brain => decision taken by Brain - Efferent (out)
Motor commands sent to PNS: Somatic or Autonomic => Command is executed
What do 9 Anatomical Directions mean?
18
- Ventral = bottom of the head/ front of body
- Dorsal = top of the head/ back of body
- Anterior/ Rostral = nose end
- Posterior = tail end
- Lateral = towards the sides
- Medial = towards the middle
- Bilateral = both sides of head/ body
- Ipsilateral = same side of head/ body
- Contralateral = opposite side off head/body
What are the 3 Anatomical planes?
6
- Horizontal Section = Middle of the forehead cut
- Sagittal section = Middle of the face cut
- Coronal section = Middle of the head (ears) cut
What are the main arteries that ensure constant blood supply to the brain?
(7)
- Anterior Cerebral Artery
- Anterior Communicating Artery
- Internal Carotid Artery
- Posterior Communicating Artery
- Posterior Cerebral Artery
- Basiliar Artery
- Vertebral Artery
What happens if the brain is depleted of resources (O2 and Glucose) for some time?
(7)
- 1 Second Interruption: Brain cannot store glucose = depleted of all resources
- 6 Seconds Interruption: Unconsciousness
- A few minutes = brain damage
What is the meninges and what are its structures?
10
- A protective layer between the skull and brain/ spinal cord and spinal column
1. Outer layer: Thick, Though, Flexible
2. Middle layer: Web-like sheet of tissue
3. Subarachnoid Space: Filled with Cerebrospinal Fluid
4. Inner Layer: Thin with rich blood supply
What are the functions of the Blood- Brain Barrier?
7
CNS cannot kill viruses
BBB keeps viruses/ bacteria. harmful chemicals out
only small and uncharged molecules can pass through (O2/ CO2)
Active Transport System pumps essentials into the brains
– some Harmful substances like nicotine and heroine can pass through but antibiotics cannot
What are the functions of the Ventricular System?
2
- 4 ventricles in the brain that allow protective Cerebrospinal Fluid to flow around
- CSF also flows in the subarachnoid space
How does the brains develop?
4
- 3 weeks: fore-brain, mid-brain and hind-brain almost equal
- 7 weeks: + fore-brain, mid-brain, hind-brain and cranial nerveless
- 11 weeks: ++ fore-brain, + mid-brain, + hind-brain
- at birth: fore-brain fully developed, mid-brain hidden, hind-brain = cerebellum and medulla
What are the structures of the adult brain?
5
- Fore-brain: Telencephalon (the hemispheres), Diencephalon (little hidden structure inside: interbrain)
- Mid-brain: Mesencephalon (bellow Diencephalon)
- Hind-brain: Metencephalon and Myelencephalon
What structures form the Central Nervous System?
- Brain: Forebrain, Midbrain, Hindbrain
- Spinal Cord
What are the structures and functions of the Myelencephalon?
4
- It is the Medulla Oblongata:
Controls vital functions: cardiovascular system, respiration, muscle tone