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
What are the structures and functions of the Metencephalon?
10
- The pons (bridge): Link between hindbrain and midbrain
also involved in: respiration, eye movement, facial expression, chewing - Cerebellum (little brain): Motor Cortex and sense organs:
Voluntary muscle movements
Balance and equilibrium maintenance
Muscle tone and posture
What are the structures and functions of the Mesencephalon?
9
Provides major pathways for sensory and motor impulses between the forebrain and the midbrain
- Tectum (roof): auditory and visual communication
- Tegmentum (covering): sensory processes, movement, motor control (substantia nigra)
What are the structures and functions of the Diencephalon?
6
- Thalamus (chamber): Receives sensory info, relays sensory processing in the cortex
- Hypothalamus (+ Pituitary Gland): Regulation of Automatic Nervous System and Endocrine System
What connects the two hemispheres of the Telencephalon?
2
- Corpus Callosum: nerve fibers that connect the hemispheres
What is the Telencephalon made out of?
4
- White matter: axons covered in myelin sheath
- Gray matter: Cortex made up of cells
What are the structures and functions of the Limbic System of the Telencephalon?
(12)
The structures are involved in stress, emotions, memory storage and retrieval:
- Cingulate Gyrus: control of emotions and behavior
- Fornix: links Hippocampus and Hypothalamus
- Amygdala: emotional processing and motivation
- Hippocampus: Involved in learning and memory (threat detection and emotionally charged memories)
What are the 3 major grooves that divide the Cerebral Cortex?
(3)
- Longitudinal Fissure
- Central Sulcus
- Lateral Fissure
What are the structures of the Cerebral Cortex?
4
- Frontal Lobe
- Parietal Lobe
- Temporal Lobe
- Occipital Lobe
How are the Lobes of the Cerebral Cortex Divided?
2
- Central Sulcus: divides frontal and parietal lobes
- lateral fissure: divides temporal lobe from frontal, parietal and occipital lobes
What are the functions of the Central Nervous System?
3
- Basic functions: breathing, swallowing, digestion, movement => Medulla - brain-stem and cerebellum
- Behaviors essential for survival: pain, pleasure, eating, fear, sex => Limbic System
- Higher order Functions: planning, perception, thinking, problem solving => Cerebral Cortex
