creierul 1 Flashcards
What is the weight of the brain?
1.4kg
What are the 3 planes of the brain?
The sagittal plane: splits brain right and left hemisphere
The horizontal plane: up and down
The frontal (coronal) plane: front and back
What are the 4 views of the brain?
Anterior vs posterior - the from front vs from the back of the brain
Superior vs inferior - higher up vs lower down
Dorsal vs ventral - looking from above vs looking from below
Lateral vs medial - towards the sides vs towards the middle
What are convolutions in the brain?
Wrinkles - the more wrinkles, the more advanced the brain is
What are the 3 surface anatomical features of the brain?
Gyri: bulges, bump, mountain, hill
Sulci: shallow folds, cracks
Fissures: deep folds
What are the 2 hemispheres of the brain divided by?
the longitudinal fissure
What are the 3 major fissures that divide each hemisphere into different lobes?
Central sulcus
Sylvian (lateral) fissure
Transverse cerebral fissure
What does the ventral view of the brain show?
- Some structures which are separate from the hemisphere e.g. brain stem and cerebellum
- Some nerves originating from the brain e.g. optic nerve
- The brain’s vascular system - system of blood vessels carrying blood to and from the brain
What is the brain’s vascular system made up of?
- Middle cerebral arteries: supply mainly the temporal and parietal lobes and some lateral surfaces of occipital lobe
- Posterior cerebral arteries: arteries that run at the back of the head: irrigates mainly the occipital lobe
- Anterior cerebral arteries: arteries that run at the front of the head: irrigates middle regions of the frontal lobe
- Basilar artery: irrigates brainstem
- Circle of willis: circular feeder system - can take blood from more than 1 source
What is the mid-sagittal view of the brain?
Splitting the brain into left and right hemisphere and looking inside
You separate along the longitudinal fissure
What are the 3 main parts of the brain?
The hindbrain
The midbrain
The forebrain
- What is the hindbrain?
Rhombencephalon
Oldest part of the brain
Controls many essential functions (e.g. breathing, heart rate, blood pressure)
Comprised of 3 main structures:
- Pons
- Cerebellum
- Medulla
What do the pons do in the hindbrain?
-Does contralateral control: left hemisphere controls right side of the body, right hemisphere controls left side of the body
-Helps coordinate hindbrain with midbrain and forebrain
-Plays important roles in: sleep, respiration, swallowing, bladder control, hearing, taste, eye movements, facial expressions and sensations, posture
What does cerebellum do in the hindbrain?
-Has 2 lobes
-Important for motor control - coordination, precision and accurate timing
-joins to rear of medulla by 3 pairs of stalks (cerebellar peduncles)
What does the medulla do in the hindbrain?
- controls breathing, heart rate, vomiting, salivation, coughing, sneezing
Damage to medulla is nearly always fatal
- What is the midbrain?
Mesencephalon
has 2 major parts:
- tectum
- tegmentum
Associated with: vision, hearing, motor control, sleep cycle, arousal, temperature regulation
What is the tectum in the midbrain?
Includes:
- superior colliculus (part of the visual system)
- inferior colliculus (part of the auditory system)
What is the tegmentum in the midbrain?
Made up of:
- Periaqueductal grey matter: controls sequences of movements
- Substantia nigra (black substance): involved in reward and movement
- Red nucleus, involved in limb control
- All important components of the motor system
- What is the forebrain?
prosencephalon
Plays an important role in perception but also all forms of higher cognition.
Structures include:
- the cerebrum
- thalamus
- hypothalamus
- limbic system
What is the thalamus in the forebrain?
2-lobed structure
sits on top of the brainstem
Massa intermedia is the bridge that connects the 2 lobes
It functions as a gateway to the higher cortical regions
Most sensory information apart form smell passes through the thalamus
Information is processed and then outputted to cortex for further processing
Plays a major role in sleep and wakefulness
Damage can lead to permanent coma
What is the hypothalamus in the forebrain?
Contains many nuclei and tracts
Controls the autonomic nervous system and the endocrine system with direct links to pituitary glands
Pituitary gland releases hormones related to stress, growth and reproduction
What is the limbic brain in the forebrain?
Important for motivation and emotion
Associated with the four Fs of survival: fleeing, fighting, feeding and fornication
What is the hippocampus in the forebrain?
Surrounds the thalamus
Seat of our spatial memory
London taxi drivers have enlarged hippocampus
What is basal ganglia?
Subcortical structures
Ganglia: clusters of nerve cell bodies
Basal: forming a bottom layer
Involved in movement and motor control
Diseases of the basal ganglia:
Parkinsons
Huntingtons
What are ventricles?
There are 4 in the brain.
They are cerebrospinal fluid chambers
there are:
- 2 large lateral ventricles in the forebrain
- 1 central ventricle below and between them
- 1 ventricle just behind the medulla and pons
What is the importance of the forebrain?
Hydrocephalus:
- a condition in which ventricles are enlarged by overfilling with CSF
- associated with cognitive deficits
