The brain

Question 1

Name all the views of the brain?

Answer 1

• Anterior
• Posterior
• Lateral view
• Sagittal section (side)
• Coronal/frontal section
• Horizontal section

Question 2

About the brain?

Answer 2

• A large, delicate mass of neural tissue containing internal passageways and chambers with cerebrospinal fluid.
• Each of four major regions has specific functions.

Question 3

Name the four main parts of the brain?

Answer 3

• Cerebral hemispheres (cerebrum); 4 lobes.
• Diencephalon; thalamus and hypothalamus.
• Brain stem; mid brain, pons and medulla oblongata.
• Cerebellum.

Question 4

Explain the cerebral hemispheres?

Answer 4

• Cell bodies form outer layer called cortex.

- Cell bodies deep are basal ganglia.

Question 5

Explain the ‘lines’ in the brain?

Answer 5

• Folded surface increases surface area.
• Elevated ridges = GYRI!!
• Shallow depressions = SULCI!!
• Deep grooves = FISSURES!!

Question 6

What is the difference between gray and white matter?

Answer 6

• Gray matter is in cerebral cortex and basal nuclei.

- White matter is deep to cerebral cortex and around basal nuclei.

Question 7

Describe the structures of the cerebrum?

Answer 7

• Gyri of neural cortex increases surface area.
• Insula of cortex lies medial to lateral sulcus.
• Longitudinal fissure separates the hemispheres.
• Lobes divide hemispheres.

Question 8

Name the 4 loves in each hemisphere?

Answer 8

• Frontal
• Parietal
• Occipital
• Temporal

Question 9

Name the 3 sulci divisions in the cerebrum?

Answer 9

• Central sulcus divides frontal and parietal lobe.
• Lateral sulcus divides frontal and temporal lobe.
• Parieto-occipital sulcus divides parietal and occipital lobes.

Question 10

Describe the diencephalon?

Answer 10

• Located under cerebrum.
• Links cerebrum with brain stem.
• Thalamus = relays + processes sensory info.
• Hypothalamus = hormone production, emotion, autonomic function.

Question 11

Describe the brain stem?

Answer 11

• Processes info between spinal cord and cerebrum.
• Mid brain = processes sight, sound and reflexes, maintains consciousness.
• Pons = connects cerebellum to brain stem, somatic and visceral motor control.
• Medulla = relays info, regulates autonomic functions, e.g. heart rare, BP.

Question 12

Describe the cerbellum?

Answer 12

• 2nd largest part.
• Two hemispheres.
• Coordinates repetitive body movements.

Question 13

Name and describe the 3 types of white matter in the cerebrum?

Answer 13

• Association fibres; connect within each hemisphere.
• Commissural fibres; connect one hemisphere with other.
• Projection fibres; connect brain with the spinal cord.

Question 14

Describe the ventricles of the brain?

Answer 14

• Lateral ventricles; Large, in each hemisphere, separated by thin medial partition.
• Third ventricle; in diencephalon, communicate with lateral via inter ventricular foramen.
• Fourth; continuous with third, extends into medulla, becomes continuous with spinal cord.

Question 15

What do the ventricles carry?

Answer 15

-Cerebro - spinal fluid!!!!

Question 16

Name and describe the 3 cranial meninges?

Answer 16

• Dura mater (outermost); 2 layers, thick and leathery.
• Arachnoid mater (middle); covers brain, contacts dura.
• Pia mater (innermost); 1 cell thick, attached to brain surface by astrocytes.

Question 17

Describe the cerebrospinal fluid (CSF)?

Answer 17

• Surrounds all exposed CNS surfaces.
• -Supports brain, transports nutrients and waste.
• Choroid plexus; in ventricles specialised cells produce+secrete CSF and remove wastes and adjust composition.

Question 18

How does CSF circulate?

Answer 18

• From choroid plexus.
• Through ventricles.
• To central canal of spinal cord.
• Into subarachnoid spaces around brain and cord.

Question 19

All about the frontal lobe?

Function, cortex’s

Answer 19

• Frontal lobe, pre central gyrus.
• Premotor cortex; learned motor skills, patterned/repetitive, several muscles groups, planning movement.
• Motor speech area- usually left called BROCA’S area!!; active as we prepare to speak.
• Prefrontal cortex; intellect, recall, personality, reasoning.
• Olfactory cortex; receives impulses from smell receptors.

Question 20

All about the parietal lobe? (Functions, cortex’s)

Answer 20

• Primary somatosensory cortex; neurones receive info from sensory receptors, allows identification of body region being stimulated.
• Sensory association cortex; connections with primary cortex, produces understanding of object stimulating senses. WENICKES area = left hemisphere, understanding language!!
• Gustatory cortex; receives impulses from smell receptors.

Question 21

All about the temporal lobe? (Functions, cortex’s)

Answer 21

• Auditory cortex!!
• Primary auditory cortex; receives info from receptors in inner ear, pitch, rhythm, loudness.
• Auditory association area; enables perception of neural info, ‘hear’ noise as speech or music. Uses memory of past events.

Question 22

All about the occipital lobe?

Functions, cortex’s

Answer 22

• Primary visual cortex; receives info from retina.
• Visual association area; communicates with primary, memory to interpret visual events, basically ‘seeing’ is done here!!

Question 23

Describe the visceral association area?

Answer 23

• Cortex of the insula!!

- Involved in conscious perception, e.g. full stomach, upset stomach, full bladder.

Question 24

What is basal ganglia?

Answer 24

• Collections of grey matter.
• Deep within white matter of cerebral hemispheres.
• Function = Coordination of learnt movements and fine control of movement.

Question 25

Types of basal ganglia?

Answer 25

- Caudate nucleus = curving, slender tail. | - Lentiform nuclei = globus pallidus, putamn.

Question 26

Describe the thalamus in detail?

Answer 26

- Largest region of diencephalon. - Receives input from somatic sensory receptors. - Mediates sensation. - Thalamic nuclei = rounded masses, relay sensory info to basal nuclei.

Question 27

Describe the hypothalamus?

Answer 27

- Main visceral control centre of body. | - Regulates body homeostasis; emotional response, sleep, food intake.

Question 28

Describe the epithalamus?

Answer 28

- Pineal gland, posteior to thalamus. | - Melatonin, regulates sleep, influences mood.

Question 29

Describe the mid brain in detail?

Answer 29

- Large pyramidal tracts. - Control occulomotor and auditory nerves. - Provide a link between the ANS and amygdala. - Two pairs of sensory nuclei = superior and inferior colliculus. - Red nucleus and substantia nigra.

Question 30

Describe the pons in detail?

Answer 30

- Messages between motor cortex and cerebellum. - Several cranial nerves from there. - Nuclei involved with respiration - Process and relay info to and from cerebellum.

Question 31

Describe the medulla oblongata in detail?

Answer 31

- Allows brain and spinal cord to communicate. - Controls visceral functions. - Nuclei in the medulla; sensory and motor nuclei. - 3 groups of nuclei = autonomic nuclei, sensory and motor, relay stations along sensory and motor. -Contains reticular formation, cardiovascular centres, respiratory centres, nuclei of some cranial nerves.

Question 32

Name the 4 functions of the reticular formation?

Answer 32

- Motor control = input from red nucleus.. - Sensory control = exerts influence on spinal reflex arc. - Visceral control = in medulla, adjusts heart rate, flow of blood. - Control of consciousness = controls levels of arousal (damage leads to coma), modulation of sleep and wake cycles.

Question 33

Describe the cerebellar peduncles?

Answer 33

- Tracts link cerebellum with brain stem and spinal cord. | - Superior, middle and inferior cerebellar peduncles.

Question 34

What is the limbic system?

Answer 34

- Establishes emotional states, links conscious functions with autonomic. - Amgdaloid body = acts as interface between system and cerebrum. - Limbic lobe = cingulate and dentate gyrus, hippocampus. - Fornix = tract of white mater.