The Nervous System Pt. 2 - The Brain

Question 1

What does the Brain look like as a three-to-four-week embryo?

Answer 1

There are three primary brain vesicles
* Prosencephalon (Forebrain)
* Mesencephalon (Midbrain)
* Rhombencephalon (Hindbrain)

Develops further until we get brain structures and spinal cord

Question 2

What is the Cerebrum?

Answer 2

Part of the Forebrain that is composed of gray matter & white matter

Gray matter includes dendrites and cell body
White matter comes from myelinated axons of neurons

Question 3

What part of the forebrain is composed of deeper gray matter?

Answer 3

Part of the Forebrain composed of Thalamus, Hypothalamus and Basal Nuclei (ganglia)

Question 4

What is a fissure?

Left and right hemisphere

Answer 4

A fissure is a divison btwm. two segments of the brain

Question 5

What is the outer most part surrounding the brain?

Answer 5

The cortex which consists of gray matter

Question 6

What are the lines that are going up and down the brain?

Answer 6

The lines going up are the gyrus and the lines going down are the sulcus

Question 7

What are the lighter coloured areas inside?

Answer 7

This is where white matter is found; made of myelinated axons

Question 8

What does the thalamus do?

Answer 8

Passes sensory signals to cerebrum via other areas of the brain

Question 9

What does the hypothalamus do?

Answer 9

Anterior-inferior to thalamus; controls autonomic N.S. & endocrine system

Question 10

Function of the Basal Nuclei (or ganglia)

Answer 10

Pass voluntary motor signals from cerebrum to other areas of the brain & spinal cord

Basal nuclei is located on either side of the thalamus

Question 11

What are central white matter tracts & what are the different tracts?

Answer 11

Central white matter tracts are myelinated axon tracts that carry info based on their direction
1. Commisural Tracts
2. Projection Tracts

Question 12

What are projection tracts?

Answer 12

Carries sensory info from cerebrum & deeper gray matter down towards spinal cord & up to cortex

Question 13

What are commissural tracts?

Answer 13

Connect right and left hemisphere for example by crossing over the midline but connect the same cortical area

Within white matter

Question 14

What are association tracts

Answer 14

Contains axons that conduct nerve impulses between gyri in the same hemisphere

Question 15

What makes up the Association Tracts?

Answer 15

• Arcuate fibers (stay within the same lobe)
• Longitudinal fasciculi (travel through the same hemisphere but crosses from one lobe to another)

Question 16

What is the brainstem composed of?

Answer 16

Midbrain + Hindbrain

Hindbrain = pons, medulla oblongata & cerebellum

Question 17

What is the peduncle?

Answer 17

Connects cerebellum to brainstem and to cerebrum

Superior, middle and inferior peduncle allow for afferent and efferent nerve fibres and tracts to leave and enter the cerebellum

Question 18

What is the midbrain responsible for?

Answer 18

• Eye movement
• Visual & auditory reflexes

Question 19

What is the Pons of the Brainstem responsible for?

Answer 19

• Regulating Breathing
• Connecting cerebellum via the peduncles

Question 20

Lateral to the Pons you can find the Superior, middle and inferior cerebellar peduncle? What do each of them do?

Answer 20

Superior: connects midbrain to cerebellum
Middle: connects to pons
Intermediate: Connect to medulla oblongata

Question 21

What is the medulla oblongata and what functions does it have?

Answer 21

• Found inferior to the Pons
• It regulates HR, breathing and BP
• Works w/ hypothalamus to regulate Autonomic Nervous System

Question 22

Where is the cerebellum and what is its main function?

Answer 22

Found posterior to the brainstem; coordinates motor actions

Question 23

What is the arbor vitae?

Answer 23

Bunch of white matter that spreads out from the middle; called “tree of life”