Lecture Exam 1 - Chapter 14 Study Guide

Question 1

What are the major parts of the brain?

Answer 1

The brain stem (medulla oblongata, pons, midbrain).
The cerebellum
The diencephalon (thalamus, hypothalamus, epithalamus).
The cerebrum - largest part of human brain.

Question 2

What are the roles of the skull, cranial meninges, CSF and blood-brain barrier?

Answer 2

Protect the brain –

CSF Function:
– mechanical protection
• floats brain & softens impact with bony walls
– chemical protection
• optimal ionic concentrations for action
potentials
– circulation
• nutrients and waste products to and from
bloodstream

Blood-brain barrier function:
– protects cells from some toxins and pathogens
– blocks proteins & antibiotics but not alcohol & anesthetics

Question 3

How is CSF formed and circulated?

Answer 3

Formed in membrane-like networks of
capillaries in the walls of the ventricles
called choroid plexuses.
Choroid plexuses are lined with ependymal
cells that form CSF by filtration of blood
plasma.

Question 4

What is the structure of the blood-brain barrier?

Answer 4

Blood brain barrier: formed by tight junctions sealing

together the endothelial cells of capillaries and a barrier formed by the neuroglial cells called astrocytes.

Question 5

What does the term hydrocephalus mean?

Answer 5

Interference in drainage of CSF and associated
increase in CSF pressure results in a condition
called hydrocephalus.
May be caused by tumors, inflammation (e.g. in
meningitis) or developmental malformations.
Sometimes CSF builds up and bulges through
fontanels of immature skull of a baby. The fluid
can be drained to prevent nerve damage.

Question 6

What are the 3 components of the brain stem?

Answer 6

Medulla Oblongata
Pons
Midbrain

Question 7

How are the 3 components of the brain stem arranged with respect to each other?

Answer 7

Most inferior = Medulla Oblongota
in the middle: Pons
Most superior = Midbrain

Question 8

What are “pyramids” in the brain stem?

Answer 8

Structures called “pyramids” in the white matter passinformation directly from cerebrum to spinal cord.

Question 9

What does the term vital function mean?

Answer 9

e.g. rate and force of heart beat, rhythm of breathing.

Question 10

What vital functions are controlled by the medulla oblongata?

Answer 10

Several of the nuclei in the medulla oblongata control vital functions e.g. rate and force of heart beat, rhythm of breathing.

Question 11

Why may injury to the medulla oblongata be fatal?

Answer 11

An injury to the medulla oblongata can be fatal if
functions maintaining heart and respiratory
rhythm are compromised.
Non-fatal injuries will usually result in cranial
nerve malfunctions, paralysis or loss of sensation
to the opposite side of the body to the injury.

Question 12

Where and what are the cerebral peduncles? What are their functions?

Answer 12

Anterior part of midbrain contains a pair of tracts called the cerebral peduncles.
The tracts in the cerebral peduncles conduct nerve impulses from the cerebrum to the spinal cord, pons and medulla oblongata. Tracts of the cerebral peduncles also contain axons of sensory neurons that are traveling to the thalamus.

Question 13

Where is the tectum and what is its function?

Answer 13

Posterior part of midbrain called the tectum - serve as reflex centers for visual stimuli.

Question 14

Where is the substantia nigra? Why is it darkly colored?

Answer 14

Substantia nigra is part of midbrain - darkly pigmented - contain neurons that release dopamine - loss of neurons here associated with Parkinson’s disease.

Question 15

What disease is associated with loss of

neurons in the substantia nigra?

Answer 15

Parkinson’s disease

Question 16

What is the reticular activating system? What is the function of the reticular activating system?

Answer 16

There is a wide region of the brain stem where white and gray matter inter-disperse and form a netlike
arrangement. This is called reticular formation.

Part of the reticular formation is called the reticular
activating system (RAS) and consists of sensory axons that go to the cerebral cortex.

The RAS helps maintain consciousness and is activeduring awakening from sleep - stimuli that awaken us (crying baby, alarm clock).

Question 17

Where is the cerebellum located?

Answer 17

At lower rear of brain (i.e. inferior and

posterior).

Question 18

How is the cerebellum separated from the cerebrum?

Answer 18

Separated from cerebrum by a deep groove -

transverse fissure.

Question 19

What are folia?

Answer 19

thin, parallel ridges called folia on the surface of the cerebellum

Question 20

How is the cerebellum attached to the rest of the brain?

Answer 20

Attached to the brain stem by the cerebellar

peduncles.

Question 21

Functions of the cerebellum:

Answer 21

evaluating effectiveness of movement, sending feedback to cerebral
cortex to correct motor errors, regulation of posture and balance. Possibly involved in cognition
and language processing.

Question 22

What is ataxia?

Answer 22

Damage to the cerebellum disrupts muscle coordination - a condition called ataxia ( a=without,
-taxia= order).

Alcohol inhibits activity of cerebellum and hence
causes ataxia.

Question 23

Would you expect ataxia if the cerebellum is damaged?

Answer 23

Yes

Question 24

What are the 3 components of the diencephalon?

Answer 24

Thalamus
Hypothalamus
Epithalamus (the pineal gland is part of the
epithalamus)

Question 25

Where are the 3 components of the diencephalon located?

Answer 25

Surrounds the third ventricle.

Question 26

What is the anatomical name for the pituitary stalk?

Answer 26

the infundibulum

Question 27

What does the thalamus do (be general)?

Answer 27

Relays sensory impulses to appropriate areas of cerebral cortex. Transmits motor information to primary motor arae of cerebral cortex.

Question 28

What are the 4 major regions of the hypothalamus?

Answer 28

1) Mammillary region - important in sense of smell. 2) Tuberal region - includes the infundibulum (pituitary stalk). 3) Supraoptic region - contains several nuclei including the paraventicular nucleus and supraoptic nucleus that generate axons that form the hypthalamo-hypophyseal tract that carry the hormones antidiuretic hormone (ADH) and oxytocin to the posterior pituitary.(ADH is the same hormone as vasopressin) 4) Pre-optic region- helps regulate autonomic function.

Question 29

Functions of the hypothalamus:

Answer 29

regulation of the pituitary function, regulation of emotional and behavioral patterns, regulation of eating and drinking, control of body temperature, regulation of circadian rhythms and states of consciousness.

Question 30

Define: Cerebral hemisphere

Answer 30

Right and left halves of the cerebrum

Question 31

Define: cerebral cortex

Answer 31

Outer rim of gray matter called the cerebral cortex | contains billions of neurons

Question 32

Define: Fissure

Answer 32

Folds called fissures.

Question 33

Define: sulci

Answer 33

Grooves between folds called sulci.

Question 34

Define: gyri

Answer 34

Elevated ridges are called gyri.

Question 35

What are the names and locations of the four lobes of the cerebrum?

Answer 35

``` Named according to the bones that cover them: Frontal lobes Parietal lobes Occipital lobes Temporal lobes ```

Question 36

What are the three types of tracts in the cerebral white matter? What are their functions?

Answer 36

Tracts are bundles of nerve fibers heading off in a particular direction to perform a particular function. 3 types of tracts: 1) Association tracts - conduct nerve impulses between gyri in same hemisphere. 2) Commissural tracts - conduct nerve impulses from gyri in one hemisphere to corresponding gyri in the other hemisphere. 3) Projection tracts - conduct nerve impulses from cerebrum to lower part of CNS and vice versa.

Question 37

What are the basal nuclei?

Answer 37

The basal nuclei are paired masses of gray matter in each cerebral hemisphere (Figure 14.13, page 550). • Connections to red nucleus, substantia nigra & subthalamus • Input & output with cerebral cortex, thalamus & hypothalamus • Control large automatic movements of skeletal muscles

Question 38

What are the structural components of the limbic system?

Answer 38

Rim of structures in the cerebral cortex on medial surface of each hemisphere. ``` Limbic lobe Cingulate gyrus Parahippocampal gyrus Hippocampus (seahorse) Dentate gyrus (toothed) Amygdala (almond-shaped) Septal nuclei Mamillary bodies of the hypothalamus Anterior nucleus and medial nucleus of the thalamus Olfactory bulbs Fornix of the forebrain ```

Question 39

Name three functions of the limbic system. What type of methods have been used to establish which areas of the brain are responsible for these functions?

Answer 39

Involved in emotions, smell and memory. Includes emotions such as aggression, pain, pleasure, affection, anger.

Question 40

Define: concussion

Answer 40

caused by abrupt, temporary loss of consciousness - results in disturbances of vision and loss of balance, drowsiness, nausea.

Question 41

Define: contusion

Answer 41

bruising of the brain.

Question 42

Define: Brain laceration

Answer 42

tear of the brain.

Question 43

Define: Sensory area (of cerebral cortex)

Answer 43

Sensory areas - receive sensory information - involved in perception (the conscious awareness of sensory system).

Question 44

Define: motor area (of cerebral cortex)

Answer 44

Motor areas - initiate movement

Question 45

Define: association area (of cerebral cortex)

Answer 45

Association areas deal with complex integrative functions such as memory, emotions, reasoning, judgment, personality traits and intelligence.

Question 46

What are thought to be the major functional differences between the right and left cerebral hemispheres?

Answer 46

The left hemisphere is more important for righthanded control, spoken and written language, and numerical and scientific skills. – The right hemisphere is more important for lefthanded control, musical and artistic awareness, space and pattern perception, insight, imagination, and generating mental images of sight, sound, touch, taste, and smell.

Question 47

What is an EEG? How can this diagnostic tool be used?

Answer 47

An electroencephalogram (EEG) may be used to diagnose epilepsy and other seizure disorders, infectious diseases, tumors, trauma, hematomas, metabolic abnormalities, degenerative diseases, and periods of unconsciousness and confusion.

Question 48

What are the four types of brain waves?

Answer 48

``` Alpha = awake and resting Beta = mental activity Theta = Emotional Stress Delta = Deep Sleep ```

Question 49

What are the major symptoms and common causes of stroke?

Answer 49

Abrupt onset of neurological symptoms e.g. paralysis, loss of sensation. Often caused by hemorrhage of a blood vessel in the brain, blood clots or atherosclerosis in the cerebral arteries. Risk factors include high blood pressure, high cholesterol, diabetes, smoking, obesity, excessive alcohol use.

Question 50

What is Alzeimer’s disease?

Answer 50

A form of senile dementia seen in about 11% of population | over 65.

Question 51

Name three structural abnormalities that can be seen on autopsy of the brains of victims of Alzeimer's disease?

Answer 51

Structural abnormalities seen at autopsy: 1) Loss of neurons that produce the neurotransmitter, acetylcholine. 2) Beta-amyloid plaques - an abnormal protein laid down around neurons. 3) Neurofibrillary tangles - abnormal bundles of filaments made of a protein called “tau”.

Question 52

How many pairs of cranial nerves are there?

Answer 52

12

Question 53

Know the names of the cranial nerves from most anterior to most posterior

Answer 53

``` 1-12 labeled anteriorly to posteriorly. 1. The Olfactory Nerve 2. The Optic Nerve 5. The Trigeminal Nerve 8 . The Vestibulochochlear Nerve 10. The Vagus Nerve ```

Question 54

Know the major functions of cranial nerves I, II, V, VIII and X. Which of these are only sensory and which are mixed?

Answer 54

I - The Olfactory nerve - smell II - The Optic Nerve - sight V - The Trigeminal nerve - touch, pain, and thermal sensations VIII - the Vestibulochochlear nerve - hearing/balance X - the Vagus nerve - taste, touch, pain, temperature