Anatomy And Physiology Chapter 14

Front 1

Brain stem

Back 1

- consists of the medulla oblongata, pons, and midbrain.

Front 2

Cerebellum

Back 2

- posterior to brain stem.

Front 3

Diencephalon

Back 3

- consists of the thalamus, hypothalamus, and epithalamus. It is superior to the brain stem.

Front 4

Cerebrum

Back 4

- is the largest part and spreads over the diencephalon like a cap.

Front 5

Describe how the brain is physically protected.

Back 5

A. Cranial bones
B. Cranial meninges:
1. Include the dura mater, arachnoid mater, and pia mater.

Front 6

Falx cerebri

Back 6

- separates the hemispheres of the cerebrum.

Front 7

Falx cerebelli

Back 7

- separates hemispheres of cerebellum.

Front 8

Tentorium cerebelli

Back 8

separates cerebrum from the cerebellum

Front 9

Blood supply

Back 9

- the brain has an extensive blood supply. It makes up only 2% of body weight but requires 20% of the O2. Also, since the brain does not store glucose it needs a constant supply. Blood vessels run along the surface of the brain and then penetrate the brain.

Front 10

Blood brain barrier (BBB)

Back 10

1. Brain capillaries are less permeable than most capillaries. Their capillary endothelial cells are sealed by tight junctions and are surrounded by thick basement membrane.
Also, astrocytes contribute to this.
2. Chemicals that can readily pass through are glucose, O2, CO2, water, and most lipid soluble ones like alcohol, caffeine nicotine and other psychoactive drugs and anesthetics.
3. Most ions and urea pass slowly.
4. Proteins and most antibiotics do not pass through.

Front 11

(CSF) functions: Mechanical protection

Back 11

- absorbs shock and floats the brain in the cranium.

Front 12

(CSF) functions:Chemical protection

Back 12

- provides right ion concentrations for optimum neuron function.

Front 13

(CSF) functions:Circulation

Back 13

- serves as a medium for exchange of nutrients and wastes between blood and CNS tissue.

Front 14

(CSF) Formation

Back 14

- networks of capillaries in ventricles (cavities) walls called choroid plexuses contain ependymal cells, which filter and secrete CSF from the blood plasma into ventricles.

Front 15

Medulla oblongata

Back 15

- it contains all ascending and descending white matter tracts that connect with the rest of the brain. It occurs between the foramen magnum and the pons.

Front 16

Medulla oblongata: Decussation of pyramids

Back 16

- is where most axons of motor tracts cross over to the other side of the medulla.

Front 17

Medulla oblongata: Gracile nucleus and Cuneate nucleus

Back 17

-relay sensory information to opposites sides of the thalamus. This is where most sensory impulses cross over to the other side.

Front 18

Medulla oblongata: Cardiovascular center

Back 18

- regulates rate and force of heartbeat and diameter of blood vessels.

Front 19

Medulla oblongata: Medullary rhythmicity area

Back 19

- regulates rhythm of breathing.

Front 20

Medulla oblongata:

Back 20

It has centers for vomiting, coughing, swallowing, and sneezing reflexes.

Front 21

Medulla oblongata:
Inferior olivary nucleus

Back 21

relays information from proprioceptors to the cerebellum.

Front 22

Medulla oblongata:

Back 22

It also contains nuclei of origin for the last 5 pairs of cranial nerves (VIII-XII).

Front 23

Pons

Back 23

- it acts as a bridge between some parts of the brain.
1. It contains transverse axons that connect right and left sides of the cerebellum.
2. Pneumotaxic and apneustic areas-are nuclei that help control breathing.
3. It contains nuclei for 4 pairs of cranial nerves (V-VIII).

Front 24

Midbrain

Back 24

1. Superior and inferior colliculi
2. Substantia nigra
3. Red nuclei
4. Also it has nuclei associated with movements of the eyeballs for two cranial nerves (III and IV).

Front 25

Superior and inferior colliculi

Back 25

- serve as reflex centers for eye, head and trunk movements in response to visual and auditory stimuli.

Front 26

Substantia nigra

Back 26

- has darkly pigmented nuclei that help control subconscious muscle activity.
Degeneration of dopamine- containing neurons here contributes to Parkinson disease.

Front 27

Red nuclei

Back 27

- help coordinate muscle movements.

Front 28

Reticular formation

Back 28

- extends from the brain stem into the spinal cord and diencephalon. It contributes to regulating muscle tone. It also contains the reticular activating system (RAS) which maintains consciousness and awakens the cerebral cortex from sleep.

Front 29

Describe the functions of the cerebellum.

Back 29

A. The cerebellum is the 2nd largest part of the brain. It consists of two hemispheres, connected by the vermis.
B. Its major function is to compare the movement intended by the cerebrum with sensory input from the body as to what is actually happening. If there are discrepancies it sends feedback to the cerebrum to correct them. Thus it helps to smooth and coordinate muscle movements.
C. It also regulates posture and balance.

Front 30

Components of the diencephalon.

Back 30

A. Thalamus
B. Hypothalamus
C. Epithalamus:
D. Circumventricular organs

Front 31

Thalamus:

Back 31

1. Serves as a principal relay center for sensory impulses from the spinal cord and other parts of the brain to the cerebrum.
2. Allows crude perception of pain, pressure, and temperature.
3. Transmits information on motor activities from other parts of the brain to the cerebrum.

Front 32

Hypothalamus

Back 32

one of the major regulators of homeostasis

1. Adjusts and coordinates activities of ANS centers in the brain stem and spinal cord. (E.g. heart rate, digestion and urination)
2. Controls the pituitary gland, a major gland of the endocrine system, by nerve impulses or by releasing hormones that control secretion of pituitary hormones.
3. Regulation of emotions and behaviors such as rage, pain, pleasure, and sexual arousal.
4. Regulation of eating and drinking.
5. Controls body temperature.
6. Regulation of circadian (daily) rhythms and states of consciousness

Front 33

Epithalamus:

Back 33

Epithalamus:
1. Pineal gland
2. Habenular nuclei

Front 34

Pineal gland

Back 34

- secretes the hormone melatonin, which seems to promote sleepiness and play a role in setting the body’s biological clock.

Front 35

Habenular nuclei

Back 35

- especially involved in emotional responses to smells.

Front 36

Circumventricular organs

Back 36

- monitor chemical changes in the blood, are thought to be the site for HIV entry into the brain since they lack a BBB.

Front 37

Cerebrum

Back 37

- serves as the seat of intelligence. It is the main processor of information for the body and is the largest part of the brain.

Front 38

cerebral cortex

Back 38

- The outer 1/8” of the cerebrum. It is composed of gray matter and is where much of the information processing occurs.

Front 39

Gyri

Back 39

- are folds or rolls on the outside of the cerebrum.

Front 40

Sulci

Back 40

- the shallower grooves.

Front 41

Fissures

Back 41

- the deepest grooves of the cerebrum.

Front 42

longitudinal fissure

Back 42

- divides the cerebrum is divided into right and left hemispheres

Front 43

corpus callosum.

Back 43

- connects the left and right hemispheres of the crebrum

Front 44

White matter

Back 44

- Association tracts - Commisural tracts - Projection tracts

Front 45

Association tracts

Back 45

- transmit nerve impulses between gyri of the same hemisphere.

Front 46

Commisural tracts

Back 46

- transmit between corresponding gyri in opposite cerebral hemispheres.

Front 47

Projection tracts

Back 47

- transmit impulses to and from various parts of the brain and to the spinal cord and back.

Front 48

Basal ganglia

Back 48

A. paired groups of 3 nuclei in each cerebral hemisphere that are rich in dopamine.
B. Help regulate initiation and termination of movements and some cognitive processes.
C. Control subconscious movements of skeletal muscles.
D. Help regulate muscle tone during specific movements.

Front 49

Limbic system

Back 49

A. a ring of structures encircling the brain stem and includes the cerebrum and the floor of the diencephalon.
B. It controls emotional aspects of behavior.
C. The hippocampus serves in recent memory along with other parts of the cerebrum.

Front 50

Somatosensory association area

Back 50

- especially integrates and interprets touch, pressure, and temperature sensations. Also it stores memories of experiences for these types of sensations.

Front 51

Prefrontal cortex

Back 51

- concerned with personality, intellect, complex learning, recall, reasoning, conscience, mood, and development of abstract ideas.

Front 52

Visual association area

Back 52

- relates past and present visual experiences for recognizing and evaluating what is seen.

Front 53

Auditory association area

Back 53

- determines whether a sound is speech, music, or noise.

Front 54

Wernicke’s area

Back 54

- recognizes spoken words and translates words into thoughts. Also it adds tonal inflection to speech.

Front 55

Common integrative area

Back 55

- allows one thought to be formed based on a variety of sensory inputs.

Front 56

Premotor area

Back 56

- controls learned movements that are complex and sequential and serve as a memory bank for these.

Front 57

Frontal eye field area

Back 57

- controls voluntary eye scanning movements

Front 58

Left hemisphere

Back 58

- is more important in language, numerical and scientific skills, and reasoning.

Front 59

Right hemisphere

Back 59

- is more important in musical and artistic awareness, spatial and pattern perception, recognition of faces, discrimination of odors, emotional content of language, and generating mental images.

Front 60

Olfactory

Back 60

-sensory smell.

Front 61

Optic

Back 61

-sensory vision.

Front 62

Oculomotor: Motor

Back 62

-movement of the eyelid and eyeball, accommodation of the lens, and constriction of the pupil.

Front 63

Oculomotor: Sensory

Back 63

-muscle sense (proprioception) from the eyelid and eyeball (esp. eyeball muscles).

Front 64

Trochlear: Motor

Back 64

-movements of the eyeball.

Front 65

Trochlear: Sensory

Back 65

-muscle sense from eyeball

Front 66

Trigeminal: Motor

Back 66

-chewing.

Front 67

Trigeminal: Sensory

Back 67

-sensation of touch, pain, and temperature from tongue, mouth, nasal cavity, part of pharynx, and most of facial skin; also muscle sense. Parts of its maxillary and mandibular branches are anesthetized in dentistry.

Front 68

Abducens: Motor

Back 68

-movements of eyeball.

Front 69

Abducens: Sensory

Back 69

-muscle sense from the eyeball.

Front 70

Facial: Motor

Back 70

-facial expression, nasal glands, and secretion of tears and saliva.

Front 71

Facial: Sensory

Back 71

-taste and muscle sense from face and scalp muscles.

Front 72

Vestibulocochlear: Motor

Back 72

-adjusts sensitivity of hair cell receptors for hearing.

Front 73

Vestibulocochlear: Sensory

Back 73

-hearing and equilibrium.

Front 74

Glossopharyngeal: Motor

Back 74

- swallowing and speech, secretion of saliva.

Front 75

Glossopharyngeal: Sensory

Back 75

-taste, monitoring of blood pressure, monitoring blood O2 and CO2, and muscle sense from swallowing muscles and back of the tongue.

Front 76

Vagus: Motor

Back 76

-swallowing, coughing, and voice production; smooth muscles of GI tract and secretion of digestive fluids, also slowing of heart rate.

Front 77

Vagus: Sensory

Back 77

-sensation from the viscera (organs) in same areas as motor; monitoring of blood pressure, blood O2,and CO2.

Front 78

Accessory: Motor

Back 78

- swallowing movements and movements of head and shoulders.

Front 79

Accessory: Sensory

Back 79

-muscle sense from head and shoulders.

Front 80

Hypoglossal: Motor

Back 80

- movements of tongue in speech and swallowing.

Front 81

Hypoglossal: Sensory

Back 81

-muscle sense from tongue

Front 82

Describe how the parts of the brain develop.

Back 82

A. Nervous system develops from ectoderm tissue.
B. By the end of the 5th week, 5 enlarged areas (brain vesicles) have developed:

Front 83

Describe the effects of aging on the nervous system.

Back 83

A. Loss of synaptic contacts.
B. Decreased processing of information due to decreased ability to send impulses.
C. Decreased impulse conduction speed, voluntary motor movements slow down, and reflex times increase.

Front 84

Cerebrovascular accident (CVA, stroke)

Back 84

- abrupt onset of paralysis, loss of sensation, or other persistent neurological defects.

Front 85

Transient Ischemic attack (TIA)

Back 85

- abrupt onset of symptoms, which reach maximum intensity almost immediately, and usually, only persist 5-10 minutes. Symptoms include dizziness, weakness, and paralysis on one side, face drooping on one side, headache, slurred speech, partial vision loss or double vision, and sometimes nausea or vomiting.

Front 86

Alzheimer disease

Back 86

- initial loss of short-term memory, become confused and forgetful, past memories disappear, loose ability to function, finally dementia. Brain autopsy shows: beta amyloid plaques, neurofibrillary tangles, and loss of neurons that liberate acetylcholine.

Front 87

Brain tumors

Back 87

- share many symptoms with TIAs but symptoms persist. Tumors of neuroglia (gliomas) are more common than those of neurons (neuromas); but can develop by metastasis from tumors elsewhere in the body.

Front 88

Attention deficit hyperactivity disorder (ADHD)

Back 88

- short attention span, impulsive behavior, consistently hyperactive. Genetic component.

Front 89

Cerebrovascular accident (CVA, stroke)

Back 89

- abrupt onset of paralysis, loss of sensation, or other persistent neurological defects.

Front 90

Transient Ischemic attack (TIA)

Back 90

- abrupt onset of symptoms, which reach maximum intensity almost immediately, and usually, only persist 5-10 minutes. Symptoms include dizziness, weakness, and paralysis on one side, face drooping on one side, headache, slurred speech, partial vision loss or double vision, and sometimes nausea or vomiting.

Front 91

Alzheimer disease

Back 91

- initial loss of short-term memory, become confused and forgetful, past memories disappear, loose ability to function, finally dementia. Brain autopsy shows: beta amyloid plaques, neurofibrillary tangles, and loss of neurons that liberate acetylcholine.

Front 92

Brain tumors

Back 92

- share many symptoms with TIAs but symptoms persist. Tumors of neuroglia (gliomas) are more common than those of neurons (neuromas); but can develop by metastasis from tumors elsewhere in the body.

Front 93

Attention deficit hyperactivity disorder (ADHD)

Back 93

- short attention span, impulsive behavior, consistently hyperactive. Genetic component.

Front 94

Agnosia

Back 94

inablity to recognize the significance of sensory stimuli such as sounds, sights, smells, tastes, and touch

Front 95

apraxia

Back 95

inability to carry out purposeful movements in the absence of paralysis

Front 96

counciousness

Back 96

a state of wakefullness in which an individual is fully alert, aware, and oriented, partly as a result of the feedback between the cerebral cortex and reticular activating system

Front 97

delirium

Back 97

transient disorder of abnormal cognition and disordered attention accompanied by disturbances of the sleep-wake cycle and the physchomotor behavior

Front 98

dementia

Back 98

permanent or progressive general loss of intellectual abilities, including impairment of memory, judgement, abstract thinking, and changes in personality

Front 99

encephalitis

Back 99

acute inflammation of the brain caused by either a direct attack by any of several viruses or an allergic reaction to any of the many viruses that are harmless to the CNS

Front 100

encephalomyelitis

Back 100

encephalitis that affects the spinal cord as well

Front 101

encephalopathy

Back 101

any disorder of the brain

Front 102

lethargy

Back 102

condition of functional sluggishness

Front 103

microcephaly

Back 103

congenital condition that involves the development of a small brain and skull and frequently results in mental retardation

Front 104

Reye's syndrome

Back 104

occurs post viral infection, particullarly chickenpox or influenza, most often in children & teens who have taken ASA; characterized by vomiting and brain dysfunction that may progress to coma and death

Front 105

stupor

Back 105

unresponsiveness from which a patient can be aroused only briefly and only by vigorous and repeated stimulation

Front 106

Telencephalon

Back 106

becomes the cerebrum.

Front 107

Diencephalon

Back 107

- becomes the thalamus, hypothalamus, & epithalamus.

Front 108

Mesencephalon

Back 108

- becomes the midbrain.

Front 109

Metencephalon

Back 109

- becomes the pons and cerebellum.

Front 110

Myelencephalon

Back 110

- becomes the medulla oblongata.