A&P Chapter 13

Question 1

Brain Stem

Answer 1

• connects spinal cord to the brain

- consists of medulla oblongata, pons, and mid brain.

Question 2

Medulla Oblongata

Answer 2

• most inferior portion of the brain stem
• gray matter organized into nuclei (reflex center)
• pyramids
  
  1. descending tracts involved in skeletal muscle.
  2. tracts crossover to other side
• olives: balance, coordination, adn inner ear sound.

Question 3

Pons

Answer 3

• superior to the medulla oblongata-
• ascending and descending tracts
• pontine sleep center: REM sleep, actually recharges you
• Pontine respiratory center: respiratory movements.

Question 4

Midbrain

Answer 4

• smallest region of brainstem
• superior colliculi (looks like a butt)
  
  1. reflex of head,eyes, and body toward stimuli.
  2. receive touch and auditory input
• inferior colliculi
  
  1. hearing and CNS auditory pathways
• red nuclei
  
  1. unconscious motor activities

Question 5

Reticular formation

Answer 5

• loosely scattered nuclei in brain stem
• receives signals from axons that innervate face
• involved in cycles of activity

Question 6

Cerebellum

Answer 6

• posterior to pons
• communicates with other regions of CNS
  
  1. superior peduncle: midbrain
  2. middle peduncle: pons
  3. inferior peduncle: medulla oblongata
• folia: ridges in cerebellar cortex
• purkinje cells: inhibitory neurons

Question 7

Cerebellum-Flocculonodular lobe

Answer 7

balance and eye movement

Question 8

Cerebellum- Vermis

Answer 8

posture, locomotion, and fine coordination ( helps to time things like swinging a bat)

Question 9

Cerebellum- lateral hemispheres

Answer 9

• divided into primary fissure into anterior and posterior lobes
• planning, practicing, and learning complex movements

Question 10

Diencephalon

Answer 10

• between brainstem and cerebrum

- consists of thalamus, subthalamus, epithalamus, and hypothalamus.

Question 11

Thalamus

Answer 11

• largest part of diencephalon
• sensory relay center of the brain
• medial geniculate: auditory information
• lateral geniculate: visual information
• ventral posterior: sensory impulses
• dorsal tier: pain
• motor function: ventral anterior and ventral lateral nucleus

Question 12

Thalamus

Answer 12

• influences mood
• anterior and medial nuclei: mood modification
• lateral dorsal nuclei: regulating emotions
• lateral posterior and pulvinar: sensory integration

Question 13

Subthalamus

Answer 13

• inferior to thalamus
• ascending and descending tracts
• subthalamic nuclei :involved in controlling motor function.

Question 14

Epithalamus

Answer 14

• superior and posterior thalamus
• consists of habenula and pineal gland
• habenula: responses to odor
• pineal gland; contolling onset of puberty

Question 15

Hypothalamus

Answer 15

• regulates pituitary secretions
• stimulates sweating and shivering
• infundibulum: connects hypothalamus to pituitary
• mammilary bodies: responses to odor
• receives inputs from internal organs, tongue, limbic system, and eyes
• efferent fibers synapse with autonomic : regulates heart rate and digestion

Question 16

Cerebrum

Answer 16

• largest portion of the brain
• logitudinal fissure: left and right hemispheres
• gyri: folds which increase surface area( grooves are sulki)
• hemispheres divided into lobes; named for skull bones

Question 17

Frontal lobe

Answer 17

voluntary motor, motivation, aggression, smell, and mood

Question 18

Parietal lobe

Answer 18

receiving and evaluating sensory info

Question 19

occipital lobe

Answer 19

visual input

Question 20

Temporal lobe

Answer 20

smell, hearing, and memory

Question 21

Structures of cerebrum

Answer 21

lateral fissure: separates temporal lobe from rest of cerebrum
cerebral cortex: gray matter
cerebral medulla: white matter

Question 22

Limbic system

Answer 22

• basic survival
• memory, reproduction(pheremones), and nutrition(hunger)
• interpretation of sensory inputs
• involved in emotion

Question 23

Basal nuclei

Answer 23

• largest nuclei in the brain
• functionality related nuclei: located in cerebrum, diencephalon, and midbrain
• control of motor function

Question 24

Cerebral medulla

Answer 24

• contains tracts that connect to CNS
• association fibers: connect areas within same hemisphere.
• commissural fibers: connects hemispheres; corpus callosum is the largest
• projection fibers: connect cerebrum to other parts of the brain

Question 25

Meninges

Answer 25

connective tissue membranes 1. Dura mater: superficial 2. arachnoid mater 3. pia mater: bound tightly to brain

Question 26

Dura mater

Answer 26

superficial and tightly bound to internal periosteum

Question 27

Arachnoid mater and subdural space

Answer 27

- thin, wispy layer | - Subdural space: between dura and arachnoid: only a small amount of serous fluid within

Question 28

Pia mater and subarachnoid space

Answer 28

pia mater: thin, delicate C.T. membrane closely adhered to the brain: follows external contours. subarachnoid space: contains web-like strands of arachnoid, blood vessels, and cerebrospinal fluid

Question 29

Ventricles

Answer 29

- CNS forms as hollow tube - lined by ependymal cells(produce cerebrospinal fluid) - lateral ventricle: large cavity in cerebral hemisphere; fusion of 1st and 2nd ventricle - third ventricle: center of diencepalon between thalamus halves

Question 30

Intraventricular formina

Answer 30

lateral ventricles communicate with 3rd ventricle

Question 31

fourth ventricle

Answer 31

base of cerebellum

Question 32

cerebral aqueduct

Answer 32

third ventricle communication with fourth

Question 33

Cerebrospinal fluid

Answer 33

- protective cushion around the CNS - brain floats - provides protection from rapid head movements - provides some nutrients - choroid plexus: ependymal cells, support tissue, blood vessels - invaginations of pia mater

Question 34

Brain blood supply

Answer 34

- brain has high metabolic rate - requires 15-20% blood pumped by the heart - interruptions can cause unconsciousness in seconds - internal carotid arteries: blood reaches brain; anterior lateral of the neck.

Question 35

Cranial nerves

Answer 35

- 12 pairs | - functions of sensory, somatic, and motor

Question 36

Olfactory (I) and optic(II)

Answer 36

smell and vision; exclusively sensory

Question 37

oculomotor (III)

Answer 37

eye and eyelid

Question 38

Trochlear nerves (IV)

Answer 38

eye movement

Question 39

Trigeminal (V)

Answer 39

mastication, middle ear, and throat

Question 40

Abducens (VI)

Answer 40

eyeball movement

Question 41

Facial (VII)

Answer 41

facial expressions, middle ear, and hyoid. Sense of taste for tongue.

Question 42

Vestibulocochlear( VIII)

Answer 42

hearing and balance

Question 43

Glossopharyngeal (IX)

Answer 43

pharynx and salivary glands, taste, sensory info from carotid arteries.

Question 44

Vagus (X)

Answer 44

- soft palate, pharynx and larynx | - sensory from aortic arch

Question 45

Accesory nerve(XI)

Answer 45

sternocledomastoid and trapezius

Question 46

Hypoglossal (XIII)

Answer 46

tongue, thyrohyoid, geniohyoid.

Question 47

VAgus

Answer 47

- vagus nerve innervates many internal organs - vagus runs behind the liver - brain shuts down innervations to lower limbs.