A & P Quiz 4

2 types of refractory periods

Absolute - open Na+ channels, 1-way

Relative - follows after absolute, some K+ open, repolarization happening

What is a good analogy for the Nodes of Ranvier?

“Tab” key analogy

What is different about axon to axon connections?

“all” not “all or nothing”

Cephalization

Formation of central integrator (head). Tied to bilateral symmetry and directional movement

Two theories of neural density trends

1. Maternal-energy hypothesis

2. Expensive-tissue hypothesis

What developmental aspect becomes the peripheral nervous system?

The neural crest

What aspect of the head develops faster?

Brain tissue develops faster than the skull, hence the gyri and sulci

What protects the CNS?

Meninges (3 layers)

CSF

BBB

What would you not find in the CSF?

RBC, is it nearly blood plasma

How much weight does the CSF take off the brain?

~98%

Where is CSF produced?

The choroid plexus (ependymal cells)

What do astrocytes do?

Support capillaries and create tight junctions with no pores

Acetylcholine

Excitatory muscles and learning

Dopamine

Reward, attention, motivation

Serotonin

Mood, sexual desire

Glutamate

Excitatory, movement

GABA

Inhibitory

Norepinephrine

fight/flight, emotion, increased HR

Endorphins

Inhibits pains

Octopamine

Invertebrates

NO

Learning and memories

Where did the notochord arise from?

Mesoderm

3 key characteristics of Chordates

1. Dorsal hollow nerve cord

2. Pharyngeal pouches

3. Post-anal tail

The eye contains what percentage of all sensory receptors?

~70%

Transduction

Converting one type of energy into another

The Limbic system contains

Grey matter of the cerebrum, hippocampus, amygdala, mamillary bodies, and hypothalamus

What is the Limbic system responsible for?

“Emotional brain” conscious and subconscious

Cingulate gyrus

Conscious manifestations of emotion

Amygdala

Center for emotional responses

Hippocampus

Short-term memory

Mamillary Bodies

Memory details

Hypothalamus

Pleasure center, stress response

3 PRIMARY Chordate characteristics

1. Notochord

2. Dorsal Hollow Nerve Cord

3. Pharynx

Notochord

Band of specialized cells along the dorsal side of animals, which supports and prevents compression of the body when muscles contract

Dorsal Hollow Nerve Chord

Dorsal tube which integrates the action of the longitudinal muscles of the body wall

Pharynx

Expanded portion of gut with pouches and slits which water passes out of animal (respiration for vertebrates, but filter feeding ancestrally)

Characteristics special to vertebrates

Notochord becomes vertebrae, Dorsal hollow root cord has anterior swelling (brain), sensory organs are concentrated in brain (cephalization), and cranium protects brain

3 layers of the meninges

Outer dura mater, arachnoid membrane, and pia mater

Optic chiasma in sheep

Ventral side, two optic nerves cross over to make an “X”

Lateral ventricle in sheep

Largest cavity

Corpus callosum

Above the lateral ventricle (connects two cerebral hemispheres)

Fornix

White area in between the lateral ventricle and third venticle

Pineal gland

Bulb right in the middle

Pituitary gland

Bulb on bottom

Arbor vitae

White tree lines in Cerebellum

Ampullae of Lorenzini

Shark sensory organs which detect electrical fields

Arachnoid granulations

Whitish bumps that reabsorb the CSF into the venous system

CN I

Olfactory (Smell)

CN II

Optic Nerve (Visual information transfer)

CN III

Oculomotor nerve (opening and moving eye including pupils)

CN IV

Trochlear Nerve (Eye oblique muscle)

CN V

Trigeminal Nerve (Sensation to skin of face and chewing muscles)

CN VI

Abducens Nerve (Movement of lateral rectus muscle of eye)

CN VII

Facial Nerve (facial movements)

CN VIII

Vestibulocochlear nerve (sound from cochlea to brain)

CN IX

Glossopharyngeal nerve (taste)

CN X

Vagus Nerve (organs)

CN XI

Accessory Nerve (Trapezium and sternocleidomastoid muscles)

CN XII

Hypoglossal nerve (Moves tongue)