Lecture 18- Nervous System Organisation

Question 1

What type of nervous system organization do Cnidarians have?

Answer 1

Nerve net

Question 2

What type of nervous system organization do Echinoderms have?

Answer 2

Nerve ring

Question 3

What type of nervous system organization do Bilateral have?

Answer 3

Brain, most clearly defined central nervous system

Question 4

What type of nervous system organization do Annelids & Arthropods have?

Answer 4

Brain
Ganglia- Sets of neurons, segmentally arranged clusters

Question 5

What type of nervous system organization do vertebrates have?

Answer 5

CNS- Composed of spinal cord and brain
PNS- Composed of ganglia and nerves

Question 6

Chitin vs. Squid

Answer 6

Chitin- slow moving -> simple
Squid- fast moving -> complex

Question 7

Adult Glial Cells (list)

Answer 7

Astrocytes
Ependmyal cells
Microglial cells

Question 8

What is the function of an astrocyte?

Answer 8

Support the blood brain barrier (neurons)

Question 9

What is the function of a microglial cell?

Answer 9

Scavengers, cleanup, cell fragments
“Picking up microplastics”

Question 10

What is the function of an ependymal cell?

Answer 10

Cerebral spinal fluid
It rhymes

Question 11

What is myelination?

Answer 11

The formation of a sheath around nerve fibers, or axons.

Question 12

Myelination in CNS versus PNS (what does it)

Answer 12

CNS- Oligodendrocytes
PNS- Shwann cells

Question 13

What do the Oligodendrocytes do?

Answer 13

They do myelination in the CNS. They are formal, they give the axon a “handshake”. (They have appendages that reach out and grab onto axons to myelinate them)

Question 14

What do the Schwann cells do?

Answer 14

They are in the PNS. They are less formal, give the axon a “hug”. (The whole Shwann cell is wrapped around axon)

Question 15

What are the two components of the CNS?

Answer 15

Brain and spinal cord

Question 16

What are the two components of the PNS?

Answer 16

Ganglia and nerves, sensory receptors

Question 17

What type of glial cells are in the embryo?

Answer 17

Radial glia

Question 18

What is the purpose of radial glia?

Answer 18

Form tracks in developing embryo. Newly formed neurons migrate from neural tube along tracks.

Question 19

What is the function of the brain?

Answer 19

CNS
Central control organ

Question 20

What is the spinal cord?

Answer 20

CNS
Link between brain, rest of NS. Dorsal, neck/back, within spine
Small central canal with fluid
Gray matter surrounds canal
White matter surrounds gray

Question 21

What are the spinal cord functions?

Answer 21

CNS
Transmits impulses to and from the brain
Reflex actions: Rapid, involuntary response to stimulus
Example: Knee-jerk reflex. Quad stretched unexpectedly-> helps to stay upright

Question 22

What makes up the PNS?

Answer 22

Nervous tissue not part of the CNS- transmits to/from CNS- sensory receptors and nerves

Question 23

Sensory Receptors

Answer 23

PNS
Detection of stimuli
Visual, auditory, chemical

Question 24

Cranial nerves

Answer 24

PNS
Originate in hind part of brain
Innervate face, head

Question 25

Spinal Nerves

Answer 25

PNS Originate in spinal cord Innervate entire body

Question 26

Afferent

Answer 26

Sensory receptors-> CNS. Receptors involved, not effectors

Question 27

Efferent

Answer 27

CNS-> effectors 2 components: Motor system and autonomic nervous system

Question 28

Motor System

Answer 28

Efferent neurons-> skeletal muscle Voluntary and reflexes

Question 29

Autonomic Nervous System

Answer 29

Efferent neurons-> glands, heart, smooth muscle Not consciously controlled 3 divisions Controls digestive, cardiovascular, excretory, endocrine

Question 30

Enteric

Answer 30

Digestive tract, pancreas, gallbladder

Question 31

Parasympathetic vs. Sympathetic

Answer 31

Parasympathetic- Rest and digest (Bodily functions associated with relaxation and conservation of energy) Sympathetic- Fight or flight. Prepares body for action in response to stressful situations.

Question 32

Vertebrate Brain

Answer 32

Embryonic development Neural tube (single tube of tissue) Anterior-> folds over-> brain Posterior-> becomes spinal cord

Question 33

Pathway of a Signal

Answer 33

Stimulus Sensory Receptor Afferent neuron CNS Efferent neuron Motor or autonomic Effector (eg muscle)

Question 34

Cerebrum

Answer 34

Most prominent structure of brain Voluntary movement Learning, perception, memory, emotion Divided into right and left hemispheres Corpus Callosum- Thick band of axons, connect L/R halves

Question 35

Cerebellum

Answer 35

Back of brain Movement, balance Motor skills, coordination Position of joints, lengths of muscles Input from ears, eyes Damage leads to permanent loss of coordination

Question 36

Diencephalon

Answer 36

Thalamus- Main input center for sensory info to cerebrum- routes to correct area Hypothalamus- Regulates pituitary, also hunger/thirst, sex, rage

Question 37

Brainstem

Answer 37

Midbrain, pons, medulla oblongata Midbrain- receives, integrates, routes sensory info Pons- Respiratory and sleep centers Medulla- Continuous w/ spinal cord Basic life functions- Respiration, heartbeat, BP, swallowing, coughing, etc

Question 38

Consciously detected stimuli

Answer 38

Somatic senses