Lecture 19

Question 1

Types of Cells - Neurons

Answer 1

• Can be classified according to function (sensory, motor, interneuron) or morphology (unipolar, bipolar, multipolar)
• Cell body (soma) usually bears one or more dendrites to receive information and usually one axon to transmit impulses (APs) - one-way transmission

Question 2

Types of Cells – Glia (Neuroglia): For protection and support (3)

Answer 2

1. Oligodendrocytes (CNS) and Schwann cells (PNS) - insulate axons with myelin
2. Astrocytes - pass nutrients between cappillaries and neurons
3. Microglia - engulf foreign material (immune cell)

Question 3

Central Nervous System (CNS):

Answer 3

Brain and spinal cord

Question 4

Peripheral Nervous System (PNS):

Answer 4

Nerves and ganglia outside CNS

Question 5

Two Kinds of PNS Neurons:

Answer 5

1. Afferent or sensory fibers - impulse from receptor organ to CNS
2. Efferent or motor fibers - CNS to receptor organ

Question 6

Somatic Nervous System:

Answer 6

Sensory or motor fibers to skin and voluntary skeletal muscles

Question 7

Visceral Nervous System:

Answer 7

Sensory or motor fibers to viscera, glands and involuntary muscle

Question 8

PNS: Autonomic Nervous System

Answer 8

• Regulates involuntary physiologic processes
• Monitor internal environment
  Controls cardiac, smooth muscles, urogenital system, glands, some respiratory organs, intrinsic eye muscles

Question 9

What are the Two Motor fibers in the Autonomic Nervous System:

Answer 9

• Sympathetic nervous system (fight or flight)
• Parasympathetic nervous system (rest and digest)

Question 10

CNS: Spinal Cord and Nerves

Answer 10

Function: to recieve incoming impulses, integrates and coordinates them, transmits them within the CNS, and sends responses to the PNS as appropriate

Question 11

CNS: Spinal Nerves (Dorsal Root):

Answer 11

Receive afferent fibers from sensory neurons with their soma located in dorsal root ganglion

Question 12

CNS: Spinal Nerves (Ventral Root):

Answer 12

Contains motor neuron efferent fibers on their way to their targets

Question 13

CNS: Spinal Nerve Distributions (Cervical (brachial plexus):

Answer 13

Neck flexors/extensors, diaphragm, shoulders/arms

Question 14

CNS: Spinal Nerve Distributions (thoracacoabdominal plexus)

Answer 14

Intercostals and trunk muscles, abdominal muscles

Question 15

CNS: Spinal Nerve Distributions (lumbar (lumbar plexus)):

Answer 15

Hip, thigh/legs

Question 16

CNS: Spinal Nerve Distributions (Sacral (sacral plexus)):

Answer 16

Hip, foot/toes

Question 17

CNS: Embryologic Development of the Brain (Prosencephalon):

Answer 17

Forebraine which is divided into two parts:
- telencephalon = cerebral hemispheres, olfactory lobes and bulbs
- Diencephalon = thalamus

Question 18

CNS: Embryologic Development of the Brain (Mesencephalon):

Answer 18

Mindbrain - one part; optic lobes

Question 19

CNS: Embryologic Development of the Brain (Rhombencephalon):

Answer 19

Hindbrain - two parts (balance and hearing)
- Metencephalon = cerebellum
- Myelencephalon = medulla oblongata

Question 20

CNS: Functions of the Brain Regions - Forebrain (2):

Answer 20

• Telencephalon (cerebrum) controls all voluntary actions
• Diencephalon coordinates the endocrine system to maintain homeostasis, and relays signals to cerebrum; includes the thalamus, hypothalamus, and pituitary gland

Question 21

CNS: Functions of the Brain Regions - Midbrain:

Answer 21

• Tectum receives sensory information
• cerebral peduncles attach cerebrum to brainstem; assist in refining motor movements, maintaining balance/posture

Question 22

CNS: Functions of the Brain Regions (Hindbrain)

Answer 22

• Pons conveys information to the cerebellum from the cerbrum
• Medulla oblongata: regulates autonomic functions (ex. breathing, heart rate, blood pressure)
• Cerbellum: maintains equilibrium, refines motor actions

Question 23

Evolution of the Brain (2):

Answer 23

1. General trend toward enlargement of the cerbrum (‘higher functions’) and the cerebellum (regulates motor movements)
2. Enlarged optic tectum in some teleost is associated with increased reliance on vision