Transcript Friday October 19th

28 October 2008
• Midterm grades: Test 1 (50%), quizzes (50%)
• Today:
– Smooth muscle (Ch 9)
– Control of body movement (Ch 10)
• Friday: begin Ch 12 cardiovascular physiology
• Lab this week: Frog Muscle # 1 (see website)
– Runs 20 minutes over
• Abstract Due Date: Friday Nov 13th
check website for details
Friday class demo of using SPSS
Chapter 9 B Properties of
Smooth Muscle
(Cardiac muscle covered later)
How does smooth muscle differ from skeletal muscle?
(innervation, membrane potentials, excitation-contraction coupling, twitch
duration, fatigue, etc. (Table 9-6 p.292)
What are the features of membrane potential of smooth muscle?
(pacemakers and slow waves)
What are the differences between single-unit and multi-unit smooth muscle?
(location, spread of excitation)
Figure 9.34
from SR and influx during Action Potential or graded potential
Graded potentials
result in graded
contractions
Special situation:
Dephosphorylation
& latch bridge
latchbridge
Know the locations of single-unit and multi-unit smooth muscles
Control of membrane potential by neurotransmitters, hormones, local
factors for some smooth muscles (02, pH, stretch, vasodilators….)
Fig. 09.06
Know this table
Except Cardiac Muscle for now
End of material for Test # 2
Begin material for Test # 3
Chapter 10: Control of somatic
motor systems
Riding a bike, playing piano,
swinging a bat or golf club….
Fig. 10.10a
Somatatopy in Primary Motor Cortex
Fig. 10.02
Formerly called “basal ganglia”,
consist of caudate, putatmen, and
globus pallidus
Decision to move
Fig. 10.01
Initiates motor command
Coordinates
secondary movements
Corticospinal and
corticobulbar
tracts
Balance and
complex
learned
movements
Pathways?
Examples of
motor
disorders:
Huntington’s
Disease and
Cerebellar
Disorder
Reflex
Local control
• Muscle spindle
– Stretch receptor
– Intrafusal muscle fiber
• What is their role?
• The stretch reflex…
– Follow the reflex arc
– Be able to differentiate
function of afferent fibers,
alpha motor neurons, and
gamma motor neurons
Spindle
Afferent
Fig. 10.05ab
Fig. 10.05c
Co-activation of alpha and gamma
motoneurons insures that the
stretch of muscle can be detected
regardless of the initial length or
state of contraction of that muscle.
Stretch Reflex
Monosynpatic excitation of motoneurons of that
muscle and synergistic muscles
and polysynaptic inhibition of motoneurons to
antagonistic muscles.
Recall frog reflex lab and existence of spinal
reflexes in single-pithed frogs.
Also, example Christopher Reeve and
patellar reflex.