Exercises 23 and 25

1
Exercises 23 and 25

• Muscles of Hip and Lower Limb
• Reflex Arc

2
Great links
http//www.gwc.maricopa.edu/class/bio201/muscle/le
g1.htm
3
Muscles that move the thigh Table 9.12

•   1.  iliopsoas groupflexes thigh (iliacus and
  psoas)
•    2.    gluteus maximus-extends and laterally
  rotates thigh
• 3.gluteus medius-abduct and medially rotate
  femur (help keep balance by shifting weight when
  walking)
• Get shots in this muscle!
• 4.   gluteus minimus-abduct and medially rotate
  femur (help keep balance by shifting weight when
  walking)
• 5.    tensor fascia latae-flexes thigh, abducts
  and medially rotates femur, braces knee when
  opposite foot is lifted (hip stabilizer)

4
Muscles that move thigh continued

• 6.   adductor longus-adducts and flexes thigh
• 7. adductor magnus-adducts and extends thigh
• 8.   gracilis-adducts femur, flexes knee,
  medially rotates tibia
• 9.pectineus (extra muscle to add to
  list)-flexes and adducts thigh

5
muscles that move the leg (table 9.13)

•  1. hamstring group (all flex leg)
• -biceps femoris- flexes and laterally rotates
  knee joint and extends thigh
• -semitendinosus-flexes and slight medial rotation
  at knee joint, also extends thigh at hip joint
• -semimembranous-flexes and slight medial rotation
  ot knee and extends thigh at hip joint

6
(No Transcript)
7
muscles that move the legContinued

• 2.   sartorius-flexes  leg and thigh, rotates and
  abducts femur laterally, used to cross legs
  (tailor muscle)
• 3.     quadriceps femoris group- all extend leg
  at knee (straighten your leg)
• -rectus femoris-also flexes hip
• -vastus lateralis
• -vastus medialis
• -vastus intermedius

8
(No Transcript)
9
(No Transcript)
10
muscles that move the foot

• 1. tibialis anterior-dorsiflex and inverts foot
• 2.     peroneus (fibularis) tertius-dorsiflex and
  everts foot
• 3.     extensor digitorum longus-extends toes,
  dorsiflex and evert foot

11
Muscles that move foot continued

• 4.     gastrocnemius-flexes leg at knee, plantar
  flex foot
• 5.     soleus-plantar flex foot
• 6.     flexor digitorum longus-flexes toes,
  plantar flex and invert foot
• 7.     peroneus  (fibularis) longus-plantar flex
  and everts the foot
• 8. Extra peroneus (fibularis) brevis-plantar
  flex and eversion of foot

12
(No Transcript)
13
(No Transcript)
14
(No Transcript)
15
Exercises 25 and 26

• Reflex arc and reflexes
• Meninges and spinal cord

16
Ex. 25

• Objectives
• to describe a reflex arc
• distinguish between a reflex and a reflex arc
• identify the reflexes listed in the following
  slides

17
Information

• A reflex is an automatic response to a stimulus
• The parts of the reflex arc include receptor,
  sensory or afferent neuron, interneuron, motor or
  efferent neuron, and effector
• go to for a diagram of the reflex arc
  http//education.vetmed.vt.edu/Curriculum/VM8054/L
  abs/Lab9/Examples/exsomarc.htm
• reflexes are an important tool to help determine
  spinal cord damage

18
Links to help

• http//www.merck.com/mmhe/sec06/ch077/ch077c.html
  MMHE_06_077_01

19
Procedure Work with a partner to demonstrate
each reflex using the reflex hammer provided

• 1. Knee jerk reflex (or patellar reflex)-sit on
  table with legs crossed and relaxed (you can also
  do this without crossing the leg)
• -gently strike the patellar ligament just below
  the patella with the rubber percussion hammer
• -normal response is slight extension of the leg
• 2. Ankle-jerk reflex
• -kneel on a chair and hand feet over the edge
  (relaxed)
• -gently strike the Achilles tendon
• -the foot should plantar flex

20
continued

• 3. Biceps-jerk reflex
• -bend elbow as shown in figure 25.2 c.
• -press thumb on the tendon of the biceps brachii
  in elbow
• -strike your thumb
• -should show slight flexion of the arm
• 4. Triceps-jerk reflex
• -you can place arm over the back of a chair or
  hold arm in position for this one. (your TA will
  demonstrate)
• -tap the tendon of the triceps near the
  olecranon process
• -the triceps brachii should extend the arm
  slightly

21
continued

• 5. plantar reflex-take off your sock and shoe
• Draw the metal tip of the rubber hammer over the
  from the sole of the heel to the base of your big
  toe
• Your toes should curl and the foot plantar flexes
• If your toes spread apart and your foot
  dorsiflexes you are showing the Babinski reflex
  which is ONLY in newborns.
• In an adult this could indicate damage to the
  spinal column