Bio 235- Midterm 2
1. Muscle insertion: place where the muscle ends
2. Deltoid: triangle shaped, covers shoulder
Origin: acromial extremity of clavicle (anterior fibers), acromion of scapula (lateral
fibers) and spine of scapula (posterior fibers)
Insertion: deltoid tuberosity of humerus
Action: lateral fibers abduct arm at shoulder joint; anterior fibers flex and medially
rotate arm at shoulder joint, posterior fibers extend and laterally rotate arm at
shoulder joint.
3. Gluteus max- sacrum to beneath greater trochanter of femur
imus: Origin: iliac crest, sacrum, coccyx, and aponeurosis of sacrospinalis
Insertion: iliotibial tract of fascia lata and superior lateral part of linea aspera
(gluteal tuberosity) under greater trochanter of femur
Action: extends thigh at hip joint and laterally rotates thigh; helps lock knee in
extension
, Bio 235- Midterm 2
4. Quadriceps covers most of anterior surface and sides of the thigh: rectus femoris, vastus
femoris: lateralis, vastus medialis, vastus intermedius
5. Rectus femoris: anterior aspect of thigh
Origin: anterior inferior iliac spine
Insertion: patella via quadriceps tendon and then tibial tuberosity via patellar
ligament
Action: Quads together extend leg at knee joint; acting alone, flexes thigh at hip
joint
6. Vastus lateralis: lateral aspect of thigh Action: extend leg at knee joint
7. Vastus medialis: medial aspect of thigh
Action: extend leg at knee joint
, Bio 235- Midterm 2
8. Vastus inter- deep to the rectus femoris between vastus lateralis and medialis
medius: Action: extend leg at knee joint
9. Ion channels: electrochemical, leak channels, ligand-gated, mechanically-gated, voltage-gated
10. Electrochemical a concentration difference plus an electrical difference = Ions move from higher
gradient: concentration to lower concentration (chemical part of the gradient) and negative
anions move toward a positive area (electrical part of the gradient)
11. Leak channel: gates randomly alternate between open and closed positions. Typically, plasma
membranes have far more K+ leak channels than Na+ leak channels, and the K+
leak channels are leakier than the Na+ leak channels. Therefore, the membranes
permeability to K+ is much higher than Na+. Leak channels are found in nearly all
cells, incl. dendrites, cell bodies, and axons of all neurons.
, Bio 235- Midterm 2
12. Ligand-gated opens and closes in response to the binding of a ligand (chemical) stimulus. Ex.
channel: NTs, hormones, ions. Ex. Ach opens cation channels that allow Na+ and Ca+ to flow
in and K+ to flow out. Located in the dendrites of some sensory neurons, such
as pain receptors, and in dendrites and cell bodies of interneurons and motor
neurons.
13. Mechanically gat- opens or closes in response to mechanical stimulation in the form of vibration
ed channel: (such as sound waves), touch, pressure, or tissue stretching. The force distorts
the channel from resting position, opening the gate. Ex: in auditory receptors in
ears, receptors that monitor GI tract stretching, and touch and pressure receptors
in skin.
14. Voltage-gated opens in response to a change in membrane potential. Participate in the gener-
channel: ation and conduction of action potentials in the axons of all types of neurons.
1. Muscle insertion: place where the muscle ends
2. Deltoid: triangle shaped, covers shoulder
Origin: acromial extremity of clavicle (anterior fibers), acromion of scapula (lateral
fibers) and spine of scapula (posterior fibers)
Insertion: deltoid tuberosity of humerus
Action: lateral fibers abduct arm at shoulder joint; anterior fibers flex and medially
rotate arm at shoulder joint, posterior fibers extend and laterally rotate arm at
shoulder joint.
3. Gluteus max- sacrum to beneath greater trochanter of femur
imus: Origin: iliac crest, sacrum, coccyx, and aponeurosis of sacrospinalis
Insertion: iliotibial tract of fascia lata and superior lateral part of linea aspera
(gluteal tuberosity) under greater trochanter of femur
Action: extends thigh at hip joint and laterally rotates thigh; helps lock knee in
extension
, Bio 235- Midterm 2
4. Quadriceps covers most of anterior surface and sides of the thigh: rectus femoris, vastus
femoris: lateralis, vastus medialis, vastus intermedius
5. Rectus femoris: anterior aspect of thigh
Origin: anterior inferior iliac spine
Insertion: patella via quadriceps tendon and then tibial tuberosity via patellar
ligament
Action: Quads together extend leg at knee joint; acting alone, flexes thigh at hip
joint
6. Vastus lateralis: lateral aspect of thigh Action: extend leg at knee joint
7. Vastus medialis: medial aspect of thigh
Action: extend leg at knee joint
, Bio 235- Midterm 2
8. Vastus inter- deep to the rectus femoris between vastus lateralis and medialis
medius: Action: extend leg at knee joint
9. Ion channels: electrochemical, leak channels, ligand-gated, mechanically-gated, voltage-gated
10. Electrochemical a concentration difference plus an electrical difference = Ions move from higher
gradient: concentration to lower concentration (chemical part of the gradient) and negative
anions move toward a positive area (electrical part of the gradient)
11. Leak channel: gates randomly alternate between open and closed positions. Typically, plasma
membranes have far more K+ leak channels than Na+ leak channels, and the K+
leak channels are leakier than the Na+ leak channels. Therefore, the membranes
permeability to K+ is much higher than Na+. Leak channels are found in nearly all
cells, incl. dendrites, cell bodies, and axons of all neurons.
, Bio 235- Midterm 2
12. Ligand-gated opens and closes in response to the binding of a ligand (chemical) stimulus. Ex.
channel: NTs, hormones, ions. Ex. Ach opens cation channels that allow Na+ and Ca+ to flow
in and K+ to flow out. Located in the dendrites of some sensory neurons, such
as pain receptors, and in dendrites and cell bodies of interneurons and motor
neurons.
13. Mechanically gat- opens or closes in response to mechanical stimulation in the form of vibration
ed channel: (such as sound waves), touch, pressure, or tissue stretching. The force distorts
the channel from resting position, opening the gate. Ex: in auditory receptors in
ears, receptors that monitor GI tract stretching, and touch and pressure receptors
in skin.
14. Voltage-gated opens in response to a change in membrane potential. Participate in the gener-
channel: ation and conduction of action potentials in the axons of all types of neurons.
