Lab Frog Muscle (Guide Experiment)

Contractility of ASM requires an increased levels of intracellular Ca2+. When surface receptors are not activated, Ca2+ levels are low. Upon activation of these cell surface receptors by contractile agonists e.g. acetylcholine, serotonin and histamine, intracellular Ca2+ increases causing a contraction (9). Smooth muscle cell contraction is controlled by both receptor and mechanical activation of proteins actin and myosin and also changes to membrane potential.

For long bones of arm and leg: Place bone with anterior side up and distal end pointed towards you

In this exercise, we will examine a fresh raw chicken bone to study bone structure.

In this experiment, contractions of the earthworm gut are measured in an organ bath with a force transducer. The effect of neurotransmitters and ionic concentrations on contraction strength and rate will be investigated.

The left metatarsophalangeal and interphalangeal (great and lesser toes) joints are held at slight flexion pressed against the ground by a concentric contraction of the flexor halluces longus, flexor digitorum longus, flexor digitorum longus. The left talocrural (ankle) is plantar flexed using a concentric contraction of the gastrocnemius and the soleus. The right talocrural (ankle) is plantar flexed by a concentric contraction of the tibialis anterior, extensor digitorum longus, peroneus tertius. The left tibiofermoral (knee) joints are being extended by a concentric contraction of the quadriceps muscles (rectus femoris, vastus lateralis, vastus medialis, vastus intermedius). The right metatarsophalangeal and interphalangeal (great and lesser toes) are being held plantar flexed due to an isometric contraction of the flexor halluces longus, flexor digtorum longus. The right tibiofermoral (knee) joints are flexed at a 90-degree angle by a concentric contraction of the biceps femoris, semitendinous, semimembranosus. During this phase the left acetabular fermoral (hip) joint is flexed due to an eccentric contraction of the rectus femoris, pectineus, iliacus, and psoas. The right acetabular fermoral (hip) joint is at slight extension due to a concentric contraction of the biceps femoris, semitendinosus, semimembranosus, and the gluteus

1) Make a graph of resting heart rates from Activity 1. Provide a physiological explanation for fluctuations in resting heart rate over time. Discuss a couple of extrinsic factors that influence the autonomic nervous regulation of resting heart rate.

|Melanocyte stimulating hormone (MSH) |A hormone secreted by the pituitary gland that regulates skin |

Biceps Brachii - It's attachments are the coracoid process, supraglenoid tuberosity, and radial tuberosity. When it contracts it causes flexion and supination. It's located close to the endangerment site the antecubital. This area is known for housing chronic pain.

In order to test the passive sufficiency of a bi-articular structure, such as a muscle, both joints which that structure crosses must first be identified. Additionally, the movements of those two joints which will constrain that structure must be identified. Next, one joint must be selected, and placed into the position that may constrain the structure. At the same time, the other joint must be placed in the position which will NOT put further strain on that structure. The selected joint must then be measured for its range of motion. Next, the same must be done with the selected joint, but in contrast, the other joint must be placed in the position which WILL further constrain the bi-articular structure. Once that has been done, the selected joint’s range of motion must be measured once more.

Abstract: In this experiment the measurements of skeletal muscle fibers of the rabbit are in millimeters. The average length for the three muscle fibers after adding the solution A which contained only 0.25% ATP in distilled water was 20 mm. The average length for the three muscle fibers after adding the solution C which contained 0.5M KCl and 0.001M MgCl2 in distilled water was 1.77 mm and the average length for the three muscle fibers after adding the solution B which contained 0.25 % ATP and 0.5 M KCl with 0.001 M Mgcl2 in water was 1.77 mm.

Materials for this laboratory included Microsoft excel to compile data, a pen and paper to record data, a 15cm ruler, string, a caliper, and a two meter ruler. Since bones often times vary in width in certain portions of the same bone due to the presence of joints and processes the bone was measured at the midpoint along its length for its true width. Measurements

Leg press -1RM for this test is to measure strength of the lower leg extension muscles.

Table 2. Correlations and meaningfulness between the sit-and-reach and modified sit-and-reach and all other flexibility variables

1. As you increase voltage to the muscle describe how it responds to the increased stimulus.

1. Why does the force begin to decrease with time? Note that a decrease in force indicates muscle fatigue.