BIOL 235 2018 - Assignment 2 - Grade 99%

Assignment 2 99%

Weight: 5%
Minimum Pass Grade: 50%

Each question is worth 10 marks.

1. Name the type of joint, and list the movements permitted at the shoulder joint.
Under each movement’s name, list the names of the muscles responsible for each
of these movements along with descriptions of their bone insertion.
The shoulder joint, also called the humeroscapular or glenohumeral joint, is a
ball-and-socket joint formed by the rounded proximal head of the humerus that
articulates with the glenoid cavity of the scapula.triaxial This joint allows
flexion, extension, hyperextension, abduction, adduction, medial rotation, lateral
rotation, and circumduction of the arm.
There are several muscles responsible for flexion of the arm. The muscles
include the pectoralis major, with its insertion at the greater tubercle and lateral
lip of intertubercular sulcus of the humerus, the deltoid, with its insertion at the
deltoid tuberosity of the humerus, the coracobrachialis, with its insertion at the
middle of the medial surface of the shaft of the humerus, and the biceps brachii,
with its insertion at the radial tuberosity of radius and bicipital aponeurosis.
There are several muscles responsible for the extension of the arm. The muscles
include the pectoralis major, with its insertion at the greater tubercle and lateral
lip of intertubercular sulcus of the humerus, the latissimus dorsi, with its
insertion at the intertubercular sulcus of the humerus, the deltoid, with its
insertion at the deltoid tuberosity of the humerus, the teres major, with its
insertion at the medial lip of the intertubercular sulcus of the humerus, and the
teres minor, with its insertion at the greater tubercle of the humerus. triceps
There are several muscles responsible for abduction of the arm. The muscles
include the lateral fibers of the deltoid, with its insertion at the deltoid tuberosity
of the humerus, and the supraspinatus, with its insertion at the greater tubercle of
the humerus.


Assignment 2 :: Biology 235: Human Anatomy and Physiology 1

, There are several muscles responsible for adduction of the arm. The muscles
include the pectoralis major, with its insertion at the greater tubercle and lateral
lip of intertubercular sulcus of the humerus, the latissimus dorsi, with its
insertion at the intertubercular sulcus of the humerus, the teres major, with its
insertion at the medial lip of the intertubercular sulcus of the humerus, and the
coracobrachialis, with its insertion at the middle of the medial surface of the
shaft of the humerus.
There are several muscles responsible for the medial rotation of the arm. The
muscles include the pectoralis major, with its insertion at the greater tubercle and
lateral lip of intertubercular sulcus of the humerus, the latissimus dorsi, with its
insertion at the intertubecular sulcus of the humerus, the deltoid, with its
insertion at the deltoid tuberosity of the humerus, the subscapularis, with its
insertion at the lesser tubercle of humerus, and the teres major, with its insertion
at the medial lip of the intertubercular sulcus of the humerus.
There are several muscles responsible for lateral rotation of the arm. The muscles
include the deltoid, with its insertion at the deltoid tuberosity of the humerus, the
infraspinatus, with its insertion at the greater tubercle of the humerus, and the
teres minor, with its insertion at the greater tubercle of the humerus.
There are several muscles responsible for circumduction of the arm. all of the
above. 10

2. What are EPSPs and IPSPs, and how are they produced? Explain how these
electrical currents are used in spatial and temporal summation to initiate or
inhibit the generation of an action potential.
EPSP is an acronym for excitatory postsynaptic potential; this is a depolarizing
postsynaptic potential caused by a neurotransmitter that causes depolarization of
the postsynaptic membrane potential, bringing it closer to threshold. Many
excitatory neurotransmitters bind to ionotropic receptors containing cation
channels. EPSPs result from opening the cation channels, allowing the
movement of Na+, K+ and Ca2+ through the postsynaptic cell membrane. Na+
inflow into the postsynaptic cell is greater than Ca2+ inflow or K+ outflow and the
inside of the postsynaptic cell becomes less negative, and therefore depolarized.

Assignment 2 :: Biology 235: Human Anatomy and Physiology 2