Assignment 2
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.
Answer:
The shoulder joint or glenohumeral joint is a ball-and-socket joint wherein one
bone's ball-shaped surface (head of the humerus) fits into the cuplike depression
of another (glenoid cavity of the scapula) with a motion that is around three axes
(triaxial). This joint allows multiple body movements like adduction, abduction,
flexion, extension, internal rotation, external rotation, and 360o circumduction.
In every shoulder movement, there are several muscles involve. For arm flexion,
muscles include the deltoid, with its deltoid tuberosity insertion of the humerus,
pectoralis major, more significant tubercle insertion, and biceps brachii radial
tuberosity of radius and bicipital aponeurosis insertion, and coracobrachialis,
with its middle surface of the humerus’ shaft insertion. Extension of the arm also
includes pectoralis major and deltoid. In addition to these two muscles, lattisimus
dorsi is also involved with its insertion at the humerus's intertubercular sulcus.
Also, there are teres major and minor with its intertubercular sulcus and greater
tubercle of humerus insertion. Abduction and adduction of the arm involve
deltoid, pectoralis major and lattisimus dorsi too. Aside from those three,
supraspinatus helps in the movement with its greater tubercle of humerus
insertion. Muscles responsible for internal and external rotation are pectoralis
major, latissimus dorsi, and deltoid, with the same insertions mentioned. In
addition to that, there is subscapularis with the lesser tubercle of humerus
insertion.
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.
Answer:
Assignment 2 :: Biology 235: Human Anatomy and Physiology 1
, EPSP or Excitatory Postsynaptic Potential is a depolarizing postsynaptic
potential. It is a neurotransmitter that is excitatory because it brings the
membrane closer to a threshold, and it does not initiate a nerve impulse. IPSP or
Inhibitory Postsynaptic Potential is a hyperpolarizing postsynaptic potential.
During hyperpolarization, the generation of an action potential is more
complicated than usual because the membrane potential becomes more negative
and thus even farther from the threshold than in its resting state. Both EPSP
(Excitatory Postsynaptic Potential) and IPSP (Inhibitory Postsynaptic Potential)
are produced when particular components bind to neurotransmitter receptors.
There are two summation types: spatial or temporal. Spatial summation is a
summation of postsynaptic potentials in response to stimuli that occur at different
locations in the postsynaptic cell membrane, which happen simultaneously. It
results from the build-up of neurotransmitters released in equal time by several
presynaptic bulbs. On the other hand, the temporal summation is a summation of
postsynaptic potentials in response to stimuli in the same location but differ in
time. It is due to a short period that ESPS or Excitatory Postsynaptic Potential
typically have. The next release of neurotransmitters must happen soon after the
first temporal summation occurs.
3. Match the items in column A with the descriptions in column B to create the
BEST MATCHES.
Items in column A can be used only once when making matches to column B.
There is only one correct answer for each blank space.
Column A Column B
1. pia mater _12__ branch of spinal nerve serving vertebrae;
2. denticulate vertebral ligaments and blood vessels of the spinal
ligaments cord
3. epidural space __6__ a group of axons with common functions within
4. dura mater the spinal cord (or brain)
5. arachnoid mater _28__ responsible for transmitting nerve impulses for
6. tract sensing crude touch
7. nucleus _10__ a group of cell bodies found outside the spinal
8. horn cord (or brain)
9. nerve _13_ branch of spinal nerve serving anterior trunk and
10. ganglion extremities
11. endoneurium _1_ composed of collagen and fine elastic fibers; highly
Assignment 2 :: Biology 235: Human Anatomy and Physiology 2
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.
Answer:
The shoulder joint or glenohumeral joint is a ball-and-socket joint wherein one
bone's ball-shaped surface (head of the humerus) fits into the cuplike depression
of another (glenoid cavity of the scapula) with a motion that is around three axes
(triaxial). This joint allows multiple body movements like adduction, abduction,
flexion, extension, internal rotation, external rotation, and 360o circumduction.
In every shoulder movement, there are several muscles involve. For arm flexion,
muscles include the deltoid, with its deltoid tuberosity insertion of the humerus,
pectoralis major, more significant tubercle insertion, and biceps brachii radial
tuberosity of radius and bicipital aponeurosis insertion, and coracobrachialis,
with its middle surface of the humerus’ shaft insertion. Extension of the arm also
includes pectoralis major and deltoid. In addition to these two muscles, lattisimus
dorsi is also involved with its insertion at the humerus's intertubercular sulcus.
Also, there are teres major and minor with its intertubercular sulcus and greater
tubercle of humerus insertion. Abduction and adduction of the arm involve
deltoid, pectoralis major and lattisimus dorsi too. Aside from those three,
supraspinatus helps in the movement with its greater tubercle of humerus
insertion. Muscles responsible for internal and external rotation are pectoralis
major, latissimus dorsi, and deltoid, with the same insertions mentioned. In
addition to that, there is subscapularis with the lesser tubercle of humerus
insertion.
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.
Answer:
Assignment 2 :: Biology 235: Human Anatomy and Physiology 1
, EPSP or Excitatory Postsynaptic Potential is a depolarizing postsynaptic
potential. It is a neurotransmitter that is excitatory because it brings the
membrane closer to a threshold, and it does not initiate a nerve impulse. IPSP or
Inhibitory Postsynaptic Potential is a hyperpolarizing postsynaptic potential.
During hyperpolarization, the generation of an action potential is more
complicated than usual because the membrane potential becomes more negative
and thus even farther from the threshold than in its resting state. Both EPSP
(Excitatory Postsynaptic Potential) and IPSP (Inhibitory Postsynaptic Potential)
are produced when particular components bind to neurotransmitter receptors.
There are two summation types: spatial or temporal. Spatial summation is a
summation of postsynaptic potentials in response to stimuli that occur at different
locations in the postsynaptic cell membrane, which happen simultaneously. It
results from the build-up of neurotransmitters released in equal time by several
presynaptic bulbs. On the other hand, the temporal summation is a summation of
postsynaptic potentials in response to stimuli in the same location but differ in
time. It is due to a short period that ESPS or Excitatory Postsynaptic Potential
typically have. The next release of neurotransmitters must happen soon after the
first temporal summation occurs.
3. Match the items in column A with the descriptions in column B to create the
BEST MATCHES.
Items in column A can be used only once when making matches to column B.
There is only one correct answer for each blank space.
Column A Column B
1. pia mater _12__ branch of spinal nerve serving vertebrae;
2. denticulate vertebral ligaments and blood vessels of the spinal
ligaments cord
3. epidural space __6__ a group of axons with common functions within
4. dura mater the spinal cord (or brain)
5. arachnoid mater _28__ responsible for transmitting nerve impulses for
6. tract sensing crude touch
7. nucleus _10__ a group of cell bodies found outside the spinal
8. horn cord (or brain)
9. nerve _13_ branch of spinal nerve serving anterior trunk and
10. ganglion extremities
11. endoneurium _1_ composed of collagen and fine elastic fibers; highly
Assignment 2 :: Biology 235: Human Anatomy and Physiology 2
