Unit 4 HBS Test

ECG:

A galvanometer and electrodes with six limb leads and six chest leads. Gives a graphic recording of the electric forces generated by the heart during depolarization and repolarization. The electrocardiogram is recorded on graph paper with divisions.

How are muscle fibers and membranes organized to form a whole skeletal muscle?

A muscle is made of tiny fibers. First it starts with one fiber that is surrounded by a layer of endomysium (connective tissue). Next a few more single strands of fibers are added to this one and wrapped around that is a layer of perimysium. this group of fibers is called a fasicle. then a bunch more fasicles get added to this one and is surrounded by a layer of epimysium. this creates the entire skeletal muscle.

How do the structure of arteries, veins and capillaries relate to their function in the body?

Arteries - Three layers of thick, fairly rigid walls to allow them to expand/contract & to handle high pressure one layer is smooth muscle Capillaries - Thin walled & microscopic in size to allow exchange of materials, often have pores to allow movement of materials Veins - Three layers of elastic/collapsible walls with valves to prevent the backflow of blood as it moves toward the heart— one layer is smooth muscle

Tendons

At the ends of the muscle, the epimysium blend together to form what

Biceps Brachii and Triceps Brachii (Classification by number of origins)

Biceps brachii has two origins on the scapula; Triceps brachii has three origins on the scapula and humerus

Sequence

Depolarization occurs in the sinoatrial (SA) node; current travels through internodal tracts of the atria to the atrioventricular (AV) node; then through Bundle of His, which divides into right and left bundle branches; left bundle branch divides into left anterior and posterior fascicles.

T wave

ECG defection representing ventricular repolarization.

P wave

ECG deflection representing atrial depolarization. Atrial repolarization occurs during ventricular depolarization and is obscured.

QRS wave

ECG deflection representing ventricular depolarization.

Depolarization:

Electrical activation of the myocardium.

Skeletal Muscle

Fascicles group together to form what..

Orbicularis Oculi and Transverse abdominis (Classification by direction of fibers)

Fibers in orbicularis oculi form a circle; Fibers in transverse abdominis "traverse" or go across the abdomen

Flexor Carpi Ulnaris and Extensor digitorum longus (Classification by action)

Flexor carpi ulnaris flexes the hand at the wrist; Extensor digitorium longus extends the foot and toes upward

Serratus Anterior

Form a saw-like structure. This muscle helps move the scapula forward and is often used at the and of big movements such as a bench press, a baseball pitch, or a swimming stroke • Origin = lateral surface of ribs 1-8 (bone only) • Insertion = medial border of the scapula

Frontalis and Temporalis (Classification by location in the body)

Frontalis is located on the frontal bone of the skull; Temporalis is located on the temporal bone of the skull

Gluteus maximus and Gluteus minimus (Classification by size)

Gluteus maximus is the largest muscle in the group; Gluteus minimus is the smallest

How do muscles assist with movement of the body and of substances around the body?

It is attached to both the bones by strong cords called tendons making the muscles contract. When the muscles contracts, usually just one bone moves.

How are muscles named?

Muscles are named according to their location, origin and insertion, direction of muscle fibers, size, shape, type of action produced, or other criteria, such as nearby bones

How does an increased or decreased cardiac output impact the body?

Normal cardiac output is needed to move oxygen and nutrients to all the body's tissues. If a person's cardiac output is lower than normal, the tissues can suffer or blood pressure can become unhealthy. An increased cardiac output from exercise can help strengthen the heart.

What is the pathway of blood in and out of the heart in pulmonary and systemic circulation?

Pulmonary Circulation: The right side of the heart collects deoxygenated blood into its atrium & then passes it into the ventricle. The right ventricle then pushes the blood to the lungs, where the CO2 is dropped off and O2 is picked up. Systemic Circulation: The blood from the lungs comes back to the left side of the heart through the left atrium. It then moves into the left ventricle and the ventricle pushes it out through the aorta (biggest artery) and into the rest of the arteries. The arteries carry oxygenated blood to all of the body's tissues. As they reach the tissues, they turn into tiny arteries called arterioles, which then become capillaries. The capillaries are the place where oxygen, nutrients and hormones are dropped off and waste products are picked up. The capillaries then turn into venules, which turn into veins, which come together as the vena cavas (biggest veins) and carry deoxygenated blood back into the right atrium of the heart.

Repolarization

Restoration of the electrical potential of the myocardial cell.

How do the structure and function of the three types of muscle tissue compare?

Skeletal muscle or voluntary muscle is anchored by tendons. Smooth muscle or involuntary muscle is found within the walls of organs and structures. Unlike skeletal muscle, smooth muscle is not under conscious control. Cardiac muscle is also an involuntary muscle but is more akin in structure to skeletal muscle, and is found only in the heart.

Sternocleidomastoid and Brachioradialus (Classification by origin and insertion)

Sternocleidomastoid has origins on the breastbone (sternum) and the collar bone (clavicle or "cleido") and insertions of the mastoid process of the skull's temporal bone; Brachioradialus has an origin on the brachium or arm and an insertion on the radius.

Electrical Process

The P wave of the EKG signals the depolarization of the atria immediately before they contract. The QRS complex corresponds to the depolarization of the ventricles immediately before they contract. The T wave corresponds to repolarization of the ventricles as they prepare for the next beat.

The process of electrical signals in the heart

The electrical signal is initiated by the SA node (located in the right atrium) and then passes through the atrial myocardium to the AV node. The atria contract. The signal passes to the AV bundle, the right and left branches, and the Purkinje fibers in the ventricular walls. The ventricles contract.

What types of muscle help move blood around the body?

The heart is the primary muscle that helps move blood & is made of cardiac muscle tissue. It is responsible for the circulation of blood & all the materials in it.

Explain the relationship between the heart and the lungs.

The heart pumps blood to the lungs to pick up oxygen and to the body to deliver this oxygen.

Epimysium

The outer membrane that binds the fiscicles

Intercostals

These muscles are found in between the ribs and extend from the front of the ribs, around back and past the bend in the bones. They help move air in and out of the chest

Fascicle

This bundle of muscle fibers (myofibrils) represents.. connective tissue covers this entirely.

What unique features of veins help move blood back to the heart?

Three layers of elastic/collapsible walls with valves to prevent the backflow of blood as it moves toward the heart— one layer is smooth muscle

Trapezius and Rhomboid minor (Classification by shape)

Trapezius is shaped like a trapezoid; A rhomboid is shaped like a rhombus

brachiocephalic artery

a first branch of this arch and serves the right arm and the head and neck. On the right side, the subclavian artery and the right common carotid artery are extensions of this

Major Arteries; Aorta

blood is pushed out of this by the left ventricle & then it branches into all other arteries in the body

Inferior Vena Cava

carries deoxygenated blood from the lower body (abdomen and legs) back to the heart

Major veins :Superior Vena Cava

carries deoxygenated blood from the upper body (arms and head) back to the heart

Pulmonary Arteries

carry blood from the right ventricle to the lungs to pick up oxygen

Pulmonary Veins

carry newly oxygenated blood from the lungs back to the left atrium

Tendon

cordlike structures that attach muscle bone, cartilage or other connective tissue.

Endomysium

each muscles fiber is enclosed by a delicate membrane called...

What do skeletal muscle structure and attachment to bones tell you about function?

it tells you that this muscle moves the bones for movement.

3 types of muscle tissues

skeletal, cardiac, and smooth

Perimysium

the membrane that a fascicle is covered by

What is cardiac output?

the volume of blood the heart pumps per minute (mL/min) out of the left side. It's calculated by multiplying heart rate (beats/min) by stroke volume (mL/beat). Stroke volume is how much blood is pushed out by the left ventricle with each beat.

Coronary Artery

this is the artery that runs across the ventral side of the heart, nourishing the cardiac tissue itself

sarcomeres

what muscles are composed of; they contract and shorten when exposed to electrical stimuli

Pectoralis Major

• the abdominal head • Origin = ribs 5-7 (actually attaches to fascia of abdominal muscles) • Insertion = lateral edge of the most proximal part of the humerus Remember that the striations of the muscle indicate the direction the muscle moves. -last part of a tennis serve, pull-down pulley system • Origin = ribs 1-5 on the lateral edge of the sternum • Insertion = lateral edge of the humerus, inferior to the insertion of the abdominal head.