CARDIAC CONTROL CENTER

Question 1

CCC

Answer 1

Found in the medulla oblongata of the brain; this is part of the Autonomic Nervous System (ANS)

Question 2

ANS HAS TWO SUB-DIVISIONS

Answer 2

1) Sympathetic (SNS)
2) Parasympathetic (PNS)

Question 3

SYMPATHETIC (SNS)

Answer 3

Carries signals that put your body’s systems on alert- speeds up heart rate via the cardiac accelerator nerve

Question 4

PARASYMPATHETIC (PNS)

Answer 4

Carries signals that return those systems to their standard activity level- slows down heart rate through the vagus nerve

Question 5

HYPOXIA

Answer 5

Oxygen debt

Question 6

CCC HAS THREE WAYS OF REGULATING OR CONTOLLING HEART RATE

Answer 6

1) Neural control (external)
2) Hormonal control (external)
3) Intrinsic control (internal controlling both rhythm and depth of HR)

Question 7

NEURAL CONTROL

Answer 7

Involved receptors picking up changes in the body as a result of an increase physical activity. These send messages to the CCC in the medulla oblongata. The ANS in the brain in return sends a message to the SA node to either speed or slow down the heart rate.

Question 8

RECEPTORS ARE…

Answer 8

1) Proprioceptors
2) Chemoreceptors
3) Baroreceptors
4) Thermoreceptors

Question 9

PROPRIOCEPTORS

Answer 9

(Golgi tendon organs) - pick up movement in joints and muscles

Question 10

CHEMORECEPTORS

Answer 10

(Found in aorta and carotid artery)
- picks up chemical changes, PH

Question 11

BARORECEPTORS

Answer 11

(Found in aorta and carotid artery)
- picks up changes in blood pressure as the result of increased intensity

Question 12

THERMORECEPTORS

Answer 12

(Found in skin, skeletal muscle and liver) - picks up changes in body temperature.

Question 13

HORMONAL CONTROL

Answer 13

Before and during exercise adrenaline and noradrenaline is released into the blood stream from the adrenal medulla in the kidneys. These hormones act directly on the SA node stimulating increase in (HR) and (SV). This explains anticipatory rise in HR. Both hormones aid the redistribution of blood to the muscles.

Question 14

INTRINSIC CONTROL

Answer 14

The heart internally controlling itself.

Question 15

INTRINISIC CONTROL THERE ARE TWO FACTORS TO CONSIDER:

Answer 15

Temperature- temp of cardiac muscle increase it speeds up nerve impulses causing increased HR

Starling’s law of the heart- as venous return increases so does SV

Question 16

MUSCLE SPINDLE

Answer 16

Detects change in muscle length

Question 17

GOLGI TENDON ORGAN

Answer 17

Detects change in muscle tension