Supportive Systems

Question 1

Circulatory system:

Answer 1

the heart, arteries, and veins that act as a transport system

► Key structures
Arteries: blood vessels carrying oxygenated blood away from the heart and to the tissues
Veins: blood vessels carrying blood toward the heart to remove waste and pick up more oxygen
Capillaries: fine-branching blood vessels forming a network between the arterioles and venules, where
transport of nutrients and oxygen or carbon dioxide occurs on a microscopic scale
Arterioles: the smaller branches of the arteries leading to the capillaries
Venules: the small branches of the veins gathering blood from the capillaries
Heart

– The heart beats about 100,000 times per day.
– For every minute of work, the heart pumps ve (5) to six (6) quarts of blood around the body.
– Atrium: one of the two upper cavities of the heart passing blood to the ventricles. The plural
is “atria.”
– Ventricle: one of the two lower cavities of the heart passing blood to the body or to the lungs
– Pulmonary arteries: blood vessels moving blood from the heart to the lungs
– Pulmonary veins: blood vessels returning oxygenated blood to the heart from the lungs
– Aorta: the main artery in the body that supplies oxygenated blood to the circulatory system
– Superior vena cava: the blood vessel moving blood from the upper body and head to the heart
– Inferior vena cava: the blood vessel moving blood from the lower body to the heart
– Atrioventricular (AV) valves: valves between the atria and ventricles preventing the backward
ow of blood during cardiac contractions
– Sinoatrial (SA) node: the pacemaker of the heart that generates the rst electrical signal of a
heartbeat and stimulates the atria to contract
– Atrioventricular (AV) node: the nerve node between the right atrium and right ventricle that
propagates the electrical signal from the SA note to more distal heart nerves that cause
ventricular contraction
– Movement of blood through the circulatory system: deoxygenated blood from body > right atrium >
tricuspid valve > right ventricle > pulmonary artery (to lungs) > pulmonary vein (oxygenated) from
lungs > left atrium > bicuspid valve > left ventricle > aorta (to body for circulation)

Question 2

Blood cells

Answer 2

– Red Blood cells
* Erythrocytes: the most numerous of all blood cells (approx. 40 percent of blood volume)
that transfer oxygen to the body tissues
– White blood cells
* Basophil: a large white blood cell that locates and destroys cancerous cells and is
responsible for the histamine response during an allergic reaction
* Neutrophil: the most numerous white blood cells responsible for the primary immune response of the ingestion or enzymatic digestion of foreign microorganisms

• Eosinophil: white blood cells that play a role in allergic reactions and immune defense
  against multicellular parasites
• Monocyte: an immune cell that helps remove dead or damaged tissues and provides
  support to the other types of white blood cells
• Lymphocyte: white blood cells that include natural killer cells, B cells, and T cells, which kill
  tumor cells, produce antibodies, and kill infected or cancerous cells, respectively

Question 3

► Key terms

Answer 3

Systole: the heartbeat phase where muscle contraction moves blood from the heart chambers to the arteries
Diastole: the heartbeat phase where the cardiac muscle relaxes and the heart chambers ll with blood
Stroke volume: the amount of blood pumped by the left ventricle of the heart in one contraction
Heart rate: the number of heartbeats per minute
– Average human resting heart rate is 60 to 100 beats per minute
Pulmonary circulation: the blood ow between the heart and the lungs
Systemic circulation: the blood ow between the heart and the rest of the body
Cardiac cycle: the action of the heart from the start of one heartbeat to the beginning of the next
Pulse: a rhythmical throbbing of the arteries as blood is propelled through them
– Measured at neck (carotid artery) or wrist (radial artery)
Blood pressure: the force of blood pushing against the walls of the arteries during the two phases of
the cardiac cycle
– ‘Normal’ range blood pressure: 120/80 mm Hg
– Hypotension: low blood pressure measuring 90/60 mm Hg or lower
– Hypertension: high blood pressure measuring more than 140/90 mm Hg
– Systolic: the pressure in blood vessels when the heart beats (ventricular contraction)
– Diastolic: the pressure in blood vessels when the heart rests (ventricular lling)
– Factors inuencing blood pressure
* Cardiac output: how much blood the heart is pumping per minute
* Blood volume: the total volume of blood contained in the circulatory system
* Peripheral resistance of arteries: the elasticity (or lack thereof) of artery walls
* Blood viscosity: the thickness of blood moving through circulation

Question 4

• Lymphatic system

Answer 4

► Key Structures
Lymph nodes
Tonsils
Spleen (largest)
Thymus
► Functions
Balancing interstitial uids
Absorbing fats and fat-soluble vitamins
Defending against illness and disease
► Key terms
Lymph: the colorless uid of the lymphatic system
Interstitial uid: the uid found between cells

Question 5

• Respiratory system:

Answer 5

the lungs and air passageways that supply oxygen to the body and remove carbon dioxide

► Key structures
Nose and nasal cavities: The nose is made of bone and cartilage. Air and particles enter the body
through the nose.
Pharynx: The pharynx is commonly called the throat and is a passageway for both air and food.
Larynx: This passageway is between the pharynx and trachea.
Trachea: This is the primary passageway for air moving into the lungs.
Bronchi: This is the passageway of air into the functional tissues of the lungs.
Lungs: The right lung has three lobes, while the left lung has two lobes. The lungs are separated by a
membrane partition called the mediastinum, which is where the heart sits.
– alveoli: the small sacs within the lungs where gas exchange occurs (by diffusion)

Question 6

• Respiratory system: Functions and Key terms

Answer 6

Providing oxygen for metabolic processes
Removing waste products of metabolism
Regulating the pH of blood

► Key terms
Respiration: the intake of oxygen and subsequent release of carbon dioxide in an organism
Pulmonary ventilation: the process of exchanging air between the lungs and the ambient air
Inspiration: breathing air into the lungs
Expiration: breathing air out of the lungs
Diaphragm: the dome-shaped muscle that separates the lungs and pleural cavity from the abdomen;
the primary muscle in pulmonary respiration
Diffusion: the passive movement of molecules or particles along a concentration gradient or from
regions of higher concentration to regions of lower concentration
Thoracic cavity: the chest cavity enclosed by the ribs, sternum, and spinal column
Intra-alveolar pressure: the pressure within the alveoli that changes throughout respiration
External respiration: the exchange of gases between the lungs and the blood
Internal respiration: the process of diffusing oxygen from the blood into the interstitial uid and into
the cells

Question 7

Endocrine system:

Answer 7

releases hormones and is responsible for metabolic activities (e.g., growth hormone [GH] is most
abundantly produced by the pituitary gland)

► Key structures
Hypothalamus: The main role of this gland is to maintain homeostasis. It either stimulates or inhibits
heart rate, blood pressure, body temperature, uid and electrolyte balance, thirst, appetite, body weight,
glandular secretions of the stomach and intestines, the release of substances inuencing the pituitary
gland, and sleep cycles.
– Electrolyte: Electrolytes are minerals in the body that have an electric charge.
Pineal gland: The only hormone this gland is known to secrete is melatonin.
Pituitary gland: Pituitary hormones control other parts of the endocrine system, including the thyroid
gland, adrenal glands, ovaries, and testes.
Thyroid: The main function of the thyroid is to regulate metabolism.
Parathyroid: There are four parathyroid glands that help regulate calcium levels in the body.
Thymus: The thymus is only active until puberty. Before puberty, it stimulates the development of T
lymphocytes, which play a role in the lymphatic system’s defense against illness and infection.
Adrenal: The adrenal glands are attached to the kidneys and are made up of the adrenal cortex and
adrenal medulla. Hormones secreted by the adrenal cortex are essential to life. Those secreted by the
adrenal medulla are not.
Pancreas: The main role of the pancreas is to maintain blood glucose balance.
Ovaries: The ovaries secrete hormones essential for female reproductive development and fertility.
Testes: The testes are responsible for maintaining male reproductive health.