CH 39 Respiratory System & 40 The Circulatory System

gills

• Increase surface area for diffusion

• Move water into the mouth, through the gills, and out of the fish through the open operculum or gill cover

Lungs

minimizes evaporation by moving air through a branched tubular passage & is covered in mucus to prevent direct contact of tissue with air. Inhaled air passes through the larynx, glottis, and trachea. Bifurcates into the right and left bronchi, which enter each lung and further subdivide into bronchioles. Produces negative pressure which draws air into the lungs.

air pressure

Air exerts a pressure downward, due to gravity. A pressure of 760 mm Hg is defined as one atmosphere (1.0 atm) of pressure

partial pressure

is the pressure contributed by a gas to the total atmospheric pressure

alveoli which are (sites of gas exchange) are surrounded by an extensive capillary network

Lungs of mammals are packed with millions of___

the rib cage

Contraction of the external intercostal muscles expands?

thorax & lungs

Contraction of the diaphragm expands the volume of?

Tidal volume

Volume of air moving in and out of lungs in a person at rest

Vital capacity

Maximum amount of air that can be expired after a forceful inspiration

hemoglobin

loads up with oxygen in the lungs, forming oxyhemoglobin

Consists of four polypeptide chains: two α and two β. Each chain is associated with a heme group that has a central iron atom that can bind a molecule of O2

Bohr shift

Hemoglobin’s affinity for O2 is affected by pH and temperature. Facilitates oxygen unloading in the tissue. If there is high levels of CO2, that means that oxygen is needed so the hemoglobin lets go of the oxygen. This pH effect is known as

plasma

About 8% of the CO2 in blood is dissolved in?

hemoglobin

20% of the CO2 in blood is bound to?

bicarbonate

Remaining 72% diffuses into red blood cells and becomes?

Hypoventilation

Insufficient breathing Blood has abnormally high PCO2

Hyperventilation

Excessive breathing Blood has abnormally low PCO2

Chronic obstructive pulmonary disease (COPD)

Refers to any disorder that obstructs airflow on a long-term basis

Asthma

Allergen triggers the release of histamine, causing intense constriction of the bronchi and sometimes suffocation

Emphysema

• Alveolar walls break down and the lung exhibits larger but fewer alveoli

• Lungs become less elastic

• Eighty to 90% of deaths are caused by cigarette smoking

invertebrate circulatory system

• Sponges, cnidarians, and nematodes lack a separate circulatory system

• Sponges circulate water using many incurrent pores and one excurrent pore

• Hydra circulate water through a gastrovascular cavity (also for digestion)

• Nematodes are thin enough that the digestive tract canalso be used as a circulatory system

• Larger animals require a separate circulatory system for nutrient and waste transport

Open circulatory system

• No distinction between circulating and extracellular fluid

• Fluid called hemolymph

Closed circulatory system

Distinct circulatory fluid enclosed in blood vessels and transported away

Fishes

• Evolved a true chamber-pump heart

• Have a 2 chambered heart

• Blood is pumped through the gills, and then to the rest of the body

Amphibians

• Advent of lungs required a second pumping circuit, or double circulation

• Pulmonary circulation moves blood between the heart and lungs

• Systemic circulation moves blood between the heart and the rest of the body

• 3 chambered heart

Reptile heart

• 3-chambered heart

• 2 atria and 2 ventricles

• But there is incomplete separation of the ventricles

Mammals, birds, and crocodilians

• 4-chambered heart

• 2 separate atria and 2 separate ventricles

• Right atrium receives deoxygenated blood from the body and delivers it to the right ventricle, which pumps it to the lungs

• Left atrium receives oxygenated blood from the lungs and delivers it to the left ventricle, which pumps it to rest of the body

Extracellular matrix – plasma

Cells – RBCs, WBCs, platelets

blood connective tissue contains?

Transportation, Regulation & Protection

Functions of circulating blood?

92% water, Nutrients, wastes, and hormones, ions, & proteins (albumin a-globulins, b-globulins)

Blood plasma is made up of?

hematocrit

___ is the fraction of the total blood volume occupied by red blood cells

RED BLOOD CELLS (ERYTHROCYTES)

• About 5 million per microliter of blood

• Mature mammalian erythrocytes lack nuclei

• Live for 120 days

• RBCs of vertebrates contain hemoglobin

• Pigment that binds and transports oxygen

WHITE BLOOD CELLS (LEUKOCYTES)

• Less than 1% of blood cells

• Larger than erythrocytes and have nuclei

• Can migrate out of capillaries into tissue fluid

Granular leukocytes

Neutrophils, eosinophils, and basophils are all types of ___

Agranular leukocytes

Monocytes and lymphocytes are all types of ___

platelets

• Cell fragments that pinch off from larger cells in the bone marrow

• Function in the formation of blood clots

arteries

Blood leaves the heart through the ___

heart

Veins carry blood back to the ___

Endothelium, elastic fibers, connective tissue and smooth muscle

Arteries and veins have walls too thick for exchange of materials & are composed of which four tissue layers?

rapid exchange of gases and metabolites between blood and body cells

Capillaries are composed of only a single layer of endothelial cells which allow?

Lymphatic system

Significant amount of water and solutes in the blood plasma filter through the walls of the capillaries to form the interstitial (tissue) fluid. Fluid that does not return to capillaries is returned to circulation in the subclavian vein. What body system is this?

Just in case

Ms. Equigua asks a question about the heart

Atrioventricular (AV) valves

Maintain unidirectional blood flow between atria and ventricles

= On the right

Tricuspid valve

= On the left

Bicuspid, or mitral, valve

Semilunar valves

Ensure one-way flow out of the ventricles to the vessels

1. Pulmonary valve

2. Aortic valve

right ventricle

Pulmonary valve located at the exit of the?

Left ventricle

Aortic valve located at the exit of the?

(diastole)

Ventricles relaxed and filling

(systole)

Ventricles contracted and pumping

AV valves closing

Lub

closing of semilunar valves

Dub

sinoatrial (SA) node

• Located in wall of right atrium

• Acts as pacemaker

• Autonomic nervous system can modulate rate

Atherosclerosis

• Accumulation of fatty material within arteries

• Impedes blood flow

Arteriosclerosis

• Arterial hardening due to calcium deposition

• Antidiuretic hormone (ADH)

• Aldosterone – encourages kidney to excrete postassium and retain sodium

• Atrial natriuretic hormone – increases sodium excretion and decreases blood pressure

• Nitric oxide (NO) – vasodialator

Blood volume is regulated by which four hormones?