GENBIO 2 - MOD 7

Cellular respiration

is the aerobic breakdown of glucose in the mitochondria to make ATP.  During cellular respiration, oxygen is used up in cells and carbon dioxide is given out

Respiratory systems

are consist of organs in animals that exchange gases with the environment

gas exchange

organisms must take in oxygen from the surrounding and release carbon dioxide from its body

Gas exchange through specialized structures

Larger animals need structures specialized for gas exchange

skin

Most amphibians and many other animals respire across their skin. Amphibians also exchange gases via lungs

papulae

have protruding papulae, which provide an increased respiratory surface area

Spiracle or tracheal system

It consists of systems of tubes called trachea and tracheoles which transport air from spiracles to and from cells

gills

The gills of fishes provide a very large respiratory surface area and countercurrent exchange. They are highly folded outgrowths that contain blood vessels and covered with a thin epithelial layer

lungs

The alveoli in mammalian lungs provide a large respiratory surface area but do not permit countercurrent exchange

Human Respiratory System

Tubular system consisting of the nasal passage, trachea, bronchi and bronchioles

lungs

consisting of millions of sac-like spherical alveoli to provide a very large surface area for efficient gaseous exchange.

alveoli

are moist, thinwalled pockets which are the 
site of gas exchange

wall of the alveolus

is very thin, consisting of a single layer 
of cells.

During inspiration

the diaphragm and intercostal muscles contract

During exhalation

these muscles relax. The diaphragm domes upwards

HEMOGLOBIN

is a protein composed of four polypeptide chains and four organic compounds called heme groups

The respiratory center

consists of groups of neurons organized into two parts, the inspiratory center and the expiratory center

The rate of respiration

is regulated by two centers in the brain: the respiratory center and the cardiovascular center situated in the medulla oblongata

Chemoreceptors

detect increases in the partial pressure of CO2 and send impulses to the respiratory center. From the inspiratory center, impulses are sent that stimulate the diaphragm and external intercostal muscles to contract, causing the lungs to expand (inhalation)

Cardiovascular center:

Chemoreceptors (neurons) of the medulla oblongata must be responsive to changes in blood PO2 and PCO2 in order to maintain homeostasis

Emphysema

become exhausted because they expend three to four times the normal amount of energy just to breathe

Lung cancer

accounts for more deaths than any other form of cancer

Stomata

In terrestrial plants, carbon dioxide is obtained from the atmosphere and oxygen produced during photosynthesis is released through the _____

Lenticels

Woody stems and mature roots are sheathed in layers of dead cork cells impregnated with suberin — a waxy, waterproof (and airproof) substance. So cork is as impervious to oxygen and carbon dioxide as it is to water

BLOOD

is a fluid that delivers necessary substances, including nutrients and oxygen, to all different parts and cells of the body

Red blood cells

These are the most common cells in the blood. These cells contain a special protein called hemoglobin that allows them to transport oxygen and carbon dioxide within the blood stream

White blood cells (WBCs/ Leukocytes)

These cells are part of the immune system, acting to defend the body from infectious diseases or intruding cells

Platelets

These cells are responsible for the clotting of blood, also referred to as ‘coagulation’

Plasma

Plasma is the liquid component of blood that the cells are suspended in. It accounts for around 50% of the total volume of blood and contains things like dissolved proteins, glucose, and platelets, as well as the blood cells themselves

HEART

pumps blood in order for it to circulate throughout the body

The cardiac cycle

sequence of events that occurs when the heart beats. There are two phases of this cycle: (1) Systole (contraction), and (2) Diastole

Systole

the phase in which both ventricles contract. When these two chambers contract, the muscles powerfully push the blood out into the blood vessels moving away from the heart

Diastole

the phase in which both ventricles are relaxed. When these two chambers are relaxed, they are refilled with blood from each atrium, getting new blood to pump out from the heart and into the blood vessels when the cycle begins again

BLOOD VESSELS

blood vessels are the part of the circulatory system that carry blood throughout the different parts of the body

Arteries

carry blood (rich in oxygen) away from the heart to the body

Capillaries

very small blood vessels that allow for exchange of gases (oxygen and carbon dioxide), water, nutrients, and waste products to and from the blood

Veins

carry blood (poor in oxygen) back to the heart

Systemic (greater) circulation

The blood flows from the left ventricle, through various parts of the body, to the right atrium, i.e. from the left to the right side of the heart through the arteries and veins which traverse the whole body

Pulmonary (lesser) circulation

The blood flows from the right ventricle, through the lungs, to the left atrium, i.e. from the right to the left side of the heart

Portal circulation

The blood passes through two sets of capillaries before draining into a systemic vein

Coronary heart disease

heart attack, angina, congestive heart failure

Cerebrovascular disease

stroke

Peripheral vascular disease

poor blood supply to limbs

Rheumatic heart disease

heart damage from bacterial infection

Congenital heart disease

heart defect present at birth

Deep vein thrombosis and pulmonary embolism

blockages of blood flow due to blood clots