Biology 2201: Circulatory, Respiratory and Digestive Systems

vasoconstriction

- blood vessels constrict in diameter and reduce the amount of blood that travels through

- helps conserve heat and raise temperature

- happens when we are cold

vasodilation

- blood vessels increase in diameter (dilate) and increase the flow of blood that travels through

- helps release heat and lower temperature

- happens when we are warm

The circulatory system

- transport materials to and away from the body cells

- distribute heat in the body

- provides défense against invading organisms

- serves as a regulator in the body (homeostasis)

arteries

- carry blood AWAY from the heart

- carry oxygenated blood EXCEPT pulmonary artery

- made of thick, muscular walls (because blood is under high pressure)

capillary

- the smallest blood vessel

- walls are one cell thick and very narrow

- site of all exchange (gas, nutrients, etc.) between the blood and body cells

veins

- carry blood TOWARD the heart

- carry deoxygenated blood EXCEPT pulmonary vein

- thinner walls, but larger diameter

- contain VALVES which allow blood to flow in one direction

components of blood

- plasma: 55%

• liquid component of blood

• water, proteins, dissolved gasses, sugars, vitamins, minerals and waste products

- red blood cells: 44%

- white blood cells and platelets: 1%

erythrocytes (red blood cells)

- red blood cells

-transport OXYGEN and carbon dioxide to and from the tissues

- cells are biconcave discs

- contain hemoglobin

- lack a nucleus

leukocytes (white blood cells)

- white blood cells

- appear colorless

- contains a nucleus

- fight foreign invaders and infection

macrophages

- cells that protect the body by engulfing and digesting foreign invaders (pathogens)

lymphocytes

- blood cells that produce antibodies

heart

- muscular organ

- responsible for pumping blood throughout the blood vessels

- located in the center of the chest, slightly left

- 4 chambers

atria (atrium)

- the upper chambers of the heart that receive blood from the veins

ventricle

- the lower chambers of the heart that receive blood from the atria and pump blood to the arteries

septum

- wall of muscle that separates the left side of the heart from the right side

- prevents mixing of deoxygenated and oxygenated blood

atrioventrical valves

- separate the atria and the ventricles

- keeps blood in the ventricle from flowing back into the atrium

- bicuspid/mitral and tricuspid valves

tricuspid valve

valve between the right atrium and the right ventricle

bicuspid (mitral) valve

valve between left atrium and left ventricle

semilunar valves

- control the flow of blood out of the heart

- pulmonary and aortic valves

pulmonary valve

valve between the right ventricle and the pulmonary artery

aortic valve

valve between the left ventricle and the aorta

inferior vena cava

vein that carries blood from lower regions of the body to right atrium

superior vena cava

vein that transports blood from the upper portion of the body to the heart

pulmonary artery

- carries deoxygenated blood to the lungs

pulmonary vein

- brings oxygenated blood to the heart from the lungs

aorta

- large artery that carries blood away from the heart and to all parts of the body

coronary pathway

pathway blood takes in the heart

pulmonary pathway

pathway blood takes from the heart to the lungs and from the lungs to the heart

systemic pathway

pathways blood takes from the heart to the body tissues and from the body tissues to the heart

sinoatrial node (SA node)

-pacemaker of the heart

-located in the wall of the right atrium

- a bundle of specialized tissue that causes the atria to contract

atrioventricular node

-a bundle of specialized tissue that causes the ventricles to contract

-located in the wall of the right atrium

sphygmomanometer

- device that measures blood pressure

- consists of an inflatable cuff, a measuring unit and a mechanism for inflation

blood pressure

- measured using a blood pressure cuff or sphygmomanometer

- blood pressure = systolic/diastolic pressure

-normal blood pressure is 120/80 mmHg

systolic pressure

- pressure in an artery wile the heart is contracting

diastolic pressure

- pressure in an artery while the heart is resting

plasma

fluid portion of blood

antibodies

Specialized y-shaped proteins that aid in destroying infectious agents

antibiotics

Medications that help stop infections caused by bacteria

vaccinations

Injecting small amounts of dead or inactive pathogens into a person's bloodstream. This triggers the immune system to produce antibodies to attack them.

The respiratory system

system responsible for taking in oxygen and releasing carbon dioxide using the lungs

mechanics of breathing — inhalation

- intercostal (rib) muscles contract, lifting the rib cage up and out

- diagram contracts and pulls downward

- negative pressure causes air to flow into the lungs, enabling them to inflate

mechanics of breathing — exhalation

- intercostal (rib) muscles relax, lifting the rib cage down and in

- diaphragm relaxes and pushes upward

- positive pressure causes air to flow out of the lungs, enabling them to deflate

residual volume

- the amount of air that remains in the lungs and respiratory system following a full exhalation

- never leaves the lungs (lungs would collapse if it did)

pharynx

throat region

nasal cavity

hollow space behind the nose

-lined with cilia cells

-secretes mucus

epiglottis

A flap of tissue that seals off the windpipe and prevents food from entering.

trachea

windpipe

-strengthened with cartilage rings

bronchi

two short branches located at the lower end of the trachea that carry air into the lungs.

-rings of cartilage, cilia cells and mucus

bronchioles

smallest branches of the bronchi

-lined with cilia and mucus

alveoli

tiny sacs of lung tissue specialized for the movement of gases between air and blood

-increases surface area of lung

-covered in capillaries

lung

organ of respiration

inspiration

breathing in

diaphragm

A sheet muscle at the bottom of the chest cavity that helps with breathing

respiratory volume

lung volume

expiration

breathing out

intercostal muscles

muscles which move the rib cage during breathing

The digestive system

Breaks down food into smaller molecules. Absorbs these nutrients into the body.

mechanical digestion

-physical breakdown of large pieces of food into smaller pieces

-occurs in mouth and stomach

chemical digestion

-enzymes and chemicals break down food into smaller molecules

-occurs in mouth, stomach and small intestine

mouth

where digestion begins

salivary glands

glands of the mouth that produce saliva, a digestive secretion

salivary amylase

enzyme in saliva that breaks down starch

esophagus

A muscular tube that connects the mouth to the stomach.

peristalsis

the process of wave-like muscle contractions of the digestive tract that moves food along

stomach

J-shaped sac that mixes and stores food. It secretes chemicals for digestion and hormones.

esophageal sphincter

a sphincter muscle at the lower end of the esophagus (top of stomach)

pyloric sphincter

Ring-like structure that controls passage of food from stomach to small intestine

small intestine

-digestive organ where most chemical digestion and absorption of food takes place

-three sections: duodenum, jejunum

and ileum

-contains villi

villi

Tiny finger-shaped structures that cover the inner surface of the small intestine and provide a large surface area through which digested food is absorbed

liver

-The largest organ inside our body

-The organ that produces bile,

gallbladder

stores bile

pancreas

A gland that produces digestive enzymes and bicarbonate, which are delivered to the small intestine (duodenum)

large intestine

Absorbs water and forms feces

rectum

A short tube at the end of the large intestine where feces is stored

anus

A muscular opening at the end of the rectum through which waste material is eliminated from the body

carbohydrases

-enzyme found in the pancreas and small intestine

-reaction takes place in the small intestine

-breaks down disaccharides to monosaccharides

pepsin

-enzyme found in the stomach

-reaction takes place in the stomach

-breaks down proteins into peptides

hydrochloric acid

-found in our stomach

-kills harmful bacteria

-softens proteins

pepidases

-enzyme found in the pancreas

-reaction takes place in the small intestine

-breaks down peptides into amino acids

bile

-made in the liver but stored in the gallbladder

-reaction takes place in the small intestine

-breaks down fat into fat droplets

lipases

-enzyme found in the pancreas

-reaction takes place in the small intestine

-breaks down fat droplets into fatty acids and glycerol

bicarbonate

-substance found in the pancreas

-reaction takes place in the small intestine

-neutralizes chyme from stomach

gastrin

Digestive hormone that stimulates sustained secretion of hydrochloric acid the stomach

secretin

A hormone secreted by the small intestine (duodenum) in response to low pH (too acidic). It promotes the release of bicarbonate from the pancreas to neutralize the chyme.

cholecystokinin

A hormone that is secreted by cells in the duodenum (when high fat content) and stimulates the release of bile into the intestine and the secretion of enzymes by the pancreas.