Biology Chapter 6: Human physiology

alimentary canal

the whole passage along which food passes through the body from mouth to anus. It includes the esophagus, stomach, and intestines.

accesory organs

teeth, tongue, salivary glands, liver, gallbladder, pancreas

Esophagus

A muscular tube that connects the mouth to the stomach.

Peristalsis

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

lumen

space within a tubular part or organ, such as the space within a blood vessel

Chyme

mixture of enzymes and partially-digested food

Serosa

outermost layer of small intestine

Longitudunal muscles

used for peristalsis

circular muscles

used for peristalsis

Submucosa

The layer of connective tissue directly under the mucosa of an open body cavity.

Mucosa

The innermost layer of the human digestive tract; in some parts of the digestive system, it contains mucus-secreting cells and glands that secrete digestive enzymes

Pancreas

An organs in the abdominal cavity with two roles. The first is an exocrine role: to produce digestive enzymes and bicarbonate, which are delivered to the small intestine via the pancreatic duct. The second is an endocrine role: to secrete insulin and glucagon into the bloodstream to help regulate blood glucose levels.

acinar cells

enzyme-secreting cells of the pancreas

Amylase

enzyme that breaks down starch to maltose

Endopeptidase

an enzyme that breaks peptide bonds other than terminal ones in a peptide chain.

Lipase

enzyme that breaks down fat

phospholipases

hydrolyze phospholipids

duodenum

first part of the small intestine

Nucleases

break down nucleic acids

Maltase

A digestive enzyme that breaks maltose into glucose.

Lactase

an enzyme that catalyzes the hydrolysis of lactose to glucose and galactose.

Exopeptidases

Release single amino acids from peptides by chopping them off the ends, one at a time

Dipeptidases

cleave the peptide bonds of dipeptides to release free amino acids

Epithelium

cells covering external and internal surfaces of the body

Villi

Fingerlike extensions of the intestinal mucosa that increase the surface area for absorption

Goblet cell

unicellular gland found in columnar epithelium that secretes mucous

capillary network

found in dermis, provides blood to the epidermis by diffusion. Dilation of these vessels helps cool the body

lamina propria

areolar connective tissue underlying a mucous membrane

lacteal

a lymph tubule located in the villus that absorbs fatty acids

simple diffusion

movement of a solute from an area of high concentration to an area of low concentration

facilitated diffusion

Movement of specific molecules across cell membranes through protein channels

active transport

Energy-requiring process that moves material across a cell membrane against a concentration difference

Pinocytosis

process by which a cell takes in liquid from the surrounding environment

Amylopectin

branched starch

Amylose

unbranched starch

Amylase

Enzyme in saliva that breaks the chemical bonds in starches

hepatic portal vein

A vein connecting the capillary bed of the intestines with the capillary bed of the liver. This allows amino acids and gluocse absorbed from the intestines to be delivered first to the liver for processing before being transported throughout the circulatory system.

dialysis

a procedure to remove waste products from the blood of patients whose kidneys no longer function

Systolic

Blood pressure in the arteries during contraction of the ventricles.

Diastolic

occurs when the ventricles are relaxed; the lowest pressure against the walls of an artery

Aorta

Largest artery in the body

Arteries

carry blood away from the heart

vasoconstriction

the constriction of blood vessels, which increases blood pressure.

Vasolidation

The enlargement of blood vessels to increase blood supply

Veins

Blood vessels that carry blood back to the heart

blood plasma

The pale yellow fluid portion of whole blood that consists of water and its dissolved constituents including, sugars, lipids, metabolic waste products, amino acids, hormones, and vitamins.

red blood cells

Blood cells that carry oxygen from the lungs to the body cells.

white blood cells

Blood cells that perform the function of destroying disease-causing microorganisms

Platlets

cell fragments that cause clotting and produce growth factors involved in tissue repair

Arterioles

smallest arteries

Capillaries

Microscopic vessel through which exchanges take place between the blood and cells of the body

interstitial fluid

fluid in the spaces between cells

Venules

small veins

superior vena cava

A vein that is the second largest vein in the human body and returns blood to the right atrium of the heart from the upper half of the body.

right pulmonary artery

takes oxygen poor blood from the right ventricle to the right lung

aortic valve

The semilunar valve separating the aorta from the left ventricle that prevents blood from flowing back into the left ventricle.

right pulmonary veins

bring oxygen-rich blood from the right lung to the left atrium

right atrium

Receives deoxygenated blood from the body

tricuspid valve

valve between the right atrium and the right ventricle

inferior vena cava

A vein that is the largest vein in the human body and returns blood to the right atrium of the heart from bodily parts below the diaphragm.

right ventricle

pumps deoxygenated blood to the lungs

interventricular septum

separates ventricles

left ventricle

pumps oxygenated blood to the body

bicuspid valve

valve between the left atrium and the left ventricle.

pulmonary trunk

carries blood from right ventricle to pulmonary arteries

Left atrium

receives oxygenated blood from the lungs

left pulmonary artery

carries poor oxygenated blood from the right ventricle to the left lung.

left pulmonary veins

bring oxygen-rich blood from the left lung to the left atrium

sinoatrial node

pacemaker of the heart

atrioventricular node

a node of specialized heart muscle located in the septal wall of the right atrium

Bundle of His

a bundle of modified heart muscle that transmits the cardiac impulse from the atrioventricular node to the ventricles causing them to contract

Purkinje fibres

Muscle fibres that conduct impulses in the walls of the ventricles

LDL (low density lipoprotein)

"bad" cholesterol
High ratio of lipid to protein
Contributes to cardiovascular disease

thrombosis

abnormal condition of a blood clot

sebaceous glands

secrete sebum (oil) into the hair follicles where the hair shafts pass through the dermis

mucous membrane

Membrane that secretes mucus that lubricates the surface of organs and keeps them moist.

Fibrinogen

plasma protein that is converted to fibrin in the clotting process

fibrin

Protein threads that form the basis of a blood clot

thrombin

enzyme that converts fibrinogen to fibrin during coagulation

coronary thrombus

is damage to the heart muscle caused by a thrombus blocking a coronary artery

Atherosclerosis

condition in which fatty deposits called plaque build up on the inner walls of the arteries

Leukocytes

white blood cells, fight infection

Macrophages

Found within the lymph nodes, they are phagocytes that destroy bacteria, cancer cells, and other foreign matter in the lymphatic stream.

B Cell

A lymphocyte that produces proteins that help destroy pathogens.

clonal selection

antigens bind to specific receptors, causing a fraction of lymphocytes to clone themselves

memory cells

General term for lymphocytes that are responsible for immunological memory and protective immunity.

HIV

A virus that attacks and destroys the human immune system.

T cell

a lymphocyte that identifies pathogens and distinguishes one pathogen from another

APC

antigen presenting cell

AIDS (acquired immune deficiency syndrome)

a life-threatening, sexually transmitted infection caused by the human immunodeficiency virus (HIV). AIDS depletes the immune system, leaving the person vulnerable to infections.

Retrovirus

An RNA virus that reproduces by transcribing its RNA into DNA and then inserting the DNA into a cellular chromosome; an important class of cancer-causing viruses.

antibiotics

Drugs that block the growth and reproduction of bacteria

Penicillin

antibiotic

Ventilation

movement of air in and out of the lungs

Bronchioles

Airways in the lungs that lead from the bronchi to the alveoli.

Alveoli

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

bronchus

Either of the two subdivisions of the trachea conveying air into the lungs.

Type I pneumocytes

extremely thin alveolar cells that are adapted to carry out gas exchange

Type II pneumocytes

produce surfactant and produce a moist surface in alveoli

inspiration

breathing in (inhalation)