Ross & Wilson Anatomy and Physiology in Health and Illness (213 page)

Catabolism
Breaking down of larger molecules into smaller ones

Catalyst
A substance that speeds up a biochemical reaction without taking part in it

Cation
A positively charged ion

Central nervous system
The brain and spinal cord

Cerebrospinal fluid (CSF)
The fluid bathing the brain and spinal cord

Chemoreceptor
A sensory receptor sensitive to chemicals in solution

Chemotaxis
The movement of a cell towards a chemical attractant

Chondrocyte
Mature cartilage cell

Chromatin
The uncoiled state of chromosomes during interphase

Chromosome
Sausage-shaped structure consisting of a tightly coiled molecule of DNA visible at the end of interphase

Chronic
Long-standing or recurring

Cilia (sing. cilium)
Microscopic cell extensions for moving materials through the lumen of a tube

Circadian rhythm
The regular, predictable fluctuation of a physiological function over a 24-hour period

Circumduction
Movement of a body part to describe a cone shape

Citric acid cycle
Important sequence of aerobic metabolic reactions in cellular energy production

Coagulation
Blood clotting

Co-dominance
The situation when more than one form of a gene is dominant

Commensal
A harmless micro-organism that lives in the body or on its surfaces, which may bring advantages to its host, e.g. by producing vitamins, or by preventing the growth of pathogens

Compound
A molecule containing more than one element

Concentration gradient
Where two areas of, e.g., liquid have different concentrations of a solute

Congenital
Inherited

Convergence
The turning of the eyes inward to focus on a close object

Cortex
The outer layer of a gland or structure

Cytoplasm
The contents of a cell except the nucleus (i.e. cytosol + organelles)

Deamination
Removal of the amine group from an amino acid

Defaecation
Expulsion of faeces from the rectum

Deglutition
Swallowing

Dehydration
Excessive loss of body water

Deoxyribonucleic acid (DNA)
The molecule in which the genetic code is written, and packaged into chromosomes in the nucleus

Diapedesis
Movement of an independently motile cell from one place to another

Diaphysis
The shaft of a long bone

Diastole
Resting period of the heart or its individual chambers

Diastolic blood pressure
The pressure recorded in the systemic circulation (often at the arm) when the pressure is at its lowest, corresponding to relaxation of the myocardium; the lower of the two measurements used to denote a blood pressure recording

Diffusion
Movement of substances down a concentration gradient, which does not require energy or presence of a membrane

Diploid
A cell with 46 chromosomes, the whole complement of 23 pairs

Distal
Further from the origin of a body part or point of attachment of a limb

Diuresis
The passing of urine

Dominant
In genetics, the preferential expression of one form of a gene over another

Efferent
Carrying or travelling away from an organ

Electrolyte
An inorganic ion in body fluids, which conducts electricity

Element
A chemical whose atoms are all of the same type

Embolus
A blood clot or other substance that travels in a blood vessel and may lodge blocking a smaller vessel

Endocrine gland
A ductless gland that secretes a hormone which travels to its target organ in the bloodstream

Endogenous
Internal, produced by the body

Endothelium
Epithelium lining blood vessels

Enzyme
A protein substance that speeds up (catalyses) chemical reactions

Epidermis
The outermost layer of the skin

Epinephrine
Another term for adrenaline

Epiphysis
Each end of a long bone

Epithelium
Tissue that lines and covers most body organs

Erythropoiesis
Production of red blood cells

Essential nutrient
A nutrient that must be eaten in the diet

Eversion
Turning the soles of the feet outwards

Exocrine gland
Gland that secretes its product into ducts for transport

Exocytosis
Process by which particulate waste is expelled from a cell

Exogenous
External; not produced by the body

Extension
An increase in the angle between two bones, straightening a limb

External respiration
Exchange of gases in the lungs

Extracellular
Outside a cell

Extrinsic pathway
Clotting process triggered by damaged extravascular tissues

Facilitated diffusion
A form of diffusion that requires carrier proteins for transfer of substances across cell membranes

Faeces
Waste product of digestion excreted through the anus

Fascia
Fibrous membrane that supports, covers and separates muscles

Fertilisation
The penetration of an ovum by a spermatozoon to form a zygote that can grow into a fetus

Fibre
Muscle cell; in nutrition, the indigestible part of the diet also known as non-starch polysaccharide

Fibrinolysis
The breakdown of a blood clot

Fibroblast
Connective tissue cell that produces collagen fibres

Filtration
The movement of small molecules, by hydrostatic pressure, through a selectively permeable membrane

Flagella (sing. flagellum)
Long cell extensions used for cellular propulsion

Flexion
The reducing of the angle between two bones; straightening a limb

Follicle
A small secretory gland

Gamete
An ovum or spermatozoon (reproductive cell)

Gene
An area on a chromosome that codes for one particular protein

Genome
All the genes in a cell

Genotype
The genetic make-up of an individual

Gestation
Pregnancy

Glia
Nervous tissue that supports neurones

Globulin
One class of plasma protein, including antibodies

Glucocorticoids
Group of steroid (fat-based) adrenal cortex hormones essential for life

Gluconeogenesis
The production of glucose from non-carbohydrate molecules

Glucose
Simple sugar used by cells for energy

Glycogen
Storage, very high molecular weight form of glucose

Glycolysis
The anaerobic breakdown of glucose to release some of its stored energy

Granulation tissue
Newly formed repair tissue following tissue damage

Granulocyte
General term for a white blood cell without cytoplasmic granules

Granulopoiesis
The production of white blood cells

Gustation
Taste

Haematemesis
Vomiting of blood

Haemolysis
The breakdown of red blood cells

Haemopoiesis
The production of blood cells

Haemorrhage
Profuse blood loss

Haemostasis
The cessation of blood flow

Haploid
A cell with 23 chromosomes (half the total chromosome complement)

Hepatic
Of the liver

Heterozygous
Genetically, a form of a gene on one chromosome that is different to the form of the same gene on the other chromosome of the pair

Hilum
Indented area of an organ where blood vessels, nerves and ducts enter and leave

Homeostasis
Maintenance of a stable internal environment

Homozygous
Genetically, a form of a gene on one chromosome that is the same as the form of the same gene on the other chromosome of the pair

Hormone
A substance secreted by an endocrine gland that is transported in the blood and acts on specific target cells elsewhere in the body

Hydrophilic
Water loving

Hydrophobic
Water hating

Hydrostatic pressure
The pressure exerted by a fluid on the walls of its container, e.g. of blood on the walls of blood vessels

Hypersecretion
Abnormally high secretion of a body product, e.g. a hormone

Hypertension
Abnormally high blood pressure

Hypertonic
A solution with a solute concentration higher than body fluids

Hyperventilation
Abnormally high respiratory effort, associated with loss of excessive amounts of carbon dioxide

Hyposecretion
Abnormally low secretion of a body product, e.g. a hormone

Hypotension
Abnormally low blood pressure

Hypothermia
An abnormally low body temperature (core temperature <35°C)

Hypotonic
A solution with a solute concentration lower than body fluids

Hypoventilation
An abnormally low respiratory effort, associated with retention of carbon dioxide

Hypoxia
Inadequate levels of oxygen in the tissues

Iatrogenic
A condition resulting from a healthcare intervention

Idiopathic
A condition of unknown cause

Immunity
Body defence mechanisms against a specific disease

Incontinence
Inability to control the voiding of urine

Infarction
Death of a region of tissue due to interruption of its blood supply

Infection
The invasion of body tissues by pathogenic organisms

Inferior
Structure further from the head

Inflammation
Non-specific tissue response to damage

Insensible water loss
Loss of water through the skin and respiratory tract

Insertion
Point of attachment of a muscle to a bone that moves most during muscle contraction

Internal respiration
Exchange of gases in the tissues

Interphase
Phase of the cell cycle when there is no division

Interstitial fluid
Fluid situated between body cells, also known as tissue fluid

Intracellular
Inside a cell

Intrinsic pathway
Clotting process triggered by damaged blood vessels

Inversion
The turning of the soles of the feet to face each other

Ion
A charged atom (which has either lost or acquired electrons)

Ionising radiation
Radiation that generates ions when it passes through atoms; can damage cells by changing the atoms in the molecules that make up living tissue, e.g. X-rays

Ischaemia
Impaired blood supply to a body part

Isometric
Muscle work where the tension in the muscle rises but the muscle does not shorten, e.g. if trying to lift a weight that is too heavy to move

Isotonic
Muscle work where the muscle shortens as the tension rises, allowing, e.g., a load to be lifted by the arm; in chemistry, solutions with a solute concentration the same as body tissues

Isotope
A form of an element that has a different number of neutrons from the principal form

Karyotype
Photographic presentation of a cell’s chromosomes as matched pairs in descending order of size

Lactation
Production of breast milk

Lateral
Structure further from the midline or at the side of the body

Leukocyte
General term for a white blood cell

Leukopenia
A low blood white cell count

Ligament
Band of connective tissue that binds one bone to another

Lipase
Enzyme that breaks down fat

Lipolysis
Breakdown of fat

Lymph
Watery fluid drained by the lymphatic system from the tissue spaces

Lysis
Destruction of a cell, e.g. haemolysis

Lysozyme
An antimicrobial enzyme present in some body fluids

Macrophage
A phagocytic cell usually found in connective tissue

Malignant
Cancerous

Mastication
Chewing

Medial
Structure that is nearer to the midline

Median plane
An imaginary line that divides the body longitudinally into right and left halves

Medulla
The inner layer of a gland or structure

Meiosis
Process of cell division by which gametes are formed

Melaena
Blood in the faeces

Menopause
Time of the female life span when reproductive function ceases

Menstruation (menses)
Regular shedding of uterine lining, usually monthly, during the reproductive period of the female life span

Metabolic pathway
Sequence of metabolic steps in cellular biochemistry

Metabolism
All the chemical reaction that take place within the body