Anatomy and Physiology of Animals/Glossary/O-P

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Word Meaning
O
Excessive accumulation of fluid in the body tissues
Oesophagus The hollow muscular tube connecting the pharynx with stomach
The female sex hormone produced by ovaries
Olfactory To do with smell
Omasum Part of the modified stomach of ruminants with a folded inner surface
Open rooted teeth Teeth in which the root opening remains wide. They grow continuously e.g. the incisors of rabbits and rats
Optic Nerve The nerve carrying impulses from the retina of the eye to the brain
Orbit The bony cavity in the skull that holds the eyeball
Organ A structure with a specific function
Organelle A structure in the cell with a specific function
Organic A compound that contains carbon and hydrogen e.g. carbohydrates, lipids and proteins
Organism A living form. One individual
Origin The attachment of a muscle to a bone that does not move
Osmosis The movement of water molecules across a semi permeable membrane from an area of high water concentration to an area of low water concentration
Osmotic pressure The pressure required to prevent water moving across a semi permeable membrane by osmosis
Ossicle A small bone
Ossification The formation of bone
Otolith A particle of calcium carbonate embedded in the membrane of the otolith organ of the inner ear
Oval window The small opening between the middle and inner ear
Ovarian cycle The series of events in the ovary associated with the maturation of the ovum
Ovarian follicle The developing ovum with the epithelial tissues surrounding it
Ovary The female gonad that produces ova.
Ovulation The release of the ovum from the mature follicle of the ovary
Ovum The egg cell (plural: ova)
Oxyhaemoglobin Haemoglobin combined with oxygen
Oxytocin The hormone from the posterior pituitary gland. Stimulates milk “let down”
P
Palate The roof of the mouth
Palmar The “walking” surface of the front paw
Pancreas The organ lying along the caudal margin of the stomach. Has endocrine and exocrine functions
Pancreatic juice The digestive secretion produced by the pancreas
Parasympathetic division One of the two parts of the autonomic nervous system. Concerned with normal “at rest” activities
Parathyroid gland One of four small endocrine glands on the dorsal surface of the thyroid gland
Parathyroid hormone The hormone secreted from the parathyroid gland
Parotid gland One of the paired salivary glands ventral to the ear
Parturition The act of giving birth
Patella The kneecap
Pathogen A disease-producing organism
Pectoral To do with the chest or breast
Pelvic cavity The caudal portion of the abdominal cavity. Contains the bladder, colon and reproductive structures
Pelvic girdle The bony structure formed by the hip bones, sacrum and coccygeal bones
Pelvis The structure formed by the two hip bones, sacrum and coccyx
Penis Male sexual organ
Pepsin A protein digesting enzyme secreted by the stomach wall
Pericardial cavity The small cavity between the two layers of the pericardial membranes
Pericardium The membrane that encloses the heart
Periosteum The tough connective tissue covering of a bone
Peripheral Located on the outer part of the body
Peripheral nervous system The part of the nervous system composed of the cranial and spinal nerves
Peristalsis The successive muscular contractions along the wall of the gut
Peritoneum The membrane that lines the abdominal cavity and covers the abdominal organ
Permanent teeth The second set of teeth that persist through life
Peyer’s Patches Large clusters of lymph nodules found in the wall of the small intestine
pH A symbol that indicates the acidity or alkalinity of a solution
Phagocytosis The process by which cells ingest particles and bacteria
Phalanges The bones of the “fingers” and “toes”
Pharynx The throat
Phospholipid bilayer The arrangement of phospholipids molecules in two layers
Phospholipids Molecules that make up the double layer of biological membranes
Photoreceptor A receptor that detects light
Photosynthesis The making of organic molecules by plants using energy from the sun
Physiology The science that deals with the functions of an organism and its parts
Pineal gland The gland situated in the brain that secretes melatoni
Pinna The projecting part of the external ear
Pinocytosis The process by which cells ingest liquid
Pituitary gland The endocrine gland lying under the caudal surface of the brain attached to the hypothalamus by a stalk
Pivot joint A synovial joint where a peg of bone articulates with a ring of bone as in the joint between the atlas and axis
Placenta The special structure through which the exchange of materials between the foetus and mother occurs
Plantar The “walking” surface of the hind paw
Plantigrade locomotion Locomotion involving placing the whole surface of the foot on the ground as in humans and bears
Plasma The fluid that surrounds the blood cells
Plasma membrane The outer membrane surrounding the cell
Platelets Cell fragments in the blood essential for clotting
Pleura Membranes that cover the lungs and line the walls of the chest and diaphragm
Pleural cavity The space between the two layers of the pleura
Plexus A network of nerves
Poikilothermic ‘Cold-blooded’ animals whose body temperature varies, to a large extent depending on the environment
Polysaccharides A carbohydrate formed from up to a thousand monosaccharides
Preen To clean, straighten and fluff feathers
Premolars The more anterior cheek teeth
Progesterone The hormone produced by the corpus luteum
Prolactin A hormone produced by the anterior pituitary gland
Prostate gland The gland caudal to bladder in males
Proteases Enzymes that split proteins into amino acids
Protein An organic compound consisting of carbon, hydrogen, oxygen and nitrogen. Made up of amino acids
Proximal Nearer to the body or to the point of origin
Pulmonary To do with the lungs
Pulp cavity The cavity within the crown and neck of a toot
Pulse The series of waves of high pressure blood passing along an artery
Pupil The hole in the centre of the iris of the eye
Pus Dead white blood cells
Pyloric sphincter The ring of smooth muscle between the stomach and the small intestine