Ocular physiology

Which of the following is NOT a function of the eyelids?

What determines the shape and width of the palpebral fissure?

Which of the following breeds is likely to have a narrow, almond-shaped palpebral fissure?

Which metabolic pathway is primarily used by keratocytes for glucose metabolism?

What is the main function of nicotinamide adenine dinucleotide phosphate (NADPH) produced by the corneal epithelium?

Which layer of the cornea has the highest glucose needs?

Which muscle is responsible for opening the upper eyelid in animals?

Which nerve innervates the levator palpebral superioris muscle?

Which reflexes are primitive reflexes with a purely subcortical course and are elicited by touch?

Which reflex is cortically mediated and is initiated by a threatening gesture?

Which layer of the tear film is the thickest and performs the primary functions of the tear film?

What is the primary purpose of the outer lipid layer in the tear film?

Which gland is responsible for producing the outer lipid layer of the tear film?

What is the approximate tear volume turnover rate in horses?

Which of the following animals has been detected to have lysozyme activity in their tears?

Which of the following immunoglobulins is present in greater concentrations in the precorneal tear film (PTF) than immunoglobulins G and M?

Which nerve provides the lacrimal gland with its parasympathetic and sympathetic fibers?

Which cells in the lacrimal gland are primarily responsible for secretion of proteins in lacrimal gland fluid?

Which test is primarily used to evaluate the aqueous portion of tears in clinical settings?

Which layer of tears is composed of tear mucins produced by the apocrine conjunctival goblet cells?

Which of the following is responsible for corneal scarring?

Which species has the highest density of goblet cells in the fornix?

What is the primary role of the corneal endothelium?

Which type of mucin is associated with the corneal and conjunctival microvilli?

What is the function of the corneal epithelium?

What is the mechanism that maintains steady-state hydration in the cornea?

Which nerve is responsible for the involuntary blinking that occurs upon stimulation of the cornea?

Which skull type has the lowest corneal sensitivity in dogs?

Which region of the cornea has the highest sensitivity?

What is the function of the sphincter muscle in the iris?

Which nerve innervates the constrictor muscle in the iris?

What is the primary function of the dilator muscle in the iris?

Which nerves primarily innervate the dilator muscle in the iris?

Which vessels in the eye are under the strong influence of sympathetic stimulation?

What is the primary cause of retinopathy of prematurity?

Which type of autoregulation is present in the eye?

Which vessels have little to no autoregulatory mechanism?

Which blood vessels supply the cornea and lens in the embryo?

Which structure is a heavily pigmented and highly vascularized source of nutrients for the inner retina in birds?

Which blood vessels supply the iris and ciliary body in most species?

Which blood vessels supply the choroid in most species?

Which barrier prevents the movement of ions and fluid from the tears into the stroma and protects the cornea from pathogens?

Which route is the most permeable for hydrophilic drugs and macromolecules?

Which barrier prevents nearly all protein movement and is effective against low-molecular-weight solutes?

Which barrier is formed by the nonpigmented layer of the ciliary epithelium and the endothelium of the iridial vessels?

Which species have been demonstrated to have species differences in the α- and β-receptors?

Which receptor is primarily responsible for the constriction of feline pupils with the use of timolol?

Which neurotransmitter is involved in enhancing adrenergic-induced contractions of the iris dilator muscles?

Which photopigment has peak sensitivity at 480 nm in dogs?

Which layer forms a size-selective barrier for molecules entering the neuroretina?

Which cells form the inner blood-retinal barrier?

What is the most permeable point of the blood-retinal barrier?

What drives the transport of water from the retina to the choroid?

Which layer forms the blood-aqueous barrier in the eye?

Which type of junctions are present in the layers forming the blood-aqueous barrier?

Which part of the eye controls the flow of fluid into the posterior chamber?

Which pathway is dependent on IOP for outflow?

What is the primary factor impacting uveoscleral outflow?

Which medication can increase uveoscleral outflow?

What is the main effect of cholinergic agonists on outflow resistance?

Which substance is found in higher concentrations in the aqueous humor (AH) compared to plasma?

Which substance has a lower concentration in the AH compared to plasma in dogs?

Which substance has a concentration in the AH that is increased in diabetic patients?

Which substance is present in lower concentrations in the AH compared to plasma due to the blood-aqueous barrier (BAB)?

Which animal species has the highest percentage of uveoscleral outflow?

What is ocular rigidity?

What is the relationship between IOP and volume of the globe?

Which enzyme is abundantly present in the non-pigmented ciliary epithelium and plays a critical role in the active secretion of aqueous humor?

What is the primary mechanism by which aqueous humor is formed in the eye?

Which layer of the ciliary epithelium forms a barrier that inhibits paracellular diffusion?

Which enzyme catalyzes the reaction of CO2 and H2O to produce bicarbonate, which is essential for the secretion of aqueous humor?

Which of the following is the primary route of aqueous humor outflow?

What is the major site of aqueous outflow resistance?

What is the primary cause of primary open angle glaucoma (POAG) in humans and likely dogs with the ADAMTS10 mutation?

What are the two routes of aqueous humor outflow in the iridocorneal angle (ICA)?