Animal Phis Part 2

Laminar Corium

The area where the convex surface of P3 blends with the longitudinal leaves of the corium (sensitive laminae).

Epidermal Laminae

Also known as insensitive laminae, these are distinct from the laminar corium.

Laminitis

A chronic condition characterized by inflammation of the laminae, causing severe pain and potential detachment/rotation of the sensitive and insensitive lamina.

Collateral Sulci

Structures that demarcate the sides of the frog from the adjacent sole.

Wind Puffs/Wind Galls

Accumulation of synovial fluid within the palmar/plantar recess associated with hard training.

Navicular Disease

A condition in horses that can involve erosion of articular cartilages, bursitis of the navicular bursa, adhesions between the deep digital flexor tendon and navicular bone, and erosion or necrosis of the navicular.

Stay Apparatus

A mechanism that prevents the stifle and hock from flexing by locking the patella.

Reciprocal Apparatus

Ensures that the hock flexes and extends in unison with the stifle.

Nervous System Functions

Movement, regulation of secretions, gathering information from the external environment, maintaining consciousness, and generating survival drive.

Peripheral Nervous System (PNS)

Comprises glands, muscles, and receptors; integrates and initiates movement from the Central Nervous System (CNS).

Autonomic Nervous System (ANS)

Subdivided into sympathetic and parasympathetic systems.

Adult Brain Subdivisions

Cerebrum (from telencephalon), cerebellum, and brainstem (from diencephalon).

Corpus Callosum

A structure that connects the left and right hemispheres of the brain.

Diencephalon Structures

Includes the thalamus, epithalamus, hypothalamus, and third ventricle.

Metencephalon

Comprises the cerebellum (dorsally) and pons (ventrally), critical for timing and execution of movement.

Myelencephalon

Develops into the medulla oblongata in adults.

Hydrocephalus

A condition caused by inadequate formation of the mesencephalic aqueduct, leading to CSF buildup and increased pressure on the brain.

Meninges Layers

Pia mater (deepest), arachnoid (middle), and dura mater (outer covering).

Cervical Spinal Nerves

Exit the foramen cranial to the vertebrae of the same number.

Thoracic Spinal Nerves

Exit the foramen caudal to the vertebrae of the same number.

Axons

Nerve fibers that carry impulses away from the cell body.

Dendrites

Nerve fibers that carry impulses towards the cell body.

Resting Membrane Potential

Typically negative inside the cell.

Factors Affecting Resting Membrane Potential

Electrogenic Na-K pump, nongated K channels, and large negatively charged molecules in the cell.

Myelinated vs

Myelinated axons propagate signals faster due to insulation.

Node of Ranvier

Gaps in myelinated axons that facilitate signal transmission.

Types of Synapses

Electrical (gap junctions) and chemical (more prevalent, involving neurotransmitter release).

Neurotransmitter Removal

Degradation by enzymes, absorption by transport systems, and diffusion away from the synapse.

Organophosphates

Inhibit breakdown of acetylcholine; treated with atropine.

Best-Known Neurotransmitters

Acetylcholine, norepinephrine, dopamine, and gamma-aminobutyric acid (GABA).

Cholinergic Receptors

Divided into nicotinic and muscarinic receptors.

Norepinephrine Receptors

Known as catecholamines or presynaptic neurons and synapses.

Inhibitory vs

Inhibitory neurotransmitters decrease neuronal activity, while excitatory neurotransmitters increase it.

Acetylcholine

Associated with the parasympathetic nervous system.

Epinephrine

Associated with the sympathetic nervous system.

Upper Motor Neuron (UMN)

Located in the brain and spinal cord; controls lower motor neurons.

Lower Motor Neuron (LMN)

Located in the peripheral nervous system; directly innervates muscles.

UMN Bladder

Characterized by increased tone and reflexive urination.

LMN Bladder

Characterized by decreased tone and inability to urinate reflexively