a&p lab practical

Divisions: Components of the CNS & PNS from worksheet
- CNS = brain & spinal cord
- PNS = cranial (12) and spinal (31) nerves 🡪 Sensory & motor, somatic (skin, skeletal muscle, joints, bone) & visceral (organs, cardiac/smooth muscle, glands)
Neurons: Parts and functions including synapse; neuron shapes

Neurons are star shaped astrocytes; contain dendrites, soma, and axon. Know monopolar, bipolar, anaxonic neurons… etc found in powerpoint

Neuroglia: Six basic cells and their basic functions; and their locations (CNS or PNS)
Oligodendrocytes: form myelin in brain & spinal cord
Ependymal cells: line cavities in CNS; secrete & circulate CSF
Microglia: phagocytize & destroy foreign or dead matter; kill microorganism
Astrocytes: multipurpose; generally, act as support and form blood brain barrier
Schwann cells: form myelin in PNS and aid in nerve fiber regeneration
Satellite cells: provide electrical insulation & regulate chemical environment

Where are the ganglia of the ANS found dorsal root of spinal nerves
What are the rami (16.9) first branches of a spinal nerve

Diagram or Model: Label the typical pathway: sensory (afferent) neurons 🡪 interneuron 🡪 motor (efferent) neurons found in powerpoint

Exer. 17: The Brain & Cranial nerves

Meninges: Know the locations of the meningeal layers on the brain

Dura mater- thicker collagenous membrane

Arachnoid mater- weblike mesh of fibers made of simple squamous epithelium

(subarachnoid mater)- filled with CSF

Pia mater- delicate and thin later adherent to spinal cord

Where does CSF flow within the meninges? Subarachnoid space

Terms: gyri (raised mounds), sulci (shallow grooves), fissure (deeper groove), rostral (anterior of brain), caudal (posterior of brain)

Differences between human and sheep brain anatomy

Sheep have a smaller cerebral cortex and proportionally larger cerebellum and midbrain, pons and medulla oblongata

LAB #2: CRANIAL NERVES

Cranial Nerves (end of Exer. 17, Table 17.2, 17.3):

You should know the name, number, whether motor/sensor/both, origination point (pons, midbrain, or medulla) and basic function of each cranial nerve
What types of tests could test cerebellar function?

Light pen pupillary reaction test- oculomotor never

Cotton ball test- facial nerve

Shoulder test- spinal or accessory nerve

Tuning fork- vestibularocular

Clove vs. mint smell test- olfactory nerve

LAB #3: THE PNS REFLEXES

Exercise 18: Nervous System Physiology: Stimuli and Reflexes (Ex. 18 & 19)

Reflexes: Characteristics include involuntary, stereotyped responses Begin on page 282:

We also introduced a lot of terminology in this lab:

Definition of monosynaptic (one synapse, no interneuron, which reflex) and polysynaptic (many synapse, interneuron/s, slower reflex) reflexes?
Know the basic characteristics of a reflex. Involuntary, predictable, automatic, rapid
What kind of receptors are the muscle spindles and Golgi tendon? (stretch)
What did we use Taylor’s Hammer to demonstrate (somatic or visceral reflexes)?
What responses did we expect with patellar tendon (extension of leg), biceps brachii (flexion/curling of the toes and plantar flexion of the foot), & calcaneal reflex (flexion of the big toe)
What is the result of the Babinski reflex experiments (positive- toes spread out and up and negative- toes flex downward) reflex
- What is normal in newborns-positive vs. adults-negative

Questions: Answer questions at the end of this lab exercise

Exer. 19: Cutaneous Senses

Terminology:

Types (modalities) of receptors like mechanoreceptors, nociceptors, etc just a reminder: receptors for cold/hot are thermoreceptors, UNLESS the question specifies very cold or very hot, then its nociceptors.
Types of reception: Like punctate (unequal distribution of receptors), absolute (actual ambient temperature), relative (what ambient temperature feels like), sensory adaptation (sensation eventually dissipates), phasic (stimulate “phases out”), tonic (stimulus is continual)
Are there more hot or cold receptors in skin? cold

Touch receptors: Know the basic results and equipment used in the following experiments:

Two-point discrimination test; Mapping warm, cool, and fine touch receptors;
Temperature judgment 🡪 absolute vs. relative
Proprioceptive judgment
Recall that our experiments in mapping, two-point, and temperature discrimination including Merkel’s discs, Meissner’s corpuscles, and free nerve endings- PLEASE review in powerpoint

What is referred pain visceral pain felt in somatic region such as skin (generally- pain in one area felt in a completely different area)

Answer the review questions at the end of the exercises

LAB #3: SPECIAL SENSES

Exercise 20: Taste and Smell

Slide: Recognize a taste bud Fig. 20.1c

Diagrams: 20.1b (label parts)

Experiments: Know the results of the following experiments:

Taste and olfaction; visual cues can affect your perception of smell and taste (red fluid marked cherry tastes like cherry) cherry bottle said cherry, so it tasted and smelled like cherry. However, it was almond. The visual cue deceived your perception of smell and taste.
Adaptation to smell; how fast or slow does this occur fast
Tasted receptors = taste hair cells in taste buds of the olfactory epithelium refer to powerpoint
Pathway of taste information to the brain refer to powerpoint

Questions: Look at the questions at the end of this lab

Exercise 21: Eye and Vision

Vision/ Eye

Diagrams: Label Fig 21.1, 21.3, 21.4 anatomy,

21.5 label neuron pathway to the brain: Retina 🡪 Optic nerve 🡪 chiasm 🡪 optic tract

Models or diagram: Identify the parts of the eye (Fig. 21.3, 21.4) and know their function including:

3 tunics: sclera, choroid and retina

Tunica fibrosa- sclera and cornea

Tunica vasculosa- choroid, ciliary body, iris

Tunica Interna- retina and optic nerve

anterior (located between the cornea and the iris) and posterior (located between the iris and ciliary processes) chambers and their fluids (aqueous humor).
cornea, conjunctiva, pupil, lens, iris, ciliary body and lacrimal glands
What is the function of circular and radial muscles or the iris? Controls amount of light that enters the eye Of ciliary bodies? Controlling the lens
Sensory receptors = Rods and cones
What forms the fovea centralis (cone photoreceptors) and the blind spot (optic disc) (Fig. 21.7)
Pathway of light information from cornea to brain Cornea->lens->retina->optic nerve->occipital (brain)
(Fig. 21.5)

Experiments:

What did test look for: astigmatism (cornea shape), visual acuity (Snellen test), pupillary reflex (pen light test), Snellen (visual acuity), Ishihara (color blindness test)
Why use an ophthalmoscope? To view retina (Fig. 21.7, 21.12)

Exercise 22: Ear, Hearing, and Equilibrium

Hearing/ Ear

Function of the parts: Auricle (pinna) directions vibration to ear canal, auditory canal, tympanic membrane, ossicles, eustachian (auditory) tube, round & oval windows, cochlea & (spiral) organ of Corti, semicircular ducts and vestibule refer to powerpoint
Functions of the macula (linear acceleration) and crista ampullaris (angular acceleration) both deal with balance (in general)

Hearing:

Sensory receptors = hair cells in Organ of Corti
Where are the sensory receptors for static equilibrium and linear acceleration? macula Angular? Crista ampullaris
Pathway of sound into the ear Auricle (pinna), auditory canal, tympanic membrane, ossicles, eustachian (auditory) tube, round & oval windows, cochlea, temporal region of brain