A&P 1: Prep for Final Worksheet

Describe the layers of the epidermis and list its tissues and cells.

--The stratum basale (also called the stratum germinativum) is the deepest epidermal layer and attaches the epidermis to the basal lamina, below which lie the layers of the dermis. The cells in the stratum basale bond to the dermis via intertwining collagen fibers, referred to as the basement membrane. A finger-like projection, or fold, known as the dermal papilla (plural = dermal papillae) is found in the superficial portion of the dermis. Dermal papillae increase the strength of the connection between the epidermis and dermis; the greater the folding, the stronger the connections made. The stratum basale is a single layer of cells primarily made of basal cells. A basal cell is a cuboidal-shaped stem cell that is a precursor of the keratinocytes of the epidermis. All of the keratinocytes are produced from this single layer of cells, which are constantly going through mitosis to produce new cells. As new cells are formed, the existing cells are pushed superficially away from the stratum basale. Two other cell types are found dispersed among the basal cells in the stratum basale. The first is a Merkel cell, which functions as a receptor and is responsible for stimulating sensory nerves that the brain perceives as touch. These cells are especially abundant on the surfaces of the hands and feet. The second is a melanocyte, a cell that produces the pigment melanin. Melanin gives hair and skin its color, and also helps protect the living cells of the epidermis from ultraviolet (UV) radiation damage. -the stratum spinosum is spiny in appearance due to the protruding cell processes that join the cells via a structure called a desmosome. The desmosomes interlock with each other and strengthen the bond between the cells. It is interesting to note that the "spiny" nature of this layer is an artifact of the staining process. Unstained epidermis samples do not exhibit this characteristic appearance. The stratum spinosum is composed of eight to 10 layers of keratinocytes, formed as a result of cell division in the stratum basale (Figure 5). Interspersed among the keratinocytes of this layer is a type of dendritic cell called the Langerhans cell, which functions as a macrophage by engulfing bacteria, foreign particles, and damaged cells that occur in this layer. The keratinocytes in the stratum spinosum begin the synthesis of keratin and release a water-repelling glycolipid that helps prevent water loss from the body, making the skin relatively waterproof. As new keratinocytes are produced atop the stratum basale, the keratinocytes of the stratum spinosum are pushed into the stratum granulosum. -The stratum granulosum has a grainy appearance due to further changes to the keratinocytes as they are pushed from the stratum spinosum. The cells (three to five layers deep) become flatter, their cell membranes thicken, and they generate large amounts of the proteins keratin, which is fibrous, and keratohyalin, which accumulates as lamellar granules within the cells (see Figure 4). These two proteins make up the bulk of the keratinocyte mass in the stratum granulosum and give the layer its grainy appearance. The nuclei and other cell organelles disintegrate as the cells die, leaving behind the keratin, keratohyalin, and cell membranes that will form the stratum lucidum, the stratum corneum, and the accessory structures of hair and nails. -The stratum lucidum is a smooth, seemingly translucent layer of the epidermis located just above the stratum granulosum and below the stratum corneum. This thin layer of cells is found only in the thick skin of the palms, soles, and digits. The keratinocytes that compose the stratum lucidum are dead and flattened (see Figure 4). These cells are densely packed with eleiden, a clear protein rich in lipids, derived from keratohyalin, which gives these cells their transparent (i.e., lucid) appearance and provides a barrier to water. -The stratum corneum is the most superficial layer of the epidermis and is the layer exposed to the outside environment (see Figure 4). The increased keratinization (also called cornification) of the cells in this layer gives it its name. There are usually 15 to 30 layers of cells in the stratum corneum. This dry, dead layer helps prevent the penetration of microbes and the dehydration of underlying tissues, and provides a mechanical protection against abrasion for the more delicate, underlying layers. Cells in this layer are shed periodically and are replaced by cells pushed up from the stratum granulosum (or stratum lucidum in the case of the palms and soles of feet). The entire layer is replaced during a period of about 4 weeks. Cosmetic procedures, such as microdermabrasion, help remove some of the dry, upper layer and aim to keep the skin looking "fresh" and healthy.

Name the two synonyms used for the sympathetic NS.

...Fight or Flight....involuntary NS

What is the sole neurotransmitter of the somatic nervous ?

Acetylcholine

Which meninx forms the structures that are responsible for reabsorption of CSF? And what is the name of these structures?

Arachnoid mater-These fingerlike processes of the arachnoid, called arachnoid villi or arachnoid granulations, are involved in the passage of cerebrospinal fluid from the subarachnoid space to the dural sinuses.

List all cranial nerve pairs involved in detecting taste.

CN VII, or the facial nerve, is responsible for taste in the anterior two-thirds of the tongue. CN IX (glossopharyngeal) and CN X (vagus) are responsible for taste in the posterior one-third of the tongue and into the pharynx. If you think about swallowing a pill and it gets stuck in your vallecula you continue to taste the horrible bitter taste and it will not go away. That is because CN IX and X are still sending the sensory input of the taste. We are able taste into the pharynx.

Which meninx forms the falx cerebri, the falx cerebelli, and the tentorium cerebelli?

Dura mater

Create a table with columns that: 1) List all spinal cord regions 2) List the number of spinal nerve pairs that arise from these regions, and add the name of these groups of nerves (e.g.cervical spinal nerves) 3) List all nerve plexuses that arise from test regions. 4) List one major nerve pair that arises from each nerve plexus. 5) List the anatomical region(s) that these nerves innervate.

Humans have 31 left-right pairs of spinal nerves, each roughly corresponding to a segment of the vertebral column: eight cervical spinal nerve pairs (C1-C8), 12 thoracic pairs (T1-T12), five lumbar pairs (L1-L5), five sacral pairs (S1-S5), and one coccygeal pair. The spinal nerves are part of the peripheral nervous system (PNS). Nerve plexuses throughout the body tend to be named after the area in which the plexus occurs and the organs, limbs, and tissues it serves. Examples include the cervical, brachial, lumbar, sacral, celiac, and coccygeal plexuses.

List all cranial nerves that are sensory nerves.

I-Olfactory, II-Optic, V-Trigeminal, VII-Facial, VIII-Vestibulocochlear, IX-Glossopharyngeal, X-Vagus

List all special senses.

In medicine and anatomy, the special senses are the senses that have specialized organs devoted to them: vision (the eye) hearing and balance (the ear, which includes the auditory system and vestibular system) smell (the nose) taste (the tongue)

List all cranial nerves that contain parasympathetic fibers.

The cranial nerves involved in the parasympathetic nervous system are the oculomotor, facial, glossopharyngeal, and vagus nerves.

Explain the difference between positive and negative feedback.

The key difference between positive and negative feedback is their response to change: positive feedback amplifies change while negative feedback reduces change. This means that positive feedback will result in more of a product: more apples, more contractions, or more clotting platelets. Negative feedback will result in less of a product: less heat, less pressure, or less salt. Positive feedback moves away from a target point while negative feedback moves towards a target.

Based on their name corticospinal tracts are decending/ascending tracts.

decending

Arrange the following structures in the correct order for the pathway of sound in the ear: tympanic membrane, ear canal, ossicles, endolymph, cochlear duct with perilymph.

ear canal -> tympanic membrane-> ossicles ->cochlear duct with perilymph -> endolymph

layers of epidermis (deep to superficial)

stratum basale, stratum spinosum, stratum granulosum, stratum lucidum, stratum corneum

What is the difference between exocrine and endocrine glands?

An endocrine gland secretes its products, for example hormones, directly into the blood. An example of an endocrine gland is the adrenal gland which secretes adenaline made in the adrenal medulla directly into the blood. An exocrine gland secretes its products for example enzymes, into ducts that lead to the target tissue. For example the salivary gland secretes saliva into the collecting duct which leads to the mouth. It's important to note that the pancreas performs both endocrine and exocrine functions. It releases insulin and glucagon directly into the blood (endocrine) and also secretes pancreatic fluid into the pacreatic duct which leads to the duodenum (exocrine).

The heart is characterized by dual innervation. What does that mean?

At each target effector, dual innervation determines activity. For example, the heart receives connections from both the sympathetic and parasympathetic divisions. One causes heart rate to increase, whereas the other causes heart rate to decrease.

List examples of free (unencapsulated) dendritic endings and list function.

-A free nerve ending is an unencapsulated dendrite of a sensory neuron; they are the most common nerve endings in skin. Free nerve endings are sensitive to painful stimuli, to hot and cold, and to light touch. They are slow to adjust to a stimulus and so are less sensitive to abrupt changes in stimulation. -1. Thermoreceptors:- Cold receptors (10-40ºC); in superficial dermis- Heat receptors (32-48ºC); in deeper dermis2. Nociceptors, responding to:- Pinching- Chemicals from damaged tissue- Temperatures outside the range of thermoreceptors- Capsaicin3. Light touch receptors:- Tactile (Merkel) discs- Hair follicle receptors

What is the difference between a neuron and nerve?

-A neuron is one nerve cell, including dendrites, axon, and soma, and a nerve is a bundle of axons, representing parts of many different neurons. -A neuron is a cell, responsible for the generation and transmission of neuronal impulses (action potentials), production of neurotransmitters and, sometimes, for detecting internal and external signals (like touch). A nerve is a bunch of axons, which are part of neurons.

How would a nicotinic cholinergic blocker affect your skeletal muscles and why?

-Nicotinic Antagonists. Drugs that bind to nicotinic cholinergic receptors (RECEPTORS, NICOTINIC) and block the actions of acetylcholine or cholinergic agonists. Nicotinic antagonists block synaptic transmission at autonomic ganglia, the skeletal neuromuscular junction, and at central nervous system nicotinic synapses. -Nicotinic antagonists block synaptic transmission at autonomic ganglia, the skeletal neuromuscular junction, and at central nervous system nicotinic synapses. A nondepolarizing nerve blocker used in addition to anesthesia to cause skeletal muscle relaxation.

Name the two methods by which bones develop in the embryo and list an example of a bone that uses that method.

-During intramembranous ossification, compact and spongy bone develops directly from sheets of mesenchymal (undifferentiated) connective tissue. The flat bones of the face, most of the cranial bones, and the clavicles (collarbones) are formed via intramembranous ossification. -In endochondral ossification, bone develops by replacing hyaline cartilage. Cartilage does not become bone. Instead, cartilage serves as a template to be completely replaced by new bone. Endochondral ossification takes much longer than intramembranous ossification. Bones at the base of the skull and long bones form via endochondral ossification.

List several examples of things that can pass through the BBB.

-In the capillaries that form the blood-brain barrier, endothelial cells are wedged extremely close to each other, forming so-called tight junctions. The tight gap allows only small molecules, fat-soluble molecules, and some gases to pass freely through the capillary wall and into brain tissue. -The blood-brain barrier restricts the passage of pathogens, the diffusion of solutes in the blood, and large or hydrophilic molecules into the cerebrospinal fluid (CSF), while allowing the diffusion of hydrophobic molecules (O2, CO2, hormones) and small polar molecules.

Based on their mode of secretion, to which group of glands to sebaceous glands belong? What about salivary glands?

-Sebaceous glands are microscopic exocrine glands in the skin that secrete an oily or waxy matter, called sebum, to lubricate and waterproof the skin and hair of mammals. -Exocrine glands (e.g., salivary, sweat, digestive) discharge their products through ducts. ...of the skin are all exocrine, that is, they secrete their products, usually through ducts, to the epidermal surface.

Specify where exactly the damage has occurred in spastic and flaccid paralysis.

-Spasticity is a result of disrupted communication between the brain and the muscles. The source of that disruption is usually the cerebral cortex (the region of the brain that controls movement) or the brainstem, where nerves connect the brain to the spinal cord. -Flaccid paralysis can be caused by infections and toxins or damage to the spinal cord or brain. Polio, botulism, and curare are examples of this type of damage. All of these problems cause flaccid paralysis by preventing messages in the brain from getting to the muscle. Flaccid paralysis occurs by the damage of lower motor neurons in the anterior horn of the spinal cord or peripheral nerves either by direct invasion or parainfectious and/or postinfectious immune-mediated mechanisms.

Where does transduction occur? Define it, please.

-transduction occurs in sensory receptors -transduction of stimuli, or how the mechanical stimulus, light, or chemical changed the cell membrane potential.

People who suffer from a high blood pressure (hypertension) are put on "alpha blockers"? Describe what this medication does to dilate the blood vessels and hereby reduce blood pressure.

...Alpha blockers lower blood pressure by keeping the hormone norepinephrine from tightening the muscles in the walls of smaller arteries and veins. As a result, the vessels remain open and relaxed. This improves blood flow and lowers blood pressure.

List all reasons for why the effects of the parasympathetic NS tend to be localized and short-lived.

...Because the terminal ganglia are located within the innervated tissue, there is typically little divergence in the parasympathetic system compared to the sympathetic system. In many organs, there is a 1:1 ratio of preganglionic fibers to postganglionic fibers. Therefore, the effects of the parasympathetic system tend to be more discrete and localized, with only specific tissues being stimulated at any given moment, compared to the sympathetic system where a more diffuse discharge is possible.

People who suffer from a fast heart rate (tachycardia) are put on "beta blockers"? Describe what this medication does to slow down the heart rate.

...Beta blockers, also known as beta-adrenergic blocking agents, are medications that reduce your blood pressure. Beta blockers work by blocking the effects of the hormone epinephrine, also known as adrenaline. Beta blockers cause your heart to beat more slowly and with less force, which lowers blood pressure.

Compared to the sympathetic ganglia, where are the parasympathetic ganglia located? Why are they called terminal ganglia?

...Parasympathetic ganglia innervating the airways, heart, and pancreas are locatedclose to, or within the organs. Parasympathetic neurons innervating the pelvic viscera are largely located in pelvic ganglia.

List examples of simple senses and add examples of simple receptors.

...Senses. Humans have five basic senses: sight, hearing, smell, taste and touch.

List what is responsible for the creation and maintenance of RMPs in all cells.

...Sodium-potassium pumps move two potassium ions inside the cell as three sodium ions are pumped out to maintain the negatively-charged membrane inside the cell; this helps maintain the resting potential.

Name the two groups of sympathetic ganglia. Describe where they are located.

...Sympathetic ganglia can be divided into two major groups, paravertebral and prevertebral (or preaortic), on the basis of their location within the body. Paravertebral ganglia generally are located on each side of the vertebrae and are connected to form the sympatheticchain, or trunk.

Which functional joint type is the most moveable, but the least stable? Which structural joint type is the most moveable, but the least stable?

...Synarthrosis: These types of joints are immobile or allow limited mobility. ... Amphiarthrosis: These joints allow a small amount of mobility. ... Diarthrosis: These are the freely-movable synovial joints.

Differentiate between temporal summation and spatial summation in both skeletal muscle as well as the nervous system.

...Temporal summation occurs when a single pre-synaptic neuron fires many times in succession, causing the post-synaptic neuron to reach its threshold and fire. Spatial summation occurs when excitatory potentials from many different pre-synaptic neurons cause the post-synaptic neuron to reach its threshold and fire.

Name the effectors for the autonomic nervous system.

...The effectors of the autonomic nervous system are cardiac muscle, smooth muscle, and glands

Describe which neurons are found in the white rami and grey communicantes: 1) to which NS branch do they belong? 2) Are they myelinated or unmyelinated? 3) Are they preganglionic or postganglionic neurons?

...The gray rami communicantes contain postganglionic nerve fibers of the sympathetic nervous system and are composed of largely unmyelinated neurons. This is in contrast to the white rami communicantes, in which heavily myelinated neurons give the ramitheir white appearance. Preganglionic sympathetic fibres from the intermediolateral nucleus in the lateral grey column of the spinal cord are carried in the white ramus communicansto the paravertebral ganglia of the sympathetic trunk.

About the non-specific lateral spinothalamic tracts: 1) Name the three tracts that make up this pathway. 2) Describe where each tract pair is located. 3) Where do they start, where do they decussate, and where do they end? 3) What are the main functions of this pathway?

...The lateral spinothalamic tract transmits pain and temperature. The pathway crosses over (decussates) at the level of the spinal cord, rather than in the brainstem like the dorsal column-medial lemniscus pathway and lateral corticospinal tract.

To which group do the sympathetic neurotransmitter receptors belong on the heart muscle cells? And on the smooth muscle of blood vessels? Be specific.

...The postganglionic effects of autonomic ganglion cells on their smooth muscle, cardiac muscle, or glandular targets are mediated by two primary neurotransmitters: norepinephrine (NE) and acetylcholine (ACh).

Name the effector that makes the hairs on your am stand up. Which specific neurons innervate this effector?

...errector pili...adrenergic receptors which bind to the neurotransmitter norepinephrine

An electrical potential that can be stronger because ion channels remain open longer after a neurotransmitter binds must be a _____ potential.

...excitatory postsynaptic potentials

Arrange the following structures in the correct order for the pathway of light in the eye: lens, aqueous humor, vitreous humor, retina

...lens ->aqueous humor ->vitreous humor ->retina

We need ATP to drive ion pumps and break cross bridges (to name just two things). Which form of metabolism produces the most ATP per glucose molecule? How do we use creatine phosphate to make new ATP very fast?

...oxidative phosphorylation So, oxidative phosphorylation is the metabolic cycle that produces the most net ATP per glucose molecule.

What type of functional neurons are only found in the sympathetic nervous system? And in the parasympathetic NS? And in the somatic NS?

...postganglionic neurons are found in the sympathetic ns; preganglionic neurons are found in the parasympathetic ns

Name the two synonyms used for the parasympathetic NS.

...rest and digest system...enteric NS

What is the total number of spinal nerve pairs? And cranial nerve pairs? (Ignore nerve 0).

...spinal nerve pairs = 31 ...cranial nerve pairs = 12

Name the simple receptor that detects when the hair on your arm is moved.

..meissner corpuscle

List examples of encapsulated dendritic endings and list function.

1. Meissner's (tactile) corpuscles—discriminative touch (found in hairless skin: nipples, fingertips, soles of feet, eyelids, external genitalia )2. Pacinian (lamellated) corpuscles—deep pressure and vibration (found in dermis, hypodermis, tendons, joints)3. Ruffini endings—deep continuous pressure (found deep in dermis, hypodermis, and joint capsules)4. Muscle spindles—muscle stretch (found in skeletal muscles, especially those of extremities)5. Golgi tendon organs—stretch in tendons (found wrapped around tendons)6. Joint kinesthetic receptors—stretch in articular capsules (found in joint capsules of synovial joints)ALL are mechanoreceptors

List all components of a reflex arc.

1. receptor 2. sensory neuron 3. integration center 4. motor neuron 5. effector

How many neurons participate in the formation of a simple spinal somatic reflex arc?

3-The reflex arc has an afferent (sensory) neuron, an association neuron, and an efferent (motor) neuron. They are activated in that order. First, the afferent neuron sends the sensory information to the spinal cord. The association neuron then routesthe signal to the efferent neuron, and finally the efferent neuron stimulates the muscle to contract.

Phasic receptors

A phasic receptor is a sensory receptor that adapts rapidly to a stimulus. The response of the cell diminishes very quickly and then stops. It does not provide information on the duration of the stimulus; instead some of them convey information on rapid changes in stimulus intensity and rate.

All spinal nerves are mixed nerves. What does this mean?

A spinal nerve is a mixed nerve, which carries motor, sensory, and autonomic signals between the spinal cord and the body. In the human body there are 31 pairs of spinal nerves, one on each side of the vertebral column. ... The spinal nerves are part of the peripheral nervous system.

tonic receptors

A tonic receptor is a sensory receptor that adapts slowly to a stimulus and continues to produce action potentials over the duration of the stimulus. In this way it conveys information about the duration of the stimulus. Some tonic receptors are permanently active and indicate a background level. Examples of such tonic receptors are pain receptors, joint capsule, and muscle spindle.

List all parts of bone tissue that is organic.

Bones consist of living cells embedded in a mineralized organic matrix. This matrix consists of organic components, mainly type I collagen - "organic" referring to materials produced as a result of the human body- and inorganic components, primarily hydroxyapatite and other salts of calcium and phosphate.

List all cranial nerves in order and identify them as sensory nerves, mostly motor nerves, or mostly mixed nerves.

CN 0 - Terminal: ? CN I - Olfactory: sensory nerves CN II - Optic: sensory nerves CN III - Oculomotor: mostly motor nerves CN IV - Trochlear: mostly motor nerves CN V - Trigeminal: mostly mixed nerves CN VI - Abducens: mostly motor nerves CN VII - Facial: mostly mixed nerves CN VIII - Vestibulocochlear: mostly sensory nerves CN IX - Glossopharyngeal: mostly mixed nerves CN X - Vagus: mostly mixed nerves CN XI - Accessory (cranial, spinal): mostly motor nerves CN XII - Hypoglossal: mostly motor nerves

Name all special sensory receptors and identify in which special sensory organ they are loacted.

Chemoreceptors detect the presence of chemicals. Thermoreceptors detect changes in temperature. Mechanoreceptors detect mechanical forces. Photoreceptors detect light during vision. More specific examples of sensory receptors are baroreceptors, propioceptors, hygroreceptors, and osmoreceptors.

Name the space that separates the dura mater from the periosteum around the spinal cord. What is located in this space? What is its function?

Epidural Space: the epidural space contains fat, veins, arteries, spinal nerve roots and lymphatics. The fat in the epidural space helps absorb shock, which protects the other contents in the area, as well as the dura.

Which spinal cord region does not give rise to a nerve plexus? Name the nerves that arise from this region and what do they innervate?

Intercostal nerves connect to the appropriate ganglion in the sympathetic trunk through rami communicantes and serve the thoracic pleura and the abdominal peritoneum. Unlike most other anterior divisions of spinal nerves, the intercostal nerves do not form a plexus.

Why is it so difficult to treat brain diseases with medication?

Large molecules do not pass through the BBB easily. Low lipid (fat) soluble molecules do not penetrate into the brain. However, lipid soluble molecules, such as barbituate drugs, rapidly cross through into the brain. Molecules that have a high electrical charge are slowed.

To which group do the neurotransmitter receptors belong on the motor end plate? Your answer should be specific so it should have two components.

Nicotinic Acetylcholine Receptors?

Are olfactory receptors examples of phasic or tonic receptors? Why? What about pain receptors?

Olfactory receptors examples of phasic receptors. Pain receptors are examples of tonic receptors.

Name the pair of cranial nerves that extends well beyond the head and neck all the way into the abdomen.

Only the vagus nerve extends beyond the neck, to innervate thoracic and abdominal viscera.

Briefly list the symptom differences between spastic paralysis and flaccid paralysis.

Paralysis can be stiff, or spastic, when your muscles are tight and jerky. Most people with cerebral palsy have spastic paralysis. It can also be floppy, or flaccid, when your muscles sag and eventually shrink. Spastic paralysis may occur in association with spinal cord injury, multiple sclerosis, cerebral palsy, or brain trauma. Flaccid paralysis is a neurological condition characterized by weakness or paralysis and reduced muscle tone without other obvious cause (e.g., trauma). This abnormal condition may be caused by disease or by trauma affecting the nerves associated with the involved muscles.

Which meninx is in contact with the cerebral cortex and white matter of the spinal cord?

Pia mater

What are proprioreceptors?

Sensory receptors located in the inner ear, muscles, tendons, and joints that use internal stimuli to detect changes in position or movement of the body or its limbs are called proprioceptors

Most tracts express somatotopy. Explain what this means in your own words.

Somatotopy is the point-for-point correspondence of an area of the body to a specific point on the central nervous system. Typically, the area of the body corresponds to a point on the primary somatosensory cortex (postcentral gyrus).

A multisynaptic reflex has a longer synaptic delay than a monosynaptic reflex. What does that mean?

Synaptic delay is defined as the time interval between peak of inward current through the presynaptic membrane and commencement of inward current through the postsynaptic membrane.

Through what part of the brain does almost all sensory information and motor information pass?

Thalamus. The thalamus is a collection of nuclei that relay information between the cerebral cortex and the periphery, spinal cord, or brain stem. All sensory information, except for the sense of smell, passes through the thalamus before processing by the cortex

Name tracts that are descending, mostly ipsilateral, and do not involve the thalamus. What are their functions?

The anterior corticospinal tract remains ipsilateral, descending into the spinal cord.

Where exactly are cell bodies of motor neurons located as these neurons leave the spinal cord?

The area of the grey matter closest to the front of the spinal cord is called the anterior horn. It contains the cell bodies of lower motor neurons. These neurons leave the spinal cord in the ventral roots and project to skeletal muscle. They are responsible for all voluntary and involuntary movements.

To which branch of the peripheral nervous system does the autonomic nervous system belong? And the somatic nervous system?

The autonomic nervous system belongs to the motor (efferent) branch. The somatic nervous system belongs to the sensory (afferent) branch.

What creates the barrier of the BBB?

The blood-brain barrier is formed by endothelial cells of the capillary wall, astrocyte end-feet ensheathing the capillary, and pericytes embedded in the capillary basement membrane.

Where exactly are cell bodies of sensory neurons located as these neurons enter the spinal cord?

The cell bodies for these sensory neurons are clustered together in a structure called the dorsal root ganglion, which is found alongside the spinal cord. The ventral root and dorsal root come together just beyond the dorsal root ganglion (moving away from the cord) to form a spinal nerve.

How are the neurons typically referred to in descending pathways? What type of functional neuron is each one of them?

The descending tracts are the pathways by which motor signals are sent from the brain to lower motor neurones. The lower motor neurones then directly innervate muscles to produce movement.

About the Dorsal Column-Medial Lemniscus Pathway: 1) Name the three tracts that make up this pathway. 2) Describe where each tract pair is located. 3) Where do they start, where do they decussate, and where do they end? 3) What are the main functions of this pathway? 4) Why are the spinal tracts also called specific spinothalamic pathways?

The dorsal column-medial lemniscus pathway(DCML) (also known as the posterior column-medial lemniscus pathway (PCML)) is a sensory pathway of the central nervous system that conveys sensations of fine touch, vibration, two-point discrimination, and proprioception (position) from the skin and joints. The first-order axons make contact with second-order neurons of the dorsal column nuclei (the gracile nucleus and the cuneate nucleus in the lower medulla. The second-order neurons send their axons to the thalamus. The third-order neurons are in the ventral nuclear group in the thalamus and fibres from these ascend to the postcentral gyrus. PrecursorNeural tube and crestSystemSomatosensory systemDecussationMedial lemniscusToSensorimotor cortexFunctionTransmit sensation of fine touch, vibration and proprioception

All dorsal roots are sensory nerves. What does this mean?

The dorsal root of spinal nerve (or posterior root of spinal nerve) is one of two "roots" which emerge from the spinal cord. It emerges directly from the spinal cord, and travels to the dorsal root ganglion. ... The dorsal root transmits sensory information, forming the afferent sensory root of a spinal nerve.

How are the neurons typically referred to in ascending pathways? What type of functional neuron is each one of them?

The initial neuron in an ascending spinal pathway is always a primary afferent neuron

It is easy to distinguish a somatic versus an autonomic reflex arc on a picture even without seeing the effectors. Why?

The main difference between the somatic and autonomic systems is in what target tissues are effectors. Somatic responses are solely based on skeletal muscle contraction. The autonomic system, however, targets cardiac and smooth muscle, as well as glandular tissue.

Name the tracts that arise in the primary motor cortex and control most of our skeletal muscles. To which pathways do they belong, direct or indirect? Where exactly do these tracts decussate? Are they contralateral or ipsilateral tracts?

The motor tracts can be functionally divided into two major groups: Pyramidal tracts - These tracts originate in the cerebral cortex, carrying motor fibres to the spinal cord and brain stem. They are responsible for the voluntary control of the musculature of the body and face. Extrapyramidal tracts - These tracts originate in the brain stem, carrying motor fibres to the spinal cord. They are responsible for the involuntary and automatic control of all musculature, such as muscle tone, balance, posture and locomotionPyramidal tracts -These tracts originate in the cerebral cortex, carrying motor fibres to the spinal cord and brain stem. -The major descending tract that controls skeletal muscle movements is the corticospinal tract. It is composed of two neurons, the upper motor neuron and the lower motor neuron.

List the only cranial nerve pair for sensing smell.

The olfactory nerve (I): This is instrumental for the sense of smell, it is one of the few nerves that are capable of regeneration.

Which groups of spinal nerves contain parasympathetic versus sympathetic fibers?

The parasympathetic preganglionic motor neurons are found in two groups, one in the brainstem and one in the sacral spinal cord.

What is hematopoiesis and where does it occur? List specific sites in the body.

The process of hematopoiesis involves the differentiation of multipotent cells into blood and immune cells. The multipotent hematopoietic stem cells give rise to many different cell types, including the cells of the immune system and red blood cells.

What is the purpose of the BBB?

The purpose of the blood-brain barrier is to protect against circulating toxins or pathogens that could cause brain infections, while at the same time allowing vital nutrients to reach the brain.

Which branch of the nervous system innervates the adrenal glands? What part of the adrenal glands? And which chemicals do these glands secrete in response to stimulation by this NS branch? Where do these chemicals end up?

The sympathetic NS innervates the adrenal glands (adrenal medulla)...The adrenal medulla, the inner part of an adrenal gland, controls hormones that initiate the flight or fight response. The main hormones secreted by the adrenal medulla include epinephrine (adrenaline) and norepinephrine (noradrenaline), which have similar functions.

List the only cranial nerve pair for sensing sounds and changes in equilibrium.

The vestibulocochlear nerve (also known as the auditory vestibular nerve and cranial nerve VIII) has axons that carry the modalities of hearing and equilibrium.

What do first order neurons and upper motor neurons have in common?

UMNs are first-order neurons which carry the electrical impulses for movement, and many descending UMN tracts coordinate movement. Upper motor neuron: a neuron that extends from the cerebral cortex or brainstem to synapse with a lower motor neuron (usually in the spinal cord). Upper motor neurons control the activity of lower motor neurons, which control the activity of muscles to produce movement. The first-order neurons carry signals from the periphery to the spinal cord; the second-order neurons carry signals from the spinal cord to the thalamus; and the third-order neurons carry signals from the thalamus to the primary sensory cortex.

List the only cranial nerve pair for vision.

Vision-> optic (I) nerve. The four cranial nerves involved in vision and movement of the eyes are the optic (I) nerve, oculomotor (III) nerve, trochlear (IV) nerve and the abducen (VI) nerve. The optic nerve is the sensory nerve for vision. It transmits information from the eyes to the brain.

What is the sole neurotransmitter of the parasympathetic nervous system, both preganglionic and postganglionic fibers?

acetylcholine The parasympathetic nervous system uses chiefly acetylcholine (ACh) as its neurotransmitter, although peptides (such as cholecystokinin) can be used. The ACh acts on two types of receptors, the muscarinic and nicotinic cholinergic receptors

Based on their name spinocerebellar tracts are decending/ascending tracts.

ascending

Which structure in the brain provides the plasma to form the CSF?

choroid plexus: CSF is produced by the choroid plexus in two steps. Firstly, a filtered form of plasma moves from fenestrated capillaries in the choroid plexus into an interstitial space, with movement guided by a difference in pressure between the blood in the capillaries and the interstitial fluid

List the four tissue categories.

connective epithelial muscular nervous

If a person can move his arm, but he cannot feel that his arm is moving, where might there be an injury? Explain each answer as either correct or incorrect. a) in the ventral roots of the spinal nerves that innervate his arm muscles. b) in the dorsal roots of the spinal nerves that innervate his arm muscles. c) in the primary motor cortex. d) in the autonomic ganglia associated with his arm muscles

correct answer->b) in the dorsal roots of the spinal nerves that innervate his arm muscles.

Name the cells that line the ventricles and the central canal. What is their function?

ependymal cells: -ependymal cells are simple cuboidal cells that line the ventricles in the brain and the central canal in the spinal cord. -the ependymal cells play an important role in the production and regulation of CSF. Their apical surfaces are covered in a layer of cilia, which circulate CSF around the CNS.

"Place the following structures in the correct order for the flow of CSF: cerebral aqueduct, interventricular foramina, central canal and/or subarachnoid spaces (keep these together), lateral ventricles, third ventricle, fourth ventricle."

lateral ventricles -> interventricular foramina -> third ventricle -> cerebral aqueduct -> fourth ventricle -> central canal and/or subarachnoid spaces

Suppose you had to build a fictitious organ in the lab that was very good at absorbing, and was quite pliable and could not break easily. What kind of epithelial tissue would you need? What kinds of connective tissues would you choose? Explain your choices carefully.

transitional ET...Loose connective tissue is a category of connective tissue which includes areolar tissue, reticular tissue, and adipose tissue.

Name the cranial nerve that senses sounds and balance changes?

vestibulocochlear nerve: Also known as the auditory vestibular nerve, this is the eighth of twelve cranial nerves, and it is responsible for transmitting sound and equilibrium (balance) information from the inner ear to the brain.