BIOL 2403 Final exam Review Updated, Exams of Nursing

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Exercise 12: Microscopic Anatomy of Muscles

- What are the functions of muscles? o Produce movement > locomotion and manipulation o Maintain body posture and body position o Stabilize joints o Generate heat as they contract o Regulate the passage of substances o Additional functions ▪ Protect organs ▪ Form valves ▪ Control pupil size ▪ Cause “goosebumps” - Also know the terms: Sarcomere, Motor Unit. o Sarcomere ▪ Smallest contractile unit (functional unit) of muscle fiber - Aka basic building block of most muscle cells ▪ Consists of area between Z discs - Contains an A band with half of an I band at each end ▪ Individual sarcomeres align end along myofibril, like boxcars of train o Motor unit ▪ Made up of a motor neuron and the skeletal muscle fibers innervated by the motor neuron’s axonal terminals ▪ All muscle fibers controlled by motor neuron. ▪ one-way motor units differ is in the number of innervated muscle fibers ▪ different depending on where they are and what they do ▪ Amount depends on load and usage ▪ eye muscles possess many motor units each with few, small muscle fibers, because they're specialized for small, fine movements. ▪ limb muscles possess fewer motor units with many muscle fibers, because they are specialized for maintaining posture and producing propulsive forces - Functions of Tendons o Attach Muscle to Bone o Provide Durability o Conserve Space - Where is acetylcholine found, what is it, when is it released? o Found in preganglionic sympathetic and parasympathetic neurons. o The most widely spread neurotransmitter ▪ neurotransmitter at the adrenal medulla, parasympathetic innervated organs, the sweat glands, and at the piloerector muscle of the sympathetic ANS o In the peripheral nervous system, when a nerve impulse arrives at the terminal of a motor neuron, acetylcholine is released into the neuromuscular junction. There it combines with a receptor molecule in the postsynaptic membrane (end-plate membrane) of a muscle fiber. ▪ This bonding changes the permeability of the membrane, causing channels to open that allow positively charged sodium ions to flow into the muscle cell Cells of Skeletal Muscles

Figure 12.1 & 12.2; Models: Microscopic Skeletal Muscle Sarcolemma o plasma membrane of a muscle cell o causes smooth muscle cells to contract in skeletal & muscle cells Myofibril o Tubular protein fiber o found within a muscle cells that has a banded appearance o Accounts for ~80% of muscle cell volume Myofilament o composed largely of 2 varieties of contractile proteins (actin or myosin) structure o create muscle contractions by allowing the myosin protein heads to walk along the actin filaments creating a sliding action Actin myofilaments o thin filaments o protein used by cells for structure o extend across I band and partway in A band o Anchored to Z discs Myosin myofilaments o thick filaments o motor protein o Extend length of A band o Connected at M line Transverse Tubule (T tubule) o formed by protrusion of sarcolemma deep into cell interior o Increase muscle fiber's surface area greatly o Allow electrical nerve transmissions to reach deep into interior of each muscle fiber o Tubules penetrate cell's interior at each A–I band junction between terminal cisterns Sarcoplasmic reticulum o regulates intracellular Calcium ion level o Stores and releases calcium ions o network of smooth endoplasmic reticulum tubules surrounding each myofibril Terminal cisternae o T- tubule flanked by enlarged sarcoplasmic reticulum o form perpendicular cross channels at the A–I band junction ▪ triad > involved in depolarization and activation of the muscle cells, resulting in contraction A band [H Zone] o A band: dark regions o H zone: lighter region in middle of dark A band I band [Z line/ Z disc] o I band: lighter regions o Z disc: coin-shaped sheet of proteins on midline of light I band Sarcomere o Smallest contractile unit (functional unit) of muscle fiber ▪ Aka basic building block of most muscle cells o Consists of area between Z discs

▪ Contains an A band with half of an I band at each end o Individual sarcomeres align end along myofibril, like boxcars of train

Organization of Skeletal Muscles Figure 12. Muscle o Bundle of fibrous tissue that contracts producing movement in or maintain the position of the body

Epimysium o dense irregular connective tissue surrounding entire muscle o epimysia blend into the deep fascia that bind muscles into functional groups, into strong cordlike structures called tendons, or sheetlike aponeuroses. Fascicle o groups of muscle fibers o layers of fibrous tissue covering and separating muscles Perimysium o fibrous connective tissue surrounding fascicles Fiber/ cell o Skeletal muscle = muscle fiber o Muscle fiber = muscle cell o enclosed in a dense connective tissue called the endomysium Endomysium o fine areolar connective tissue surrounding each muscle fiber Tendon o A flexible but inelastic cord of dense fibrous tissue attaching a muscle to a bone Aponeurosis o Sheet of pearly white fibrous tissue that takes the placement of a tendon in flat muscles having a wide area of attachment o fibrous or membranous sheet connecting a muscle & the part it moves

Neuromuscular Junction Figure 12.5; Models: Microscopic Skeletal Muscle Neuromuscular Junction (Myoneural Junction) o where the neuron and the muscle fiber interact o the motor axons of the neurons branch into axon terminals Synaptic cleft o gap between the axon terminal of the neuron and the sarcolemma Synaptic vesicles o contain neurotransmitter acetylcholine (ACh) o transport proteins involved in neurotransmitter uptake o traffics proteins that participate in synaptic vesicle exocytosis, endocytosis, and recycling Axon Terminals o end of axon and muscle fiber are separated by gel-filled space called synaptic cleft o contain vesicles which have a neurotransmitter called acetylcholine (Ach) o when impulse reaches axon terminal, calcium channels open, and calcium ion enters axon terminal Acetylcholine (ACH) o Neurotransmitter o diffuses across cleft and binds with receptors on sarcolemma o Quickly broken down by enzyme acetylcholinesterase = stops contractions

Exercise 13: Gross Anatomy of Muscles Classification of Skeletal Muscles

Prime Movers (Agonists) o muscles that are responsible for producing a particular movement Antagonists o Muscles that oppose or reverse a movement Synergists o muscles that aid the action of the agonists by reducing undesirable movement. Fixators o Specialized synergists that immobilize the origin of the prime mover so that all tension is exerted at the insertion. Criteria for Naming Muscles Direction of Fibers o ex: fibers run parallel = rectus Shape o EX: trapezoid shape = trapezius Size o EX: largest = maximus, smallest = minimus Location o EX: frontalis muscle overlies the frontal bone Number of origins o EX: two origins = biceps, three origins = triceps Actions o EX: extensor muscles of the wrist extend the wrist Location of origin and insertion o EX: sternocleidomastoid has origin on the sternum and clavicle and inserts on the mastoid process

• Know the muscles from the Identification of Human Muscles Handout (Available on Blackboard) Fig. 13.2 – 13.5; Models: PAT, Muscle Arm, Muscle Leg
• Know the Cat Muscles for Dissection (Available of Blackboard) pg. 705 - 722; Demo Cat

HEAD & NECK

• Platysma
• Trapezius
• Orbicularis oris
• Orbicularis oculi
• Masseter
• Sternocleidomastoid
• Temporalis HIP & THIGH (posterior)
• Gluteus maximus
• Gluteus medius
• Biceps femoris
• Semimembranosus
• Semitendinosus THORAX, SHOULDER & ARM
• Pectoralis major
• Deltoid
• Latissimus dorsi
• Tricieps brachii
• Biceps brachii
• Brachialis
• Brachioradialis

FOREARM & WRIST

• Flexor carpi radialis
• Palmaris longus
• Flexor carpi ulnaris ABDOMINAL WALL
• Internal oblique
• Transversus abdominis
• Rectus abdominis THIGH & LEG (anterior)
• Gracilis
• Sartorius
• Rectus femoris
• Tensor fasciae latae
• Vastus lateralis
• Pectineus

FORELIMB MUSCLES

(lateral surface)

1. Triceps brachii, lateral head
2. Triceps brachii, long head
3. Triceps brachii, medial head
4. Brachialis
5. Brachioradialis
6. Extensor carpi ulnaris FORELIMB (medial surface)
7. Biceps brachii
8. Palmaris longus
9. Flexor carpi ulnaris LEG (lateral)

• Gastrocnemius
• Soleus
• Tibialis anterior
• Extensor digitorum longus

LEG

10. Sartorius
11. Gluteus medius
12. Gluteus maximum
13. Tensor fasciae latae
14. Biceps femoris
15. Semimembranosus
16. Gastrocnemius
17. Soleus
18. Tibialis anterior
19. Extensor digitorum longus
20. Gracilis
21. Vastus lateralis
22. Rectus femoris
23. Vastus medialis
24. Adductor femoris

ABDOMINAL WALL

25. External oblique
26. Internal oblique
27. Rectus abdominis
28. Transversus abdominis

ANTERIOR NECK

31. Sternomastoid
32. Mylohyoid SUPERFICIAL SHOULDER, dorsal Truck & Neck
33. Latissimus dorsi
34. Clavotrapezius
35. Clavodeltoid
36. Acromiotrapezius

SUPERFICIAL CHEST

29. Pectoralis major
30. Pectoralis minor

Exercise 15: Histology of Nervous Tissue

- Know the 6 Neuroglia, what were their functions and which division of the nervous system did they belong to? Figure 15. Astrocytes central nervous system (CNS) support and brace the neurons and anchor them to their nutrient supply lines, play a role in making exchanges between capillaries and neurons helping determine capillary permeability, control the chemical environment around DEEP MUSCLES, Dorsal Trunk & Neck 37. Serratus ventralis 38. Scalenes 39. Splenius 40. Rhomboideus

neurons where their most important job is “mopping up” leaked potassium ions and recapturing and recycling released neurotransmitters Oligodendrocytes Central Nervous System (CNS) line up along the thicker nerve fibers in the CNS and wrap their processes tightly around the fibers, producing an insulating covering called a myelin sheath Microglial Cells Central Nervous System (CNS) processes touch nearby neurons, monitoring their health when they sense that certain neurons are injured or in other trouble, the microglial cells migrate toward them, invading microorganisms or dead neurons are present the microglial cells transform into a special type of macrophage that phagocytizes the microorganisms or neuronal debris, protective role is important because cells of the immune system have limited access to the CNS Ependymal cells central nervous system (CNS) line the central cavities of the brain and the spinal cord, where they form a fairly permeable barrier between the cerebrospinal fluid that fills those cavities and the tissue fluid bathing the cells of the CNS, beating of their cilia helps to circulate the cerebrospinal fluid that cushions the brain and spinal cord Schwann Cells (Neurolemmocytes)

- Peripheral Nervous System (PNS) - surround all nerve fibers in the PNS and

form myelin sheaths around the thicker nerve fibers, in this way, they are functionally similar to oligodendrocytes Schwann cells are vital to regeneration of damaged peripheral nerve fibers. Satellite Cells

• Peripheral nervous system (PNS)
• surround neuron cell bodies located in the peripheral nervous system and are thought to have many of the same functions in the PNS as astrocytes do in the CNS
• Be able to differentiate between the functions of neurons and neuroglia. o Neurons - transmit messages from one part of the body to another in the form of nerve impulses o Neuroglia - serve the needs of the delicate neurons by supporting and protecting the - Be able to identify the neuron and neuroglia on a slide. Pyramidal neuron from the cerebral Nerve^ cells,^ Spinal^ cord Purkinje cell from the cerebellar cortex Human Cerebral Cortex

Dorsal root ganglion cells Neuroglial Cells

- Know the neuron structures listed on handout “Exercise 15 ” Figure 15.2; Model: Neuron

Unipolar

- AKA pseudounipolar neurons. One very short process divides in the peripheral and central processes. Peripheral process section contains receptive endings. Located in CNS. Very abundant. Impulse moves TOWARD the CNS. - Explain how a nerve impulse is transmitted from one neuron to another. o The transmission of a nerve impulse along a neuron from one end to the other occurs as a result of electrical changes across the membrane of the neuron - Be able to state the functions of axons, dendrites, axon terminals, neurofibrils, and myelin sheaths. o Axon ▪ nerve fibers when they are long, form the impulse generating and conducting region of the neuron o Dendrites ▪ receptive regions that bear receptors for neurotransmitters released by the axon terminals of other neurons o Axon terminals ▪ form synapses with neurons or effector cells o Neurofibrils ▪ provide support for the cell and a means to transport substances throughout the neuron o Myelin sheaths ▪ myelin electrically insulates the fibers and greatly increases the transmission speed of nerve impulses - Know the terms: nuclei, ganglia, tracts, nerves, afferent, efferent o Nuclei : Neuron cell bodies make up the gray matter of the CNS, and form clusters there o Ganglia: In the PNS, clusters of neuron cell bodies o Tracts: In the CNS, bundles of axons o Nerves: In the PNS, bundles of axons o Afferent: conduct impulses only toward the CNS o Efferent: carry impulses only away from the CNS Neuron Classified by Structure Figure 15. *Know the structure, location, abundance, and direction of impulse for each

Bipolar

- Two processes attached to the cell body. Very rare. Located only as part of the receptors of the eye, ear, and olfactory mucosa. Impulse TOWARD the CNS. Multipolar - Many processes (most of them are dendrites and a single axon). Make up motor neurons. Location: Make up MOST of the brain and spinal cord. Axons carry impulse AWAY from the CNS. Neuron Classified by Function Figure 15.7; Model: Reflex Arc Nerve Classification *Know the functional neuron type based on direction of impulse, structure and

- Sensory o afferent o Conduct impulses only towards the CNS o Typically, UNIPOLAR - Motor o efferent o Carry impulses only away from the CNS o Mostly MULTIPOLAR - Interneuron o Stimulated between and contribute to pathway that connect sensory and motor neurons o Mostly MULTIPOLAR - Mixed o Nerves carrying both sensory (afferent) and motor (efferent) fibers, most nerves of the body, including all spinal nerves, are mixed nerves.

• Know the structure of a nerve: Nerve (Epineurium) - > Fascicle (Perneurium) - > Fiber/Axon (Endoneurium) Figure 15.8

Exercise 17: Gross Anatomy of the Brain and Cranial Nerves

• Know the Organization of the Nervous System
• Know the External Anatomy of the Brain Fig. 17.2 – 17.3; Model: Brain Cerebrum - cerebral hemispheres o gyri o sulci ▪ central sulcus ▪ lateral sulcus o fissures ▪ longitudinal fissure ▪ transverse cerebral fissure o frontal lobe o parietal lobe o occipital lobe o temporal lobe Diencephalon olfactory bulbs and tracts optic nerves optic chiasma mammillary body pituitary gland infundibulum Brain Stem midbrain o cerebral peduncle o corpora quadrigemina o superior and inferior colliculi pons medulla oblongata

Cerebellum vermis

• Know the Internal Anatomy of the Brain Fig. 17.4 – 17.6; Model: Brain Cerebral hemispheres corpus callosum fornix septum pellucidum Diencephalon hypothalamus thalamus intermediate mass of thalamus pineal gland Brain Stem midbrain o cerebral aqueduct

Cerebellum outer region (cerebral cortex) – gray matter) inner region- white matter arbor vitae

• 3 layers of the Meninges: Dura Mater, Arachnoid Mater, Pia Mater Fig. 17.7 o Dura mater ▪ a double-layered membrane. One of its layers (the periosteal layer) is attached to the inner surface of the skull, forming the periosteum. o Arachnoid mater ▪ The middle meninx, the weblike arachnoid mater, underlines the dura mater o Pia mater ▪ Highly vascular and clings tenaciously to the surface of the brain - Where is the Cerebrospinal Fluid formed? o The cerebrospinal fluid (CSF), much like plasma in composition, is continually formed by the choroid plexuses, small capillary knots hanging from the roof of the ventricles of the brain - Conditions: Meningitis, Hydrocephalus, Encephalitis o Meningitis ▪ inflammation of the meninges is a serious threat to the brain because of the intimate association between the brain and meninges o Hydrocephalus ▪ In infants ▪ literally, “water on the brain” is indicated by a gradually enlarging head ▪ The infant’s skull is still flexible and contains fontanelles, so it can expand to accommodate the increasing size of the brain. o Encephalitis ▪ infection spread to the neural tissue of the brain itself, life-threatening - How many cranial nerves are there? What is so special about the Vagus nerve? Fig. 17.9 o 12 pairs of cranial nerves primarily serve the head & neck