Question | Answer |
Chapter 10: Muscle Tisssue
There are 3 types of muscles in the body: | 1. Skeletal
2. Cardiac
3. Smooth |
Properties of Muscle Tissue | Excitability – input receptive
Contractility
Elasticity: tension is not a problem
Extensibility: stretching is all good |
Functions of Skeletal Muscle Tissue | Body movement
Maintenance of posture
Temperature regulation
Storage and movement of materials
Support |
Endomysium: | _______ layer that surrounds and electrically insulates each muscle fiber |
Perimysium: | Surrounds the ________
Dense irregular connective tissue |
Epimysium: | Surrounds the entire muscle
Dense irregular connective tissue
Deep fascia surrounds each muscle and separates muscles from each other
Superficial fascia separates muscle from skin |
Muscle Attachments: | The less moveable point of attachment is called the origin
The more moveable point of attachment is called the insertion |
Skeletal Muscle Anatomy:
There are 2 main structures that are unique to muscle fibers: | Transverse tubules (T-tubules): Deep passageways of the sarcolemma that extend into the cytoplasm
Form a network of tubules that enables muscle impulses to spread quickly internally
Terminal cisternae: Blind sacs of the sarcoplasmic reticulum
Two te |
Muscle Fiber/Cell components:
Myofibrils | Has contractile properties
Is a long cylinder
Made of myofilaments.
Have the ability to shorten, resulting in contraction of the muscle fiber |
Myofibrils and Myofilaments: | Myofilaments
Thick filaments:
Composed of bundled molecules of myosin
Myosin molecule has a head and elongated tail
The heads form crossbridges with the thin filaments during contraction |
Myofilaments slide #2: | Thin filaments:
Composed 2 actin molecules twisted into a spiral shape (helix).
Two regulatory proteins are also part of the thin filament:
Tropomyosin
Troponin |
sarcomere : | is the functional contractile unit in a skeletal muscle fiber
Defined by the area between two adjacent Z discs/Z – lines
“From Z-line to Z-line” = ______
Myofibrils contain multiple and repeating sarcomeres
Sarcomeres shorten, and thus the muscle |
Components of the Neuromuscular Junction: | Synaptic knob: Expanded tip of an axon
Synaptic vesicles: Membrane sacs filled with acetylcholine (ACh)
Motor end plate: Region of sarcolemma that has folds and indentations to increase the surface area covered by the synaptic knob
Synaptic cleft: Narr |
Mechanism of contraction: | A nerve impulse causes ACh to be released into the synaptic cleft
ACh binds to receptors in the motor end plate initiating a muscle impulse along the sarcolemma and T-tubule membranes
Spread of the impulse down T-tubules causes Ca++ to leak out of termi |
Mechanism of contraction cont...: | Calcium ions bind to troponin, causing tropomyosin to uncover active sites on G-actin
*Basically Ca allows thick filaments to bind to actin.
Myosin heads bind to actin and form crossbridges
In the presence of ATP, myosin cycles through attachment, piv |
Muscle tone : | refers to the constant tension in a resting muscle
Motor units are stimulated randomly to avoid fatigue |
2 types of muscle contraction: | 1. Isometric contraction: Length is constant; tension is changing
2. Isotonic contraction: Tension is constant; length is changing
Concentric contraction: Muscle is shortening
Eccentric contraction: Muscle is lengthening |
Chapter 14 Nervous System:
Nervous System Intro
What is the function?
Perception and response system
Integrates information
Examples…
External Stimuli?
Internal Stimuli? | Made possible by neurons – can conduct signals respond to other neurons chemically. |
What’s it doing in the Nervous system?: | It connects with the brain and spinal cord.
Brings impulses to and fro
Examples
Sense organs to the eyes
Impulses from CNS to muscles and glands
12 cranial nerves
31 spinal nerves |
Structural Organization: Central and
Nervous system has 2 subdivisions: | The brain and spinal cord is the _Central______
The ____Peripheral Nervous Systems:______ Includes the cranial |
Cranial nerves originate from the ___ | brainstem |
Spinal nerves originate from the ___ | spine cord |
Somatic sensory- | General senses such as touch, pain, pressure, vibration, and proprioception |
Visceral sensory- | Impulses from viscera |
Somatic motor- | Impulses from the CNS that cause paralysis______________. |
Autonomic motor- | transmit impulses to smooth muscle, cardiac, and glandular tissue. |
Glial cells- | Nonexcitable cells that support and protect the neurons |
Neuron Anatomy
“The List”
Cell Body containing:
Nissl bodies (chromatophilic | RER (protein syn) and microtubules
Nucleus and Nucleolus |
Nuclei/Nucleus- | a cluster of neuron cell bodies in the CNS |
Ganglion (“swelling”)/ganglia - | a cluster of neuron cell bodies in the PNS |
Functional Neuron Classification: | Sensory (afferent):
Af - toward
Motor (efferent): Ef - away
Interneurons: Facilitate communication between sensory and motor neurons |
4 types of glial cells in CNS | 1. Astrocytes
2. Ependymal cells
3. Microglial cells
4. Oligodendrocytes |
Microglial Cells- | Small motile cells
Patrol the CNS and respond to infection
Phagocytic role thus similar to macrophage. |
Oligodendrocytes- | Associated with CNS axons only
Wrap themselves around the axons like electrical tape wrapped around a wire
Produce myelin, which insulates the nerve impulses |
2 types of glial cells are found in the PNS: | 1. Satellite cells
2. Neurolemmocytes |
Myelination of Axons | Affects the ability of neurons to conduct nerve impulses, also called action potentials
Myelination is the process of wrapping the axon with a myelin sheath
Formed by neurolemmocytes in the PNS and oligodendrocytes in the CNS
Serves as insulation |
Myelination Nerves | A bundle of axons running like a cable parallel to one another.
Surrounded by 3 connective tissue wrappings
Endoneurium: Around each axon
Perineurium: Around individual fascicles
Epineurium: Around the entire nerve |
Synapses – “a joining together”
A junction point between one axon and another neuron, muscle cell, or gland cell
A typical synapse consists of: | Pre-synaptic neuron
Post-synaptic neuron
Synaptic cleft |
Chapter 16 Spinal Cord:
Gross Anatomy – parts of the Spinal Cord | 1. Cervical
2. Thoracic
3. Lumbar
4. Sacral
5. Coccygeal
Each associated with a spinal n. pair.
Parts cont..
The end part that tapers = conus medullaris
More distally, the nerve roots resemble a horse’s tail |
cauda equina- | project from the spinal cord |
filum terminale- | which is a thin strand of pia mater that helps anchor the conus medullaris to the coccyx |
Epi-dural space: | Lies between the dura mater and periosteum covering the inner walls of the vertebra
Houses areolar connective tissue, blood vessels, and fatty connective tissue for padding. |
Dura mater: | Dense CT is in contact with bone
Forms a tube like wrap around the spinal cord. |
Arachnoid mater: | is deep to the dura mater and the subdural space |
Subarachnoid space: | b/t the arachnoid mater and the pia mater is the CSF zone. |
Pia mater: | Innermost meninx that adheres directly to the spinal cord
Highly vascularized thus it helps to support the vessels of the spinal cord. |
Gray Matter: | Dendrites and cell bodies of neurons, unmyelinated axons, and glial cells |
White Matter: | Myelinated axons in tracts of sensory and motor neurons. |
Centrally located in spinal cord
Sectioned shape the letter “H”
Subdivided into: | Anterior Horns
Lateral Horns
Posterior Horns
Gray Commissure – the cross bar of the H
Central canal - *continuous with ventricle system. What is it filled with? |
Partitioned into three regions, each called a funiculus: | Posterior funiculus
Lateral funiculus
Anterior funiculus
Anterior funinculi connected by the white commissure |
Spinal Nerves – PNS
Made up of motor and sensory axons
Contain connective tissue wrappings: | Endoneurium- Around each axon.
Perineurium- Around individual fascicles
Epineurium- Around the entire nerve |
Posterior rootlets- | rootlets are derived from a single posterior root |
Posterior roots- | contain sensory axons only |
the posterior root ganglion- | which is attached to the posterior root |
Nerve Plexuses- | is a network of interweaving anterior rami of spinal nerves
The anterior rami of most spinal nerves form nerve plexuses
Plexuses split into multiple named nerves that inn body structures
Ex: Brachial plexus |
Reflexes- | are rapid, automatic, involuntary reactions of muscles or glands to a stimulus
A stimulus is required to initiate a response to sensory input
A rapid response requires that few neurons be involved and synaptic delay be minimal |
Reflex arc- | arc is the neural wiring of a single reflex
Always begins at a receptor (sensory neurons) in the PNS
Communicates with the CNS
Ends at a peripheral effector (organ)
Ex: skeletal muscle |
Stretch reflex- | knee-jerk
(Monosynaptic) Sensory axons synapse directly on motor neurons, whose axons project to the muscle (effector) |
Withdraw reflex- | (Polysynaptic) More complex pathways that exhibit a number of synapses involving interneurons within the reflex arc |
Chapter 18 Autonomic Nervous System:
somatic nervous system (SNS)- | includes processes that are perceived (sensory) or controlled consciously “skeletal muscle” – voluntarily |
autonomic nervous system (ANS)- | includes processes regulated automatically subconscious level |
ANS Motor PW w/ neurons
1st neuron- | is the preganglionic neuron, and its cell body is in the brain or spinal cord |
preganglionic axon- | extends to the second cell body housed within an autonomic ganglion in the peripheral nervous system |
2nd neuron- | is called a postganglionic neuron |
postganglionic axon- | extends from its cell body to the target |
Parasympathetic division- | Conservation of energy and replenishment of nutrient stores (“rest-and-digest”); maintains homeostasis
Constant set parameters |
Sympathetic division- | Preparation of body for emergencies (“fight-or-flight”); increased alertness and metabolic activity – excitement, etc., |
preganglionic neurons- | are located in cranio-sacral zone/division
Brainstem and sacral regions |
Autonomic ganglion - | synapse b/t the pre and post - is close to or built into the organ wall – in the wall of the organ it controls – the so called target organ. |
thoracolumbar division- | are housed between first thoracic (T1) and second lumbar (L2) of the spinal cord.
Originate from lateral horns
Autonomic ganglion is in the sympathetic trunk (and pre-vertebral) |
sympatho-adrenal medulla pathway- | involves the adrenal medulla
This is the internal region (medulla) of adrenal gland that releases hormones within the bloodstream to help promote fight-or-flight response
The hormones are epinephrine and norepinephrine
Prolongs the “fight-or-flight res |
Autonomic function : | is influenced by the:
Cerebrum |
Hypothalamus- | oversees the brainstem and the spinal cord
Controls viscera
Can regulate emotional response – fight-or-flight |
Brainstem- | Controls visceral reflexes |
Spinal cord | Controls lower level reflexes |
Chapter 19 Sensory Receptors
General senses : | temperature, pain, touch, stretch, and pressure |
Special senses : | gustation, olfaction vision, equilibrium, and hearing |
Structures that detect stimuli | Can be structurally complex (the eye) or very simple (dendritic endings in the nose)
Sensory impulses may terminate in the cortex and then they are consciously interpreted. |
transducers- | where they change one form of energy into another |
Receptors | can be tonic or phasic
Basis of sensory adaptation |
Tactile Receptors
Located in the dermis and subcutaneous layer of the skin
2 types: | 1. Unencapsulated: Endings not wrapped in connective tissue or glial cells- skip
2. Encapsulated: Endings wrapped in connective tissue or glial cells |
Gustatory cells | are taste receptors located in specialized organs called taste buds |
Taste buds | are located on the dorsal aspect of the tongue in epithelial and connective tissues elevations called papillae |
4 types of papillae | 1. Filiform papillae – threadlike; ant. 2/3rds
2. Fungiform papillae – knob-like; tip and sides.
3. Vallate papillae – largest & least numerous
4. Foliate papillae – back on sides |
Papillae and Taste Buds of the Tongue: | Each taste bud is composed of numerous cells called gustatory cells, which are enclosed in supporting cells
Each gustatory cell has a dendritic ending (free dendritic nerve ending) called a gustatory microvillus or taste hair
The taste hair pokes out th |
5 taste sensations include: | 1. Sweet
2. Salt – ions like Na+ & K+
3. Sour – acids
4. Bitter – alkaloids like “dark” chocolate
5. Umami – related to amino acids like glutamic acid – “meaty” flavor. |
Olfaction: | The sense of smell
Detect odors |
Olfactory epithelium: Consists of 3 distinct cell types – in nasal cavity | 1. Olfactory receptor cells (nerves)
in nasal mucosa
2. Supporting cells
3. Basal cells – a kind of neural stem cell |
Olfactory Pathways for Axons: | Axons (CN I axons) from neurons of the nasal mucosa pass through the foramina (holes) of the cribriform plate (ethmoid) and enter the olfactory bulbs |
Olfactory Pathways for Neurons: | Neurons within the olfactory bulbs project axon bundles, called olfactory tracts, to the olfactory cortex of the temporal lobe |
Vision | The receptors for vision reside in the eye
These photoreceptors are capable of detecting light, color, and movement
There are accessory structures of the eye that prevent foreign objects from coming in contact with the eye and ensure that the surface of |
External Eye Accessory Structures: | Eyebrows – cuts down on sweat issues
Eyelashes
Eyelids are movable anterior protective covering for the eye
Tarsal glands (sebaceous gland) are located within both eyelids; help prevent tear overflow and keep the eyelids from sticking together |
Conjunctiva: | lines the anterior surface of the eye (but not the cornea) and the inner surface of the eyelid
This is a major zone for moistening the eye via built in goblet cells & blood supply deliver to the sclera |
Lacrimal Apparatus- | Produces, collects and drains lacrimal fluid (tears) from the eye
F(x):
-Lubrication
-Contain the enzyme lysozyme |
Lacrimal Apparatus
Consists of the following components: | Lacrimal caruncle: Contains modified sweat glands – on the medial aspect of eye
Lacrimal puncta: Small “holes” in the caruncle
Lacrimal canaliculus: Drains lacrimal fluid into lacrimal sac
Nasolacrimal duct: Receives tears from the lacrimal sac and dra |
Fibrous Tunic
Composed of 2 regions:
Cornea: | Transparent, avascular layer that receives oxygen and nutrients from lacrimal fluid and aqueous humor; Helps bend light into the eye |
Sclera: | Makes up the majority of the fibrous tunic; considered the “white” of the eye and allows for the attachment of the extrinsic eye muscles to the eye |
Retina: | Pigmented layer – next to middle choroid
Provides nutrient and waste exchange plus provides Vit. A to neural layer
Neural/photo layer – transducing layer
Has the photoreceptors
Rods (dim light receptors)
Very numerous & located on the peripheral ma |
optic disc : | is a “blind spot” on the retina
Located where ganglion cell axons exit retina to form optic nerve (CN II) and retinal arteries and veins enter and exit the retina
Lacks photoreceptors |
fovea centralis | is an area of retina that contains the highest proportion of cones and almost no rods
Area of sharpest vision |
Visual Pathways | pathway between light input and the perception of vision:
Light is detected by photoreceptors in the neural layer.
Stimulus to other nerves and ganglion cells
Axons of the ganglion cells form the optic nerve.
Ultimately, from the thalamus, axons proj |
Chapter 27 Urinary System:
Urinary Organs: | Ureters – carry urine from the kidney to the bladder
Urethra that conducts urine to the environment |
Coronal section of kidney | kidney is divided into an outer renal cortex and an inner renal medulla renal cortex, called renal columns, project into the renal medulla and subdivide the medulla into renal pyramids (medullary pyramids)
A typical kidney contains 8 to 15 renal pyramid |
Other Coronal kidney section | Each renal papilla projects into a hollow funnel-shaped structure called the minor calyx
Several minor calyces fuse to form a major calyx
The major calyces fuse to form the renal pelvis, which collects the total urine output from one kidney and transpor |
Blood Supply to the Kidney | structure called the renal corpuscle and form a tuft (ball) of capillaries called the glomerulus
Some plasma is filtered out of the capillaries into the capsular space within the renal corpuscle.
The remaining blood exits the glomerulus and the renal co |
Nephrons | functional filtration unit of the kidney
Each nephron consists of a renal corpuscle, a proximal convoluted tubule, a nephron loop, and a distal convoluted tubule
There are two types of nephrons:
Cortical nephrons: About 85% of all nephrons; the bulk of |
Renal Corpuscle - part of the nephron
Composed of two structures: | Glomerulus: a specialized mass of fenestrated capillaries
Glomerular capsule (Bowman’s): An epithelial capsule surrounding the glomerulus |
Renal Corpuscle - part of the nephron prt2: | Has a vascular pole, where the afferent arteriole enters and the efferent arteriole exits,
Has a tubular pole, where the proximal convoluted tubule exits |
PCT | Begins at tubular pole of renal corpuscle
Walls are composed of simple cuboidal epithelium with tall microvilli
Cells reabsorb almost all nutrients leaked through the filtration membrane |
Nephron Loop
The nephron loop (loop of Henle) projects into the medulla and contains 2 parts: | Descending limb: Extends from the cortex into the medulla
2. Ascending limb: Returns from medulla into cortex
Both parts involved in reabsorption of water and solutes |
Distal Convoluted Tubule | Found in renal cortex
Secretes K+ and H+ from peritubular capillaries into tubular fluid
Responds to ADH and aldosterone
For example, increasing levels of these hormones will increase water and sodium reabsorption in the DCT |
Urinary Tract
Composed of the following components | Ureters
Urinary bladder
Urethra |
Urinary Bladder | The posteroinferior triangular area of the urinary bladder is called the trigone
It is defined by the two ureteral opening and the urethral opening |
Urethra | is a fibromuscular tube that originates at the neck of the urinary bladder. |
cont... Urethra prt 2 | conducts urine to the exterior of the body
2 sphincters control the release of urine from the urinary bladder in to the urethra:
Internal urethral sphincter
External urethral sphincter |
Female Urethra: | The female urethra transports urine out of the body |
Male Urethra | male urethra has urinary and reproductive functions because it serves to transport both urine and semen
The male urethra is partitioned into 3 segments:
Prostatic urethra
Membranous urethra
Spongy urethra
Ends as an opening called the external urethr |