Exam 2 Flashcards
1
Q
What is an articulation? (2)
A
Site where two or more bones meet (joint)
Give the skeleton mobility and stability
2
Q
What is functional classification?
A
Based on the amount of movement occurring at the joint
Includes synarthroses, amphiarthroses, and diarthroses
3
Q
Synarthroses (& examples)
A
Nonmovable
Tooth to jaw, sutures, costochondral joints, epiphyseal plates
4
Q
Amphiarthroses (& examples)
A
Slightly movable
Articulation between radius and ulna, between the tibia and fibula, pubic symphysis, intervertebral disc articulations
5
Q
Diarthroses (& examples)
A
Freely movable
Hinge (knee), Pivot (alatoaxial), ball and socket (hip, shoulder), saddle (between carpal and first metacarpal), condylar (metacarpo-phalangeal) joints
6
Q
+Diarthroses further classifications
A
Diarthroses are classified as uniaxial (for movement in one plane), biaxial (for movement in two planes), or multiaxial joints (for movement in all three anatomical planes).
7
Q
+Uniaxial, biaxial and multiaxial joints
A
A uniaxial joint only allows for a motion in a single plane (around a single axis). The elbow joint, which only allows for bending or straightening, is an example of a uniaxial joint.
A biaxial joint allows for motions within two planes. An example of a biaxial joint is a metacarpophalangeal joint (knuckle joint) of the hand.
A joint that allows for the several directions of movement is called a multiaxial joint This type of diarthrotic joint allows for movement along three axes. The shoulder and hip joints are multiaxial joints.
8
Q
What is structural classification?
A
Based on what tissue type binds the bones together
Includes fibrous joints, cartilaginous joints, and synovial joints
**Further classified by joint shape
9
Q
Fibrous joints
A
Held together by dense regular connective tissue, holds bones in close contact
3 types: syndesmosis, suture, gomphosis
10
Q
Syndesmosis
A
2 long bones bound by a sheet or bundle of dense connective tissue
Amphiarthrotic - flexible, may twist
11
Q
Gomphosis
A
Cone-shaped bony process in a socket in jawbone - maxilla and mandible
Synarthrotic - immovable
12
Q
Suture
A
Between flat bones of skull
Thin layer of connective tissue (sutural ligament) connects bones
Synarthrotic - immovable
13
Q
Cartilaginous tissue types
A
Synchondrosis and Symphysis
14
Q
Synchondrosis
A
Bands of hyaline cartilage unite bone
Some are temporary: epiphyseal plate
Some are permanent: between manubrium and first rib only - synarthrotic
15
Q
Symphysis
A
Pad of fibrocartilage between bones
Amphiarthrotic: limited movement by joint compression
Pubic symphysis, between bodies of adjacent vertebrae (intervertebral discs)
16
Q
Synovial Joints
A
(all diarthroses)
Bones are separated by a fluid filled joint cavity
Very movable; joints of the limbs, most joints of the body
17
Q
List the 5 Distinguishing Features of synovial joints
A
Articular cartilage, a joint (synovial) cavity, synovial fluid, a joint capsule, and reinforcing ligaments
18
Q
Articular cartilage
A
Hyaline cartilage found on the ends of long bones (provides smooth surface, reduces friction, absorbs shock)
19
Q
Joint (synovial cavity)
A
Space that surrounds joint (filled with synovial fluid)
20
Q
Synovial fluid
A
Reduces friction, nourishes cartilage cells
21
Q
Joint (articular) capsule
A
Encloses the joint
Composed of a fibrous capsule and a synovial membrane
22
Q
Fibrous capsule
A
Outer layer of joint capsule
Composed of dense irregular connective tissue
23
Q
Synovial membrane
A
Lines inside of fibrous capsule
Produces synovial fluid
24
Q
Reinforcing ligaments
A
Can be found inside and outside of joint cavity
Can form part of the joint capsule
25
Other structures associated with synovial joints
Bursae (bursa sacs) and tendon sheaths
26
Bursae
Sacs filled with synovial fluid that reduce friction
27
Tendon sheaths
Elongated bursae which wrap around tendons, reduce friction
28
The types of synovial joints are...
Ball and socket joint, condylar joint, plane joint, hinge joint, pivot joint, saddle joint
29
Ball and socket joint
Ball and cup shaped cavity
Widest range of motion
Multiaxial, plus rotation
Least stable
30
Condylar joint
Oval condyle fits into elliptical cavity
Back and forth, side to side movements
No rotation
Example: between radius and carpals
31
Plane Joint
Also called gliding joint
Almost flat, or slightly curved
Back and forth, gliding and twisting
Example: between carpal bones
32
Hinge joint
Convex surface fits into concave surface of other bone
Uniaxial movement (in 1 plane)
Example: elbow, knee, ankle, interphalangeal joints
33
Pivot joint
Cylindrical surface rotates within ring of other bone
Rotation only
Example: between axis and atlas
34
Saddle joint
Both bones have concave and convex surfaces
Biaxial movement (in 2 planes)
Example: between trapezium and first metacarpal
35
How to classify fractures
Displaced vs nondisplaced fractures
(displaced - ends out of alignment)
Incomplete vs complete
(complete - bone broken through)
Simple (closed) vs compound (open)
(compound: bone is exposed to outside through opening in skin or mucous membrane
36
Greenstick fracture
Incomplete, and the break occurs on the convex surface of the bend in the bone
37
Fissured fracture
Incomplete, longitudinal break
38
Comminuted fracture
Complete, and fragments the bone
39
Transverse fracture
Complete, and the break occurs at a right angle to the axis of the bone
40
Oblique fracture
Occurs at an angle other than a right angle to the axis of the bone
41
Spiral fracture
Caused by excessive twisting of a bone
42
Simple fracture repair steps (explain in detail)
Fracture needs to be reduced (realigned) and then immobilized
1) Hematoma - Large blood clot
Blood escapes from ruptured blood vessels and forms a hematoma
2) Fibrocartilage callus - fibroblasts and chondrocytes form callus reconnecting broken ends
Spongy bone forms in regions close to developing blood vessels, and fibrocartilage forms in more distant regions
3) Bony callus - osteoblasts invade, hard callus fills space
A hard (bony callus) replaces fibrocartilage
4) Remodeling - Bone restored close to original shape and structure
Osteoclasts remove excess bony tissue, restoring new bone structure like original
43
Temporomandibular Joint
Formed by the mandibular condyles of the mandible and the mandibular fossae of the temporal bones
44
++TMJ additional
This small, complex articulation is the only movable joint between skull bones.
Loose articular capsule surrounds joint and promotes extensive range of motion
POORLY stabilized, forceful anterior or lateral movement of mandible can result in partial or complete dislocation of mandible.
Joint contains an articular disc, thick pad of fibrocartilage separating the articulating bones and extending horizontally to divide the joint cavity into 2 separate chambers.
Really 2 synovial joints, one between temporal bone and articular disc, second between articular disc and mandible
45
Shoulder (glenohumeral) Joint
Most moveable joint in the body
Formed by the head of the humerus and the glenoid fossa (cavity) of the scapula
46
Associated structures of the shoulder joint?
Glenoid labrum, ligaments of the shoulder, rotator cuff muscles
47
Glenoid labrum
Rim of fibrocartilage which deepens the joint cavity
48
Ligaments of the shoulder
Help stabilize the shoulder (relatively little)
Major ligaments associated with shoulder include:
glenohumeral, acromioclavicular, coracoclavicular, coracoacromial ligaments
49
Rotator cuff muscles
Major mole in stabilizing the shoulder joint
Supraspinatus, infraspinatus, teres minor, subscapularis work as a group to hold the head of the humerus in the glenoid cavity
++The tendons of these ligaments encircle the joint (except inferior portion) and fuse with articular capsule. because inferior portion lacks rotator cuff muscles, area is weak and most likely site of injury
50
Hip (coxal) Joint
Very strong, stable joint
Formed by the head of the femur and the acetabulum of the coxal bone
51
++Hip Joint stability
Much stronger and more stable than that of glenohumeral joint.
Secured by a strong articular capsule, which extends from the acetabulum to trochanters of femur, preventing head from moving away from acetabulum
52
associated structures of the hip?
Acetabular labrum and ligaments
53
Acetabular labrum
Circular rim of fibrocartilage that helps deepen the joint cavity
54
Ligaments of the hip
Major ligaments associated with the hip include the ligaments of the joint capsule and ligament of the head of the femur (ligamentum teres)
55
Ligaments of the joint capsule
Thickenings of the joint capsule that help strengthen the coxal joint
56
Ligamentum teres (and role)
Attaches the head of the femur to the acetabulum
Plays no role in strengthening the coxal joint
Contains an artery that helps supply oxygenated blood to the head of the femur, damage to this artery can result in arthritis
57
Knee Joint
Most complex joint in the body
Formed by the medial and lateral condyles of the femur and the medial/lateral articular surfaces (condyles) of the tibia
2 joints: tibial and femoral condyles and also patellar surface of femur and patella
58
What does knee joint allow?
For some rotation and gliding when flexed
59
associated structures of the knee?
menisci, ligaments, and bursae
60
Menisci (medial and lateral)
Fibrocartilage discs located between the tibial condyles and femoral condyles
Help deepen the joint cavity and help absorb shock
61
Ligaments of the knee
Help stabilize the knee joint
Major ligaments associated include the patellar, medial collateral, lateral collateral, anterior cruciate and posterior cruciate ligaments
62
Patellar ligament (and what it attaches)
Continuation of the patellar tendon
Attaches the quadriceps to the tibial tuberosity of the tibia
Used to test knee-jerk reflex
63
Medial (tibial) collateral ligament (attachments and function)
Proximal attachment: medial epicondyle of the femur
Distal attachment: medial tibia
Function: strengthens the knee joint medially
64
Lateral (fibular) collateral ligament (attachments and function)
Proximal attachment: lateral epicondyle of the femur
Distal attachment: head of the fibula
Function: strengthens the knee joint laterally
65
Anterior cruciate ligament (attachments and function)
Proximal attachment: lateral condyle of the femur
Distal attachment: anterior portion of the intercondylar eminence
Function: prevents anterior sliding of the tibia on the femur and hyperextension of the knee
66
Posterior cruciate ligament (attachments and function)
Proximal attachment: medial condyle of the femur
Distal attachment: posterior portion of the intercondylar eminence
Function: prevents posterior sliding of the tibia on the femur and hyperflexion of the knee
67
Bursae
Help reduce friction
Number of bursae associated with knee joint (like prepatellar bursa)
68
Sprain
When ligament is stretched or torn
Heals very slowly
69
Dislocation
Bones forced out of alignment
70
The 3 types of muscle tissue
Skeletal, cardiac, smooth
71
What is the basis for shortening of stimulating muscle?
Sliding filament mechanism
Myosin filaments bind to and move actin filaments
72
Skeletal Muscle Tissue
Attached mainly to bones, striated, voluntary
Cells are long, cylinder like, multinucleated
73
Cardiac Muscle Tissue
Found in heart, striated, involuntary
74
Cardiac muscle cells
Shorter in length than skeletal muscle fibers and are branched
Have many intercalated disks, contains gap junctions
75
Smooth Muscle Tissue
Located in the walls of hollow organs and blood vessels, nonstriated, involuntary
Very different from skeletal and cardiac muscle tissue
76
Name the 4 Unique Characteristics of Muscle
1) Excitability
2) Contractability
3) Extensibility
4) Elasticity
77
Excitability (for each type of muscle tissue)
Like neurons, muscle cells can respond to a stimulus with a change in Vm
Stimulus = varies by muscle type
Skeletal muscle - release of neurotransmitter from motor neuron
Cardiac - depolarization from AR cell
Smooth - reflex/NT release/spontaneous
78
Contractability
Ability to shorten forcefully - actively generates force
consumes large amounts of ATP and generates heat
79
Extensibility
When muscles are relaxed they can be stretched like a rubber band without damage
80
Elasticity
After stretching muscles cell recoil back to their origin resting length
81
What two functions passively generate force in muscle contraction?
Extensibility and elasticity
No ATP is consumed, but force is generated by elastic properties of muscle tissue (like a rubber band)
82
Name the functions of Muscle Tissue
Movement, Posture/protection, Blood Pressure/Flow regulation, generates heat
83
How is muscle tissue involved in movement?
Skeletal: Walking, running, assisting venous return
Cardiac: pumps blood in heart
Smooth: propels food in digestive system and lymph in lymphatic system
84
How is muscle tissue involved in posture/protection?
Skeletal: maintains posture and abdominal wall
85
How is muscle tissue involved in blood pressure/flow regulation?
Smooth: vasodilation/constriction matches blood flow to metabolic rate with maintaining system BP
86
How is muscle tissue involved in generating heat?
Skeletal: Heat is generated during the process of muscle contraction, through voluntary movement and shivering
87
The 3 layers of connective tissue associated with skeletal muscles
Epimysium, perimysium, endomysium
All 3 layers of connective tissue are continuous with one another and help form the tendons of muscle
88
Epimysium
Layer of dense irregular connective tissue that surrounds the entire external surface of a muscle
89
Perimysium
Layer of dense irregular connective tissue that surrounds each fascicle (group of muscle fibers)
Also contains blood vessels
90
Endomysium
Layer of areolar connective tissue that surrounds each muscle fiber; also contains blood vessels
muscle fiber = muscle cell
++ Contains reticular fibers to help bind together muscle fibers and support capillaries near these fibers
91
Muscle cells structure
Highly specialized plasma membrane is the sarcolemma.
Contains capillaries, nuclei and transverse tubules
Carry electrical signals deep into muscle cell
92
Sarcoplasm (and what it contains?)
Cytoplasm of a muscle cell, also highly specialized.
Contains high amounts of:
- glycogen (storage form of glucose)
- myoglobin (red pigment that stores O2 in muscle cells)
- Mitochondria (high demand for ATP)
OF course, myofibrils as well.
93
Myofibrils
Composed of contractile units (sarcomeres) linked together end-to-end
94
2 types of myofilaments
Thick (myosin) and thin (actin)
95
Thick myofilaments (and structure)
Composed of the protein myosin
Resembles 2 golf clubs twisted together
Each myosin protein has a tail and several head groups.
Active portion of sarcomere- contains ATPase activity
96
Myosin Tail
2 intertwined heavy chains
Structured
97
Myosin head groups
4 light chains form a globular head
Binding sites - 2 for ATP and 2 for thin filament
98
How is the cross bridge formed?
Head group of myosin forms "cross bridge" with active sites thin filament
Uses ATPase activity to hydrolyze ATP to "pull" thin filament
99
Thin Myofilaments
Composed of the proteins actin, tropomyosin, and troponin.
Thin filament = regulatory protein of sarcomere
100
Actin (and structure)
Structural portion of thin filament
2 intertwined strands of g-actin = forms f-actin
Each molecule has a myosin binding site (active site)
101
Tropomyosin
String like protein
Covers the myosin binding sites on actin when a muscle cell is at rest
102
Troponin (and its units)
Contains 3 subunits
Troponin T: moves tropomyosin
Troponin I: Hold troponin complex in place
Troponin C: Binds Ca2+
103
What moves tropomyosin away from active sites?
Ca2+ is trigger to move tropomyosin away from active sites, and initiates cross-bridge formation
104
Sarcomere Structure
each sarcomere extends from Z line to next Z line and contains:
I (isotropic) band: contains only thin myofilaments and titin protein bisected by Z line
A band: overlapping thin and thick myofilaments
H zone: contains only thick myofilaments
M line: Middle of H zone, contains proteins that anchor thick myofilaments in center of sarcomere
105
How many actin filaments can each myosin interact with?
Each myosin interacts with 6 actin filaments.
106
How many myosin filaments can each actin interact with?
Each actin can interact with 3 myosin filaments.
107
Sarcoplasmic Reticulum (function only)
Stores Ca2+
Plays critical role in muscle contraction
108
SER structure
Dilated ends of SR are called terminal cisternae - located on both sides of a T tubule
109
Transverse tubules
Infoldings of the sarcolemma
110
What makes a triad?
T tubules and terminal cisternae
111
NMJ
specialized synapse between a motor neuron and the sarcolemma of a muscle cell
112
Synaptic cleft
Space between the motor neuron and sarcolemma
113
Presynaptic terminal
Terminal portion of motor neuron
Release neurotransmitters - chemical messengers of the nervous system that open or close ion channels
114
What are neurotransmitters stored in?
Synaptic vesicles
115
Postsynaptic membrane
region of sarcolemma located at NMJ
Deepening of membrane: motor end plate
High density of acetylcholine receptors, folds to increase SA
116
Motor units
Control contraction
Single motor neuron and all of the muscle fibers it controls
117
Innervation ratio
Number of neurons: fibers
118
High vs low innervation ratio
High (1:1)
Fine motor control
Weak response
Low (1:100)
Low motor control
Strong response
119
Sliding filament model
Thick and thin myofilaments slide past one another and cause sarcomeres to shorten
120
Explain the steps (mechanism) of muscle contraction - part 1
*stop at opening of Ca2+ on terminal cisternae of SR
Action potential (nerve impulse) travels through neuron reaches presynaptic terminal
Opening of Ca2+ channels at presynaptic terminal (driven by gradient)
Release of NTs from pre-synaptic terminal
- Ca2+ causes synaptic vesicles to fuse with plasma membrane, acetylcholine enters cleft, crosses, binds to acetylcholine receptors (AchR) on the postsynaptic membrane
Action potential travels along sarcolemma, enters T-tubules
Results in opening of Ca2+ channels located on terminal cisternae of SR
121
Explain the steps (mechanism) of muscle contraction - part 2
Ca2+ flows out of SR into sarcoplasm
Binds to troponin C
Pulls tropomyosin away from active sites on actin
Myosin heads now bind to actin (cross-bridge formation)
Energized myosin heads swivel and pull thin myofilaments closer (shortens sarcomere)
122
At rest, the myosin heads are...
energized, ATP = already hydrolyzed
123
Sarcomere shortening
Myosin head pulls on actin
124
Cross Bridge Release
New ATP molecule binds myosin head groups
Sarcomere returns to resting length
Only way to release myosin head
125
Rigor Mortis
We die, cells begin to undergo autolysis
Leaking of Ca out of SR
Ca2+ binds to troponin, triggers the binding of the myosin heads to actin
ATP not made, so myosin cannot be released from actin
results in stiffness, last 24 hours until tissues begin to die
126
Termination of Muscle Contraction
Cessation of motor neuron APs = no Ach release
Synapse Ach level decrease
Diffusion out of synapse
Acetylcholinesterase
Cessation of Ca2+ release from SR, pump Ca2+ back into SR
127
Muscle Fiber - Type 1
(slow oxidative)
High oxidative capacity
Myoglobin and mitochondria
Low ATPase activity
Postural muscles
128
Muscle Fiber - Type 2a
(fast oxidative)
High oxidative/intermediate glycolytic capacity
Some myoglobin
Higher ATPase activity
Walking
129
Muscle Fiber - 2b
(fast glycolytic)
Highest ATPase/glycolytic capacity
Jumping/sprinting
130
Where are the muscle fibers located? For postural muscles, or large muscles?
all 3 types in a skeletal muscle
Postural muscles: predominantly Type 1
Large muscles: predominantly Type 2b
Amount of tension needed determine which fibers will be recruited - all 3 contribute overall tension
131
Major Functions of the Nervous System
Receive information on body position/environment
Decide on/coordinate response = stimulate muscles or glands to maintain homeostasis
(some voluntary some autonomic)
132
2 cell types in neural tissue
Neurons: send/receive nerve impulses for communication, integrate and relay information
Neuroglia: surround and support neurons
133
Central Nervous System
Integration center for nervous system
Process sensory info and form a division
Brain and spinal cord - dorsal body cavities
134
Peripheral nervous system (components)
connects CNS to all other body parts
cranial nerves, spinal nerves, ganglia, plexuses
135
Cranial nerves
special senses and head/eye movement, balance - 12 pairs
136
Spinal nerves
motor/sensory info to and from spine - 31 pairs
137
Ganglia
collections of neuron cell bodies in PNS
138
Plexuses
Interweaving network of anterior spinal nerves
139
The 2 main fiber types of the sensory afferent divison
Somatic (body) sensory fibers - temperature, pressure, pain, joint/muscle position.
Visceral sensory fibers -
sensory info about organs, like lung inflation level, stomach distension, etc.
140
2 branches of motor (efferent) division
Somatic nervous system - voluntary nervous system, consciously control muscle activation
Automatic nervous system - regulation activity of organs - heart muscle activity, GI tract activity, gland secretions, smooth muscle
141
Sympathetic nervous system vs parasympathetic
Fight or Flight
Increased HR/breathing, sweating, dilated pupils
Parasympathetic - rest and digest, conserve energy
142
Glia (neuroglia)
supports cells, most numerous, originally thought to be structural only
143
The glial cells of the CNS are...
Astrocytes, microglia, ependymal cells, oligodendrocytes
144
The glial cells of the PNS are...
Schwann cells, satellite cells
145
Astrocytes
support cells, most numerous of all glia, nourish neurons
Control extracellular environment of neurons
Mop up excess neurotransmitters and/or ions released by neurons
Facilitates the exchange of nutrients and waste between capillaries
Form the blood-brain barrier
146
Microglia
"immune system" of the CNS
Destroy invading cells which have entered into the CNS
Remove the remains of dead neurons
147
Why are microglia important?
Very important: white blood cells cannot excess the CNS
148
Ependymal cells
Wrap around inside of dorsal body cavities
Produce cerebrospinal fluid (CSF)
Maintains ion composition and pH of CNS tissue, ciliated: helps to circulate CSF
149
Oligodendrocytes
Form myelin sheaths around neuron processes
Increase how rapidly electrical signals travel down axon
150
Schwann cells
Similar to oligodendrocytes in CNS
Form myelin sheath in PNS
Vital to nerve regeneration (little/no CNS regeneration)
151
Satellite cells
Similar to astrocytes, maintain environment surrounding peripheral neuron
Sympathetic and parasympathetic ganglia
Enteric glia
152
Enteric glia
Also like astrocytes - repair intestinal epithelium
153
Amitotic
Neurons are amitotic: Formed during embryonic development, most do not divide in adulthood
Begin as radial glia - neuron/glial progenitor cell
Two brain areas which generate new neurons in adulthood (neurogenesis) - hippocampus and subventricular zone (for olfaction)
154
Clusters of cell bodies in CNS are ...
Nuclei
Usually all have a similar function = division of labor
155
Clusters of cell bodies in PNS are ...
Ganglion
156
Cell Body of neuron
Usual organelles
Neurofilaments: microtubules that extend into axon
Grey matter
157
Dendrites
Antennae: receive info from other neurons
Contain dendritic spines-
Increases surface area of dendrites
Improves neurons ability to respond to small stimuli
158
Axons
Carry electrical signals to another neuron/effector
Occasionally have collaterals - branch points in axon, usually one one or two
159
Axon hillock
Where electrical signal is initiated
160
Axon terminal
10,000 terminal branches
Synaptic knob (boutons): release neurotransmitters
161
What is the inventory problem, in relation to neurons?
Release neurotransmitters from terminals
NTs are manufactured in cell body (RER)
162
Axonal transport
Carry substances via neurofilaments along length of axon
163
Anterograde vs retrograde transport
Anterograde: towards terminal
Vesicles containing neurotransmitters
Retrograde transport: back to soma, organelles to be recycled
164
Multipolar neurons
99% of neurons
Many processes, 1 axon, multiple dendrites
165
Bipolar neurons
1 axon and 1 dendrite
rare: eyes, ears, nose
166
Unipolar neurons
Receive sensory information
One process in T-formation from cell body
Peripheral process in PNS: dendrites
- closely associated with specialized sensory cell
Central process in CNS: axon terminals
- Sensory info is relayed to CNS
167
Afferent neuron
Usually unipolar
Transmits sensory info to CNS
Dendrites and soma are located outside CNS
- Dendrites associated with sensory receptor, soma = clustered with ganglion
Central process = much shorter
Axon terminal to enter CNS to relay sensory information to CNS neurons
168
Interneuron
Soma and processes entirely in CNS
Most abundant: 99% of all neurons
Main job: shuttle information between sensory neurons, brain, and motor neurons
In between sensors and effectors
169
Motor neurons
Carry information away from CNS out to effectors
- skeletal muscle, smooth muscle (GI) or glands
Cell body and part of axon in CBS
- axon terminal in periphery
170
The bundling of axon in PNS vs CNS
PNS = afferent and efferent axons bundle together
- nerve = axons, blood vessels, connective tissue
CNS = afferent and efferent are kept separate
- tract
171
What 2 factors determine conductance speed?
Myelination and diameter - both increase conductance speed
172
How much faster does the signal go along axon with myelin?
Impulse moves up to 30 times faster.
173
Multiple sclerosis
autoimmune = myelin is attacked by a person's own antibodies
Scars left behind, blocks electrical impulses
Without input from motor neurons, muscles stop contracting and atrophy
fatal - diaphragm atrophies and stop contracting
174
Fiber Group: A
Structure: large myelin
Function: motor neurons/pressure
Speed: 150 m/s
175
Fiber Group: B
Structure: small myelin
Function: autonomic
Speed: 15 m/s
176
Fiber Group: C
Structure: small; no myelin
Function: pain/painful heat
Speed: 1 m/s
177
4 parts of brain
Cerebrum, diencephalon, brain stem, cerebellum
178
2 tissue types of brain?
White matter and grey matter
179
White matter
Bundles of myelinated axons (tracts)
- information is transmitted
180
Grey matter
Clusters of neuronal cell bodies (nuclei)
- information is processed or relayed
181
Basic pattern of CNS tissue
tissue contained in dorsal body cavities surrounded by CSF
grey and white matter well organized into distinct region
182
Cerebrum pattern of tissue
Outer layer of grey matter called a cortex and nuclei scattered in white matter called basal nuclei
183
Gyri vs sulci
Gyri are elevations.
Sulci are grooves (deeper grooves are called fissures)
184
Deepest groove of cerebrum
Longitudinal fissure (divides the cerebrum into left and right cerebral hemispheres)
185
Central sulcus
Divides the frontal lobe from the parietal lobe
186
Lateral fissure
Separates the frontal and parietal lobes from the temporal lobe
187
Parieto-occipital sulcus
separates the parietal lobe from the occipital lobe
188
General Functions of the Cerebrum
Involved with cognitive and emotional processing (thinking)
Receives and interprets sensory inputs
Controls voluntary motor movements
189
The superficial layer of the cerebrum
Cerebral cortex
Contains regions called functional reas
190
3 kinds of functional areas are:
Motor, sensory, and association areas
191
Motor areas
Control voluntary muscular movement
Example: primary motor cortex (pre central gyrus)
192
Pre -central gyrus
Located anterior to central sulcus
Controls contraction of skeletal muscle
Specific regions of the precentral gyrus control specific muscles
193
Sensory areas
Process sensory information
pressure, pain, temperature, body position, special senses
Example: primary somatic sensory cortex (post-central gyrus) and visual cortex
194
Post-central gyrus
Located posterior of the central sulcus
Anterior parietal lobe
Receives sensory impulses (pain, pressure, and temperature) from sensory receptors located in the skin and skeletal muscle
Organized similar to pre-central gyrus
195
Visual cortex
Located on occipital lobe
Receives impulses conveying visual information
196
Association areas
Involved with integrative functions
Integrates sensory/motor areas with memory
Examples: somatic sensory association area
197
Somatic sensory association area
Located posterior to the post-central gyrus
Involved with the ability to recognize an object by touch
198
Broca's area location and function
Located on left frontal lobe just superior to the lateral fissure
Controls muscles responsible for the production of speech (initiates speech)
199
Wernicke's area location and function
Located on left parietal lobe
Involved with understanding the formulating speech
200
Diencephalon
Divided into 3 deep brain regions: thalamus, hypothalamus, epithalamus
201
Thalamus
Relay station for most sensory impulses that reach the cerebral cortex
Sorts sensory info from all parts of the body, relays info to appropriate area of cortex
Somatosensory info: post-central gyrus
Visceral input (gut) and emotion from hypothalamus
202
Hypothalamus
Located inferior to the thalamus
Controls and integrates activities of the ANS - master regulator of autonomic function, controls pituitary gland
Major role in regulating basic survival needs, feelings of rage, aggression, pain, pleasure
Water and food intake
Regulate body temperature
203
Epithalamus
Contains the pineal gland
Size of a small pea, secretes melatonin (produced during darkness)
May contribute to the setting of the sleep-wake cycle
204
Brain stem
Most primitive part of the brain: mostly control autonomic function
Contains 3 parts: midbrain, pons, medulla oblongata
Functions: relay motor and sensory impulses (pain processing)
Involved with hearing and visual reflexes
205
Pons
Contains nuclei related to cardiovascular function
Controls timing and depth of breathing
Coordinates non-breathing related airway behaviors
- coughing, sneezing, vomiting, hiccupping
relays information from cerebrum to the cerebellum
206
Medulla oblongata
regulates heart rate and blood pressure
Contains respiratory rhythm generating neurons and several central chemoreceptors (sense CO2 levels)
207
Cerebellum (old + new)
Old view: regulates coordinates skeletal muscle movements, posture, balance
New view: cognition, memory, emotion, breathing, control, learning
208
Larger cavities for CSF
Ventricles
Roofs lined with clusters of ependymal cells (neuroglia) called choroid plexuses
Produce and circulate CSF
209
Largest cavities for CSF are...
Lateral ventricles
Bilateral
Separated by septum pellucidum (thin membrane)
210
Circulation of CSF...
CSF produced in lateral ventricles flows to another fluid pocket - third ventricle via interventricular foramen
CSF then flows through thin passageway called cerebral aqueduct to fourth ventricle
CSF exits via central canal - nourish spinal cord
Also exits 2 lateral apertures and one median aperture
- enters web like network of cavities surrounding cortex - subarachnoid
211
Subarachnoid
Arachnoid mater
One of 3 protective layers surrounding cortex - meninges
212
Meninges
Cover and protect CNS
Protect underlying blood vessels
Contain CSF (similar to plasma in ion composition)
3 layers: dura mater, arachnoid mater, pia mater
213
Dura Mater
Outermost layer, extremely tough
"tough mother," 2 layers of connective tissue: Layers separate in certain areas to form pockets of venous blood called dural venous sinuses
214
Arachnoid mater
Thin layer of connective tissue on top of subarachnoid space
Web like connection anchoring membrane to brain tissue
CSF and larger arteries and veins located
Poorly protected - protection comes from dura mater
215
Pia Mater
"gentle mother," thin layer of connective tissue, plastic wrap surrounding every contour of brain, contains very small blood vessels
216
Blood Brain Barrier
Internal protection of CNS
Neuronal activity is highly dependent on a constant pH and ion composition
Still needs to exchange nutrients with blood
To protect brain from normal fluctuations in blood - hormones, ion composition, nutrient levels
We have this barrier to regulate movement of these substances into CNS - regulates what enters CSF via transporters
217
Deep Brain circulation
brain is highly vascular, requires a large and constant supply of blood and oxygen
Protective mechanism in case any large cerebral arteries get obstructed
218
Circle of Willis
Cerebral Arterial Circle
Equalize pressure between anterior and posterior of brain
