Unit 1 Flashcards
Two major tissue layers of skin
Epidermis (outer) and dermis (inner)
Epidermal layers (outer to inner)
- Stratum corneum
2-4. Three basal layers - Stratum basale
Epidermis cell type
Stratifiedvis squamous epithelial cells; keratinized
Where does epidermis get nourishment and innervation?
Epidermal layer is avascular, so it needs its nutrients and innervation from dermal layer
Dermis cell type
Dense, irregular CT filled w/ collagen and fibroblasts
Dermis contains these things that help provide it with nutrients and innervation
Blood vessels (nutrients) Nerve endings (innervation)
Hypodermis cell type
Adipose (FAT)
Skin functions
- Barrier btwn internal structure of body and external environment
- Barrier to friction and abrasion
- Waterproof (keeps out water, keeps in water)
- Screens out UV rays
- Sensory organ
- Excretory organ (eliminates urea through sweat glands)
- Thermoregulation
- Vitamin D source
Describe stratum corneum
Most superficial epidermal layer
Dead keratinized cells constantly being sloughed off and replaced by cells that gradually move outward from stratum basale
2 types of stratum corneum
Thin skin and thick skin
Thin skin is part of which epidermal layer? Give example of thin skin.
Stratum corneum
Anterior abdominal wall, eyelids
Thick skin is part of which epidermal layer? Give example of thick skin.
Stratum corneum
Palm of hands, soles of feet
Describe the intermediate basal layers of epidermis
Cells from stratum basale come to these basal layers to transform into keratinized cells
Describe stratum basale
Deepest layer of epidermis
Constant mitotic activity (cells always being made)
Name the specialized cells of epidermis
Stratum basale
- Melanocytes
- Langerhands cells
- Merkel cells
Function of melanocytes
Located in stratum basale.
Produce melanin pigments that protect deeper tissue layers from UV rays
Function of Langerhan cells
Located in intermediate basal layer (stratum spinosum).
Macrophages that eat antigens and activate immune system.
Function of Merkel cells
Located in stratum basale.
Type of sensory receptor for touch. Transmits info to sensory nerve endings in underlying dermis.
What do keratinocytes do?
They make up most of epidermis and responsible for:
- Waterproof barrier
- Barrier against friction
- Antibacterial properties
How does dermis give nutrients to epidermis?
Diffusion
2 dermal layers
- Papillary layer
2. Reticular layer
Where and what is the significance of papillary layer?
Located in dermis.
- Anchors epidermis to dermis using dermal papillae and epidermal ridges
- Contains vascular loops and nerve endings
- Diffusion
Where and what is the significance of reticular layer?
Located in dermis.
- Can see cleavage lines/tension lines/Langer’s lines
- Makes up 75% of dermal layer
Significance of cleavage lines/tension lines/Langer’s lines?
The lines correspond to natural orientation of collage fibers and are generally parallel to orientation of underlying muscle fibers.
Useful for when doctor’s need to cut through skin. They wanna cut according to the lines to help healing go faster.
True/False: Hypodermis is part of skin
False!
Where is hypodermis located?
It’s a loose CT located btwn dermis and fascia of bones
Hypodermis functions
- Helps thermoregulate and insulate
2. Cushions bony structure/absorbs shock
Derivative appendages of epidermal layer include…
- Nails
- Hair
- Sebaceous glands
- Sweat glands
Hair, subaceous glands, and sweat glands located in which layer of skin?
Dermis
Nails are derived from which epidermal layer?
Stratum corneum
Hair is derived from which epidermal layer?
Stratum basale
Sebaceous glands derived from which epidermal layer?
Stratum basale
Sweat glands derived from which epidermal layer?
Stratum basale
Arrector pili muscles associated w/ which appendage and does what?
These smooth muscles are associated w/ hair bc it helps hair stand.
That’s why we get “goosebumps”
How does innervation to skin travel?
Travels to and from spinal cord via spinal nerves and their branches, the dorsal and ventral rami.
What are dermatomes?
An area of skin that is supplied sensory/cutaneous branches from a single spinal nerve.
All innervation to skin comes from which skin layer?
Dermis
Sensory fibers from cutaneous nerves do what?
Convey sensation from skin to CNS
Sympathetic fibers from cutaneous nerves do what?
Innervate sweat glands, arrector pili muscles, and blood vessels
Skin cancers derive from cells of which skin layer?
Epidermis
Name two types of skin cancer tumors
- Basal cell carcinomas
2. Melanomas
Basal cell carinomas are…
tumors of keratinocytes of stratum basale
Which skin cancer is easiest to treat? Which is deadliest? Why?
Basal cell carcinomas contained in epidermis,
rarely spreads to other tissues (easiest)
Melanomas can spread beyond epidermis into dermis, and metastasize into lymphatic system (deadliest)
Melanomas are…
tumors of melanocytes of epidermis
Common cause of melanomas
Excessive UV radiation exposure
Classify burns based on how many layers of tissue are injured
1st degree: epidermis damaged, not destroyed
2nd degree: epidermis destroyed and also some dermis
3rd degree: epidermis and dermis destroyed, can extend into hypodermis
1st degree burns characteristics
Red, swollen, painful, but not serious. Will heal w/o scarring.
2nd degree burns characteristics
Blisters, wet/weeping, extremely painful, scarring after healing
3rd degree burns characteristics
Dry, not painful. Cannot heal, needs grafting.
The general phases of wound healing are called
- Inflammation
- Repair and proliferation
- Remodeling
What happens during the inflammation phase of wound healing?
First 4 days, lots of edema.
Fluid leaks from dermal blood vessels to allow migration of many immune cells to site of wound.
What happens during the repair/proliferation phase of wound healing?
Wound contracts and damaged edges of skin start to move closer together.
Epithelial cells proliferate to cover wound; fibroblasts make collagen to close wound and makes a scar.
What happens during the remodeling phase of wound healing?
The scar tissue will start to change to match surrounding tissues.
This happens through induction by neighboring tissues and also due to tension on scar.
OT interventions for wound healing process
- Apply PRESSURE to wound to prevent excessive abrasive forces from re-opening wound and reduce excess collagen production.
- STRETCHING collagen fibers to preserve/extend ROM and prevent contraction of scar.
Nervous tissue consists of
- Neurons
2. Neuroglia
What are neurons?
Functional cells of nervous system that conduct electrical impulses
What are neuroglia?
Cells that support and protect neurons
2 types of neurons based off of the info they carry:
- Sensory/afferent neurons
2. Motor/efferent neurons
Sensory neurons
Neurons that send info from body to the brain
Motor neurons
Neurons that send info from brain to body
Two major types of nervous system
- Central
2. Peripheral
CNS consists of
Brain and spinal cord
PNS consists of
Ganglia
Somatic sensory signal
Touch, pain, temp, pressure, vibration, proprioception
Somatic sensory target
Skin, body wall, limbs
Visceral sensory signal
Stretch, pain, temp, irritation, nausea, hunger
Visceral sensory target
Organs
Somatic motor signal
Motor info
Somatic motor target
Skeletal muscles
Visceral motor/autonomic signal
Motor info
Visceral motor/autonomic target
Cardiac, muscle, smooth muscle, glands
Neurons consist of
Cell body
Dendrites
Axons
Synapse
A group of cell bodies in CNS is called
Nuclei
A group of cell bodies in PNS is called
Ganglia
Cell body of neuron contains
Nucleus and organelles
Dendrites of neuron contains
Receptors of electrical impulses bringing them to cell body
Axons of neurons are
processes that carry electrical impulses away from cell body (only one axon/neuron)
Synapse of neuron is
A site where one neuron communicates with another neuron
Three types of neurons based off of their structure
- Multipolar neuron
- Unipolar neuron
- Bipolar neuron
Multipolar neuron characteristics
Many dendrites on cell body and a single axoin
Generally acts as motor or integration neurons.
Unipolar neuron charcateristics
Have one short process that connects to a central process and a peripheral process (that make an axon). Has no dendrites.
Conducts sensory info.
Bipolar neuron characteristics
Have single axon and single dendrite from cell body.
RARE and found in specific spots of body (ear, eye, nose)
Nerves v. Neurons
They’re NOT synonymous!
Neuron: a single cell found in brain, spinal cord, and PNS. Conduct nerve impulses
Nerves: made from group of neurons only in PNS; transmit info to parts of body
Neurons are in the brain
Action potential
Electrical impulses that travel along neurons
Where can you find the spinal cord in the vertebral body?
Vertebral canal
Conus medullaris
The terminal portion of the spinal cord
Cervical and lumbar enlargements
The part of the spinal cord where the diameter is bigger b/c of increased neural input/output (plexuses).
Segments of spinal nerves
8 cervical spinal nerves 12 thoracic spinal nerves 5 lumbar spinal nerves 5 sacral spinal nerves 1 coccygeal spinal nerves
Cauda equina
Elongated nerve rootlets where the more caudal nerve roots (esp at lumbar and sacral region) run in almost vertical direction to reach appropriate intervertebral foramina
Spinal cord made up of two components
- White matter
2. Gray matter
White matter consists of and does what
Myelinated nerve fibers that run up and down spinal cord to convey info btwn CNS and spinal cord
Gray matter consists of what
Consists of cell bodies of neurons, their dendrites, and proximal parts of axons.
Gray matter divided into
Dorsal horns (posterior grey column) Ventral horns (anterior grey column) Grey commissure
Dorsal horns in gray matter contains
Cell bodies of interneurons that talk w/ incoming sensory nerve fibers
Ventral horns in gray matter contains
Large somatic motor neuron cell bodies along whose axons impulses are sent to striated, skeletal muscles
Gray commissure contains
Part of gray matter.
Contains nerve fibers connecting right and left halves of spinal cord.
Spinal cord has hollow tube filled w/
Cerebrospinal fluid
The spinal nerves, T1-S5, are associated w/ the vertebral body/pedicle they pass (inferiorly / superiorly) to.
Inferiorly
The spinal nerves, C1-C7, are associated w/ the body/pedicle they pass (inferiorly / superiorly) to.
Superiorly
Cell bodies of motor neurons in ventral horns and lateral horns send axons OUT of spinal cord through the _________.
Ventral rootlets
Interneurons in dorsal horn receive sensory fiber info INTO spinal cord through the _________.
Dorsal rootlets
Ventral rootlets converge to form
Ventral roots, carrying motor fibers (both somatic and autonomic)
Dorsal rootlets converge to form
Dorsal roots, carrying sensory fibers
True/False: Dorsal roots/rootlets cannot carry BOTH motor or sensory fibers
True!
The dorsal and ventral roots join at the ________ and, from there, the motor and sensory fibers mix together at the spinal nerve
Intervertebral foramen
When the mixed spinal nerve pass through intervertebral foramen, it makes 2 branches:
- Dorsal ramus
2. Ventral ramus
Dorsal ramus
Supply sensory and motor fibers to the INTRINSIC back muscles and skin along dorsum of neck and trunk.
Ventral ramus
Carries motor and sensory fibers to everything else that the dorsal ramus doesn’t carry to (except the head).
Some ventral rami interconnect w/ each other to form 3 plexuses:
- Cervical plexus (C1-C4): innervates structures in neck
- Brachial plexus (C5-T1): innervates upper limb
- Lumbosacral plexus (L4-S2/3): innervates lower limb
Dorsal root ganglia contains these fibers/cell body types:
- Somatic sensory
2. Visceral sensory
Ventral horn contains this fibers/cell body types:
Somatic motor
Lateral horn (T1-L2) contains this fibers/cell body types:
Preganglioninc sympathetic
Sympathetic chain ganglia or collateral ganglia contains this fibers/cell body types:
Postganglionic sympathetic
Brainstem or lateral horn of gray matter (S2-S4) contains this fibers/cell body types:
Preganglionic parasympathetic
Terminal ganglia contains this fibers/cell body types:
Postganglionic parasympathetic
Spinal disc herniation
A tear in the outer, fibrous ring (annulus fibrosus) of an intervertebral disc allows the soft, central portion (nucleus pulposus) to bulge out beyond the damaged outer rings
For disc herniations, how do we know which spinal nerve is being affected?
The nerve that is compressed is named after the second intervertebral disc.
Ex: If L4/L5 disc is herniated; L5 spinal nerve is affected
Which spinal nerve does NOT have sensory fibers that distribute to areas of skin?
C1
C2 is the landmark for which dermatome?
Back of head
T4 is the landmark for which dermatome?
Nipples
T10 is the landmark for which dermatome?
Umbilicus
T12 is the landmark for which dermatome?
Suprapubic
What are shingles?
A viral disease that takes advantage of axonal transport (from sensory neurons to skin). Stems from childhood infection (chicken pox) where virus is transported from skin lesions to cell bodies of dorsal root ganglion. When immune system is weakened, the viruses multiply and come back through sensory axons to skin. This causes rash!
What’s the singles virus called and where does it stay?
Varicella-zoster virus stays in dorsal root ganglion w/ somatic sensory/visceral sensory cells
Meninges
Encloses brain and spinal cord w/ its 3 CT layers and gives protection and support of CNS
Meningeal layers
- Dura mater
- Arachnoid layer
- Pia mater
Dura mater
Outermost meningeal investment made of dense collagen.
What’s the space btwn the vertebral canal and dura mater called and what does it do?
Epidural space allows for movement of vertebral column w/o affecting spinal cord
What’s the epidural space filled with?
Fatty tissue and a venous plexus
How is the dura mater in the skull different than the other parts?
There’s no epidural space; instead, it’s fused w/ inner layer of periosteum
Arachnoid layer
Intermediate meningeal investment made of loose CT
What’s the space btwn the dura mater and arachnoid layer called?
Subdural space
What’s the space btwn the arachnoid layer and pia mater called?
Subarachnoid space
What’s the subarachnoid space filled with?
Cerebrospinal fluid
What does the cerebrospinal fluid do?
Provides brain and spinal cord buoyancy for CNS since these things suck at holding up their own weight
Pia mater
Loose CT that invests brain and spinal cord and its nerve roots. Blood vessels going on the brain or spinal cord travel within this layer!
Denticulate ligament
Attachment that extends from both sides of pia mater and attaches to arachnoid layer and dura mater. Helps suspend the cord within the subarachnoid space.
Terminal filum
Thin strand of pia mater extends from conus medullaris and anchors the spinal cord in the dural sac.
Lumbar puncture or spinal tap
A medical procedure in which a needle is inserted into the subarachnoid space of spinal canal (usually made in the midline between L3/L4 or L4/L5), most commonly to collect cerebrospinal fluid (CSF) for diagnostic testing.
3 layers of muscle make up thoracic body wall
- External intercostal muscles
- Internal intercostal muscles
- Innermost intercostal muscles
Intercostal muscles function
Maintain appropriate spacing btwn ribs during respiration
Neurovascular bundle consists of and is located in
Consists of intercostal nerve, artery, and vein
One bundle located btwn internal and innermost intercostal muscles within intercostal space; another is located btwn transversus abdominisc and internal oblique muscles.
Intercostal nerves are extensions of
Ventral rami of T1-T11
Thoracic body wall gets blood from
Intercostal arteries and veins
Abdominal body muscles functions
Retain, support, compress abdominal viscera
Function in movements of trunk.
3 muscles that form major portion of anterolateral abdominal wall, but their muscle fibers do not completely encircle the trunk
- External abdominal oblique
- Internal abdominal oblique
- Transversus abdominis
Linea semilunaris
A curved tendinous intersection found on either side of the rectus abdominis muscle.
What is aponeurosis and its function?
Flat, broad tendons that joins muscles and the body parts the muscles act on, whether it be bone or muscles
Linea alba
Runs from xiphoid process of sternum to pubic symphysis. It’s formed by fusion of aponeuroses of abdomen and it separates the left and right rectus abdominis muscles.
External abdominal oblique attaches to
- Last seven ribs
- Crest of ilium
- Linea alba
- Inguinal ligament
External abdominal oblique actions
Bilaterally: flexion; compression
Unilaterally: lateral flexion (SAME side); rotation (OPPOSITE side)
External abdominal oblique innervation
Ventral rami of T5-T12
Internal abdominal oblique attaches to
- Lumbar vertebrae (thoracolumbar aponeurosis)
- Crest of ilium
- Lateral 1/2 of inguinal ligament
- Linea alba
- Last 7 ribs
Internal abdominal oblique actions
Bilaterally: flexion; compression
Unilaterally: lateral flexion (SAME side); rotation (SAME side)
Internal abdominal oblique innervation
Ventral rami of T6-L1
Transversus abdominis attachments
- Last 7 ribs
- Lumbar vertebrae (thoracolumbar aponeurosis)
- Crest of ilium
- Lateral 1/2 of inguinal ligament
- Linea alba
Transversus abdominis action
Compression
Transversus abdomins innervation
Ventral rami of T6-L1
Rectus abdominis attachments
- Pubic symphysis and pubic crest
- Xiphoid process
- 5th and 7th costal cartilages
Rectus abdominis actions
Flexion
Rectus abdominis innervation
Ventral rami of T6-T12
Rectus sheath is formed by
the aponeurosis of external oblique, internal oblique, and transversus abdominis
What’s the “6-pack” muscle?
A vertically oriented muscle called rectus abdominis
What gives the rectus abdominis its “6-pack” feature and what does it do?
Tendinous inscriptions anchor rectus abdominis to rectus sheath
Arcuate line
A horizontal line that demarcates the lower limit of the posterior layer of the rectus sheath. It is also where the inferior epigastric vessels perforate the rectus abdominis.
What does the arcuate line help do?
Provides collateral circulation and communication around abdomen and to lower limbs.
Abdominal wall muscles are innervated by
Ventral rami of lower thoracic
Inguinal ligament
Band running from the pubic tubercle to the anterior superior iliac spine. It’s the base for the inguinal canal
Superficial inguinal ring
It’s the “opening” end of the canal in the aponeurosis of the external oblique that acts as the “exit” of a passageway in the abdominal wall
Inguinal canal
Passages in the anterior wall goes which convey spermatic cord (in men) or round ligament (in women)
In males, what passes through inguinal canal and where does it go?
In males, spermatic cord passes through inguinal canal from abdomen to scrotum.
In females, what passes through inguinal canal and where does it go?
In females, round ligament passes through inguinal canal and continues to labia majora.
Inguinal hernia
Protrusion of a loop of bowel through inguinal canal.
Why is inguinal hernia more common in males than females
Because males have a bigger superficial inguinal ring than females.
Femoral hernia
A portion of tissue pushes through the wall of the femoral canal.
Why is femoral hernia more common in females than males?
Pregnancy and childbirth
Two groups of back muscles
- Extrinsic back muscles
2. Intrinsic back muscles
Extrinsic back muscles move what?
Upper limb (not the trunk)
Intrinsic back muscles move what?
Axial skeleton
Extrinsic back muscles include
- Trapezius
- Latissimus dorsi
- Rhomboids
- Serratus posterior inferior
- Thoracolumbar aponeurosis
Extrinsic back muscles are innervated by
Cranial nerves or branches of ventral rami of cervical spinal nerves
Intrinsic back muscles are innervated by
Dorsal rami of spinal nerves
Trapezius is innervated by
Cranial nerve XI (spinal accessory nerve)
Trapezius attaches to
Nuchal region of cranium
Trapezius actions
Extension
Latissimus dorsi is innervated by
Thoracodorsal nerve
Latissimus dorsi attaches to
Distal humerus and proximal vertebrae
Latissimus dorsi actions
Movement of upper limb
Rhomboids are innervated by
Dorsal scapular nerve
Rhomboids attach to
Medial scapula and vertebral column
Rhomboids actions
Pulls scapula medially
Serratus posterior inferior innervated by
Intercostal nerve (T9-T12)
Serratus posterior inferior action
Depress lower ribs
Intrinsic back muscles include 3 groups
- Spinotransversus group
- Erector spinae group
- Transversospinae group
Intrinsic back muscles main function
Maintain erect posture and to stabilize the trunk during movements of the limbs and head.
Intrinsic back muscles fiber is primarily what and why
Slow-oxidative bc it keeps you standing
Intrinsic back muscles are invested in what type of fascia and what does it do
Thoracolumbar aponeurosis helps muscles maintain erect posture
Spinotransverse group is attached to what and how?
Caudal attachments of the spinotransverse group are attached to the spinous processes of vertebrae; cranial attachments are attached to the transverse processes of vertebrae.
Spinotransverse group muscles include
Splenius
Spinotransverse group (splenius) actions
Bilaterally: extension
Unilaterally: lateral flexion (SAME side); rotation (SAME side)
Erector spinae group muscles include
- Iliocostalis
- Longissimus
- Spinalis
Erector spinae group (ILS) actions
Bilaterally: extension
Unilaterally: lateral flexion (SAME side)
Transversospinae group muscles include
- Semispinalis
- Rotatores
- Multifidus
Transversospinae (SRM) actions
Bilaterally: extension
Unilaterally: rotation (OPPOSITE side)
Transversospinae group attachments
Attachments of these muscles run from more caudal transverse processes to more cranial spinous processes
What muscle divides the posterior and anterior cervical triangles of the neck?
Sternocleidomastoid
Sternocleidomastoid receives innervation from
Spinal accessory nerve (CN XI)
Sternocleidomastoid actions
Unilaterally: rotates head (to OPPOSITE side); lateral flexion of head (to SAME side)
Bilaterally: extension at atlanto-occipital joint; flexion at other cervial jointssup
Hyoid bone articulates with…
no other bone.
What are the three triangles of the neck?
- Anterior cervical triangle
- Posterior cervical triangle
- Suboccipital triangle
Torticollis
“Wry neck”: shortening of sternocleidomastoid; neck is laterally flexed one side, rotated
Which hyoid muscles are considered “two belly” muscles?
Omohyoid and digastic
Suprahyoid (digastric) action
Moves head up
Infrahyoid (omohyoid) action
Moves hyoid down
3 scalene muscles
- Anterior scalene
- Middle scalene
- Posterior scalene
Scalene attachments
Cranial attachments are to the transverse processes of cervical vertebrae. Caudal attachments are to the first rib (scalenus anterior) or the second rib (scalenus medius and posterior).
Scalene actions
Bilaterally: flexion, flex neck
Unilaterally: lateral flexion (SAME side)
Which muscles are affected by whiplash?
Longus colli and longus capitis
Longus colli and capitis action
Bilaterally: flexion
Longus colli and capitis innervated by
Cervical ventral rami
Suboccipital triangle muscles:
- Rectus capitis posterior major
- Obliquus capitis superior
- Obliquus capitis inferior
Suboccipital triangle actions:
Extension (rectus capitis and obliquus capitis superior)hy
Rotation (to SAME side) (obliquus capitis inferior)
Suboccipital triangle innervation
Suboccipital nerve (C1 dorsal ramus)
What’s whiplash?
Sudden hyperextension-hyperflexion of neck that causes muscle strain.
What are the severe effects of whiplash?
You can tear ligament of spinous processes; you can crush vertebral disc
Sagittal plane corresponds with which axis?
Transverse axis
Coronal plane corresponds with which axis?
Anterior-posterior axis
Transverse plane corresponds with which axis?
Vertical axis
Examples of long bones
Long shafts such as femur, humerus, radius, ulna, tibia, etc
Examples of short bones
Carpals and tarsals
Examples of flat bones
Parietal, occipital, frontal
Examples of irregular bones
Vertebrae, os coxa
3 basic components of connective tissue
Cells, fibers, and ground substance
2 basic components of extracellular matrix
Fibers and ground substance
Cartilage and bone have roles in hemopoesis and as a calcium reserve, but their main role is to provide _______________ for the body with their rigid extracellular matrix.
Support
Cartilage cells include
Chondrocytes
Chondroblasts
Bone cells include
Osteocytes
Osteoblasts
Osteoclasts
Cartilage is composed of this fiber
Type II collagen
Bone is composed of this fiber
Type I collagen
Ground substance of cartilage is rich in this proteoglycan
Aggrecan
Ground substance of bone is rich in _______________ proteins.
Non-collagenous
Bone is surrounded by
calcium phosphate (mineralized extracellular matrix)
3 cartilage types
- Hyaline
- Elastic
- Fibrocartilage
What does hyaline cartilage consist of?
Type II collagen
What does elastic cartilage consist of?
Elastic fibers
What does fibrocartilage consist of?
Type I and II collagen
Hyaline cartilage trait
Resistant to compression
Elastic cartilage trait
Flexible
Fibcrocartilage
Resists deformation; assists repair
Where is hyaline cartilage found?
Joint surfaces, developing skeleton, thorax
Where is elastic cartilage found?
Ear, auditory tube
Where is fibrocartilage found?
Intervertebral discs and knee menisci
Where in the cartilage extracellular matrix are chondrocytes found?
Lacunae
What is aggrecan?
A hydrophilic protein in ground substance that helps maintain the structure of cartilage.
Cartilage is avascular. This means nutrients have to get chondrocytes via diffusion. What are two limitations of this means of receiving nutrients?
- Size of cartilage–can’t be too big
2. Limit on healing of damaged cartilage–not the most efficient
Interstitial growth
Growth from within.
Appositional growth
Growth from outside by adding to surface layer
Most cartilage is invested in this dense layer of connective tissue called _______.
Perichondrium
Chondrogenic layer
The inner layer of perichondrium with cells that have the potential to become chondroblasts.
Where is perichondrium NOT found?
Articular, hyaline cartilage surfaces of synovial jointss
How do nutrients diffuse to chondrocytes?
Chondrocytes within their lacunae receive nutrients via diffusion through ground substance from vessels located in surrounding cartilage.
How does interstitial growth work in cartilage?
Chondroblasts divding and secreting extracellular matrix within cartilage
How does appositional growth work in cartilage?
Perichondral cells differentiating into chondroblasts and secreting ECM
Osteocytes are located where in the extracellular matrix?
Lacunae
Osteocytes
Maintain bone tissue; communicate through canaliculi
Osteoblasts
Secretes ECM; becomes an osteoblast once it is surrounded by ECM
Osteoclasts
Resorbs bone cells; multinucleated
_____ marrow is hemopoetic
Red
_____ marrow is fat
Yellow
Periosteum surrounds what structure?
Bone
What lines the inside of the bone?
Endosteum
Endosteum consists of one layer–what is it?
Cellular layer
Periosteum consists of two layers–what are they?
A fibrous layer and cellular layer
Trabecular bone is found in ends of long bones and vertebral bodies bc why?
Those areas receive multiaxial loads
How do osteocytes in trabecular bone get nutrients and communicate?
Nutrients diffuse through marrow space btwn trabeculae, and go through canaliculi open to marrow space. From first osteocyte, the nutrients travel through canaliculi to adjacent osteocytes.
What happens if there is unused trabecular bone?
Osteoclasts resorb it for calcium bc, otherwise, the bone is high maintenance.
What is the result of the means of receiving nutrients on the size of an individual trabecula?
Trabecula cannot be too big bc the nutrients have to reach osteocyte before it is diminished
Purpose of having Haversian/Osteon systems in cortical bone
It allows cortical bone to be further from marrow space while still letting nutrients to reach cells via diffusion through canaliculi
General mechanism for osteoporosis
Osteoclasts resorb bone faster than osteoblasts create new bone. This loss of bone mass makes bone more susceptible to fractures.
Cortical bone found in
Shafts of long bones or as outer shell of bone
What’s a Diploe bone?
Cortical bone on either side of trabecular bone–makes a sandwich
Bone can grow appositionally or interstitially?
Appositionally
How can we avoid osteoporosis?
Diet rich in calcium and also do exercise
Osteogenic layer
The inner, cellular layer of periosteum which can form new bone.
Where in the bone is marrow found in cortical bone?
Medullary cavity
Haversian canal/central canal
Canals of osteons which contain blood vessels that supply nutrients for osteocytes in lacunae.
2 types of bone growth
- Intramembranous ossification
2. Endochondral ossification
Intramembranous ossification
CT membrane precursor exists in same spot the resulting bone will be in. Osteoblasts are recruited to a particular spot on the membrane and they use the membrane as a surface to lay down bone
What bones are created via intramembranous ossification?
Flat skull bones and ribs
How does skull grow to accommodate brain increasing in size during development?
Bone added to outside of skull and removed from inside of skull simultaneously.
5 steps of endochondral ossification
- Periosteum at midshaft makes osteoblasts that make bony collar
- Cartilage at primary ossification center breaks down
- Blood vessels invade medullary cavity and bring in osteoblasts and osteoclasts
- Blood vessels invade end bones to make secondary ossification centers
- Growth in length occurs at growth plate
5 epiphyseal plate zones
- Resting/reserve
- Proliferation
- Hypertrophic
- Calcification
- Ossification
What is the resting/reserve zone of epiphyseal plate?
All chondrocytes found in this zone at epiphyseal end
Epiphysis
Cartilaginous ends of long bones
Diaphysis
Shaft of long bones
What is the proliferation zone of epiphyseal plate?
Chondrocytes undergo rapid mitosis
What is the hypertrophy zone of epiphyseal plate?
Chondrocytes stop mitosis and undergo hypertrophy by getting bigger and bigger
What is the calcification zone of epiphyseal plate?
Chondrocytes start to die and the cartilaginous matrix starts to calcify
What is the ossification zone of epiphyseal plate?
Osteoclasts and osteoblasts from diaphysis break down cartilage and replace w/ mineralized bone tissue. Growth plate closes.
What kind of growth is the proliferation zone of eipiphyseal plate?
Interstitial growth
What kind of growth is the hypertrophy zone of eipiphyseal plate?
Interstitial growth
What kind of growth is the ossification zone of eipiphyseal plate?
Appositional growth
Epiphyseal plate
Growth plate. Where growth in length occurs.
How is trabecular bone remodeled?
Appositionally. Osteoclasts eat bone, osteoblasts make new one.
How is cortical bone remodeled?
Osteocyte tells group of osteoclasts to eat through the old osteons of bone and then tells group of osteoblasts to follow osteoclasts to create new osteons.
4 bone repair steps
- Hematoma formation
- Fibrocartilaginous callus (unorganized)
- Bony callus (unorganized)
- Bone remodeling (osteoclasts and osteoblasts remodel to create optimal structure for loads placed on bones)
What specialized CT is important for bone repair?
Periosteum
Osteoblasts arrange themselves in concentric layers of cortical bone around the central canal called
Lamellae
Synarthrosis
Joints that do not move.
Amphiarthrosis
Joints that move a little.
Diarthrosis
Joints that move freely.
3 kinds of joint structures
- Fibrous
- Cartilaginous
- Synovial
Fibrous joints
- Bones held together by dense CT
- No joint cavity
- Little to no movement
3 major types of fibrous joints
- Sutures
- Gomphosis
- Interosseous membranes
Cartilaginous joints
- Bone united by cartilage
- No joint cavity
- Slight movement
2 types of cartilage that can unite bones of cartilaginous joints
- Hyaline cartilage
2. Fibrocartilage
The pubic symphysis and intervertebral discs have this kind of joint
A type of cartilaginous joint called fibrocartilage
Synovial joints
- Bones united by joint capsule
- Has joint cavity
- Free movement usually
What is the joint cavity on synovial joints?
Cavity filled w/ lubricating synovial fluid to minimize friction btwn articulating surfaces of adjacent bones
Explain how weeping lubrication works in synovial joints?
When synovial fluid is not in use due to lack of pressure on joints, it is taken up into articular cartilage. Once under compression, synovial fluid is squeezed out of articular cartilage into the joint cavity to facilitate lubrication of joint during movement.
Why can’t hyaline cartilage (like those lined on articular surfaces of bones at synovial joints) heal if damaged?
Lack of perichondrium means lack of chondroblasts to create new cartilage cells.
_____ are passive stabilizers because they work without actively contracting.
Ligaments
6 categories of synovial joints by shape
- Ball and socket
- Condyloid
- Gliding
- Hinge
- Pivot
- Saddle
Articular surface of bones at synovial joints is lined with what type of cartilage?
Hyaline
How does articular cartilage in a synovial joint receive nutrients?
Nutrition and waste removal occurs by diffusion from the underlying bone and from the synovial fluid in the joint cavity
Classify plane (gliding) joint by its degree of movement
Multiaxial
Classify hinge joint by its degree of movement
Uniaxial
Classify condyloid joint by its degree of movement
Biaxial
Classify saddle joint by its degree of movement
Multiaxial
Classify ball-and-socket joint by its degree of movement
Multiaxial
How can you tell when a ligament is limiting movement?
Whatever movement puts tension on the ligament is the movement being limited by that ligament.
Intracapsular ligaments
Inside joint cavity
Capsular ligaments
Thickenings of joint capsule
Extracapsular ligaments
Stabilize joint but are located outside the joint and joint capsule.
Interarticular discs
Fibrocartilaginous disks interposed between the articular surfaces of synovial joints. Can make the skeletal elements more congruous w/ each other or may facilitate movement by increasing the ROM of joint
Bursae
Closed sacs of synovial membrane filled w/ synovial fluid that help reduce friction btwn bone & tendon and bone & skin.
Sprain
Extreme stretch or tear of a ligament beyond usual ROM.
What’s the difference btwn osteoarthritis and rheumatoid arthritis?
Former is “wear and tear” arthritis and latter is an autoimmune disease that attacks parts of body and causes joint inflammation.
3 types of muscles
- Smooth muscle
- Cardiac muscle
- Skeletal muscle
What do smooth muscles move?
Organs and blood vessels
What do cardiac muscles move?
The heart
What do skeletal muscles move?
The skeleton
How do skeletal muscles attach to stuff?
It’s CT components “coalesce” into tendon that continues to the attachment site.
Explain the myotendinous junction
The muscle forms tendon by converging endomysium, perimysium, and epimysium
What’s aponeurosis?
A thin, flat sheet of tendon
Where can you find aponeuroses?
On flat muscles like anterolateral abdominal wall muscles, latissimus dorsi and trapezius.
What’s happening in the sarcomere during muscle contraction?
Myofilaments, actin and myosin, slide along each other to shorten the muscle.
How do muscle fibers receive nutrients and oxygen?
Diffusion from blood vessels running in the CT surrounding the muscle.
Which muscles are voluntary? Which muscles are not?
Skeletal muscles are voluntary. Smooth and cardiac muscles are not voluntary.
Which muscle has intercalated discs btwn its adjacent muscle fibers?
Cardiac muscle
Which muscle is the strongest?
Skeletal muscle
Which muscle fatigues most easily?
Skeletal muscle
Sarcomere
Unit of contraction of skeletal muscle (contains actin and myosin)
Slow-twitch, slow oxidative, or Type 1 fibers
Best for sustained, tonic contraction; highly resistant to fatigue; rich supply of oxygen and nutrients for muscle fibers.
Fast-twitch, fast glycolytic, or Type 2B fibers
Obtain energy via anaerobic glycolysis; rapid access to energy stores; less efficient and sustainable
How does anaerobic glygolysis work?
Glycogen is converted into lactic acid. Once glycogen is all used, it must replenish and lactic acid must be removed.
Fast oxidative fiber or Type 2A fiber
Fast-contracting and fatigue-resistant
Muscle hypOtrophy
Shrinking of muscle fibers, loss of proteins (actin and myosin)
What site do nerve fibers terminate on to initiate muscle contraction?
Neuromuscular junction
4 steps of excitation-contraction coupling for muscle contraction
- Ach released from axon binds to receptors on sarcolemma
- AP generated and goes down t-tubule
- Calcium released in sarcoplasmic reticulum
- Calcium binds to troponin. Cross bridge forms btwn actin and myosin
Motor unit
Made up of a motor neuron and the skeletal muscle fibers innervated by that motor neuron’s axonal terminals
Recruitment of motor units
Gradation in strength of contraction is brought about the excitation of larger and larger numbers of motor units
Neuropathies
Disorders of the motor nerve cell or its axon
Poliomyelitis
A viral infection that results in the destruction of motor nerve cell bodies in the spinal cord, followed by atrophy of the associated muscle groups
Myasthenia gravis
A disorder of the neuromuscular junction that is thought to be due to the presence of antibodies to acetylcholine receptors at the neuromuscular junction
Myopathies
Disorders of the muscle fibers themselves
Muscular dystrophy
A condition characterized by the destruction/loss of muscle fibers and their replacement by fat and connective tissue
Myotonia
A “malfunction” of the muscle cell membrane so that there is a prolonged period of contraction
Skeletal muscle composed of
Muscle fibers and CT
Connective tissue investment of the entire muscle
Epimysium
Connective tissue investment of fascia
Perimysium
Connective tissue investment of individual muscle fibers
Endomysium
Fascicle
A group of muscle fibers
CT component of muscle fibers serve these functions
- “Skeletal framework”
- Allows deformability/stretching
- Elasticity/stiffness
- Pathway for nerves, blood vessels, and lymphatics
Proprioceptive muscle fibers do what
Sense position and stretch of muscle and initiate reflexes
Muscle hypERtrophy
Increase in cross-sectional area of muscle by gaining protein (actin and myosin)
2 types of skeletal muscle fiber orientations
- Oblique
2. Parallel
This muscle fiber orientation has a long range of motion
Parallel muscle fibers
This muscle fiber orientation has a strong force
Oblique muscle fibers
Types of contraction
- Concentric
- Eccentric
- Isometric
Concentric contraction
Shortening of muscle
Internal force > External resistance
Ex: lifting weight up
Eccentric contraction
Muscle lengths
Force < resistance
Ex: slowly putting weight down
Isometric contraction
Muscle length stays same
Force = resistance
Ex: wall sits
Prime movers or agonists
Muscles that are consistently active in initiating and maintaining a movement
Antagonists
Muscles that wholly oppose the movement, or initiate and maintain the opposite movement
Fixators
Prime movers and antagonists contract together
Synergists
Muscles called upon to “assist” in accomplishing a movement
Myofiber is also known as
Muscle cells or muscle fibers
Loss of proprioception may result in…
Loss of reflexes, coordination and tone
Loss of motor innervation may result in…
Atrophy of muscle fibers
Attachment origin
Attachment that is fixed (does not move)
Attachment insertion
Attachment that is mobile (moves)
Atlas (C1)
Articulate w/ base of skull and have no body or spinous process
Axis (C2)
Has large prominence on cranial side of its body called dens or odontoid process
How many cervical vertebrae?
7
How many thoracic vertebrae?
12
How many lumbar vertebrae?
5
How many sacral vertebrae?
4-5
How many coccyx vertebrae?
3-4 fused
What kind of bone are vertebrae made of?
Trabecular bone
What kind of cartilage surrounds the articular surfaces of vertebral bodies (endplates)?
Hyaline cartilage
Cervical vertebrae facet joints face which direction?
Obliquely
Thoracic vertebrae facet joints face which direction?
Coronally
Which vertebrae looks like a giraffe?
Thoracic vertebrae
Which vertebrae looks like a moose?
Lumbar vertebrae
Lumbar vertebrae facet joints face which direction?
Sagittally
Intervertebral discs consist of these 2 parts:
- Nucleus pulposus
2. Anulus fibrosus
What kind of cartilage is in intervertebral discs?
Fibrocartilage
Disc herniation
Weakness of anulus fibrosis (fibrocartilage) in intervertebral disc combined with force placed on nucleus pulposus (gel).
What region and direction is the most common for disc herniations?
Lumbar region; posterolateral direction.
Anterior longitudinal ligament
Ligament that runs down the anterior surface of the spine (from head to coccyx)
What movement does the anterior longitudinal ligament prevent?
Hyperextension
Posterior longitudinal ligament
Situated within the vertebral canal, and extends along the posterior surfaces of the bodies of the vertebrae, from the axis to coccyx
What movement does the posterior longitudinal ligament prevent?
Hyperflexion
Ligamentum flava
Ligament that runs between the neural arches/laminae of the vertebrae for the length of the column
What movement does the ligamentum flava prevent?
Hyperflexion
Ligamentum nuchae
Ligament extended from supraspinous ligament in cervical region and attaches to the skull and serves as an attachment point for neck muscles
What movement does the ligamentum nuchae prevent?
Hyperflexion
Interspinous ligament
Ligament positioned between adjacent spinous processes
Supraspinous ligament
Ligament that runs along the tips of the spinous processes
What movement does the interspinous ligament prevent?
Hyperflexion
What movement does the supraspinous ligament prevent?
Hyperflexion
Kyphosis
Exaggerated thoracic curvature
Lordosis
Exaggerated lumbar curvature
Scoliosis
Right thoracic/left lumbar curvature in frontal plane.
Which vertebral region(s) can engage in flexion/extension movements?
Cervical and lumbar (not thoracic)
Which vertebral region(s) can engage in lateral bending movements?
Cervical and thoracic (not lumbar)
Which vertebral region(s) can engage in rotational movements?
Cervical and thoracic (not lumbar)
Which joint is the “yes” joint?
Atlanto-occipital joint
Which joint is the “no” joint?
Atlanto-axial joint
What does the axial skeleton consist of?
Skull, vertebral column, and rib cage
Which ligament in vertebral column helps prevent herniated disc?
Anterior longitudinal ligament
At which level does the first rib articulate with the sternum?
Sternoclavicular joint
Where does the subarachnoid space end?
S2 vertebral level
Intervertebral foramen
The space between the superior notch of the adjacent vertebra and the inferior notch of the vertebra
Which part of the brain is responsible for integrating information (visceral sensations) for the ANS?
Hypothalamus
This nervous system is considered a 2-neuron system.
Autonomic nervous system
Primary function of autonomic nervous system
Control visceral MOTOR functions that operate “automatically” and are regulated largely without conscious control. NO SENSORY here.
The autonomic nervous system is also called
The visceromotor system
Describe a one-neuron system
In the somatic nervous system,
Cell bodies in ventral horn –> Motor innervation of striated skeletal muscle
Describe a two-neuron system
In the autonomic nervous system, First neuron (preganglionic neuron) cell body in the brain stem or lateral horn --> synapses with the second neuron (postganglionic neuron) in the peripheral nervous system --> postganglionic neuron then travels to the target organ and innervates it.
Which fibers of the peripheral motor system are heavily myelinated with Schwann cells?
Somatomotor fibers (visceromotor fibers are either light myelinated [preganglionic] or not myelinated [postganglionic])
2 parts of autonomic nervous system
- Sympathetic nervous system
2. Parasympathetic nervous system
Where are sympathetic preganglionic cell bodies located?
Thoracolumbar division (Lateral horns of T1-L2)
Where are parasympathetic preganglionic cell bodies located?
Craniosacral division (Brainstem or lateral horns of S2-S4)
Where are sympathetic postganglionic cell bodies located?
Sympathetic chain ganglia and collateral ganglia
Where are parasympathetic postganglionic cell bodies located?
Terminal ganglia (organ walls)
What are the fiber lengths of sympathetic axons?
Short preganglionic, long postganglionic
What are the fiber lengths of parasympathetic axons?
Long preganglionic, short postganglionic
Postganglionic neurotransmitter for sympathetic nervous system
Norepinephrine
Postganglionic neurotransmitter for parasympathetic nervous system
Acetylcholine
Sympathetic cell bodies use a specialized pathway to distribute out to the entire body. What is this pathway structure called?
Sympathetic chain
What are sympathetic chain ganglia connected to?
Communicating rami (white and gray)
What travels through the white communciating ramus?
Preganglionic cell bodies
What travels through the gray communicating ramus?
Postganglionic cell bodies
Target organs of sympathetic fibers divided into 2 regions:
- Body wall (sweat glands, arrector pili muscles or blood vessels in the skin and limbs)
- Organs (heart, stomach, bladder, etc)
If sympathetic fibers are destined to innervate the body wall, where will they always synapse?
Sympathetic chain ganglia
If sympathetic fibers are destined to innervate the organs, where will they always synapse?
Sympathetic chain ganglia or collateral ganglia
Explain the sympathetic pathway for innervating a sweat gland in T4 dermatome.
- Preganglionic cell body in lateral horn travels to ventral root of T4 spinal nerve
- Through the mixed spinal nerve
- Through the ventral ramus
- Through the white communicating ramus
- To the chain ganglion where it synapses on a postglangionic cell body
- Postganglionic cell body exits chain ganglion via gray comunicating ramus
- Travels to sweat gland in T4 dermatome to innervate it
White communicating rami are located at which spinal nerves of the spinal cord?
T1-L2
Gray communicating rami are located at which spinal nerves of the spinal cord?
All spinal nerves
Explain the sympathetic pathway for innervating a sweat gland in C7 dermatome.
- Preganglionic cell body in lateral horn travels to ventral root of spinal nerve
- Through the mixed spinal nerve
- Through the ventral ramus
- Through the white communicating ramus
- To the chain ganglion where the fiber ascends to chain ganglion at C7 (by this point the synapse of preganglionic cell body can occur in any of the chain ganglia it goes through as it ascends)
- Postganglionic cell body exits chain ganglion via gray comunicating ramus at C7 spinal nerve
- Travels to sweat gland in C7 dermatome to innervate it
Splanchnic nerves
Alternative exit from sympathetic chain (instead of gray communicating rami) for sympathetic pathways to organs
Explain the sympathetic pathway for thoracic organs.
- Preganglionic cell body in lateral horn travels to ventral root of spinal nerve
- Through the mixed spinal nerve
- Through the ventral ramus
- Through the white communicating ramus
- To the chain ganglion where the fiber ascends to chain ganglion at cervical level and synapse
- Postganglionic cell body exits chain ganglion via cervical splanchnic nerves
- Through cardiopulmonary plexus
- To organ target (heart and lungs)
True or false: There’s a sympathetic chain ganglion at each level of spinal cord.
True
Explain the sympathetic pathway for abdominal organs.
- Preganglionic cell body in lateral horn travels to ventral root of spinal nerve
- Through the mixed spinal nerve
- Through the ventral ramus
- Through the white communicating ramus
- To the chain ganglion where IT EXITS IMMEDIATELY (no synapse!)
- Through thoracic splanchnic nerves
- To the collateral ganglia where they synapse with postganglionic cell body
- Through autonomic plexus
- To target organs (digestive system, kidneys)
Explain the sympathetic pathway for pelvic organs.
- Preganglionic cell body in lateral horn travels to ventral root of spinal nerve
- Through the mixed spinal nerve
- Through the ventral ramus
- Through the white communicating ramus
- To the chain ganglion where IT EXITS IMMEDIATELY (no synapse!)
- Through lumbar or sacral splanchnic nerves
- To the collateral ganglia where they synapse with postganglionic cell body
- Through autonomic plexus
- To target organs (bladder and reproductive organs)
Explain the sympathetic pathway to the medulla of the adrenal gland.
- Preganglionic cell body in lateral horn travels to ventral root of spinal nerve
- Through the mixed spinal nerve
- Through the ventral ramus
- Through the white communicating ramus
- To the chain ganglion where IT EXITS IMMEDIATELY (no synapse!)
- Through thoracic splanchnic nerves
- Through the collateral ganglia (STILL NO SYNAPSE!)
- To adrenal medulla chromaffin cells where they finally synapse and release norepi and epi into bloodstream.
True/False: Parasympathetic nervous system innervates only organs
True! Parasympathetic nervous system innervates ONLY organs while sympathetic nervous system innervates both organs and body wall
In addition to lateral horns S2-S4, parasympathetic preganglionic cell bodies are also located in these 4 specific cranial nerves of the brainstem.
- Oculomotor (CN III)
- Facial (CN VII)
- Glossopharyngeal (CN IX)
- Vagus (CN X)
Which splanchnic nerve is the only one that follows parasympathetic pathway?
Pelvis splanchnic nerve
Explain the parasympathetic pathway to structures of the head.
Preganglionic cell body in CN III, VII, and IX synapse at ganglia near their target tissue.
Explain the parasympathetic pathway to thoracic and abdominal viscera.
Preganglionic cell body in CN X go:
- Down to neck through cardiopulmonary plexus to synapse at target organs, heart and lung
- Down to thorax through esophageal plexus through anterior/posterior trunks to abdomen to synapse at terminal ganglia on/near target organs in foregut and midgut
Explain the parasympathetic pathway to sacral portion.
Preganglionic fibers in lateral horn S2-S4 travel through ventral root, through spinal nerve, through ventral ramus, through pelvic splanchnic, through autonomic plexus, to synapse at terminal ganglia on/near target organs.
True/fase: Viscerosensory neurons are part of the visceromotor system/autonomic nervous system.
FALSE! Visceromotor system/autonomic nervous system is ONLY motor fibers! Not sensory.
Viscerosensory fibers function
Collect sensory information from organs that focus on chemoreceptors (chemical signals), baroreceptors (pressure), stretching, hunger and nausea
Where are viscerosensory cell bodies located?
Dorsal root ganglia of spinal nerves (shares with somatosensory cell bodies)
What does viscerosensory innervation have to do with the autonomic nervous system?
Even though viscerosensory innervation is not part of autonomic nervous system, viscerosensory fibers follow sympathetic fibers from the organ back to its origin.
Referred pain
Pain from an organ is sensed in a dermatome on the skin because visceral sensory fibers synapse in dorsal horn shared with somatic sensory fibers.
Autonomic dysreflexia
An uninhibited sympathetic response (increased blood pressure and decreased heart rate) of the nervous system in persons with cervical and thoracic spinal cord injuries as a result of noxious stimuli (e.g., pressure, trauma or distension) below the level of the injury.
Sympathetic chain extends from ____ to ____.
From skull to coccyx
The 12 pairs of cranial nerves emerge from where?
Brain or brainstem, instead of spinal cord
In cranial nerves, cell bodies of sensory fibers are located in ___.
Ganglia just outside of brainstem.
In cranial nerves, cell bodies of motor fibers are located in ___.
the brainstem.
General sensory fibers
Transmit pain, touch, temperature, and pressure sensations from the face and head.
Special sensory fibers
Transmit information from the special sensory organs: vision, olfaction, taste, hearing, and equilibrium
What are the 4 different fiber types that can be carried by cranial nerves?
- General sensory fiber
- Special sensory fiber
- Voluntary motor fiber
- Parasympathetic nerve fiber (visceromotor)
Cranial nerve I
Name:
Fiber type(s):
Foramina:
Name: Olfactory
Fiber type(s): Special sensory (smell)
Foramina: Cribiform plate
Cranial nerve II
Name:
Fiber type(s):
Foramina:
Name: Optic
Fiber type(s): Special sensory (vision)
Foramina: Optic canal
Cranial nerve III
Name:
Fiber type(s):
Foramina:
Name: Oculomotor
Fiber type(s): Voluntary motor to 5 extraocular muscles (move eyeball, open eyelid);
Visceromotor/Parasympathetic to pupillary sphincter of eye (smooth muscle)
Foramina: Superior orbital fissure
Cranial nerve IV
Name:
Fiber type(s):
Foramina:
Name: Trochlear
Fiber type(s): Voluntary motor to 1 extraocular muscle (moves eyeball)
Foramina: Superior orbital fissure
Cranial nerve V
Name:
Fiber type(s):
Foramina:
Name: Trigeminal
Fiber type(s): General Sensory (Pain, Touch, Temperature) from face (V1, V2, V3);
Voluntary motor to muscles of mastication (V3)
Foramina: Superior orbital fissure (V1);
foramen rotundum (V2);
foramen ovale (V3)
Cranial nerve VI
Name:
Fiber type(s):
Foramina:
Name: Abducens
Fiber type(s): Voluntary motor to 1 extraocular muscle (moves eyeball)
Foramina: Superior orbital fissure
Cranial nerve VII
Name:
Fiber type(s):
Foramina:
Name: Facial
Fiber type(s): Special Sensory (Taste) from anterior 2/3 of tongue;
Voluntary motor to muscles of facial expression;
Visceromotor/Parasympathetic to most glands in the head (includes lacrimal gland; does not include parotid gland)
Foramina: Internal acoustic meatus;
Motor component travels through stylomastoid foramen and branches out 5 ways
Cranial nerve VIII
Name:
Fiber type(s):
Foramina:
Name: Vestibulocochlear
Fiber type(s): Special Sensory (Hearing) cochlea;
Special Sensory (Balance) vestibular system
Foramina: Internal acoustic meatus and cranial cavity
Cranial nerve IX
Name:
Fiber type(s):
Foramina:
Name: Glossopharyngeal
Fiber type(s): General Sensory (Pain, Touch, Temperature) from posterior 1/3 of tongue and pharynx;
Special Sensory (Taste) from posterior 1/3 of tongue;
Voluntary motor to one muscle of pharynx;
Visceromotor/Parasympathetic to parotid gland
Foramina: Internal jugular foramen
Cranial nerve X
Name:
Fiber type(s):
Foramina:
Name: Vagus
Fiber type(s): General Sensory (Pain, Touch, Temperature) from larynx;
Special Sensory (Taste) from epiglottis;
Voluntary motor to muscles of larynx and pharynx;
Visceromotor/Parasympathetic to thoracic and abdominal viscera
Foramina: Internal jugular foramen
Cranial nerve XI
Name:
Fiber type(s):
Foramina:
Name: Spinal accessory
Fiber type(s): Voluntary motor to sternocleidomastoid and trapezius
Foramina: Internal jugular foramen
Cranial nerve XII
Name:
Fiber type(s):
Foramina:
Name: Hypoglossal
Fiber type(s): Voluntary motor to muscles of the tongue
Foramina: Hypoglossal foramina
Brainstem/spinal cord passes through what foramina?
Foramen magnum
Why do the cranial nerves take weird routes through skull?
Embryology! As the skull develops, it actually grows around the already-formed nerves, leaving specific holes (foramina) through which the nerves pass
How are the facial nerve (CN VII) and the parotid gland related?
They’re not functionally related but the CN VII passes through parotid gland to get from stylomastoid foramen to the muscles of facial expression. If the gland gets a tumor, then it affects the CN VII
11 muscles of facial expressions that we need to know:
- Depressor anguli oris
- Depressor labii inferioris
- Mentalis
- Orbicularis oris
- Buccinator
- Zygomaticus major
- Levator labii superioris
- Levator anguli oris
- Orbicularis oculi
- Occipitofrontalis
- Platysma
Depressor anguli oris
Cranial nerve(s)/fiber type:
Function:
CN/Fiber: Facial (VII)/voluntary motor
Function: Draws the corner of the mouth downward and laterally; for frowning
Depressor labii inferioris
Cranial nerve(s)/fiber type:
Function:
CN/Fiber: Facial (VII)/voluntary motor
Function: Draws the lower lip downward; for pouting
Mentalis
Cranial nerve(s)/fiber type:
Function:
CN/Fiber: Facial (VII)/voluntary motor
Function: Elevates and protrudes the lower lip
Orbicularis oris
Cranial nerve(s)/fiber type:
Function:
CN/Fiber: Facial (VII)/voluntary motor
Function: (The sphincter of the mouth) purses the lips, or “puckering”; essential for articulate speech
Buccinator
Cranial nerve(s)/fiber type:
Function:
CN/Fiber: Facial (VII)/voluntary motor
Function: (Forms the wall of the cheek) compresses the cheek wall against the teeth; important for sucking and keeping food within teeth for effective chewing
Zygomaticus major
Cranial nerve(s)/fiber type:
Function:
CN/Fiber: Facial (VII)/voluntary motor
Function: Draws the angle of the mouth upward and laterally; it’s the smiling muscle
Levator labii superioris
Cranial nerve(s)/fiber type:
Function:
CN/Fiber: Facial (VII)/voluntary motor
Function: Raises and everts the upper lip
Levator anguli oris
Cranial nerve(s)/fiber type:
Function:
CN/Fiber: Facial (VII)/voluntary motor
Function: Raises the angle of the mouth; for sneering
Orbicularis oculi
Cranial nerve(s)/fiber type:
Function:
CN/Fiber: Facial (VII)/voluntary motor
Function: (The sphincter of the eye) closes the eyes & spreads tears across the surface of the eye
Occipitofrontalis (epicranius)
Cranial nerve(s)/fiber type:
Function:
CN/Fiber: Facial (VII)/voluntary motor
Function: wrinkles the forehead and raises eyebrows (frontalis only); move scalp (both)
Platysma
Cranial nerve(s)/fiber type:
Function:
CN/Fiber: Facial (VII)/voluntary motor
Function: Draws down the lower lip and corners of the mouth; for expressions of horror and for saying the word ‘platysma’
Damage or lesions to the motor component of anywhere on the facial nerve (CN VII) can lead to
Facial paralysis
Masseter
Cranial nerve(s)/fiber type:
Function:
Cranial nerve(s)/fiber type: Trigeminal (V) (V3)/Voluntary motor Function: Elevation of the mandible, but also protracts slightly
Temporalis
Cranial nerve(s)/fiber type:
Function:
Cranial nerve(s)/fiber type: Trigeminal (V) (V3)/Voluntary motor Function: Elevation and retraction of mandible
Lateral pterygoid
Cranial nerve(s)/fiber type:
Function:
Cranial nerve(s)/fiber type: Trigeminal (V) (V3)/Voluntary motor Function: Protract mandible (bilateral); deviate mandible to the opposite side (unilateral)
Medial pterygoid
Cranial nerve(s)/fiber type:
Function:
Cranial nerve(s)/fiber type: Trigeminal (V) (V3)/Voluntary motor Function: Elevation of the mandible, with slight protraction
CN V (V1) cutaneous branch:
Foramina:
Innervates:
CN V (V1) cutaneous branch: Supraorbital nerve
Foramina: Supraorbital foramen
Innervates: General sensation of upper face, head, and orbit
Corneal reflex
CN’s/fibers involved:
CN V (V1) (general sensory) CN VII (voluntary motor --> orbicularis oculi)
CN V (V2) cutaneous branch:
Foramina:
Innervates:
CN V (V2) cutaneous branch: Infraorbital foramen
Foramina: Infraorbital foramen
Innervates: General sensory of mid-face skin region, upper teeth, posterior parts of nasal cavity, and maxillary sinus
CN V (V3) cutaneous branch:
Foramina:
Innervates:
CN V (V3) cutaneous branch: Inferior alveolar nerve; mental nerve
Foramina: Mandibular foramen; mental foramen
Innervates: General sensory of lower teeth; general sensory of chin skin
4 muscles of mastication are
- Masseter
- Temporalis
- Medial pterygoid
- Lateral pterygoid
Temporomandibular joint
Synovial, fibrocartilage joint btwn mandibular condyle and mandibular fossa
The upper joint cavity and lower joint cavity of the TMJ is separated by what structure
Fibrocartilaginous interarticular disk
Upper joint cavity and lower joint cavity involvement of jaw opening
Upper joint cavity: Forward gliding (protraction) movements of TMJ when mouth open wide
Lower joint cavity: Hinge movements of TMJ when mouth open to 15 degrees
3 sets of cardinal movements at TMJ
- Protraction/retraction (gliding forward/backward): upper joint cavity
- Depression/elevation: upper and lower joint cavity
- Rotation/deviation (side-to-side): upper joint cavity
Mylohyoid muscle
Cranial nerve(s)/fiber type:
Function:
Cranial nerve(s)/fiber type: Trigeminal (V) (V3) voluntary motor Function: play role movements in mandible and in swallowing
Anterior belly of digastric muscle
Cranial nerve(s)/fiber type:
Function:
Cranial nerve(s)/fiber type: Trigeminal (V) (V3) voluntary motor Function: play role movements in mandible and in swallowing
Common causes of temporomandibular joint disorder
- Erosion or misalignment of interarticular disk
- Damage to articular cartilage
- Injury due to an impact to jaw
What kind of cells are the surface of the tongue covered with
Stratified squamous epithelium, keratinized (like epidermis!)
Taste buds
Cranial nerve(s)/fiber type:
Function:
Cranial nerve(s)/fiber type(s): Facial (VII), Glossopharyngeal (IX), and Vagus (X)/chemosensory (special sensory) Function: Taste!
Intrinsic muscles of the tongue
Cranial nerve(s)/fiber type:
Function:
Cranial nerve(s)/fiber type: Hypoglossal (XII)/voluntary motor Function: Changes the shape of the tongue in the mouth
Hypoglossus (external muscle) Cranial nerve(s)/fiber type: Function:
Cranial nerve(s)/fiber type: Hypoglossal (XII)/voluntary motor Function: Flattens and depresses the tongue by pulling it down
Styloglossus (external muscle) Cranial nerve(s)/fiber type: Function:
Cranial nerve(s)/fiber type: Hypoglossal (XII)/voluntary motor Function: Pulls the tongue upward and backwards (retrusion)
Genioglossus (external muscle) Cranial nerve(s)/fiber type: Function:
Cranial nerve(s)/fiber type: Hypoglossal (XII)/voluntary motor Function: Pulls the tongue forward (protrusion)
Which cranial nerve is affected if the protruding tongue deviates to one side?
Hypoglossal (XII)
What 5 cranial nerves innervate the tongue, what fibers, and what areas of the tongue?
- Trigeminal (V3): general sensory of anterior 2/3 tongue
- Facial (VII): special sensory of anterior 2/3 tongue
- Glossopharyngeal (IX): general sensory and special sensory of posterior 1/3 tongue
- Vagus (X): special sensory at base of tongue/epiglottis
- Hypoglossal (XII): voluntary motor of entire tongue
2 phases of the patterned motor response in swallowing
- Voluntary phase: moves bolus from mouth to oropharynx
2. Involuntary (reflexive) phase: moves bolus through pharynx and into esophagus
What actions are being done in voluntary phase and what cranial nerve(s) is involved?
Contraction of intrinsic and extrinsic muscles of tongue (CN XII)
What actions are being done in involuntary (reflexive) phase and what cranial nerve(s) is involved?
- Elevation of palate, pharynx, hyoid bone, and larynx (CN V, VII, IX, X)
- Sequential constriction of muscles of pharynx (CN X)
- Closure of larygneal opening, to protect airway (CN X)
- Relaxation of upper esophageal sphincter (CN X)
Sensory and motor input for:
If something touches your eye, you blink
Sensory input from corneal surface: via V1
Motor output to orbicularis oculi muscle: via VII
Sensory and motor input for:
If something is flying toward your eye, you blink
Sensory input from retina (vision): via II
Motor output to orbicularis oculi muscle: via VII
(Same output as the corneal reflex, but a different input)
Sensory and motor input for:
Shine a light in your eye, pupils constrict
Sensory input from retina (vision): via II
Motor output to pupillary sphincter (a smooth muscle): via III (visceromotor/parasympathetic)
Sensory and motor input for:
Something irritates your nasal mucosa, you sneeze
Sensory input from lining of nasal cavity: via V1 or V2
Motor output to diaphragm, thoracic and abdominal wall muscles: via spinal cord
Sensory and motor input for:
Something irritates your upper airway, you cough
Sensory input from larynx: via X
Motor output to diaphragm, thoracic and abdominal wall muscles: via spinal cord
Sensory and motor input for:
Something irritates the inside of your pharynx, you gag
Sensory input from lining of pharynx: via IX
Motor output to pharyngeal muscles: via X
4 sites of facial nerve (CN VII) damage
- Within cranial cavity: acoustic neuroma
- Within bones of skull: fracture of temporal bone
- On surface: parotid gland tumor
- Through course of VII: viral infection (Bell’s Palsy)
TMJ replacement
Mandibular condyle w/ metal
Mandibular fossa w/ plastic
DISK IS NOT REPLACED.
Levator papebrae
Cranial nerve(s)/fiber type:
Function:
Cranial nerve(s)/fiber type: Oculomotor (CN III)/voluntary motor Function: opens eyelid
Pharynx muscles
Cranial nerve(s)/fiber type:
Function:
Cranial nerve(s)/fiber type: Vagus (CN X)/voluntary motor Function: Peristalsis and retroperistalsis
Larynx vocal apparatus structure
Vestibular fold (false vocal cord), ventricle (space), vocal fold (true vocal cord)
Larynx muscles
Cranial nerve(s)/fiber type:
Function:
Cranial nerve(s)/fiber type: Vagus (CN X)/motor Function: Change length and tension of vocal ligaments and regulate airway
3 salivary (spit) glands and their cranial nerves
Parotid gland: Glossopharyngeal N. (IX)
Submandibular & Sublingual glands: Facial N. (VII)
Lacrimal (tear) gland innervated by which cranial nerve?
Facial (CN VII)
Glands of nasal and oral mucosa (snot) innervated by which cranial nerve?
Facial (CN VII)
4 bones of the pterion region
- Frontal
- Parietal
- Temporal
- Sphenoid
Zygomatic arch formed by which bone?
Zygomatic bone and temporal bone
Hard palate separates which two cavities?
Nasal cavity and oral cavity
Neurocranium
Part o f the skull that surrounds brain
Viscerocranium
Part of skull that comprises of facial skeleton
Neurocranium divided in 2 parts:
- Calvaria (skull cap): covers bone on top
2. Cranial base: separates brain from rest of head)
Middle meningeal artery
Located deep to pterion, it enters cranial cavity to supply dura mater surrounding brain
3 bones of orbit region
- Frontal
2 Maxilla - Zygomatic
3 bones of medial wall of orbit
- Lacrimal
- Ethmoid
- Palatine
Bone of posterior orbit
Sphenoid
3 sutures of the skull
- Coronal suture
- Sagittal suture
- Lambdoid suture
4 paranasal sinuses
- Frontal
- Sphenoid
- Ethmoid
- Maxillary
Systemic circulation
Arteries v. Veins
Arteries: carry oxygenated blood to body
Veins: carry deoxygenated blood from body
Pulmonary circulation
Arteries v. Veins
Arteries: carry deoxygenated blood to lungs
Veins: carry oxygenated blood from lungs
Which side of the heart is associated w/ pulmonary circulation?
Right heart takes deoxygenated blood from body to lungs
Which side of the heart is associated w/ systemic circulation?
Left heart takes oxygenated blood from lungs to body
Blood flow starting w/ right heart to left heart
Right heart
1. Deoxygenated blood from body goes into IVC and SVC –> right atrium –> tricuspid valve –> right ventricle –> –> semilunar valve –> pulmonary trunk –> lungs
Left heart
2. Oxygenated blood from lungs goes into pulmonary veins –> left atrium –> bicuspid valve –> left ventricle –> aortic valve –> aorta –> body
Interventricular septum
Wall separating ventricles of heart
Fossa ovalis
Depression in the interatrial septum of the right atrium (remnant of fetal circulation)
Atrioventricular valves
Regulate blood flow from atria to ventricles. Open in right heart when atria contracts (tricuspid); close in left heart when ventricles contract (bicuspid/mitral)
Semilunar valves
Regulate blood flow from ventricles to aorta/pulmonary trunk. Close when atria contract (pulmonary valve); open when ventricles contract (aortic valve).
Coronary circulation
Provides oxygenated blood supply from heart to heart tissue
Where does the deoxygenated blood go in coronary circulation?
Deoxygenated blood in all coronary veins drain into coronary sinus, which empties into right atrium
Stent
Mesh stent keeps coronary artery open
Coronary bypass
Vessels taken from other parts of body and attached to aorta on one end and existing vessel on the other
Common vessels taken for coronary bypass
- Great saphenous vein
- Radial artery
- Internal thoracic artery
Lymphatic system
Leftover plasma that weren’t able to get reabsorbed back to blood during capillary exchange get stuck in interstitial fluid. The lymphatic system provides an accessory return route to blood in thorax for the leftover plasma.
Lymph nodes
Filters out pathogens from plasma fluid and try to stop infection before it gets returned to venous system.
Right lymphatic duct
Drains right upper limb, thorax, and head
Thoracic duct
Drains majority of body, empties at junction of left internal jugular vein/subclavian vein
Lymphedema
Any disruption of lymphatic vessels can cause accumulation of extra fluid and particles in tissues.
Common treatment for lymphedema
Compression bandages or hand “milking” (pushing fluid back into venous system)
2 respiratory system airways
- Conducting airways
2. Respiratory airways
Conducting airways functions
Condition, filter, and transport incoming air in respiratory system (nasal cavity, pharynx, larynx)
Respiratory airways function
Gas exchange in respiratory system (lungs)
Pleural sac
Encases each lung w/ double-walled sac (parietal and visceral layers w/ fluid in-btwn) and allows friction-free movement during respiration
Hilum of each lung
Hilum is the large triangular depression where the connection btwn the parietal pleura (covering rib cage) and visceral pleura (covering lung) is made.
Root of the lung
Located at each hilum and is formed by:
- Bronchii
- Pulmonary A/V (for oxygenation)
- Bronchial A/V (to supply lung tissue)
- Lymphatics
- Nerves
Branching of airways of respiratory tract
Trachea –> primary bronchii (to right or left lung) –> secondary bronchi (to each lobe of lung; 2 on left, 3 on right) –> tertiary bronchi (to each bronchopulmonary segment)
What happens if you remove a bronchopulmonary segment?
Each segment is an anatomically and functionally independent unit. Each can be removed without affecting the rest of the lung
Gas exchange between pulmonary artery and lungs
Pulmonary artery (deoxygenated blood) runs with airway to alveoli where gas exchange occurs; pulmonary vein (oxygenated blood) runs separately from airway.
Thoracoabdominal diaphragm
Sheet of muscle (separating thoracic cavity and abdominal cavity) that has receives motor innervation from phrenic nerve to allow lungs to contract and flatten for inspiration
How much does thoracoabdmoinal diaphragm move with each breath?
4-6 cm
3 major foramina of thoracoabdmoinal diaphragm
- Vena caval foramen
- Esophageal hiatus
- Aortic hiatus
What runs through the vena caval foramen of the thoracoabdominal diaphragm?
Inferior vena cava, right phrenic nerve
What runs through the esophageal hiatus of the thoracoabdominal diaphragm?
Esophagus, right and left vagal trunks
What runs through the aortic hiatus of the thoracoabdominal diaphragm?
Aorta, thoracic duct
Anterior cervical triangle contains
Common carotid artery and internal jugular vein
Posterior cervical triangle contains
Sensory branches of cervical plexus and spinal accessory (CN XI)
Suboccipital triangle contains
Skeletal muscles that send proprioceptive info from the heads
Suprahyoid (digastric) innervated by
Cranial nerves
Infrahyoid (omohyoid) innervated by
Ansa cervicalis
Scalenes innervated by
Cervical ventral rami
Hyoid muscles assist with…
Swallowing and speaking
Ansa cervicalis is made of the motor portion of…
Cervical plexus (C1-C3)
Which ribs articulate directly with the sternum?
Ribs 1-7
Which ribs articulate with the sternum through common costal cartilage?
Ribs 8-10
Which ribs do not articulate with the sternum?
Ribs 11-12
How many vertebrae covered by each muscle in transversospinae group?
- Semispinalis (4-6)
- Rotatores (1-2)
- Multifidus (2-4)
Classify pivot joint by its degree of movement
Uniaxial
Lumbar cistern
Filled with CSF; cauda equina here; place for lumbar puncture
What layers would a needle have to go through to get to CSF in lumbar cistern?
- Supraspinous ligament
- Interspinous ligament
- Ligamentum flava
- Epidural space
- Dura mater
- Arachnoid layer
Which 2 cranial nerves innervate mechanical digestion in oral cavity and pharynx via use of muscles of mastication and movement of tongue?
CN V3 (muscles of mastication) and CN XII (muscles of tongue)
The patterned motr response of swallowing starts when food enters the ___.
Oropharynx
Steps of swallowing
- Soft palate pulled up to block nasal cavity.
- Pharynx contract in series to move bolus inferiorly. Pharynx innervated by CN X.
- At same time, epiglottis pushed down to close off airway and food is directed down laryngopharynx.
- Laryngopharynx is continuous inferiorly w/ esophagus.
Nasopharynx
Air only; ends at inferior border of uvula (soft palate)
Oropharynx
Soft palate to epiglottis; respiratory and digestive
Laryngopharynx
Air and food superiorly; only food inferiorly; contin. w/ esophagus
Pyloric sphincter of the stomach releases food into the ___.
Small intestine
2 ducts join to empty into proximal duodenum
- Common bile duct
2. Pancreatic duct
Name the segments of large intestine in the order that food would pass through it
- Ascending colon
- Transverse colon
- Descending colon
- Sigmoid colon
What vein corresponds with the anterior interventricular artery?
Great cardiac vein
What vein corresponds with the posterior interventricular artery?
Middle cardiac vein
What vein corresponds with the marginal artery?
Small cardiac vein
