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