Anatomy Test 2 Flashcards
Remember that to cause movement, a muscle must ______ this ______ the muscle and changes the distance between two bones
contract, shortens
Relationship between muscles and joints
-MOST muscles that cross a joint work around all axes of rotation associated with that joint (but best around 1 of those axes)
Since their action on the skeleton depends on WHERE they are located, you should be able to figure out the movements which muscles cause, by….
- looking at the direction of the muscle fibers, how the muscle fibers contract and shorten?
- determining which pair of movements around each axis that muscle may perform
- will it flex or extend, abduct or adduct, medially or laterally rotate?
The biceps _____ and the distance between the arm and forearm is _____
contracts (shortens), reduced
Muscles never _____
push
When bending arm to touch face, what muscles, joints, rotation, and movement being done?
muscle: biceps
joint: elbow
axis of rotation: horizontal
movement: flexion
Generality: the muscles that cross the elbow joint move the forearm
The muscles that cross the SC joint move the ______
shoulder (sternoclavicular joint)
The muscles that cross the ______ move the shoulder
SC joint (sternoclavicular joint)
The muscles that cross the shoulder joint move the _____
arm
The muscles that cross the _______ move the arm
shoulder joint
The muscles that cross the elbow joint move the ______
forearm
the muscles that cross the _______ move the forearm
elbow joint
The muscles that cross the wrist joint move the _____
hand
The muscles that cross the ______ move the hand
wrist joint
The muscles that cross the joints of digits move the _______
fingers
The muscles that cross the ____________ move the fingers
joints of digits
Origin means…
fixed
Insertion means…
moved
Rule of thumb (muscles information)
- most anterior muscles are flexors and MEDIAL ROTATORS (there are of course EXCEPTIONS) (for example from the knee down)
- most posterior muscles are extensions and LATERAL ROTATORS (with some exceptions) (for example from the knee down)
- abduction or adduction depend on whether muscle is superior or inferior to joint (Except: knee down)
Axial Muscles:
- associated with head, vertebral column and thoracic cage
- =60% of skeletal muscles
Appendicular Muscles:
- associated with pectoral and pelvic girdles and limbs
- =40% of skeletal muscles
- appendicular muscles will out weigh the axial muscles because they are larger muscles
What are the muscle groups of the head and neck?
- facial expression
- mastication (chewing)
- eye (control direction of our eye so where we are looking)
- pharynx
- tongue
- larynx
- move the head
Muscles of facial expression are…
frontalis, orbicularis oris, orbicularis oculi, levator labii superioris, zygomaticus, buccinator, depressor labii inferioris
Frontalis
raises eyebrows
Orbicularis oris
puckers lips
Orbicularis oculi
closes eye
Levator labii superioris
raises lip
Zygomaticus
smile
Buccinator
tightens cheecks
depressor labii inferioris
pull lips down
What do these mean?
- orbicularis
- oculi
- oris
- labii
- buccinator
orbicularis=circle oculi=eye oris=mouth labii=lips buccinator=cheek
Muscles of Mastication
“masseter”=chewer
- muscles attach to the mandible
- if you clench your teeth you can feel these muscles contract
- mandible elevators
- masseter and temporalis
Anterior Muscles of the Neck
- Suprahyoid muscles elevate hyoid bone and depress mandible
- chewing, swallowing, talking, singing
- Infrahyoid muscles depress hyoid bone and elevate larynx and pharynx
- head extensor/neck rotator
- sternocleidomastoid, insertion is at the mastoid process, helps with moving head
Posterior Muscles of the Neck
-Longissimus capitis (cut), semispinalis captious, and longissimus capitis are head (neck) extensors
Muscles of the vertebral column
- the overworked muscle group
- extend trunk (keep the trunk erect)
- helps us stand and sit upright
- series of small muscles that keep adding more and interconnect, like a french braid
Muscles of the Anterior Body Wall (1)
- 2 intercostals maintain distance between ribs
- 2 obliques rotate trunk
- transverse abdominis flattens abdomen
- rectus abdominis flexus trunk
- internal and external obliques are used when doing like crunches where you move outwards (or side)
Muscles of Anterior Body Wall (2)
- 3 layers of the abdominal muscles in cross section superficial to deep
- rectus abdominis fibers run up and down
- diaphragm is the primary muscle respiration
Muscles of the Pelvic Floor
- urethral sphincter and anal sphincter
- controls urination and defecation
- contract to hold in pee and relax to pee
Muscles associated with an appendage are ______
layered
Anterior Trunk Muscle
- shoulder protractor
- pulls scapula into back
- serratus anterior
- winged scapula-serratus anterior weak
Posterior Trunk Muscles
- shoulder elevators, depressors and retractors
- weight bearing
- attach to anterior surface of scapula
- shrug shoulders and move backwards to exercise the trapezius
- retraction adduction downward rotation
- levator scapulae, rhomboid group, rhomboid major (deep)
- trapezius (superficial)
Shoulder muscle
- arm abductor
- deltoid
- superficial
Anterior and Posterior Trunk Muscles
- arm medial rotator horizontal adduction=pectoralis major
- arm extensor medial rotator=latissimus dorsi
- superficial
Anterior Shoulder Muscle
- Subscapularis=rotator cuff
- arm rotator; it mainly protects the joint and stabilize
- deep
Posterior shoulder muscles
- 4 muscles: SIT s
- rotator cuff
- subscapularis, infraspinatus, teres minor, supraspinatus
- not teres major
- arm adductor
- deep
Anterior Arm Muscles
- joints are crossed
- deep
- biceps is also a supinator
- coracobrachialis, biceps brachia short head, biceps brachia long head, brachial
- arma and forearm FLEXORS
Posterior Arm Muscles
- triceps brachia long head, triceps brachia lateral head
- arm and forearm EXTENSOR
- triceps means three heads
- joints crossed
- deep
Anterior Forearm Muscles (1)
- pronator teres, brachioradialis, flexor carpi ulnaris (flexes the carpals)
- you can name most forearm muscles by where their tendons attach
- wrist flexors, ct pronator
- superficial
- travels right along radius, hand shake muscle
Anterior Forearm Muscles (2)
- flexor pollicis longus, flexor digitorum superficialis, flexor digitorum profundus
- deep
- finter and thumb flexors
Posterior Forearm Muscles (1)
- extensor carpi radialis longus, extensor carpi radialis brevis, extensor carpi ulnaris, extensor digitorum
- writs and finger extensor
- superficial
Posterior Forearm Muscles (2)
- supinator (deeper), tendon of extensor pollicis longus (deep)
- thumb extensors, ct supinators
- supinator and pronator form a “V” shape
Hand Muscles
-palmar surface
-dorsal surface
-thenar compartment
-hypothenarcompartment
abductors and adductors are intrinsic in the hand, so they are inside the hand
Thenar
thumb
Hypo
little
Gluteal Muscles (1)
- hip extensors and abductors
- gluteus medius, gluteus maximus, tensor fascia latae, gluteus minimus, iliotibial tract
- IT Band Problems for runners (iliotibial tract)
Gluteal Muscles (2)
- hip “lateral rotators”
- piriformis and sciatica
Muscles of the Pelvis and Medial Thigh
- Iliopsoas, iliacus, psoas major are hip flexors
- adductor magnus, adductor brevis, adductor longus, gracilis are hip adductors
muscles of the Posterior Thigh
- easy muscles to tear
- hamstrings
- all hip extensors and knee flexors because they are biarticular muscles
- semitendinosus, biceps femoris long head, semimembranosus, biceps femoris short head
Muscles of Anterior Thigh
- quadriceps, this muscle group is the only one that extends the knee
- group of 4 muscles located on the anterior of knee
- uniarticular muscles (all 3 vastus muscles)
- rectus femoris, vastus lateralis, vastus intermedius, vastus medialis
- sartorius does not do what other quadriceps do
- knee flexor runs medially
Muscles of the Anterior Leg
- toe and foot extensors (dorsiflexors)
- tibialis anterior, extensor hallucis longus, extensor digitorum longus
- tibialis anterior- biarticular muscle, crosses ankle anteriorly
- shin splints
Muscles of the lateral leg
- foot flexors (plantar flexors)
- eversion
- fibularis longus, fibularis brevis
Muscles of Posterior leg
- gastrocnemius lateral head, gastrocnemius medial head, soles, are superficial
- foot flexors (plantar flexors)
- smaller ankles, can jump higher and run faster vs. those with larger calfs
- calcaneal tendon attaches to the calcareous, aka achilles tendon
- toe flexors
Dorsal foot muscles
-toe extensors
Plantar foot muscles
-toe flexors
Anatomical Divisions of the Nervous System
- central nervous system (CNS), includes all nervous tissue in the brain and spinal cord
- peripheral nervous system (PNS), includes all nervous tissue outside of the (“peripheral to”) the CNS, the peripheral nerves
Functions of the CNS (1) (sensory)
- to interpret sensory information from the PNS
- this is incoming or afferent information:
- that is, sensations (pain, temperature, touch)
- from inside and outside the body
- example: you just ate; your stomach gets stretched. You just touched something; it feels HOT!
- CNS=the commander
Functions of the CNS (2) (motor)
- to send motor responses to the PNS
- these are outgoing or efferent commands:
- that is, signals that produce movement
- it controls the actions of muscles in the organs and systems in response to sensations
- Example: your stretched stomach muscles contract to churn the food. You contract a series of skeletal muscles to withdraw your hand from he hot object
Functions of the CNS (3)
- to process and coordinate “higher functions”
- conscious (aware)
- intelligence (ability to recall info)
- memory (storing information)
- learning (how get info)
- emotions
Functions of the PNS
- To deliver sensory information
- from receptors in the periphery (that is, in skin and muscles)
- to the CNS
- To deliver motor commands
- from the CNS
- to muscles in the periphery
The Divisions of the Motor portion of the PNS (1)
- Somatomotor Nervous System (somata=body wall)
- These nerves control skeletal muscle contractor
- Skeletal muscles are associated with:
- Skeleton that is, the body wall
- voluntary (conscious) muscle contractions
- some reference (involuntary muscle contractions)
The 2 Divisions of the MOTOR portion of the PNS (2)
- Autonomic Nervous System (ANS)
- AKA visaromotor nervous system
- these nerves influence smooth and cardiac muscle contractions
- smooth and cardiac muscles are associated with:
- visceral organs (heart, blood vessels, gut)
- involuntary (unconscious) contractions
- glandular secretions (saliva, sweat, tears, gastric juices) because glands are surrounded by smooth muscle
The 2 divisions of the Autonomic Nervous System (ANS)
- Sympathetic division:
- stimulates the body
- fight or flight (heart rate up)
- no clue how it got its name because it is NOT SYMPATHETIC
- Parasympathetic division:
- relaxes the body
- rest and dies (heart rate down)
- “para”= “around” and this system works around the sympathetic
Two Basic Cell Types of Nervous Tissue
- Neurons (nerve cells):
- communicates with send signals to other neurons or muscles in the body
- the longest cell - Neuroglia cells:
- support the neurons
- regulate the ionic environment around neurons
- are essential for the survival and proper functioning of neurons
- act like the secret service for the neurons
Glia=
glue
Components of a typical Neuron (1)
- Cell body:
- contains the nucleus, all the typical organelles
- receives and sums incoming signals from other neurons
- Dendrites:
- may short branches extending from the cell body
- receive incoming signals from other neurons
- information flows from left to right
- 80% of our dendrites form after birth, basically means as babies we are helpless
Components of a typical Neuron (2)
- Axon “nerve fiber”: 1/cell:
- 1 long, thin extension off the cell body
- carries outgoing signals to other neurons or to muscle
- Synaptic or nerve terminals:
- ends of the axon
- transfer signals to other cells
An Action Potential
- Is an electrical signal
- that travels along the axon
- is transmitted (transferred) between two cells
- at the synapse from the presynaptic neuron’s nerve terminals to postsynaptic cell (another neuron/a muscle cell)
Synapse
- is the site of contact between a neuron’s terminals and another cell
- this is how a neuron communicates with other cells
Types of Synapses
- Neuron/neuron junction:
- a synapse between two neurons
- Neuromuscular junction (NMJ):
- a synapse between a neuron and a muscle fiber
Neuron Cell Types
- Sensory neurons
- motor neurons
- interneurons
Sensory Neurons
neurons to deliver/interpret sensory information
Motor Neurons
neurons to deliver motor commands
Interneurons
- neurons between (“inter”) other neurons
- to integrate information: e.g. CNS interneurons process and coordinate “HIGHER FUNCTIONS”
Sensory Receptors
- to detect (“receive”) sensations, pain, temperature, touch
- are also neurons usually
- all this info is carried to the CNS on PNS sensory nerves
- Physical to Electrical
Glial Cells are found in ________ and ________.
peripheral nervous system and central nervous system
Glial cells comprise ______ of the volume of the nervous system.
50%
Schwann
- surrounded axons in PNS
- are responsible for myelination of peripheral axons
- participate in repair process after injury
Oligodendrocytes
- Myelinate CNS axons
- provide structural framework
- looks like a hot dog bun
- myelin helps protect axons
Astrocytes
- maintain blood brain barrier
- provide structural support
- regulate ion, nutrient, and dissolved gas concentrations
- absorb and recycle neurotransmitters
- form scar tissue after injury
- part of CNS
Microglia
- removes cell debris, wastes, and pathogens by phagocytosis
- part of CNS
Myelination
- Myelin:
- is composed of lipids (actually the glia’s cell membrane that wraps around and around the axon!)
- insulates axons (like the insulation around a copper wire)
- increases the speed of action potentials
- Myelin is like fat, not good conductor of electricity
Schwann Cells
- myelinate axons in the PNS
- 1 Schwann cell myelinated only 1 segment of 1 axon
Oligodendroglial Cells
- myelinate axons in the CNS
- 1 Oligodendroglial myelinated only 1 axon segment, but of many axons
Axons are not _____, they are a part of ______.
nerves, neurons
The Spinal Meninges
- Connective tissue layers:
- wraps around the spinal cord from the most superficial to the deepest
- provide the spinal cord with:
1. protection
2. oxygen and nutrients (via the blood vessels) - dura mater (dense irregular C.T.)
- Arachnoid (loose connective tissue)
- Pia Mater (loose connective tissue)
Cerebrospinal Fluid (CSF)
- In a space between arachnoid and pia matter
- this is called the subarachnoid space
- it contains CSF
CSF provides the spinal cord with:
- Chemical protection:
- has an ionic composition similar to blood
- provides nutrients and removes wastes from the neuronal tissue
- Physical protection:
- it absorbs shocks
- it allows the spinal cord to “float” in the vertebral canal
Gross Anatomy of the Spinal Cord Vertebrae:
-Cervical, thoracic, lumbar, sacral
Th Conus Medullaris and Cauda Equina
- conus medullaris
- the caudal end of the spinal cord (cns)
- cauda equina
- means “horse’s tail”
- spinal nerves inferior to the conus modulars (pns)
The spinal cord ends at vertebral level _____ and only _____ _____ extend below the ______ vertebra.
L2, spinal nerves, L2
Spinal Cord Divisions (CNS)
-the spinal cord is divided into gray matter and white matter
(Inner) Gray Matter of the SP.C (CNS)
- Composed of neuron cell bodies:
- Dorsal (posterior) gray matter:
- cell bodies of sensory neurons receive and sum signals from PNS sensory neurons
- Ventral (anterior) gray matter:
- all bodies of motor neurons receive and sums signals from brain motor neurons
(Outer) White Matter of the SP. C (CNS)
- Surrounds the gray matter
- Contains ascending and descending fiber (axons) pathways
- the ascending pathways relay sensory info from the spinal cord to the brain (dorsal afferent)
- descending pathways relay motor commands from the brain to the spinal cord (ventral)
Spinal Nerves (PNS)
- peripheral nerves (bundles of axons)
- mixed nerves:
- contain axons from both sensory and motor neurons
Near the Spinal cord the spinal nerve divides into (1)
- a dorsal root:
- contains axons whose cell bodies are in a dorsal root ganglion (a collection of neuron cell bodies)
- carry sensory info from peripheral receptor to the spic
Near the Spinal Cord the Spinal nerves divide into (2)
- and a ventral root:
- contains axon whose cell bodies are in the spic
- carry motor info from the spinal cord to muscles
A spinal nerve travels through an _________ __________.
intervertebral foramen
Each spinal nerve contains thousands of axons surrounded by __________ _________ wrappings
connective tissue
Different connective tissue wrappings (spinal nerve and axons)
Epineurium, perineurium, endoneurium
Epineurium
- the outermost layer
- surrounds entire spinal nerve
- composed of dense irregular connective tissue
Perineurium
- wraps axons into fascicles (smaller axon bundles)
- composed of dense irregular connective tissue
Endoneurium
- surrounds individual axons
- composed of loose connective tissue
- just outside of the Schwann cell!
Lesion of spinal nerve: “polyneuropathy” both _____ and _____ nerves affected.
sensory and motor
Lesion of spinal nerve: “polyneuropathy” both sensory and motor nerves affected. Characteristics and causes
-loss of sensations and muscle paralysis starting distally at toes and fingers and moving proximally
- Some causes:
1. Diabetes
2. Nutritional problems, alcoholism (neurotoxic; nerve degeneration)
3. Some infections, ex: guillain barre syndrome (aka psotinfectious polyneuritis)
(autoimmune disease following viral or bacterial infection; myelin attacked)
- Lesion of Dorsal root: _____ axons affected
sensory
- Lesion of Dorsal root: sensory axons affected. Characteristics and causes
Characteristics: pain, tingling, or numbness
Some causes: injury (herniated disk), herpes zoster virus (shingles) (flare up of latent chicken pox virus leading to inflammation in DRG)
- Lesion of ventral root ____ axons affected.
motor
- Lesion of ventral root motor axons affected. Characteristics and causes
Characteristics: muscle paralysis
Most common cause:
-polio virus (virus that destroys motor nerves)
- Spinal nerve lesion
- Dorsal root lesion
- Ventral root lesion
a. sensory loss only (pain, numbness)
b. motor loss only (muscle paralysis)
c. sensory and motor loss
- -c
- -a
- -b
Intercostal Nerves
- spinal nerves that travel between ribs
- ribs keep them separated
- innervate: mixed
- muscles of the trunk, motor axons do this
- skin of the trunk, sensory axons do this
Spinal Nerve Plexuses
- Plexus=an interwoven mesh of axons
- Sp.N above and below the ribs form “plexuses”
- innervate:
- muscles of the neck and limbs motor, motor axons do this
- skin of the neck and limbs, sensory axons do this
The Major Spinal Nerve Plexuses
- cervical plexus
- brachial plexus
- lumbosacral plexus
Cervical Plexus
Innervates:
- muscles (motor axons) and skin (sensory axons) of neck
- motor to muscles and sensory from skin to neck
Brachial Plexus
Innervates:
- muscles (motor axons) and skin (sensory axons) of pectoral girdle and upper limbs
- axillary nerve
- median nerve
- ulnar nerve
- radial nerve
- musculocutaneous nerve
Lumbosacral Plexus
Innervates:
-muscles (motor axons) and skin (sensory axons) of pelvic girdle and lower limb
Musculocutaneous Nerve
Its motor innervation: muscles of all anterior (flexor arm)
Its sensory innervation: skin of anterior forearm
Median Nerve
Its motor innervation: most muscles of anterior (flexor) forearm
Its sensory innervation: skin of hand
Ulnar Nerve
Its motor innervation: most muscles of hand
Its sensory innervation: skin of hand
Radial Nerve
Its motor innervation: all muscles of posterior (extensor) arm and forearm
Its sensory innervation: skin of posterior arm, forearm, and hand
Axillary Nerve
Its motor innervation: muscles of shoulder
Its sensory innervation: skin of shoulder
The nerves of the Lumbosacral Plexus
- genitofemoral nerve
- iliophypogastric nerve
- ilioinguinal nerve
- lateral femoral cutaneous nerve
- orbturator nerve
- femoral nerve
- superior and inferior part of Gluteal nerves
- sciatic nerve
- saphenous nerve
Femoral Nerve
Its motor innervation: all muscles of anterior thigh
Its sensory innervation: skin of anterior thigh
Obturator Nerve
Its motor innervation: all muscles of medial thigh
Its sensory innervation: skin of medial thigh
-groin region
Sciatic Nerve
It’s motor innervation: muscles of posterior thigh all thigh and leg and foot
Its sensory innervation: skin of posterior thigh all leg and foot
- note that the sciatic nerve divides into the:
- Tibial nerve (medial, like the bone!)
- Fibular nerve (lateral, like the bone!)
The Cranial Meniges
3 layers:
- dura mater
- drachnoid matter
- pia matter
Function:
-protection of the brain from trauma and of cerebral blood vessels
Cerebral Spinal Fluid (CSF)
- surrounds the entire CNS (in the subarachnoid space)
- Functions of CSF:
- cushions the brain
- provides nutrients to the brain
- removes wastes from the brain
Ventricles of the Brain
- series of fluid-filled chambers deep in the brain
- function: to synthesize and secrete (cerebrospinal fluid)(CSF)
Major Regions of the Brain
- cerebrum
- brianstem
- midbrain
- pons
- medulla
- cerebellum
Cerebrum
- largest part of CNS
- associated with conscious thoughts and behaviors
- conscious and subconscious regulation of skeletal muscle contractions
- memory storage and processing
- conscious thought processes, intellectual functions
- Also controls higher mental functions (intelligence, memory, learning, emotions)
Mid Brain
- processing of visual and auditory date
- generation of reflexive somatic motor responses
- maintenance of consciousness
Pons
- Relays sensory information to cerebellum and thalamus
- subconscious somatic and visceral motor centers
Medulla
- Relays sensory information to thalamus and to other portions of the brain stem
- Autonomic centers for regulation of visceral function (cardiovascular, respiratory, and digestive system activities)
Cerebellum
- coordinates complex somatic motor patterns
- adjusts output of other somatic motor centers in brain and spinal cord
Gray and White Matter of the Cerebrum
- Gray Matter
- composed of neuron cell bodies: - outer surface of the brain called the cerebral cortex
- and some deep areas (the colored regions)
- White Matter
- composed of myelinated axons deep to the cerebral cortex
- axons run inward
The Cerebral Cortex (1/2)
-longitudinal fissure separates cerebral cortex into right and left hemispheres
- the lateral cerebral cortex of each hemisphere is divided into:
- Frontal lobe (somatomotor) (only sends messages to skeletal muscles)
- Parietal Lobe (somatosensory) (info. coming from the skin)
- Temporal lobe (audition, hearing)
- Occipital lobe (vision)
The Cerebral Cortex (3) (Gyri and Sulci)
- Gyri and Sulci increase surface are of each hemisphere
- Gyrus (bulge)
- Sulcus (invagination)
-some bulges and invaginations are the same for every human being, but sometimes they are different
The Cerebral Cortex (4) Lateral Sulcus
-it separates frontal and parietal lobes from temporal lobes
The Cerebral Cortex (5) Central Sulcus
-it separates frontal lobes from parietal lobes
Primary Moto and Sensory Areas of the Cerebral Cortex (1) Precentral Gyrus
- anterior to central sulcus
- part of the frontal lobe
- called the primary somatomotor region
- associated with simple movements (flex/extend a limb)
Motor Homunculus
- neurons in the primary motor cortex correspond point by point with specific regions of the body
- motor homunculus on primary motor cortex of left cerebral hemisphere
- the homunculus provides an indication of the degree of fine motor control for different body regions:
- hands, face, and tongue are capable of complex movements appear very large (many neurons control their muscles)
- the trunk is relatively small (fewer neurons)
- motor commands go out of the brain to the skeletal muscles, if you cut a nerve you cut an axon
- axons carry info from a neuron cell body
-hand, foot, or etc… might twitch when stimulated by electrodes
Primary Motor and Sensory Areas of the Cerebral Cortex (2) Postcentral Gyrus
- posterior to central sulcus
- part of parietal lobe
- is the primary somatosensory region
- associated with basic sensations (pain, temperature)
Sensory Homunculus
- the representation of the human body of the primary sensory cortex
- sensory homunculus of left cerebral hemisphere
- the number of neurons in the sensory cortex devoted to a particular body region is not proportional to the size of that body region, but to the number of sensory receipts associated with that body region
- might feel pain, or hotness like something on fire when stimulated by electrodes, feel sensation
- these areas are more sensitive
- more receptors coming into this region of the brain, which is why more sensitive
- sending more descriminate sensations
- lips, genitalia, toes, hand, etc…
Primary special sensory of the cerebral cortex: Primary visual cortex
- basic info from visual receptors (light vs dark)
- part of occipital lobe
Primary special sensory of the cerebral cortex: Primary auditory cortex
- basic info from auditory receptor (a tone)
- part of temporal lobe
Primary special sensory of the cerebral cortex: Primary Olfactory cortex
- basic info from olfactory receptors (simple odor) (your nose)
- part of temporal lobe
List the primary special sensory’s of the cerebral cortex
- primary visual cortex
- primary auditory cortex
- primary olfactory cortex
Association Cortex (areas)
- The rest (MOST) (i.e.neuron cell bodies) of the cerebral cortex
- for “higher order info”
- Sensory association cortex: interprets sensory info, how do I FEEL about that pain in my arm
- Motor association cortex: plans, coordinates complex motor info, opening a can of pop
Examples of Association Areas: Speech Centers
- Wernicke’s area= the sensory region for understanding speech being spoken to you
- Broca’s area= the motor region for speaking (that is, replying to what has been spoken to you)
- Ex: Gabby Gifford had a gun shot wound to the broker’s area
- so she can understand what people are saying because wrenches’ area was fine, but can not talk or write because Broca’s are is affected
Examples of Association Areas: Prefrontal Cortex
-important for associations between actions and their consequences, reason, moral judgments, appropriate behavior, working memory (short term memory) and consciousness, self awareness, willpower
- Prefrontal lobotomy: prevents the above from occurring
- Pre= meaning more anterior
- individuals with a lot of concussions often fall into depression, rage outburst, alzheimers, due to damage to prefrontal cortex
- strokes in prefrontal cortex often go unnoticed in nursing homes, result in little behavior changes, called minor strokes
- Phineus gage
- rod in head
- changed who ppl. though of brain
Cerebral White Matter
- internal capsule:
- axons that connect neuron cell bodies between the cerebral cortex and the spinal cord - association fibers:
- axons that connect neuron cell bodies (that is, cortical regions) within 2 hemispheres
- Ex: between somatosensory and somatomotor neurons - corpus callosum
- axons that connect neuron cell bodies between the hemispheres
Principle functions of the cerebrum
- Each cerebral hemisphere receives sensory information from, and sends motor commands to, the opposite (contralateral) side of body
- The 2 hemispheres have some different functions although their structures are alike (ex: speech is primarily associated with the left hemisphere)
Hemispheric Lateralization
- each cerebral hemisphere performs certain functions not performed by the other hemisphere
- the corpus callosum informs one side as to what the other is doing
- in most people, the left hemisphere is considered dominant
The discovery of hemispheric differences
- the left hemisphere is associated with speech
- the right hemisphere is associated with manipulative tasks
The Limbic System
-consists of cell bodies and axon tracts (colored regions) of the medial cerebral cortex that are associated with: emotions and memory
Thalamus
- “gateway to the brain”
- a group of neuron cell bodies that process sensory info from the spinal cord
- send it to the cerebral cortex (consciousness)
Hypothalamus
- hypo=below
- Has 3 roles:
- As nervous tissue: controls the ANS
- As the Integrator between the nervous and endocrine systems: Secretes regulatory hormones that control endocrine cell secretion in the pituitary gland
- As an Endocrine organ: secretes the hormones ADH and oxytocin, oxytocin released it is a smooth muscle contraction
- Oxytocin released in labor and stress
- ADH= antidiarreatichormones
Pituitary Gland
- major endocrine gland (hormone producer)
- connected to hypothalamus via infundibulum (stalk)
-infundibulum is what attaches the pituitary gland
The Basal Ganglia
- neuron cell bodies embedded in the white matter of the cerebrum
- involved with: planning movements before they occur
- pathology associated with Parkinson’s Disease, resting tremor
- deep gray matter
Cerebellum
- means “the little cerebrum”
- contains neuron cell bodies and axon tracts
- involved with: intention tremor, coordination and balance of movements as they occur
- refinement of skills also associated with this area
- learning a new motor skill
The Brain Stem, location and components
- location: between spinal cord and cerebrum
- Components: midbrain, pons, medulla
Function of the Brain Stem
- composed of axons carrying information between spinal cord and cerebral cortex which extend out and form 12 pairs of cranial nerves to control most basic functions necessary for survival, including:
- breathing
- heart rate
- digestion
- circulation
