Functional Human Anatomy Exam 2

Layers of the head to brain

Scalp

Epicranial Aponeurosis

Cranium (bone layer)

Dura Mater

Arachnoid mater

Pis mater (covering cerebral cortex)

6 major regions of the brain

Cerebrum

Cerebellum

Medulla oblongata

Pons

Mesencephalon (midbrain)

Diencephalon

Cerebral Hemispheres (cerebrum)

left:

- receives and send motor output to the right side of the body

right:

- receives info and sends motor output to the left side of the body

What separates both hemispheres

Longitudinal fissure

what connects both hemispheres

Corupus callosum

Cortex (gray matter)

sulci - the groves

gyri- folds/ridges

both make up the surface of the cortex

Basal Ganglia

produces dopamine

subcortical - under cerebral cortex

Limbic System

nuclei & cortical structures:

- thalamus

- hypothalamus

- hippocampus

- amygdala (memory, decision making)

- olfactory bulb (sense of smell, emotion & memory)

what are the 4 lobes of the cerebrum?

frontal, parietal, temporal, occipital

frontal lobe

- contains prefrontal cortex

- primary motor cortex

- center for motor control

parietal lobe

- primary somatosensory cortex

- somatosensory association area

- takes in sense info & process it in the association area

temporal lobe

- auditory cortex

- olfactory cortex

occipital lobe

- center for vision

- visual association area

cerebellum

- controls balance & smooth motor functions

- "little brain" in latin

medulla oblongata

relays sensory info to thalamus and other portions of the brainstem

pons

- relays sensory info to cerebellum and thalamus

- "bridge" in latin

- point of cranial nerves

mesecephalon (midbrain)

- processing of visual and auditory data

- generating reflexive somatic motor response

- maintaining consciousness

- "middle" in Greek

Diencephalon (subdivisions)

- subcortical area

Subdivisions:

- epithalamus (3rd eye)

- thalamus

- hypothalamus

epithalamus

- 3rd eye

- pineal gland (endocrine gland) produce melatonin to support sleep cycles

- posterior to thalamus and hypothalamus

thalamus

relays and processes sensory information

hypothalamus

- inferior to thalamus

- important to nerve and endocrine systems

- role in controlling emotions

Ventricles of the brain (4)

- cerebral spinal fluid is made here

-lateral ventricles (1&2, in the 2 hemispheres)

-3rd ventricle

-4th ventricle

interventricular foramen

allows communication from lateral ventricles to 3rd ventricle

cerebal aqueduct

allows communication fronm 3rd ventricle to 4th ventricle

cranial nerves (12 pairs, CNI - CnXII)

Olfactory

Optic

Oculomotor

Trochlea

Trigeminal

Abducens

Facial

Vestibulocochlear

Glossopharyngeal

Vagus

Accessory

Hypoglossal

nemonic: oh oh oh to touch ad feel very good velvet ah heaven

sensory, motor, both nemonic for cranial nerves

some say marry money but my brother says big brains matter more

4 nerve plexuses

cervical, brachial, lumbar, sacral

cervical plexus

C1-C4

- provide sensory input from head, neck, shoulder

- nerve root

- 2 cranial nerve 11 & 12

- 11 (accessory)

- 12 (hypoglossal nerve)

brachial plexus

C5-T1 (most complicated)

- spinal cord > 6 roots > 3 trunks > 2 division > 3 cords > nerves (read the damn cadaver notes)

- nerves come off of cords with specific names and functions

roots (C5-T1)

trunks (superior, middle, inferior)

division (anterior & posterior)

cords (posterior, lateral, medial)

trunks of brachial plexus

superior C5-C6

middle C7

inferior C8&T1

Lateral cord of brachial plexus

superior division of (superior and middle trunk)

Medial cord of brachial plexus

anterior division of inferior trunk

posterior cord of brachial plexus

takes all trunks

lumbar plexus

T12-L4

- provide innervation to some abdominal muscles

- innervate to thigh

- sensory to regions of the thigh, genitalia, leg, foot

sacral plexus

L4-S4

- provide muscular innervation to glutes, leg muscles

- sensory to posterior thigh & leg

- motor of sphincter muscles

- sensory to genitalia

sciatic nerve (sacral plexus)

- biggest nerve in human body

- runs down posterior leg

- splits into tibial and common fibular nerve

Dermatomes (sacral plexus)

area of the skin that is mainly supplied by branches of a single spinal sensory nerve root

Reflex

- immediate involuntary motor response

Reflex arc

- neural "wiring" of a single reflex

- begins at a sensory receptor and ends at a peripheral effector

Contralateral

on the opposite side of the body from another structure

CNI

Olfactory (Sensory):

- smell

- olfactory nerves fibers from from cribriform plate of ethmoid

CNII

Optic (sensory):

- vision

- visual info to ganglia

CNIII

Oculomotor (motor):

- eye muscles

- 6 extra ocular muscles that move the eye ball around

- 4/6 controlled by ocular motor nerves

- innervates the levator palpebral (muscles that controls the eyelid)

- superior/inferior & medial rectus muscles & inferior oblique muscles innervated by oculi motor nerves

- inferior oblique contracts makes pupils go outward an dup

CNIV

Trochlea (motor):

- innervate superior oblique muscle

- when contracted draws pupils inferiorly & outward, opposite of inferior oblique

CNV

Trigeminal (sensory & motor):

- pick up sensory info from head and face

- provide motor muscles and mastication

CNVI

Abducens (motor):

- innervate lateral rectus muscles

CNVII

Facial (sensory):

- innervate muscles of facial expression

- provide sensation for part of ear and part of face

CNVIII

Vestibulocochlear (sensory):

CNIX

Glossopharyngeal (sensory & motor):

- vestibular division (balance)

- choclear division (hearing sensation)

- vertigo (damage to nerves, loss sense of balanceO

CNX

Vagus (sensory & motor):

- comes from brain stem and extends into visceral systems

- picks up sensory info from visceral systems and some external ear

CNXI

Accessory (motor):

- innervate accessory muscles (inspiration)

- used when trying to breath when you have difficulty

- receives fibers from cervical plexus

- sternocleidomastoid (inspiration muscles)

- trapezius (inspiration muscles)

CNXII

Hypoglossal (motor):

- sensory for tongue and pharynx

- motor to pharynx

The autonomic nervous system (ANS) functions.......?

outside of our conscious awareness

the ANS works hard to maintain....?

homestasis

the ANS controls?

body temp and internal systems (respiratory, digestive, reproductive, cardiovascular, excretory)

Neurons of autonomic nervous system

efferent axons: innervate visceral organs

afferent axons: originate in visceral sensory

receptors

Neurons in somatic nervous system

efferent axons: innervate skeletal muscles

afferent axons: originate in the skeletal

muscles, joints, and skin

subdivisions of ANS

sympathetic and parasympathetic

sympathetic divison

- also known as thoracolumbar division

- fight or flight system

- most active during time of stress, excitement, emergency

preganglionic neuron (sympathetic)

- located in lateral horns of spinal segments (T1-L2)

- release acetylcholine (ACh) which stimulates ganglionic neurons

ganglionic neurons

located in:

sympathetic chain ganglia

collateral ganglia

adrenal medulla

postganglionic fibers (sympathetic)

- release norepinephrine

organs during sympathetic (fight or flight)

-heart/respiratory rate increases

- digestive system, urination system & reproductive system inhibited

- pupils dilate

Adrenal medulla

-releases epinephrine (adrenaline) and norepinephrine (noradrenaline)

- circulating blood distributes these hormones throughout the body

parasympathetic division

- also known as craniosacral division (rest & digest)

- more active during resting conditions

preganglionic neuron of parasympathetic division

-located in brainstem and lateral portion of anterior horns of spinal segments (S2-S4)

-release ACh, excite & stimulates ganglionic neurons

- form distinct pelvic nerves

ganglionic neurons of parasympathetic

located in peripheral ganglia within or adjacent to the target organs

Enteric Nervous System (ENS)

- 3rd division of autonomic nervous system

- neurons located in walls of digestive tracts

- many visceral reflexes are initiated by ENS, but receive input from ANS

effects of sympathetic stimulation

-increase alertness (pupil dilation)

- feeling of energy & euphoria (excitement, high adrenaline)

- increased cardiovascular activity (faster Hr, more blood to muscles)

- increased respiratory activity (more O2 in)

- elevation in muscle tone

- mobilization of energy reserves ( fuel muscles, getting body ready for action)

effects of parasympathetic stimulation

- constrict pupils

- secretion of digestive glands

- secretion of hormones promoting nutrient absorption

- increased smooth muscle activity along digestive tract

- stimulate and coordination of defecation

- contracting urinary bladder during urination

- reduction of Hr

- constrict respiratory passageway

- sexual arousal

relationship between sympathetic and parasympathetic divisions

-duals innervation: most vital organs are innervated by both divisions

-both divisions often have opposite/ antagonistic effects

-part of maintaining homeostasis

release of ACh

sympathetic - preganglionic release ACh, postganglionic release noreepinephrine

parasympathetic - both pre- & postganglionic release ACh

Upper respiratory system

noce, nasal cavity, paranasal sinuses, and pahrynx

lower respirtory system

larynx, trachea, bronchi, lungs, bronchioles, alveoli

Functions of the Repiratory System

- gas exchange between air & blood

- moves air to and from exchange surface of lungs

- protects respiratory system from dehydration

- protection against invading pathogens

- produces sound in verbal communication

Respiratory Epithelium

contains numerous mucous cells that produce sticky mucus that bathes the exposed surfaces

contamination of inspired air by pathogens/debris will?

damage the delicate surfaces of respiratory system

what happens in the conducting portion of respiratory system?

filtration, warming and humidification of inhaled air

alveolar ducts and sacs / alveoli

alveolar duct: attachment point for respiratory bronchioles

alveolar sacs: end of alveolar ducts

alveoli: 150 million in each lung

capillaries surrounding alveolus

extensive network of capillaries drop off carbon dioxide and pick up oxygen

type 1 alveolar cells

lines alveoli

type 2 alveolar cells

- scattered among type 1 alveolar cells

- secrete surfactant that prevents alveolar collapse

alveolar macrophages

wander around phagocytizing (ingest) particulate matter

Gas exchange occurs where?

blood air barrier:

- alveolar cell layer

- capillary endothelium

- fused basement membrane between alveolar cells and capillary endothelium

gas exchange process

- CO2 leaves capillaries and enters the alveolar sacs

- O2 leaves alveolar sacs and enter the capillaries

blood supply to lungs

- pulmonary arteries branch repeatedly within lungs before supplying the pulmonary capillaries

- pulmonary veins deliver blood to heart

lung cancer

- aggressive class of malignancies

- affects epithelial cells lining conducting passageways or alveoli

right and left pleural cavities are separated by the... ?

mediastinum

serous membrane

- lines each lung

- made of 2 continuous layers (pleura)

visceral pleura: covers outer surface of lung

parietal pleura: covers inner lining of thoracic wall, mediastinum and superior surface of diaphragm

plerual cavity

fluid-filled space between visceral and parietal pleurae

pleural fluid

- reduced friction when lungs move upon inhalation and exhalation

pleurisy

may cause membranes to produce and secrete excess pleural fluid or cause inflamed pleurae to adhere to one another

ANS in pulmonary ventilation

adjust breathing rate and depth to body's metabolic needs

intricate neural circuits (ventilation)

relays info from brain, lungs and other sensors throughout the body to coordinate ventilatory control

what governs the normal respiratory cycle?

inherent activity of inspiratory neurons w/ cell bodies in medulla oblongata

what is known as the respiratory center?

medulla oblongata

neurons of medulla oblongata

activate diaphragm and intercostal muscles to cause lungs to inflate

What % of body weight is blood?

7%

pregnant women has ____% more blood

50%

blood helps to stabilize?

body temp