human anatomy Flashcards
anatomical position
Standing, with head, palms and feet facing
forward, penis erect
prone (face down) & supine (face up)
superior (cranial) meaning
toward crown/nearer to the head
inferior (caudal) meaning
toward sole/nearer to feet
anterior (ventral)
toward/nearer to front of body
posterior (dorsal)
toward/nearer to back of body
medial
toward midline
lateral
away from midline
proximal
toward centre
distal
away from centre
superficial
near surface
deep
away from surface
transverse/horizontal/axial plane
splits the body into superior (upper) and inferior (lower) sections
coronal/frontal plane
splits the body into anterior (front) and posterior (back) sections
sagittal plane
splits the body into left and right sections. the median or mid-sagittal plane sits directly in the midline of the body.
describe where the 5th intercostal space is
the 5th intercostal space is the gap inferior to the 5th rib, superior to the 6th rib.
what is faecal mass
waste matter eliminated from the bowels; excrement.
what is fascia?
a sheet or band of fibrous connective tissue enveloping, separating, or binding together muscles, organs, and other soft structures of the body
what does necrotic mean?
dead
what is the inguinal ligament?
the tough, fibrous ligament that stretches between the lateral edge of the pubic bone and the anterior superior iliac spine
what is pericarditis?
inflammation of the lining around the heart (pericardium) causing chest pain and accumulation of fluid around the heart (pericardial effusion)
what is the pyloric sphincter?
a ring of smooth muscle fibres around the opening of the stomach into the duodenum
what is severe peritonitis?
inflammation of the peritoneum
can result from infection, injury and bleeding, or diseases
what is the peritoneum?
the tissue layer of cells lining the inner wall of the abdomen and pelvis
what are gonadocorticoids?
sex hormones, e.g. testosterone and oestrogen
what is a ureter?
a tube that carries urine down from the kidney to the bladder
what is systemic sepsis?
the presence of bacteria or other infectious organisms or their toxins in the blood or in other tissue of the body.
what is the vermiform appendix?
a small outpouching from the beginning of the large intestine
what is dorsum?
dorsal surface part of hand or foot, opposite to palm/sole.
what is meant by contralateral?
opposite side of median plane
what is meant by ipsilateral?
same side of median plane
how many cervical vertebrae are there?
7, termed C1-C7
how many thoracic vertebrae are there?
12, T1-T12
how many lumbar vertebrae are there?
5, termed L1-L5
how many sacral vertebrae are there
5, termed S1-S5
what are the sections of the vertebrae (from superior to inferior)?
cervical vertebrae
thoracic vertebrae
lumbar vertebrae
sacral vertebrae
coccygeal vertebrae
name 2 important structure that sit within the neck
larynx and oesophagus
what are the 3 sections of the trunk?
thoracic, abdominal, and pelvic cavities
what are the boundaries of the thorax?
superior boundary - superior thoracic inlet
inferior boundary - diaphragm
posterior boundary - ribs and thoracic vertebrae
anterior boundary - ribs, costal cartilage and sternum
what are the regions of the thoracic cavity?
left pleural cavity, right pleural cavity, mediastinum.
mediastinum sits medially and contains the heart, pericardium and associated structures.
what are the main organs found in the abdominal cavity?
liver, gallbladder, oesophagus, stomach, spleen, small intestine, large intestine, kidneys, adrenal glands
name 2 ways of describing the regions of the abdomen
the nine region model and the four quadrant model
what are the three parts to the pelvic cavity?
ilium, ischium, pubis
the ilium articulates with the sacrum posteriorly
define a body system
a group of body organs that together perform one or more vital functions
features and and function of cardiovascular system
consists of heart, blood vessels, and blood
function - transport nutrients and o2-rich blood to all parts of the body and carry deoxygenate blood back to the lungs
features and function of respiratory system
consists of nasal cavity, larynx, trachea-bronchial tree, and lungs
function - breathing and gas exchange
features and function of skeletal system
consists of all bones, cartilage, tendons and ligaments in the body.
function - structure and locomotive
features and function of integumentary system
consists of epidermis, hypodermis, associated glands hair, and nails.
function - largest organ of the body that forms a physical barrier between the external and internal environment
features and function of muscular system
consists of specialised cells (muscle fibres) that are attached to bones or other structures.
function - movement
features of genitourinary (GU) /urogenital system
consists of kidney, ureters, bladder, urethra, sexual organs.
this system is sometimes split into the urinary and reproductive systems
features and function of gastrointestinal (GI)/digestive system
consists of the mouth, pharynx, oesophagus, stomach, small & large intestine, rectum, and anus, as well as salivary glands, liver, gallbladder, and pancreas.
function - these help make digestive juices and enzymes which help the body digest food and liquids
features and function of the immune system
consists of a network of biological processes that protect an organism from diseases.
function - detects and responds to a wide variety of pathogens.
features and function of the nervous system
consists of the brain, spinal cord, peripheral nerves, sensory organs and other nervous tissue.
function - coordinates actions and sensory information by transmitting signals to and from different parts of the body.
features and function of the endocrine system.
consists of feedback loops of the hormones released by internal glands into the circulatory system, regulating target organs.
four main functions of the skeleton
- protection of major organs
- forming the mechanical basis for movement
- haemopoesis
- storage of salts in bone
two types of mature (Haversian) bone
compact and spongy
describe compact bone
strong and dense, all the bones have a superficial, thin layer of it
describe spongy bone (cancellous bone)
less dense, with numerous air spaces and forms the core of most bones, except when replaces by a medullary (marrow) cavity. this means that bones are lighter which aids movement, while the compact layer provides strength.
3 types of cartilage
hyaline cartilage, fibrocartilage, elastic cartilage
where is hyaline cartilage found?
-most widely present type of cartilage in the body
-present in adults as articular cartilage in joints and in the respiratory system as support for the airways
where is fibrocartilage found?
-found in articular disks within joints, in intervertebral discs and around the edge of ball and sockets to enlarge the surface area of the socket
-tougher than hyaline cartilage
where is elastic cartilage found?
-highly resilient due to the elastic fibres contained in its structure
-found in external ear, auditory tube, epiglottis and parts of the larynx
what does the axial skeleton include?
-all the bones along the body’s long axis
-includes the bones that form the skull, vertebral column, and thoracic cage
what does the appendicular skeleton include?
limbs and girdles that ‘append’ to the axial skeleton
e.g. pelvis, legs and arms etc.
what is osteomalacia?
soft bones, often caused by vitamin D deficiency
what is the neck of the femur/
joins the head of the femur to the shaft of the femur or thigh bone
what is the head of the femur?
the most proximal part of the femur, which articulates with the pelvis at the acetabulum
what is osteoporosis?
-a disease of aging
-characterised by a decrease in bone mass and bone strength with no change in the proportion of calcified to uncalcified base material
how does cartilage obtain oxygen and nutrients?
via continuous diffusion and via osmosis from bone
what is osteoarthritis?
progressive degeneration of the hyaline cartilage between bones in a joint. leads to bones rubbing against each other, causing pain and inflammation.
what does the CNS consist of?
brain and spinal cord
what does the PNS consist of?
all the neurones carrying information to (affecter neurones) or from (effector neurones) the CNS
3 parts of a neuron
- axon
- cell body
- dendrites
how is information relayed electrically along axons and dendrites?
through the movement of ions
what does myelin do to an action potential?
ensheathes many axons and increases speed of conduction of action potentials
what does the axon do?
carries information away from the cell body
what do dendrites do?
carry information to the cell body
what is multiple sclerosis (MS)
-a disease with a chronic relapsing course
-unknown cause
-consists of ‘plaques’ of demyelination and axon loss throughout the CNS
what does the CNS do?
-information is relayed to the CNS by afferent neurons in the PNS
-the CNS collects and processes this information, this is stored and responded to (if appropriate).
-information is transported out of the CNS to effector cells by the efferent neurons of the PNS
function of the left hemisphere of the brain
controls logic, numbers and language. processes the sensory and motor pathways for the right side of the body.
function of the right hemisphere of the brain
involved with creativity, imagination and rhythm and processes the sensory and motor pathways of the left side of the body.
what joins the two hemispheres of the brain?
corpus callosum
what is the corpus callosum?
a neural bridge of nerve fibres. allows the two halves of the brain to communicate
how can the corpus callosum be seen/
superiorly by looking down the deep fissure between the two halves of the brain, or in a medial view by separating the cerebral hemispheres
what does the brain consist of?
forebrain, midbrain, hindbrain
what does the forebrain consist of?
cerebrum, thalamus, hypothalamus
what does the hindbrain consist of?
cerebellum, pons, medulla
what does the brainstem consist of?
midbrain, pons, medulla
function of the midbrain
controls higher functions than the other regions of the brainstem, for example eye movements and the auditory system
function of the medulla
controls very basic, life-sustaining functions such as breathing and heart rate
function of the pons
roles in consciousness and posture
structure of the cerebellum
two mounds of folded tissue posterior to the brainstem
how is the cerebellum connected to the brainstem?
3 peduncles (bands of neurons resembling a stalk)
function of the cerebellum
concerned mainly with motor functions. plays a vital role in motor learning, as all motor skills are stored in cerebellar memory.
where does the cerebellum receive inputs from?
-ascending sensory pathways from the body
-descending motor pathways from the cerebrum
-other information from the brainstem
function of the thalamus
the majority of information passing to the cerebral hemispheres passes through the thalamus first. the thalamus then relays the information to the relevant part of the cerebrum.
function of the hypothalamus
main function is homeostasis.
directly controls:
-blood pressure
-body temp
-fluid and electrolyte balance
-body weight
heart rate, vasoconstriction, digestion and sweating are controlled by the hypothalamus via inputs to the medulla.
function of the cerebral cortex/cerebrum
intelligence, personality, interpretation of sensory impulses, motor function, planning and organisation, touch sensation
what is the cerebral cortex/cerebrum?
most of the volume of the cerebral hemispheres consists of white matter. white matter contains axons. these axons connect the cell bodies found in the grey matter.
this grey matter makes up the cerebral cortex/cerebrum.
what are sulci?
infoldings of the brain. often used to demarcate (mark the boundary of) different functional areas
what are gyri?
sticky out bits between sulci. these are areas of functional grey matter. adjacent gyri may have very different functions
what are meninges?
a layer of tissue separating the CNS from the rest of the body
what are the 3 layers of the meninges
- pia mater - adherent to the brain itself and dips down into the sulci of the brain
- arachnoid mater - in the middle
- dura mater - outermost and very tough layer
what is the CNS bathed in, within the meninges?
cerebrospinal fluid (CSF)
what do the meninges and CSF do?
cushion the brain and protect it from damage
what is the CSF produced by?
specialised epithelium (choroid plexus) lining cavities within the brain known as ventricles
what does the choroid plexus do?
actively secretes components of blood plasma into the ventricles, producing a clear fluid that is lower in proteins, cells and most ion than plasma
describe CSF movement
circulates through the ventricles (cavities) within the brain before exiting onto the surface of the brain (still within the meninges) to bathe the brain and spinal cord.
CSF is then reabsorbed into the venous circulation at specialised points called arachnoid granulations
what are arachnoid granulations?
where CSF is reabsorbed into the venous circulation
what does the CSF have a higher concentration than plasma of?
sodium, chloride and magnesium ions, as these chemicals are actively transported by the epithelium into the CNS
what are ventricles (brain?
spaces or cavities within the brain linked by passageways called aqueducts.
allow CSF to circulate through the brain and open onto the surface of the CNS or into the central canal of the spinal cord.
where is the end of the spinal cord in children?
level with the L3 vertebrae
where is the end of the spinal cord in adults?
level with L1, it is no longer a single cord, but made up of several spinal nerves that all run through the vertebral canal
what is the spinal cord protected by?
vertebrae
what is the vertical tunnel running through a vertebra called?
vertebral foramen
what do the foramen form?
the vertebral canal, that runs the whole length of the vertebral column (spine), contains the spinal cord and provides it with some protection
what does a vertebra consist of?
a vertebral body and vertebral arch, which form the vertebral foramen
what is the vertebral arch formed of?
2 pedicles
2 lamina
2 transverse process
1 spinous process
4 articular processes
function of vertebral body
support of body weight
function of vertebral arch
protection of spinal cord
function of spinous process and transverse processes
muscle attachment and movement
function of articular processes
restriction of movement
function of the lamina
connects the spinous process and the transverse process
function of the pedicle
serve as a bridge, joining the front and back parts of the vertebra
what is a symphysis?
a fibrocartilaginous joint
purpose of the invertebral disc forming a symphysis between 2 adjacent vertebrae?
to allow slight movement, act as shock absorbers and to hold the 2 together
what does the invertebral disc contain?
annulus fibrosus - outer fibrous ring made up of laminae of fibrocartilage to withstand compression
nucleus pulposus - gel-like centre that helps distribute pressure evenly across the disc to act as a shock absorber
a layer of hyaline cartilage
what is the outer section of the spinal cord formed of?
white matter - consists of axons of neurons that form ascending or descending pathways
what do ascending pathways of spinal cord do?
travel from the body to the brain. tend to carry sensory information, such as touch, pain, and proprioception.
what do descending pathways of spinal cord do?
travel from the brain to the body. they tend to carry motor instructions, to initiate and control movement.
what is the inner section of the spinal cord formed of?
grey matter - where cell bodies of neurons are located and where synapses occur between these cell bodies, their dendrites, and the axons of other neurons
how do nerves from the body enter the spinal cord?
through the dorsal roots (dorsal horn)
how do nerves exit the spinal cord?
through the ventral root (ventral horn)
what is the ventral median fissure?
a deep groove, a useful landmark for the anterior surface of the spinal cord. useful to identify as the other regions of the spinal cord are names for whether they are ventral or dorsal (anterior or posterior)
what type of nerves do the ascending and descending tracts carry?
somatic nerves
where do autonomic nerves run?
alongside the spinal cord in a separate chain or neurons and ganglia
name some ascending tracts within the spinal cord
dorsal column - ascending sensory neurons carrying fine touch and proprioception information from the limbs
anterolateral fasciculus - ascending sensory neurons carrying pain and temperature fibres
name a descending tract within the spinal cord
lateral column - descending motor tracts from the cerebral cortex
What are the nerves inferior to the termination of the spinal cord, within the meninges called?
the cauda equina
what is a lumbar puncture/spinal tap?
when the CSF is removed from the space below the end of the spinal cords, with a needle.
there is not enough space around the spinal cord to allow safe removal of CSF superior to its termination.
below L1, if a needle is inserted, the spinal nerves can float out of the way. above L1, the needle would be at risk of piercing the spinal cord.
what can increased levels of white blood cells indicate (from CNS)?
infection such as meningitis
what can increased levels of red blood cells indicate (from CNS)?
a brain haemorrhage or stroke
why does the PNS exist?
to carry information to and from the CNS
which nerves travel to the CNS?
afferent nerves (afferents arrive)
which nerves travel from the CNS?
efferent nerves (efferents exit)
what are the two main divisions of the PNS?
autonomic and somatic nervous systems
define homeostasis
the maintenance of a constant, balanced environment within the body
what is a ganglia
plural of ganglion - in the PNS they are groups or knots of cell bodies
what is the autonomic nervous system?
the ‘subconscious’ control of our bodies, generally innervating smooth muscle of tissues or glands.
which actions is the PNS involved with?
involved with actions such as temperature control (via sweating and vasomotor), continence, secretions and gastric motility
where do autonomic neurons arise?
from the brain and spinal cord.
where do autonomic neurons have ganglia?
outside the spinal cord, where their axons synapse.
how many neurons does it take the autonomic system to reach its target?
two - there are pre-ganglionic and post-ganglionic autonomic neurons
what does the sympathetic system do?
prepares the body for intense physical activity (‘fight or flight’)
what does the parasympathetic system do?
relaxes the body and inhibits high energy functions (‘rest and digest’)
what does activation of sympathetic nervous system do?
-increased heart rate and force of contraction
-dilation of pupil
-relaxation of airway smooth muscle
-reduced peristalsis
-decreased gut motility
what does activation of parasympathetic nervous system do?
-decreased heart rate and force of contraction
-constriction of pupil
-contraction of airway smooth muscle
-increased stomach motility and gastric secretions
-increased peristalsis
-increased gut motility
where are sympathetic cell bodies present?
in the thoracis and lumbar spinal cord segments. these connect to a paravertebral ganglion chain, the sympathetic chain, or to individual ganglia that are still quite distant from the target organ.
where do parasympathetic neurons arise?
from the cranial nerves or from the lumbo-sacral spinal cord.
where are parasympathetic ganglia located?
located close to the target organ, they are not grouped together in a chain
what do somatic sensory nerves (afferent) do?
detect pain, temperature, touch and proprioception
what is the somatic nervous system responsivle for?
conscious control of our bodies and the corresponding feedback
what do somatic efferent nerves do?
they are motor to effector skeletal muscle
what do somatic neurons do once they’ve left the CNS?
they project directly to their target cell via a single neuron, they do not synapse
what are the 2 types of somatic nerves?
spinal nerves - arise from spinal cord
cranial nerves - arise directly from the brain
describe where the spinal nerves leave the spinal cord
below each vertebra (T1, T2 etc) except in the cervical region where they exit superior to the vertebrae.
C7 has one above (C& nerve) and one below (C8 nerve)
how many spinal roots are there?
- there is an additional root from the coccyx
where do dorsal and ventral roots emerge from?
the spinal cord, at each vertebral level
what are the dorsal (posterior) roots?
usually afferent/sensory, carrying information from the periphery to the CNS
what are the ventral (anterior) roots?
usually efferent/motor, carrying information from the CNS to the periphery in somatic motor and autonomic neurons
what is a plexus?
a network of vessels or nerves in the body.
many spinal nerves may blend together to form a plexus such as the lumbar plexus
what makes up the lumbar plexus?
spinal nerves arising from the spinal cord below vertebrae T12-L5
what are dermatomes?
a distinct area of skin supplied by spinal nerves
what are myotomes?
a group of muscles supplied by spinal nerves
where does the sciatic nerve run?
muscles - motor to muscles of posterior thigh (the hamstrings that act to flex the knee)
sensory - sensory afferent from the skin over the lateral side of leg (below knee) and skin on soe and dorsum of foot
how is the region between hip and ankle divided anatomically?
thigh - above knee
leg - below knee
where does the femoral nerve run?
muscles - motor to muscle of anterior thigh (the quadriceps that act to extend the knee)
sensory - sensory afferent from anterior thigh and medial leg
how many cranial nerves are there?
- they mainly innervate structures of the head and neck
what do cranial nerves supply?
‘special senses’ e.g. taste
as well as the usual somatic and autonomic functions
function of CNI - olfactory nerve
special sense. innervates nasal mucosa, carries information related to smell.
function of CNII - optic nerve
special sense. afferent for vision from the retina
function of CNIII - oculomotor nerve
somatic division controls movements of the eye and some control of eyelid. autonomic division is motor to pupil constrictors.
function of CNIV - trochlear
somatic - motor to one muscle that moves the eye
function of CNV - trigeminal
somatic - afferent from surface of face, senses touch from skin of face. motor efferent to muscles of mastication.
function of CNVI - abducent
somatic - motor efferent to one muscle of the eye
function of CNVII - facial nerve
special sense - taste from anterior tongue and palate
somatic division - motor efferent to muscles of facial expression
autonomic division - motor efferent to glands that secrete saliva
function of CNVIII - vestibulocochlear nerve
special sense - hearing from cochlea of ear. balance from vestibular apparatus of ear.
function of CNVXI - glossopharyngeal nerve
special sense - taste from posterior tongue
somatic division - motor efferent to help with swallowing. afferent sensation from external ear.
autonomic division - secretomotor to one saliva gland (parotid)
function of CNX - vagus nerve/’wandering nerve’
somatic division - motor to muscles of pharynx, larynx and palate.
autonomic division - parasympathetic innervation of smooth muscle in trachea, bronchi, GI tract and cardiac muscle. afferent sensation from GI tract, heart and airways
function of CNXI - accessory nerve
somatic - motor to two big muscles in the neck
function of CNXIII - hypoglossal nerve
somatic - motor to the muscles of the tongue
what is Bell’s palsy?
an idiopathic (of unknown cause) palsy of the facial nerve CNVII.
result in unilateral facial paralysis due to loss of motor innervation to muscles of facial expression.
what is Guillain-Barre syndrome (GBS)?
a condition that can occur after an infection. the immune system fights off the infection but then attacks the myelin sheath of peripheral nerves, which disproportionately affects the long nerves first.
people often develop tingling (parasthesia) and muscle weakness (paresis) in their feet and hands. as the disease progresses, the symptoms become more severe distally (e.g. paralysis) and ascend proximally, up the arms and legs - often called a ‘glove and stocking’ distribution. it is a common feature of other peripheral neuropathies.
what are the two systems that the heart pumps blood around?
the pulmonary and systemic systems
what are the four chambers of the heart
2 atria and 2 ventricles
what is the specialised cardiac muscle of the heart known as?
myocardium
define a heartbeat
each cycle of contraction and relaxation
what is systole
contraction of the ventricles
what is diastole
relaxation of the ventricles
is the pulmonary circulation pumped at high or low pressure? why?
low. not much force is required to send blood the short distance through the lungs from the right to the left heart and high pressure in pulmonary capillaries would force fluid out of the blood, into the lung tissue and we would drown.
does blood pumped from the right ventricle to the lungs have a high or low oxygen concentration?
low
where does the systemic circulation feed?
into and out of all the organs of the body, except the lungs
where is the origin and termination of the systemic circulation?
origin - left ventricle
termination - right atrium
does the systemic circulation operate at a high or low pressure?
a high pressure (compared to the pulmonary). considerable force is required to adequately perfuse all the tissues in the human body and the blood has a much larger distance to travel from left to right heart than right to left
what does the thoracic cage do?
protects the contents of the thorax
what does the thoracic cage do?
protects the contents of the thorax
what does the thoracic cage consist of?
ribs, costal cartilage, sternum, and thoracic vertebrae
how many ribs are there on each side?
12
where is the mediastinum?
the central compartment of the thoracic cavity, situated between the lungs.
it extends from the superior thoracic aperture (superiorly) to the diaphragm (inferiorly) and from the sternum and costal cartilages (anteriorly) to the bodies of the thoracic vertebrae (posteriorly)
describe the structure of the mediastinum
-contains all the thoracic structures except the lungs
highly mobile region because it consists primarily of hollow visceral structures which are joined by loose connective tissue.
what is the sternal angle?
the joint between the manubrium (top part) and the body (middle part) of the sternum
what is the thoracic plane?
imaginary horizontal plane drawn from the sternal angle to the level between T4 and T5
what compartments does the thoracic plane divide the mediastinum into?
superior mediastinum and inferior mediastinum
name the subdivisions of the inferior mediastinum
anterior mediastinum, middle mediastinum, and posterior mediastinum
what does the anterior mediastinum contain?
mainly consists of fat and the thymus
what does the middle mediastinum contain?
mainly the heart and pericardium
what does the posterior mediastinum contain?
the descending aorta, the oesophagus, the thoracic duct, the azygos system of veins and the sympathetic chains
what is the azygos system of veins?
a H-shaped configuration of the azygos, hemiazygos, and accessory hemiazygos veins
what does the azygos system of veins do?
drains the posterior thoracic wall
where are the sympathetic chains?
external to the spinal column, adjacent to the vertebral bodies. it is a paired structure (one on each side of the body)
what is the thoracic duct? what does it do?
the main lymphatic vessel for the return of chyle/lymph to the systemic venous system.
it drains lymph from both lower limbs, abdomen (except the convex area of the liver), left hemithorax, left upper limb and left side of face and neck.
what is the thymus?
a T-cell producing lymphoid organ that plays a role in the development of the immune system particularly, maturation of T-cells.
what is the phrenic nerve?
a paired nerve (one of the left and one on the right) that supplies the diaphragm. it comes from the nerve roots C3, C4, C5.
what is the vagus nerve?
-tenth cranial nerve (CNX).
-paired
-provides the bulk of the parasympathetic input to the gastrointestinal system and to the heart.
-a complex mixed sensory, motor and parasympathetic nerve.
what is the pericardium?
a membrane that covers the heart
what are the 2 layers of the pericardium?
- an outer fibrous layer
- an inner thin serous layer that reflects from the inside of the fibrous sac onto the surface of the heart
characteristics of the fibrous pericardium
-outer layer
-continuous with great vessels adventitia (aorta and pulmonary trunk)
-blended inferiorly with the central tendon of the diaphragm.
-rigid structure
characteristics of the serous pericardium
-contained within the fibrous pericardial sac
-analogous to pleural membrane
-double layer: visceral layer/epicardium (inner layer) and parietal layer (outer layer).
between the double layer is a lubricating fluid
functions of the pericardium
protection from infection
fixes the heart in the mediastinum and limits its motion
lubrication
prevents rapid overfilling of the heart
what is cardiac tamponade?
blood/fluid accumulates in the pericardium, compresses the heart, preventing the ventricles from expanding fully and impeding its blood supply
what is pericarditis?
inflammation of the pericardium
what is a dissecting aortic aneurysm?
a tear occurs in the inner layer of the (aorta). blood rushes through the tear, causing the inner and middle layers of the aorta to split (dissect)
what is an acute myocaridla infection?
blood flow to the heart muscle is abruptly cut off, also known as a heart attack
what is pericardiocentesis?
a procedure done to remove fluid that has built up in the sac around the heart (pericardium)
which great vessels are on the right side of the heart?
superior vena cava, inferior vena cava, and the pulmonary trunk
what does the superior vena cava do?
brings deoxygenated blood to the right atrium from the systemic circulation superior to the heart
what does the inferior vena cava do?
brings deoxygenated blood to the right atrium from the systemic circulation inferior to the heart
what does the pulmonary trunk do?
exits the right ventricle, taking deoxygenated blood to the lungs.
immediately superior to the heart it bifurcates into the right and left pulmonary arteries which run into their respective lungs
which great vessels are on the left side of the heart?
the pulmonary veins and the aorta
what do the pulmonary veins do?
enter the left atrium on the posterior aspect of the heart, carrying oxygenated blood from the pulmonary circulation.
there are 4 pulmonary veins:
left superior and left inferior, right superior and right inferior.
what does the aorta do?
carries high pressure, oxygenated blood to the body in the systemic circulation
where is the anterior (sternocostal) surface of the heart?
formed mostly from the right ventricle, this surface is related anteriorly to the sternum and ribs
where is the inferior (diaphragmatic) surface of the heart?
formed mostly by the left and partly from the right ventricle. it is related inferiorly to the centre of the diaphragm.
where is the left (pulmonary) surface of the heart?
formed mostly by the left ventricle. it is related laterally with the left lung and occupies a depression in this lung know as the cardiac impression.
where is the base of the heart situated?
on the posterior aspect, directed towards the vertebrae T6-9
what does the base of the heart consist of?
formed mostly from the left and partly from the right atrium and extends from the bifurcation of the pulmonary trunk superiorly to the atrioventricular groove inferiorly
where is the apex of the heart located?
lies posterior to the 5th intercostal space in the midclavicular line. it is directed antero-inferiorly and to the left
what is the right border of the heart?
formed by the right atrium, extends from the superior to inferior vena cava.
what is the inferior border of the heart?
roughly horizontal and mostly formed by the right ventricle, with a small contribution by the left ventricle
what is the left border of the heart?
mostly formed from the left ventricle with the superior portion being formed by the auricular appendage of the left atrium
what is the superior border of the heart?
formed by both atria, the aorta and pulmonary trunk arise from this border and the superior vena cava enters the heart at the right side of the superior border
where does the superior border of the heart reach?
as high as the third costal cartilage on the right side of the sternum and the second intercostal space on the left side of the sternum
where does the right margin of the heart extend to and from?
from the right third costal cartilage to near the right sixth costal cartilage
where does the left margin of the heart extend to and from?
descends laterally from the second intercostal space to the apex located near the midclavicular line in the fifth intercostal space
where does the lower margin of the heart extend to and from?
extends from the sternal end of the right sixth costal cartilage to the apex in the fifth intercostal space near the midclavicular line
what are the 3 layers of the heart?
epicardium, myocardium, endocardium
what does the epicardium consist of?
a layer of connective tissue and provides a protective layer over the heart (most superficial)
what is the myocardium?
muscular component of the heart wall, it consists of myocytes or cardiac muscle cells
what is the endocardium?
layer of epithelium and connective tissue lines the heart and covers the heart valves. continuous with the endothelial lining of blood vessels (most deep)
