Human Anatomy Flashcards
What plane separates the anterior and posterior parts of the body
The frontal plane
What plane separates the left and right sides of the body
The sagittal plane
What plane transects the upper and lower halves of the body?
The transverse plane
What terms would you use to describe something towards the midline v.s away from the midline
Lateral - Away from the midline
Medial - Towards the midline
What terms would you use to describe something towards a base v.s away from the base
Proximal - toward a base
Distal - away from a base
What terms would you use to describe towards the head v.s towards the tail
Cranial - towards head
Caudal - towards tail
What are the four parts of thoracic cavity?
- Left pleural cavity
- surrounds left lung - Mediastinum
- contains the trachea, oesophagus, and major vessels - Pericardial cavity
- surrounds heart - Right pleural cavity
- surrounds right lung
What are the two components of the abdominopelvic cavity?
- Abdominal cavity
- contains many digestive glands and organs - Pelvic cavity
- contains urinary bladder, reproductive organs, last portion of digestive tract
What separates the thoracic and abdominopelvic cavities?
The diaphragm
What does each letter represent?
A - Hypochondriac
B - Lumbar
C - Ingual
D - Epistatic
E - Umbilical
F - Hypogastric
What are the levels of molecular organisation from smallest to largest?
Atoms combine to form _Organic/Inorganic molecules _which interact to form Cells which secrete and regulate Extracellular material/fluids. The two of these combine to form tissue, which is either epithelial, connective, muscle or nervous. These tissues combine to form _organs _which interact to form organ systems
A - Cephalic
B - Cervical
C - Thoracic
D - Brachial
E - Antebrachial
F - Carpal
G - Manual
H - Abdominal
I - Pelvic
J - Pubic
K - Inguinal
L - Lumbar
M - Gluteal
N - Femoral
O - Patellar
P - Crural
Q - Sural
R - Tarsal
S - Pedal
T - Plantar
Identify and describe this tissue
Epithelial tissue:
- Covers exposed surfaces
- Lines internal passageways and chambers
- Produces glandular secretions
Identify and describe this tissue
Connective tissue:
- Three main components:
* Specialised cells
* Extracellular protein fibres
* Matrix (refers to collection of fibres and “ground” substance (ie blood has a liquid matrix called plasma)
- Defining characteristic is that that most cells are not in contact with each other
- Role is to provide structural support, protect organs, and store energy
Identify and describe this tissue
Fluid connective tissue:
- Blood, contained in cardiovascular system
- Lymph, contained in lymphatic system
Identify and describe this tissue
Loose connective tissue:
- Fibres create loose, open framework
* Areolar tissue
* Adipose tissue
* Reticular tissue
Identify and describe this tissue
Left - Connective Dense regular
Right - Connective Dense irregular
Identify and describe this tissue
Elastic connective tissue
Identify and describe this tissue
Left - Hyaline cartilage
Middle - Fibrous cartilage
Right - Elastic cartilage
Identify and describe this tissue
Bone
Identify and describe this tissue
Skeletal muscle:
- Cells are long, cylindrical, striated and multinucleated
- Location: Combined with connective tissues and neural tissues in skeletal muscles
- Functions: Moves or stabilises the position of the skeleton; guards entrances and exits to the digestive, respiratory, and urinary tracts; generates heat; protects internal organs
Identify and describe this tissue
Cardiac muscle
- Cells are short, branched, and striated, usually with a single nucleus; cells are interconnected by intercalated (inserted/fitted within) discs
- Found in the heart
- Functions to circulate blood and maintain blood pressure
Identify and describe this tissue
Smooth muscle
- Cells are short, spindle-shaped, and nonstriated, with a single central nucleus
- Location: Found in the walls of blood vessels and in digestive, respiratory, urinary and reproductive organs
- Functions: Moves food, urine, and reproductive tract secretions; controls diameter of respiratory passageways; regulates diameter of blood vessels
Identify the letters on the diagram
A - Axon
B - Axon hillock
C - Nucleus
D - Nucleolus
E - Glials
F - Dendrites
Identify and describe this tissue
A - Simple Squamous (lung tissue)
B - Simple Cuboidal (kidney)
C - Simple Columnar (stomach)
D - Transitional (Bladder)
E - Stratified Squamous (Oesophagus)
F - Stratified Cuboidal (Sweat gland)
G - Stratified Columnar (Salivary duct)
H - Simple Pseudostratified Columnar (trachea)
Like wtvr man just look at this idek if you need to know it
Describe the organisation of muscle tissue from smallest to largest
What are the six organs/components of the integumentary system and their functions?
What are the three accessory structures of the integumentary system?
What are two components of the cutaneous membrane (skin)?
Corny
Luck
Granules
Spin
Basal
Cancer
Identify and describe this tissue
Describe the subcutaneous layer
What are the four steps to skin repair
- Bleeding occurs at the site of injury immediately after the injury, and mast cells in the region trigger an inflammatory response
- After several hours, a scab has formed and cells of the stratum basale are migrating along the edges of the wound. Phagocytic cells are removing debris, and more of these cells are arriving via the enhanced circulation in the area. Clotting around the edges of the affected area partially isolates the region
- One week after the injury, the scab has been undermined by epidermal cells migrating over the meshwork produced by fibroblast activity. Phagocytic activity around the site has almost ended, and the fibrin clot is disintegrating
- After several weeks, the scab has been shed, and the epidermis is complete. A shallow depression marks the injury site, but fibroblasts in the dermis continue to create scar tissue that will gradually elevate the overlying epidermis
Describe the sebaceous gland
Describe holocrine secretion
- Cell disintegration: In holocrine secretion, the entire cell disintegrates to release its contents, including oils, lipids, or other substances. The cell ruptures, and its contents become the secretion.
- Occurs in sebaceous glands: A prime example of holocrine secretion is in the sebaceous glands of the skin, which produce sebum to lubricate and protect the skin and hair.
- Cell replacement: After the holocrine cells disintegrate, new cells are produced by mitosis to replace them, maintaining the cycle of secretion.
What’re the two types of exocrine glands?
Sebaceous glands
Sweat glands
What’re the two types of sweat glands?
Describe osteocytes
Function:
Primary role is to maintain the mineral content of the bone matrix and regulate bone turnover. They are critical for sensing mechanical stress in bones and relaying signals to other bone cells (osteoblasts and osteoclasts) to initiate bone formation or resorption as needed. They also help regulate the flow of nutrients and waste within the bone by extending cytoplasmic processes through canaliculi.
Location:
Osteocytes are embedded deep within the bone matrix inside small cavities called lacunae. The lacunae are interconnected by thin, tube-like channels known as canaliculi, allowing the osteocytes to communicate and share nutrients with neighbouring cells.
Describe Lacunae
Function:
Lacunae serve as protective cavities that house osteocytes, keeping them isolated but connected to the larger network of bone tissue. They provide a structural niche where osteocytes can monitor bone integrity and communicate via the canaliculi system. Lacunae contribute to bone’s ability to withstand stress and strain without losing function.
Location:
Lacunae are found throughout both compact (cortical) and spongy (trabecular) bone. They are small, hollow spaces within the bone matrix, scattered between the layers of lamellae (concentric rings of bone tissue) in compact bone.
Describe Osteoblasts
- Function: Osteoblasts are bone-forming cells responsible for producing the organic components of the bone matrix, primarily collagen type I, which forms the bone’s framework. They initiate the mineralization process by depositing calcium and phosphate into the matrix, leading to the hardening of bone tissue. Their activity is regulated by hormones like parathyroid hormone (PTH) and growth factors.
- Location: Osteoblasts are typically found on the surface of bone tissue, in regions of active bone formation, such as growth plates, the periosteum (the outer layer of bone), and regions undergoing repair. They are particularly active during childhood and adolescence when bone growth is rapid.
Describe Osteoclasts
- Function: Osteoclasts are large, multinucleated cells responsible for breaking down bone tissue during the process of bone resorption. They dissolve the mineral and organic components of bone by secreting acids and proteolytic enzymes, which release calcium and phosphate into the bloodstream. This process is essential for bone remodelling, growth, and the regulation of blood calcium levels.
- Location: Osteoclasts are typically found on the surface of bones in regions undergoing active resorption. They are particularly prevalent in areas undergoing remodelling, such as near fractures or along trabecular bone in the spongy region.
Describe Osteoprogenitor Cells
- Function: Osteoprogenitor cells are stem cells capable of differentiating into osteoblasts, which are responsible for new bone formation. These precursor cells are crucial for bone development, growth, and repair, particularly after fractures or other injuries. They also play a role in the normal turnover of bone tissue by providing a continuous supply of osteoblasts for bone maintenance.
- Location: Osteoprogenitor cells are located in the inner layer of the periosteum, the endosteum (the lining of the marrow cavity), and in the bone marrow. They are most active during growth periods, healing, or bone remodeling.
What are the parts of the appendicular skeletal system?
- Pectoral girdle (clavicle , scapula)
- Upper limb
- Pelvic girdle (supporting bones and sacrum)
- Lower limb
What are the parts of the axial system
Skull
Sternum
Ribs
Vertebrae
Sacrum
Super sharp razors vanquish soldiers
What are the first four steps of bone development and ossification?
What are the last three steps of bone development of ossifiction?
An ____, also known as a ____ _____, is the fundamental structural unit of compact bone. It consists of concentric rings of bone tissue called ______ arranged around a central canal known as the ____ canal. This canal contains blood vessels and nerves that supply the bone tissue with nutrients and remove waste
osteon
Haversian system
lamellae
Haversian
Describe the difference between periosteum and endosteum
- Location
- Periosteum: Outer surface of bones (except at joints).
- Endosteum: Inner surface of bones, lining the medullary cavity and spongy bone spaces. - Structure
- Periosteum:
Two layers:
* Outer fibrous layer (collagen-rich).
* Inner osteogenic layer (contains osteoblasts and osteoclasts).
- Endosteum:
* Thin, single layer of cells (osteoblasts and osteoclasts). - Function
- Periosteum:
* Provides attachment for muscles and tendons.
* Supplies blood to the bone.
Involved in bone growth and repair.
- Endosteum:
* Participates in bone remodeling.
* Maintains the inner bone structure and medullary cavity.
What are the four stages of bone development through life
Appositional vs Interstitial
- Definition
- Appositional: Increases bone thickness.
- Interstitial: Increases bone length. - Location
- Appositional: Periosteum (outer surface).
- Interstitial: Epiphyseal plate (growth plate). - Process
- Appositional: Osteoblasts add new bone on the outside.
- Interstitial: Chondrocytes expand cartilage from within. - Outcome
- Appositional: Thickens bones; continues for life.
- Interstitial: Lengthens bones; stops after puberty
Define concentric lamellae
- Definition
- Circular layers of calcified bone matrix arranged around a central canal (Haversian canal) in compact bone, forming an osteon. - Function
- Provide strength and structure to bones.
- Resist twisting and compressive forces.
- House osteocytes in lacunae for bone maintenance. - Location
- Found in osteons, the cylindrical units of compact bone, surrounding the Haversian canal. - Structure
- Collagen fibers in each layer are oriented in different directions to resist fractures and mechanical stress
Define interstitial lamallae
Definition:
- Interstitial lamellae are remnants of old osteons that have been partially resorbed during the process of bone remodeling. They fill the spaces between newly formed osteons in compact bone.
Function:
- Interstitial lamellae provide additional strength to the bone by filling in the gaps between osteons, making the bone more solid and cohesive. They help maintain the structural integrity of compact bone.
- Location:
Interstitial lamellae are found between osteons in compact bone, filling the spaces that would otherwise be empty. These remnants are irregularly shaped and incomplete compared to the concentric lamellae of osteons. - Structure:
They consist of fragments of lamellae that do not form a complete circular structure, as they are the remnants of previously resorbed osteons
Describe the trabeculae of spongy bones and why that makes those bones “spongy”
- Description
- Trabeculae are the thin, needle-like or plate-like structures that form the network within spongy (cancellous) bone. They consist of lamellae with embedded osteocytes, and are oriented along lines of stress to provide structural support. - Why They Make Bones “Spongy”
- Trabeculae create a porous, lattice-like structure with many spaces in between. These spaces are often filled with bone marrow (red or yellow) and blood vessels. The porous nature of this network gives spongy bone a lightweight and spongy appearance while still providing strength and support to the bone
Describe compact bones
Compare and contrast compact v.s spongy bones in terms of structure, function, location, bone marrow, blood supply and presence of osteons
What contributes to the regulation of development/growth of bones?
- Hormones: Growth hormone (GH), thyroid hormone, and sex hormones (estrogen and testosterone) stimulate bone growth and development, especially during puberty.
- Nutrients: Adequate intake of calcium, phosphorus, and vitamin D is crucial for bone mineralization and strength.
- Mechanical Stress: Physical activity and weight-bearing exercises stimulate bone remodeling and increase bone density.
- Genetics: Genetic factors determine the overall size and shape of bones, as well as the peak bone mass one can achieve.
Give me the description, function and an example of sutural bones
Description:
Small, flat, irregular bones found between the flat bones of the skull
Example:
Sutures of the skull (e.g., between parietal bones)
Function:
Fill gaps in the skull and add strength to the structure
Give me the description, function and an example of irregular bones
Description:
Complex-shaped bones with irregular surfaces
Example:
Vertebrae, pelvic bones
Function:
Provide protection, support, and attachment for muscles
Give me the description, function and an example of short bones
Description:
Cube-like bones with equal length, width, and thickness
Example:
Carpals (wrist bones), tarsals (ankle bones)
Function:
Provide stability and support with limited movement
Give me the description, function and an example of pneumatized bones
Description:
Bones that are hollow or contain air-filled spaces (sinuses)
Example:
Ethmoid bone (in the skull)
Function:
Reduce bone weight and enhance voice resonance
Give me the description, function and an example of flat bones
Description:
Thin, flattened bones with parallel surfaces
Example:
Skull, ribs, sternum, scapula
Provide protection for internal organs and muscle attachment
Give me the description, function and an example of long bones
Description:
Long, cylindrical bones with expanded ends
Example:
Femur, humerus, tibia, radius
Function:
Support body weight and facilitate movement
Give me the description, function and an example of sesamoid bones
Sesamoid bones are small, round structures that are embedded within tendons, typically found at locations where tendons cross over joints, such as the patella (kneecap) in the knee and the flexor hallucis brevis in the foot. These bones serve several important functions: they help to reduce friction between the tendon and the underlying bone, enhance the leverage of the muscles by altering the direction of tendon pull, and distribute stress across the joint during movement, which can help protect the tendon from wear and injury. By improving the mechanical efficiency of the musculoskeletal system, sesamoid bones play a crucial role in facilitating smooth and effective joint function
Describe sutures
Describe orbits
Describe the nasal complex
Describe paranasal sinuses
Describe the hyphoid bone
Describe the vertebral column
Describe the thoracic cage
What is a demifacet
A demifacet is a half-sized facet on a vertebra that forms part of a joint. It is a small, flat surface on the side of a vertebral body where the head of a rib connects. These demifacets allow ribs to articulate with two adjacent vertebrae.
Example:
In the thoracic vertebrae (specifically T2 through T9), there are superior and inferior demifacets. For example, the T6 vertebra has a superior demifacet that articulates with the head of the sixth rib and an inferior demifacet that articulates with the head of the seventh rib.
Describe the appendicular skeletal system
Describe the pelvic girdle
Describe the scapula
What articulates with the glenoid cavity?
The glenoid cavity articulates with the head of the humerus. This articulation forms the shoulder joint, also known as the glenohumeral joint, which allows for a wide range of arm movements.
Describe the three components of the hand
Mnemonic:
So
Long
To
Pinkie
Here
Comes
The
Thumb
What are the three components of the feet?
Describe synarthrosis joints
Describe amphiarthrosis joints
Describe diarthrosis joints
Describe plane, pivot and saddle joints
Describe hinge, condylar and ball-and-socket joints
What are the different types of movement at the joints?
Describe the Temporal mandibular jaw
Sternoclavicular joint
Describe the elbow and radio-ulnar joints
Describe the joints of wrist and hand
- Carpometacarpal joint
Connects the metacarpals to the distal carpals - Intercarpal joint
Connects one carpal bone to another - Metacarpophalangeal joint
Connects metacarpals to the proximal phalanges
-Interphalangeal joint
Joint between the proximal, middle, & distal phalanges
From medial to lateral, brachial plexus structures are organized how?
roots - trunks - divisions - cords - nerves
The brachial plexus is composed of cutaneous and muscular branches of the ventral rami of spinal nerves __-__
C5-T1
Describe the hip joint
Describe the knee joint
Describe the joints of the ankle and foot
Describe the joints of the foot
What are the three layers of skeletal muscle?
Epimysium
Endomysium
Perimysium
The collagen fibres of all three layers come together to form a tendon that attaches the muscle to bone, cartilage, skin or another muscle
Describe the outer epimysium
- Layer of dense irregular connective tissue surrounding the entire skeletal muscle
Separates the muscle from surrounding tissues and organs and is connected to the deep fascia - A fascia is a sheath of stringy connective tissue that surrounds every part of your body. It provides support to your muscles, tendons, ligaments, tissues, organs, nerves, joints and bones.
Describe the central perimysium
Divide the muscle into internal compartments each of which contains a bundle of muscle fibres called a fascicle.
Contains collagen and elastic fibres, and numerous blood vessels and nerves supply each fascicle
Describe the inner endomysium
- Surrounds each individual muscle cell and bind each muscle fibre to its neighbour as well as supports the capillaries that supply the individual fibre
- Scattered myosatellite cells, which are cells that differentiate and become skeletal cells, lie between the endomysium and the muscle fibres
Tendons connect skeletal ______ to a skeletal _____
Tendons that form thick, flattened sheets are called ______
muscle
bone
aponeuroses
Neuromuscular junctions (NMJ) are located within what layer of the skeletal muscle organ?
The endomysium
In the skeletal muscle cell, the plasma membrane is called the _____, and within that the ______ acts as cytoplasm but exclusively within muscle cells
sarcolemma
sarcoplasm
Some myoblasts do not fuse with developing muscle fibres, but remain in adult skeletal muscle tissue as stem cells called _____ ____
myosatellite cells
What conducts electrical impulses within the sarcolemma?
Transverse tubules (T tubules)
The _______ ______ is a membrane complex that acts as a storage and release site of calcium ions which regulate individual myofibril contractions
sarcoplasmic reticulum
On each side of a T (transverse) tubule, the tubules of the SR enlarge, fuse, and form expanded chambers called ______ _____ which in combination with a T tubule is known as a ______. The membranes of that are in close contact and tightly bound together, but there is no direct connection between them
terminal cisternae
triad
The overall organisation levels from largest to smallest goes:
- Muscle fascicle
- Sarcomere
- Skeletal muscle
- Myofibril
- Muscle fibre
3, 1, 5 , 4, 2
What are the four proteins the thin filament contains
- Actin – The primary protein that forms the backbone of the thin filament. It provides binding sites for myosin during muscle contraction.
- Tropomyosin – A protein that wraps around the actin filament, blocking the myosin-binding sites on actin when the muscle is relaxed.
- Troponin – A complex of three proteins (Troponin T, Troponin I, and Troponin C) that regulate the position of tropomyosin and, consequently, the access of myosin to actin. It binds calcium ions to trigger muscle contraction.
- Nebulin – A large protein that is associated with the actin filament and helps to stabilise its structure, although its role is not as prominent as the other three
Describe the structure of the thick filament
- Myosin Molecules – The thick filament is primarily made up of hundreds of myosin molecules. Each myosin molecule has two main parts:
- Myosin Heads: These are the globular heads of myosin that extend outward from the filament. Each head contains an actin-binding site and an ATPase site that hydrolyzes ATP to provide energy for muscle contraction.
- Myosin Tails: The long, rod-like tail regions of myosin molecules bundle together to form the backbone of the thick filament.
- Arrangement – The myosin molecules are arranged in a staggered, overlapping fashion. The heads of myosin protrude outwards at regular intervals, creating a pattern that allows them to interact with the actin filaments during muscle contraction. These heads are oriented in opposite directions at either end of the filament.
In the centre of the thick filament, there is a region where no myosin heads project. This is called the ____ zone or the __ zone. This region corresponds to the middle of the sarcomere and does not interact with the thin filament.
bare
H
The thick filaments are anchored in the centre of the sarcomere at the _____, which helps maintain the alignment of the filaments.
M line
The thick filament is crucial in muscle contraction. When stimulated by an action potential, the myosin heads bind to the actin in the thin filament, forming ___-_____. This interaction, powered by ATP hydrolysis, allows the myosin heads to “pull” the actin filaments toward the centre of the sarcomere, leading to muscle shortening and contraction.
cross-bridges
Just look at this
Describe the five steps of a muscle contraction
Six steps of something man
What are the steps for both the initiation and depression of muscle contraction
Describe motor neurons
A motor unit is a single motor neuron and all of the muscle fibres it controls. Some motor neurons control a single muscle fibre, but most control hundreds. The smaller the size of a motor unit, the finer the control of movement will be. In the eye, where precise muscular control is critical, a motor neuron may control only two or three muscle fibres. We have less precise control over power-generating muscles, such as our leg muscles, where a single motor neuron may control up to 2000 muscle fibres
The resting tension in a skeletal muscle is called ____ ____
muscle tone
_____ _____ are monitored by sensory nerves that control the muscle tone in the surrounding muscle tissue
Muscle spindles
______ occurs in muscles that have been repeatedly stimulated to produce near-maximal tension; the intracellular changes that occur increase the amount of tension produced when these muscles contract.
_____is the opposite and is a result of lack of use and stimulation of the muscle
Hypertrophy
Atrophy
What are the three types of muscle fibres
Slow (red)
Fast (white)
Intermediate
Describe slow muscle tissue
= Small diameter and take up to 3x as long to contract
Specialised to continue contracting for long times
Fatigue slowly bcuz their mitochondria continue producing ATP throughout the contraction process
= Utilise aerobic metabolism which requires oxygen from two different sources:
Skeletal muscles containing slow muscle fibres have a larger network of capillaries than muscles dominated by fast muscle fibres. This means that there is greater blood flow to the muscle, and the red blood cells can deliver more oxygen to the active muscle fibres.
= Slow fibres are red because they contain the red pigment myoglobin (MĪ-ō-glō-bin). This globular protein, like haemoglobin (the oxygen-binding pigment found in red blood cells), binds oxygen molecules. As a result, slow muscle fibres contain large oxygen reserves that are mobilised during a contraction.
Describe white muscle tissue
= Have a large diameter
= Densely packed myofibrils
= Large glycogen reserves
= Relatively few mitochondria
= Contract quickly upon stimulation
= Tension produced is directly proportional to the number of myofibrils, however the contractions use large amounts of ATP and are supported primarily by anaerobic metabolism (glycolysis)
= Glycolysis does not require oxygen and converts stored glycogen to lactic acid. Fast fibres fatigue rapidly because their glycogen reserves are limited and because lactic acid builds up and the resulting acidic pH interferes with the contraction mechanism.
Describe intermediate type muscle tissue
Have properties between those of fast and slow fibres. For example, intermediate fibres contract faster than slow fibres but slower than fast fibres
What are the four muscle configurations in the body?
Describe parallel muscles
- Muscle fibres run parallel to the long axis of the muscle.
- Tend to have a relatively uniform width and can contract over a greater distance, though they typically generate less force compared to other muscle types.
- Muscle fibres are aligned along the direction of pull, usually in a straight line.
- They can be flat (e.g., rectus abdominis) or spindle-shaped with a thicker belly and tapered ends (e.g., biceps brachii).
Describe convergent muscles
- Fibres are spread out over a broad area but converge toward a single point or tendon.
- Versatile movement as the muscle can pull in different directions depending on which fibres are activated.
- Spread out from a wide origin (often broad and fan-shaped) and converge to a single point, typically at a tendon or a small insertion.
- Often have a triangular or fan-like shape. Like the pecs.
Describe pennate muscles
- Muscles where the fibres are arranged obliquely to their tendons, resembling a feather. This arrangement allows for a greater number of fibres in a given area, which helps increase the force of contraction, although the range of motion is reduced compared to parallel muscles.
- The muscle fibres attach diagonally to a central tendon, resembling the structure of a feather. Depending on how the fibres are arranged, they can be classified into three types
- Pennate muscles generate high force but have a limited range of motion due to their angled fibre arrangement.
What are the three types of pennate muscles
- Unipennate: Fibres are on one side of the tendon (e.g., extensor digitorum).
- Bipennate: Fibres are on both sides of the tendon (e.g., rectus femoris).
*Multipennate: Multiple tendons with fibres attaching from different angles (e.g., deltoid).
Shape: The feather-like arrangement can vary depending on whether it’s unipennate, bipennate, or multipennate.
Describe circular muscles
- A circular muscle, or sphincter, the fibres are concentrically arranged around an opening . When the muscle contracts, the diameter of the opening decreases. An example is the orbicularis oris of the mouth
Each muscle begins at an ____, ends at an ____, and contracts to produce a specific action. The origin of a muscle usually remains stationary, and the insertion moves, or the origin is proximal to the insertion.
origin
insertion
Muscles are grouped into four categories according to their primary actions
= Agonist (Prime Mover): This is the main muscle responsible for producing a specific movement. It provides the majority of the force. For example, during elbow flexion, the biceps brachii acts as the agonist.
= Antagonist: This muscle opposes the action of the agonist. It helps control or slow down the movement, and it relaxes when the agonist contracts. For instance, in elbow flexion, the triceps brachii is the antagonist.
= Synergist: These muscles assist the agonist by adding extra force or reducing unwanted movements. They help stabilise joints and ensure smooth movement. An example is the brachialis, which assists the biceps during elbow flexion.
= Fixator (Stabiliser): Fixators stabilise the origin of the agonist so that it can work more efficiently. They hold certain body parts steady while the movement occurs. For example, the muscles of the shoulder girdle act as fixators during arm movements.
____: The force applied by muscles to move a load.
____: The weight or resistance being moved (e.g., body parts or external objects).
____: The pivot point, typically a joint, where movement occurs.
Effort
Load
Fulcrum
What are the three types of fulcrums?
= First-class lever: The fulcrum is between the effort and the load (e.g., neck movement, where the atlanto-occipital joint is the fulcrum, neck muscles provide effort, and the head is the load).
= Second-class lever: The load is between the fulcrum and the effort (e.g., standing on tiptoes, with the ball of the foot as the fulcrum, body weight as the load, and calf muscles providing effort).
= Third-class lever: The effort is between the fulcrum and the load (e.g., elbow flexion, with the elbow as the fulcrum, biceps applying effort, and the forearm and hand as the load).
Describe pulleys
Pulleys change the direction of muscle force. For example, the patella acts as a pulley, redirecting the force of the quadriceps tendon to improve the efficiency of leg extension at the knee.
Describe the compartment and sectional anatomy of the upper arm
What are the four types of CNS glial cells
Describe the subdivisions of the nervous system
Describe the cells of the nervous system
Describe the PNS nervous system glial cells
Describe the four types of neurons
What are the five types of neuron pathways / circuit types
Describe action potentials
Describe myelination
Look at this
Describe chemical synapses
Describe the spinal cord
Describe the meninges of the spinal cord
Describe white matter and grey matter
Describe the organisation of the spinal cord
Describe the spinal nerves
Describe ramus communicans
Describe the cervical plexus
Describe the brachial plexus
Describe the lumbar plexus
Describe the sarcal plexus
Describe for ways to explain reflexes
Describe the sensory tracts of the spinal cord (1st, 2nd and 3rd order neurons)
Describe the somatosensory tracts
Note difference between anterior and posterior spinocerebellar tracts and the directionality and destination of their pathways through the CNS
Describe the corticospinal tract
See also, the homonculus and how it looks
Describe the four motor pathway tracts
IMPORTANT
Describe the levels of somatic motor control
Describe effectors
Describe day 23-30 of brain embryo development
- Day 20–21: Formation of the Neural Plate
Neural Plate Formation: Around day 20, the ectoderm, which is the outermost layer of the embryonic tissue, thickens along the dorsal midline, forming the neural plate. This thickening marks the beginning of nervous system development.
Somite Formation: At the same time, mesodermal tissue on either side of the neural plate forms paired blocks called somites. These somites are critical for later development of the vertebrae, skeletal muscles, and dermis. - Day 22–24: Neural Groove and Neural Fold
Neural Groove: The neural plate starts to invaginate (fold inwards), forming a groove along its midline called the neural groove.
Neural Folds: The lateral edges of the neural plate rise, forming neural folds. These folds will eventually come together and fuse. - Day 25–26: Neural Tube Formation
Closure of the Neural Tube: By about day 25, the neural folds begin to fuse in the middle and zip up in both directions, eventually creating a hollow structure called the neural tube. The neural tube is the precursor to the brain and spinal cord.
Neural Crest Cells: As the neural tube closes, cells at the edges of the neural folds, known as neural crest cells, begin to migrate away. These cells will give rise to various structures, including peripheral nerves and other specialised cell types. - Day 27–30: Early Brain and Spinal Cord Development
Formation of Brain Regions: By day 28, the anterior portion of the neural tube starts to develop into the primary brain vesicles—prosencephalon (forebrain), mesencephalon (midbrain), and rhombencephalon (hindbrain).
Spinal Cord Formation: The remainder of the neural tube, extending caudally from these vesicles, begins differentiating into the spinal cord. - At day 30, the basic structure of the central nervous system has been established, with regional specialisation evident in the brain and spinal cord.
Describe mesencephalon
Mesencephalon (Midbrain)
The mesencephalon, or midbrain, lies between the forebrain and hindbrain and is a relatively smaller region. It plays a crucial role in processing auditory and visual information and controlling motor movements. The midbrain houses structures like the tectum and tegmentum, which coordinate eye movements, reflexes to visual and auditory stimuli, and basic functions related to arousal and alertness.
* The mesencephalon does not subdivide, but its walls thicken and the neurocoel becomes a narrow passageway with a diameter similar to that of the central canal of the spinal cord.
Describe Rhombencephalon (Hindbrain)
The rhombencephalon, or hindbrain, is the posterior part of the brain and subdivides into the metencephalon and myelencephalon. The metencephalon develops into the pons and cerebellum, essential for coordinating movement and maintaining balance. The myelencephalon forms the medulla oblongata, which controls vital autonomic functions like breathing, heart rate, and blood pressure. Together, these structures support essential survival functions and smooth motor control.
Describe Metencephalon
The metencephalon is a part of the hindbrain that develops into the pons and cerebellum. The pons functions as a communication hub, linking various parts of the brain and playing a role in sleep and respiration. The cerebellum coordinates voluntary motor activities, fine-tuning movement and maintaining balance and posture. It also contributes to motor learning and cognitive functions, such as attention and language processing.
Describe The falx cerebri
Is a sickle-shaped fold of dura mater located between the cerebral hemispheres in the longitudinal fissure. It attaches anteriorly to the crista galli and posteriorly to the internal occipital crest and tentorium cerebelli, containing two major venous sinuses: the superior sagittal sinus and the inferior sagittal sinus.
- Beneath the arachnoid mater lies the ____ ____, which contains a web-like network of collagen and elastic fibre that connect the arachnoid to the pia mater.
- Finger-like extensions of the arachnoid mater, known as _____ _____, penetrate the dura mater and extend into the superior sagittal sinus, allowing cerebrospinal fluid (CSF) to flow into the venous circulation.
- This layer acts as a protective roof over cranial blood vessels, while the pia mater beneath serves as the floor. The arachnoid _____, which consist of connective tissue fibre, support the cerebral arteries and veins and are surrounded by cerebrospinal fluid, helping to cushion and stabilize the brain.
subarachnoid space
arachnoid granulations
trabeculae
Describe the blood-brain barrier (BBB)
- The blood-brain barrier (BBB) is a critical mechanism that isolates the central nervous system (CNS) from general circulation, ensuring a stable environment essential for proper neuronal function and control.
- It is formed by capillary endothelial cells that are tightly interconnected by tight junctions, preventing the diffusion of materials between cells and allowing only lipid-soluble compounds to pass into the brain’s interstitial fluid.
Describe the Posterior Pituitary Gland and BBB
- Direct Hypothalamic Connection: The posterior pituitary lacks a BBB, allowing it to act as an extension of the hypothalamus, enabling fast transport of neurohormones like antidiuretic hormone (ADH) and oxytocin.
- Rapid Response Hormone Release: Hormones such as ADH (which controls water balance) and oxytocin (affecting uterine contractions and lactation) are released directly into the bloodstream, providing immediate physiological responses.
- Neuroendocrine Coordination: The posterior pituitary’s design ensures it works in sync with the hypothalamus, acting as a hub for hormone release, bypassing the BBB to regulate blood volume, stress responses, and reproductive functions.
Describe the Choroid Plexus and BBB
- Primary Site of CSF Production: The choroid plexus, located in the third and fourth ventricles, produces cerebrospinal fluid (CSF) which circulates within the CNS, providing cushioning and nutrient transport.
- Selective Blood–CSF Barrier: Specialized ependymal cells within the choroid plexus form a barrier, filtering blood and controlling the entry of ions, vitamins, and nutrients into the CSF, similar to BBB selectivity.
- Dual Protective Role: The choroid plexus prevents toxins and pathogens from reaching the CNS through blood vessels, adding another layer of defense that complements the BBB in protecting the brain’s microenvironment.
Describe the CSF Flow and BBB
- CNS Pathways and CSF Circulation: CSF flows from the lateral ventricles to the third and fourth ventricles, then into the subarachnoid space, providing a medium for nutrient distribution and waste removal throughout the CNS.
- Selective Reabsorption Mechanism: CSF is reabsorbed into the bloodstream via arachnoid granulations, which prevent large molecules from entering the CSF, preserving the brain’s protected environment similarly to the BBB.
- Minimised Direct Blood Exposure: CSF reabsorption carefully limits the brain’s contact with blood, reducing exposure to blood-borne toxins or pathogens and supporting the BBB’s role in maintaining CNS isolation.
Describe the diencephalon
- The diencephalon comprises about 2% of the grey matter in the central nervous system (CNS), yet it plays a crucial role due to its extensive connections. Almost all motor and sensory systems in the CNS synapse within this region.
- The diencephalon serves as a link between the brainstem and the cerebral hemispheres, consisting of the epithalamus, the left and right thalamus, and the hypothalamus. Various figures illustrate the diencephalon’s position and its relation to other brain structures.
Describe the The Epithalamus
- The epithalamus forms the roof of the third ventricle and houses the pineal gland.
The epithalamus includes a membranous anterior section with a choroid plexus that extends through the interventricular foramina into the lateral ventricles. Its posterior part contains the pineal gland, an endocrine organ responsible for secreting melatonin. - Melatonin is believed to regulate circadian rhythms, and may also influence reproductive functions.
Describe the adrenal medulla
Describe the parasympathetic region
How does an afferent signal start?
Describe gustation (taste) as a sense
Describe retinal organisation
Describe visual pathways
Describe the eye orbit
Describe balance as a sense
Describe the somatic nervous system
Describe the autonomic nervous system
What are the eight functions of blood
What are the four different types of plasma proteins
- Albumins:
* Percentage: About 60% of plasma proteins.
* Function: Key contributors to osmotic pressure, helping to maintain fluid balance in the blood. They also transport fatty acids, thyroid hormones, and some steroid hormones. - Globulins:
* Percentage: Roughly 35% of plasma proteins.
* Types: Includes immunoglobulins (antibodies) that support immune defence, and transport globulins that bind small ions and hormones, especially those that are insoluble or would be filtered out by the kidneys. - Fibrinogen:
* Percentage: Approximately 4% of plasma proteins.
* Function: The largest plasma protein, crucial for blood clotting. Fibrinogen converts to fibrin, forming the structural framework of a blood clot. If blood is not treated to prevent clotting, fibrinogen is transformed into fibrin, resulting in serum when clotting proteins are removed.
What are the types of other solutes in plasma
What are the formed elements in blood
Describe the erythrocyte life cycle
Describe erythropoiesis
- Erythropoiesis Process: RBC formation (erythropoiesis) occurs mainly in adult red bone marrow, especially in the vertebrae, sternum, and pelvis. In extreme cases, yellow marrow can convert to red marrow to increase RBC production.
- Nutritional Requirements: Amino acids, iron, and vitamin B12 are essential for proper erythropoiesis.
- EPO Regulation: Erythropoietin (EPO), produced by the kidneys and liver in response to low oxygen, stimulates cell division in erythroblasts and speeds up RBC maturation. Under peak conditions, bone marrow can produce up to 30 million RBCs per second.
Describe the four blood types
Describe the Rhesus factor in pregnant women
Look at this list of possible end products of hematopoietic stem cells
Describe the development of the heart
Describe the autonomic control of the heart
Describe the overall flow of the circulatory system
What three major veins contribute to the hepatic portal vein
Look at this
Look at this
Describe cardiovascular changes that occur at birth
Describe the distribution of lymph nodes
Describe the aortic arches at 4 weeks of cardiovascular development
Describe the vena cava at 4 weeks of cardiovascular development
Describe the hepatic portal and umbilical vessels at 4 weeks of cardiovascular development
Just read
Describe the lobes of the lung
Describe the trachea
Describe bronchi and bronchioles
Describe the lungs
Describe Alveoli & Blood Air Barrier
Describe the development of the respiratory system
Describe the Pleural Cavities & Fluid
Describe inhalation
Describe the respiratory regulation centers of the brain
Describe the glomerulus
Describe Circulation to a Nephron
Describe the Macroscopic Kidney
Describe Microscopic Kidney
Look at this
Describe urine transport
Describe the Micturition Reflex
Micturition = the act of urinating
What components make up the endocrine system? (8)
How does the endocrine system work?
Describe the hypothalamus and hypophysis
What are the six types of hormone classification
Describe thyroid follicles
Describe the parathyroid gland
What are the three zones of the adrenal cortex that produce corticosteroids
Describe the pancreas
Describe the pineal gland
What hormones interact with the kidneys (3)
How does the heart respond to high blood pressure?
Describe the development of the reproductive system before differentiation (3-6 weeks)
Describe the development of the male reproductive system (week 7 - month 7)
Describe spermiogenesis
What are the three accessory glands of the male reproductive system?
Describe the testes
Describe the descent of the testes
Describe the development of the female reproductive system as of 7 weeks to birth
Describe ovaries and oogenesis
This is oogenesis in the ovaries btw
What are the four steps in the formation of the tertiary ovarian follicle
Just look at this
Describe the ovarian cycle
Also look at this
