Unit 1: Human Cells and Body Structures - Part 2

Anatomical planes

• Sagittal

• Frontal (coronal)

• Transverse (horizontal)

• Median (midsagittal)

• Oblique

Transverse plane

Horizontal plane → superior and inferior

Frontal plane

Coronal plane → anterior and posterior

Sagittal plane

Unequal right and left parts

Median or midsagittal plane

Equal right and left parts

Sagittal section

Section through sagittal plane

Vertical line parallel to median plane

Parasagittal plane

Anatomical sections

• sagittal

• Frontal (coronal)

• Transverse (cross section)

• Oblique

Frontal section

Coronal section → through coronal plane

Transverse section

Cross-section → section through horizontal plane, perpendicular longest axis of structure

Oblique sector

Oblique to long axis of structure

Body regions

• head (cranium)

• neck (cervical)

• thorax

• abdomen

• pelvis

• upper limb

• lower limb

• back

Axilla

Armpit, where arm connects to body

Parts of upper limb

Axilla, brachial, antebrachium, hand

Parts of lower limb

Gluteal, thigh, leg, foot

2 main body cavities

Dorsal and ventral

All the cavities

Cranial, vertebral, thoracic, abdominal, pelvic

Dorsal cavity

Cranial and vertebral

Ventral cavity

Thoracic, abdominal and pelvic

Cranial cavity

Surrounded by skull → contains brain

Vertebral canal → spinal cavity

Surrounded by vertebral column → contains spinal cord and nerve origins

Thoracic cavity

Surrounded by ribcage → contains heart and lungs

Thoracic cavity → subdivisions

Pleural and mediastinal cavity

Pleural cavity

In thoracic cavity → each contains a lung

Mediastinal cavity

In thoracic cavity

• superior mediastinum

• Pericardial cavity → contains heart

What lines the cavities

Serous membrane

Abdominal cavity

Stomach, spleen, liver, gallbladder, small intestine and most of large intestine

Pelvic cavity

Urinary bladder, part of large intestine and internal reproductive organs

9 abdomen pelvic subdivisions

Right/left hypochondriac regions

Epigastric region

Right/left lumbar region

Umbilical region

Right/left iliac region

Hypogastric region (suprapubic)

9 region pattern lives

Subcostal, intertubercular, midclavicular line

Subcostal line

Horizontal line connecting last costal cartilages of rib cage ( first horizontal line )

Intertubercular line

Second horizontal live connecting anterior superior iliac spines of hip bone

Midclavicular lines

Vertical lines through midpoint of clavicles

Layers of serous membrane

Parietal and visceral layer

Parietal layer

Outer layer → lines cavity walls

Visceral layer

Inner layer saltached to organ surfaces

Purpose of space between membrane layers

Has serous fluid which allows organs to move slightly without friction

Pericardium

Membrane that lines mediastinum → covers heart and origins of great vessels

Pleurae

Membrane that lines thoracic cavity → specially surround lungs

Peritoneum

Membrane lines abdominopelvic cavity and covers most organs

Attaches organs to one another and to posterior abdominal wall

What is a cell?

Basic structural and functional unit of life

Genetically identical

Main components of human cell

Plasma membrane, cyto plasm, nucleus

Plasma membrane

• outer boundary of cell

• Phospholipid bilayer

• Selective permeable membrane

• Passive and active transport

Passive transport

No energy input → more along concentration gradient (high → low)

Types of passive transport

1. Simple diffusion

2. Facilitated diffusion

3. Osmosis

4. Filtration

Simple diffusion

Passive transport → solutes move from high to low concentration across membrane until equilibrium reached

Facilitated diffusion

Passive transport → substances require a channel ( transmembrane protein ) to cross belayer

Osmosis

Passive transport → movement of water across membrane until equilibrium reached (cells require isotonic state)

Happens through simple diffusion and aguaporins

Hypotonic

Too much water in cell

Hypertonic

Too much water leaves cell → not enough water in cell

Isotonic

No het movement S water moves equally in both directions

Filtration

Passive transport → solutes move from high to low pressure hydrostatic pressures

Envision water hose with water running through

Active transport

Energy required → adenosine triphosphate (ATP) broken down

Against concentration gradient ( low → high )

Types of active transport

1. Active transport pumps

2. Endocytosis

3. Exocytosis

Active transport pump

Active transport → movement of solutes through transmembrane proteins (with energy cost)

Endocytosis

Active transport → moving substance into cell without protein

Ex. Phagocytosis

Exocytosis

Active transport → moving substance out of cell without protein

Ex. Vesicles → release substances from cell

Cytoplasm

Contents between plasma membrane and nucleus

1. Cytosol

2. Organelles

Cytosol

Intracellular fluid → mostly water

Organelles

Subcellular structures with specific functions

Rough endoplasmic reticulum (Er)

Protein synthesis and ribosomes attached

Smooth endoplasmic reticulum (Er)

Lipid synthesis

Ribosomes

Loose in cytoplasm or attached to rough Er

Site of protein synthesis

Golgi apparatus

Modify, sort and package proteins to release from cell

Lysosomes

vesicles from golgi complex

Break down and digest unwanted materials in cells → enzymes

Centrosomes

Always 2 → play role during cell division (mitosis)

Mitochondria

Produce energy → ATP

Contains its own DNA → can divide independently

Cristae = folds of inner membrane

Matrix = central fluid filled cavity

Nucleus

Control centre → contains DNA ( chromosomes)

Nucleolus

Centre of nucleus

Makes ribosomes

Nuclear envelope

Double membrane that separates nucleus from cytoplasm

Nuclear pores

Openings in nuclear envelope that controls movement of substances in and out of nucleus

Genes

Hereditary units → control activity and structure of cell

Chromosomes

Molecules of DNA + protein prolecules

Why are there so many

If only I knew :)